HomeMy WebLinkAbout5054; LAKE CALAVERA IMPROVEMENTS; CONCEPTUAL PLANNING AND PRELIMINARY DESIGN; 1973-08-03[
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Carlsbad Municipal Water District
LAKECALAVERAIMPROVEMENTS
CONCEPTUAL PLANNING AND
PRELIMINARY DESIGN REPORT
in Association with POWELLJPBS&J
ENGINEERS
October 2001
Table of Contents
CHAP'fER 1 BACKGROUND ........................................................................ 1-1
Purpose and Scope of Study .......................................................................... 1-1
llistory ............................................................................................................ 1-1
Area and Site Characteristics ......................................................................... 1-5
Geology and Soils .................................................................................... 1-5
Land Use .................................................................................................. 1-5
Climate and Vegetation ............................................................................ 1-6
Hydrology and Stream Flow .................................................................... 1-8
Reservoir and Dam Site Features ................................................................... 1-9
Existing Physical Features ....................................................................... 1-9
Reservoir Volume and Area Curves ...................................................... 1-11
General Safety and Operational Considerations .................................... 1-IJ
CHAPTER 2 BASIS OF EVALUATION ....................................................... 2-1
Study Approach ............................................................................................. 2-1
Underlying Assumptions ......................................................................... 2-2
Environmental Considerations ................................................................. 2-2
Planning Considerations .......................................................................... 2-2
Facility Planning and Preliminary Design Criteria ........................................ 2-4
Remedial Worl<s ....................................................................................... 2-6
RW Conversion Facilities ........................................................................ 2-7
Project Cost Criteria ....................................................................................... 2-8
Construction Costs ................................................................................... 2-9
Construction Contingencies ..................................................................... 2-9
Engineering and Administration .............................................................. 2-9
Cost Index and Price Escalation ............................................................ 2-10
CHAPTER3 EVALUATION OF REMEDIAL WORKS ............................ 3-1
Description of Present Conditions ................................................................. 3-1
Outlet Tower ............................................................................................ 3-1
Spillway and Channel .............................................................................. 3-3
Access Road ............................................................................................. 3-3
Site Security ............................................................................................. 3::-6
Evaluation of Alternatives ............................................................................. 3-6
Outlet Tower ............................................................................................ 3-7
Spillway and Channel .............................................................................. 3-8
Access Road ............................................................................................. 3-9
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Table of Contents (Continued)
Site Security ........................................................................................... 3-10
Recommended Alternative Improvements .................................................. 3-11
CHAPTER 4 PRELIMINARY DESIGN OF REMEDIAL WORKS .......... 4-1
l/0 Works Improvements .............................................................................. 4-1
Objective and Approach .......................................................................... 4-1
Results ...................................................................................................... 4-1
Spillway and Channel Improvements ............................................................ 4-9
Objective and Approach .......................................................................... 4-9
Results .................................................................................................... 4-10
Access Road Improvements ...................................................................... , .. 4-10
Objective and Approach ........................................................................ 4-10
Results .................................................................................................... 4-11
Site Security Improvements ......................................................................... 4-15
Objective and Approach ........................................................................ 4-15
Results .................................................................................................... 4-15
Remedial Works Summary .......................................................................... 4-16
CHAPTER 5 SEASONAL STORAGE ANALYSIS ...................................... 5-1
Comparison with Other Storage Reservoirs .................................................. 5-1
RW Storage Reservoirs in Califorhia ...................................................... 5-1
Comparable Capacity Reservoirs in San Diego County .......................... 5-3
Other North County Reservoirs ............... , ............................................... 5-3
Tributary Runoff Diversion ........................................................................... 5-5
Hydrology ................................................................................................ 5-5
Development of Alternatives ................................................................... 5-5
Cost Analysis and Results ........................................................................ 5-6
Seasonal Storage Potential ............................................................................. 5-9
Demand Analysis ..................................................................................... 5-9
Supply Analysis ..................................................................................... 5-11
Seasonal Balancing ................................................................................ 5-1 l
Other Storage Considerations ................................................................ 5-13
CHAPTER 6 RECYCLED WATER CONVERSION FACil,JTIES .......... 6-1
Future Conversion for RW Storage ............................................................... 6-1
Existing RW Piping and Pumping Facilities ........................................... 6-1
Investigation of Future RW Piping and Pumping Facilities .................... 6-4
Constructed Wetlands for Runoff Quality Control ...................... , ........... 6-7
Aeration/Destratification System ........................................................... 6-j 1
Post-Storage Treatment Processes ......................................................... 6-13
Comparison of Alternative Facility Concepts .............................................. 6-13
Alternative Conversion Improvement Cost Comparison ....................... 6-14
Non-monetary Comparison .................................................................... 6-15
Conclusions ............................................................................................ 6-17
CGvL ENGINEERS 1N ASSOC IATION WITH POWELLiPBS&J ii
Table of Contents (Continued)
CHAPTER 7 REPORT RECOMMENDATIONS ........................................ 7-1
Remedial Works ............................................................................................. 7-1
Project Costs ............................................................................................ 7-1
Reconnajssance-Level Surveys and Initial Agency Review .................... 7-1
Implementation ........................................................................................ 7-2
RW Conversion Facilities .............................................................................. 7-5
Economic Assessment ............................................................................. 7-5
Implementation ........................................................................................ 7-5
Water QuaHty Monitoring Program ............................................................... 7-9
Pre-Conversion ........................................................................................ 7-9
Post-Conversion ....................................................................................... 7-9
REFERENCES .......................................................................................................... R-1
APPENDIX A RECYCLED WATER DEMAND ANALYSIS ................... A-1
APPENDIX B SEASONAL STORAGE MODEL RUNS ............................ B-1
APPENDIX C PROJECT COST OPINIONS .............................................. C-1
APPENDIXD ADDITIONAL SITE PHOTOS ............................................ D-1
APPENDIX E OUTLET TOWER VIDEO SURVEY .................................. E-1
APPENDIX F GEOTECHNICAL AND ENVIRONMENTAL
SERVICES ............................................................................... F-1
LIST OF TABLES
Table 1-1 Existing Lake Calavera Features .. ,. ................................................ 1-10
Table 2-1 Underlying Assumptions .................................................................. 2-3
Table 2-2 Hydrologic and Hydraulic Criteria ................................................... 2-6
Table 2-3 Small Dam Safety and Operational Requirements ........................... 2-6
Table 3-1 Outlet Tower Improvement Options ............................................... , 3-7
Table 3-2 SpiJlway and Channel Improvement Options .................................. 3-8
Tab le 3-3 Access Road Improvement Options ............................................... 3-10
Table 3-4 Site Security Improvement Options ............................................... 3-11
Table 4-l Lake Calavera 1/0 Hydraulic Parameters ......................................... 4-4
Table 4-2 Water Level Control Alternatives for J/0 Tower Construction ....... 4-6
Table 4-3 Cost Opinion for 1/0 Works Improvements ..................................... 4-8
Table 4-4 Cost Opinfon for Remedial Works ................................................. 4-16
Table 5-1 Other RW Seasonal Storage Reservoir Features .............................. 5-3
Table 5-2 Comparison with Comparable Size San Diego County Reservoirs . 5-4
Table 5-3 Comparison with Other Nearby North County Reservoirs .............. 5-4
Table 5-4 Upper Calavera Creek Hydrology .................................................... 5-5
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Table of Contents (Continued)
Table 5-5 HBC-I Computed Discharge Results ............................................... 5-6
TabJe 5-6 Cost Opinion For Diversjon Facilities .............................................. 5-7
Table 5-7 CMWD Recycled Water Supply Availabibty ................................ 5-11
Table 5-8 CMWD Peak-Month Supply/Demand Balance ............................. 5-12
Table 5-9 Lake Calavera's SeasooaJ Storage Benefit to CMWD ................... 5-13
Table 6-1 Alternative Conversion Cost Comparison ...................................... 6-1 5
Table 6-2 Non-monetary Factors and Issues .................................................. 6-16
Table 6-3 Alternative Non-monetary (Subjective) Comparison ..................... 6-16
Table 6-4 Cost Opinion For Future RW Conversion Facilities ...................... 6-17
Table 7-1 Cost Opinion for Remedial Works ................................................... 7-2
Table 7-2 Lake CalaveraRemedial Works Action Items ................................. 7-2
Table 7-3 Economic Assessment of RW Conversion at Phase Il Conditions .. 7-6
Table 7-4 Economic Assessment of RW Conversfon at Ultimate Conditions . 7-7
Table 7-5 Pre-Conversion Lake CalaveraMonitoriog Program ....................... 7-9
Table 7-6 Post-Conversion Lake Calavera Monitoring Program ................... 7-10
LIST OF FIGURES
Figure 1-1 Lake Calavera Location Map ........................................................... 1-7
Figure 1-2 Lake Calavera Volume and Surface Area Curves .......................... 1-12
Figure 2-1 Ultimate RW Distribution System Schematic .................................. 2-5
Figure 4-1 Proposed Remedial Works Plan ....................................................... 4-2
Figure 4-2 Proposed 1/0 Works Profile ............................................................. 4-3
Figure 4-3 Preliminary Plan View of Access Road and Fencing
Improvements ................................................................................. 4-13
Figure 4-4 Preliminary Centerline Profile of Access Road Improvements ..... 4-14
Figure 5-1 Alternative Storm Water Diversion Facilities .................................. 5-8
Figure 5-2 CMWD Six-Year RW Demand Hydrograph ................................. 5-10
Figure 6-1 Alternative A -RW Storage -Diversion Concept .......................... 6-2
Figure 6-2 Alternative B -RW Supply-Wetlands Concept ............................ 6-3
Figure 6-3 Alternative RW Transmission Pipeline Alignments and Pumping
Station Sites ...................................................................................... 6-6
Figure 6-4 Constructed Terraced Wetlands Concept for Treatment of
Runoff ............................................................................................... 6-9
Figure 6-5 Constructed Terraced Wetlands Hydraulic Profile ........................ 6-10
Figure 6-6 Aeration/Destratification System Concept.. ................................... 6-12
Figure 7-1 Implementation Schedule for Remedial Improvements ................... 7-4
Figure 7-2 RW Conversion Facilities Design and Construction Schedule ........ 7-8
CGvL ENGINEERS [N ASSOCIATION WITH PowELL/PBS&J IV
Table of Contents {Continued)
LIST OF PHOTOS
Photo 1-1 Lake Calavera Site ............................................................................ 1-3
Photo 1-2 Existing Outlet Tower and Reservoir ............................................... 1-3
Photo 1-3 Dam Outlet Box and Old Water Pipeline ......................................... 1-4
Photo 1-4 Decomrnissjoned Water Pipeline ...................................................... 1-4
Photo 1-5 Spillway Channel .............................................................................. 1-6
Photo 1-6 SpilJway Apron, Walk.-way Abutment and Outlet Tower ............... 1-11
Photo 3-1 Existing Outlet Tower ...................................................................... 3-2
Photo 3-2 Outlet Tower, Rock Blanket and Walkway Abutment .................... 3-2
Photo 3-3 Spillway Apron and Upstream Channel ........................................... 3-4
Photo 3-4 Spill way Apron and Downstream Channel ... , .................................. 3-4
Photo 3-5 Spillway and Access Road ................................................................ 3-5
Photo 3-6 Paved Access Road and Dam ........................................................... 3-5
Photo 3-7 Calavera Dam Crest and Outlet Tower. ............................................ 3-6
Photo 4-1 Upper Oso Reservoir I/O Ports ........................................................ .4-5
Photo 4-2 Proposed Control Building Site ........................................................ 4-8
Photo 4-3 Bast End of Calavera Dam ............................................................. .4-12
Photo 4-4 Proposed Access Road Transition Ramp Area ............................... 4-15
Photo 6-1 Candidate RWPS Site A ................................................................... 6-5
Photo 6-2 Candidate RWPS Site B ................................................................... 6-5
Photo 6-3 Inlet Area to Lake Calavera .............................................................. 6-8
CGvL ENGINEERS IN ASSOCIATION WITH POWELLIPBS&J V
Background
Chapter 1
Background
PURPOSE AND SCOPE OF STUDY
Carlsbad Municipal Water District (CMWD) wishes to make immediate remedial
improvements to Lake Calavera for protection and preservation of the site as well
as to evaluate the feasibility of using the reservoir for future seasonal storage of
water as a component of its expandjng recycled water (RW) system, This report
deals with both conceptual planning of future RW conversion projects and
preliminary design issues associated with a set of remedial works needed soon.
The primary technical tasks associated with this planning and preliminary design
report are:
a Investigation of the reservoir's history and operational background
□ Examination of current limitations/constraints on storage operations and
control facilities
□ Analysis of the effects of storage volume under various RW system expansion
milestones
□ Evaluation of alternatives to determine the b~st combination of actions to
pursue for both remedial works and future projects
□ Provision of a cost opinion associated with the proposed improvements
□ Recommendations for project implementation
This report is intended to meet two basic objectives: first, to define a set of
remedial improvements (modifications and repairs) needed to preserve the
existing assets, features and function of the storage system; second, to identify a
conceptual facility plan for future improvements that would allow cost-effective
incorporati.on of the storage system as an integral part of CMWD's expanding
RW operations.
HISTORY
Calavera Dam is a compacted ea11h-fill dam constructed in the early 1940s by the
Carlsbad Mutual Water Company (CMWC) in order to create a water storage
reservoir. Initially called Fraser Dam, the name was later changed to Calavera
after Cerro de la Calavera, a prominent volcanic plug lying adjacent to the dam
near its east end. The dam was primarily designed to capture surface runoff from
upper CaJavera Creek for storage within a 520-acre-foot (AF) reservoir named
Lake Calavera. The storage system was constructed to aJso wpound
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Background
supplemental groundwater supplies diverted from wells in the San Luis Rey River
(Lower Missjon) basin. The general site of the reservoir and Calavera Dam
facilities is presented in Photos 1-1 and l-2. Additional photos of specific site
features and facilities are provided in Appendix D.
Construction of the dam was completed in 1942. At that time, CMWC obtained a
license to diven 150 acre-feel per year (AFY) of runoff from the upper Calavera
Creek watershed. The company also installed a well in the lower reaches of
Calavera Creek lO further augment their supply. In excess of 2,000 AFY of water
were delivered within the company's approximately 2,500-acre coastal service
area, which extended from mid-Oceanside to the north shore of Agua Hedionda
Lagoon. Throughout the late 1940s and early 1950s supply came from the
company's five San Luis Rey Valley wells, the one well on lower Calavera Creek,
and from upstream nmoff. In addition to Lake Calavera storage, the company
owned and operated six small storage tan.ks within its distribution system.
The early CMWC water delivery system also included a treatment plant, used to
process supplemental groundwater supplies throughout the 1950s. Following
completion of the San Diego Aqueduct and supply of Colorado River water to the
region in 1957, the reservoir and plant continued to be used during peak water
demand periods for supplemental (dry-weather) supply. However, as
groundwater salinity commonly reached in excess of 1,500 mg/L (as total
dissolved solids), the ooastal wells not only yielded poor quality bllt also were
costly to operate. With increased reliance on lower-cost imported water, the
Calavera treatment -plant was abandoned and dismantled in the early 1960s. For
the past four decades, Lake Calavera has been used for limited storm water
protection and flood control. The prope1ty surrounding the Lake has provjded an
attractive open space for a number of passive recreational uses.
The Carlsbad Public Utility District (CPUD. formerly CMWC) was formed
during the early 1950s in order to obtain Colorado River water as a public
member of the San Diego County Water Authority. With decommission of the
water treatment system, the original CMWC water use license for "irrigation and
potable supply" was subsequently changed to "recreational use and fire
protection." The current CMWD was created iii 1954 to replace the CPUD.
CMWD became a subsidiary of the City of Carlsbad (City) government in 1990.
The City owns the Lake Calavera site, while the facilities are operated and
maintained by CMWD.
The Calavera water pipeline system has not operated since the treatment plant was
dismantled some 40 years ago. Segments of the old 24-incb steel pipeline yet
remain below the dam along lower Calavera Creek between the outlet box and the
old water treatment plant pumping station site. Ponions of the pipeline can be
seen in Photos 1-3 (immediately below the dam) and 1-4 (further downstream).
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Photo 1 • 1 Lake Calavera Site
Viewing east from knoll above Tamarack A venue at Strata Drive.
Lower Calavera Creek access road in foreground. (June 13, 2001)
Photo 1-2 Existing Outlet Tower and Reservoir
Viewing upstream (northeast) from dam crest. (March 8, 2001)
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Photo 1-3 Dam Outlet Box and Old Water Pipeline
Left foreground and center, resp., viewing south from dam crest. (March 8, 2001)
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Photo 1-4 Decommissioned Water Pipeline
Right center, viewing Calavera Creek across paved access road and site of old
pumping station several thousand feet downstream of dam. (March 8, 2001)
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AREA AND SITE CHARACTERISTICS
Characteristics of the Lake Calavera site, including area geology and soils, land
use, hydrology, and climate and vegetation, that are germane to the study are
presented in the following pages.
Geology and Soils
The Lake Calavera site lies at the western edge of the Upland Foothill Range and
the Pacific Coastal Plain pbysiographic provinces. Geologic formations consist of
partly consolidated a.on-marine sandstones, mudstones, siltstones and shales of
the late Cretaceous Period interceded by earlier (c. late Mesozic/early Cenozoic)
plutonic igneous meta-volcanics. Cerro de la Calavera and, most likely, the
gorge rocks south of the dam constitute western outliers of batbolitic and
associated intrusive basement rock formations of the Peninsular Range extending
east to the Elsinore Fault.
The shallow soils of the Lake Calavera site are of the Fallbrook-Vista
Association, including Salinas clay loam, Altamont clays, Los Flores loamy fine
sand, and Cienaga-Fallbrook rocky sandy loam. AJJ were developed in material
weathered from granitic rock of the Foothill Uplands. Surface soils of this upland
drainage area are situated over decomposed granitic rock and basic intrusive
gabbro rock, as observed in the immediate vicinity of the spillway channel, as
shown in Photo 1-5. The alluvial soils of the upper Calavera Creek drainage
channel immediately upstream of the reservoir are primarily Salinas clay loams,
as used for growing citrus, truck crops, tomatoes, flowers and pasture fodder1 plus
more recent (Tertiary-age) Santiago Formation silty-sands to clayey-silts often
occurring as lenses of claystone and siltstone.
Land Use
Lake Calavera is situated within a 266-acre property owned by the City. The
parcel is bordered on three sides by residential development, as shown on
Figure 1-1.
The Phase I Calavera Heights residential development (1,100 homes) is to the
immediate west. The Phase II Calavera Highlands (781 additional units)
development is to the northwest of the site. City of Oceanside housing
developments, including Lake Boulevard, Melrose and others, extend along the
northern and eastern boundaries of the site.
The southern boundary of the Lake Calavera site adjoins a large open-space
parcel, termed the Calavera Reserve, owned by The Environmental Trust. The
Reserve represents part of a proposed extensive stewardship inducting Box
Canyon in La Costa, which is known to contain diverse native and endangered
habitats typical of the entire North County area prior to development.
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Photo 1-5 Spillway Channel
Viewing west of Calavera Dam, decomposed granitic rock and overlying shallow
soils exposed on west side. (March 8, 2001)
To the south-southwest lies another large open-space parcel owned by the City
that represents a major portion of the lower Calavera Creek watershed. The
Rancho Carlsbad Mobile Home Park is situated at the confluence of the lower
Calavera and Agua Hedionda creeks.
Climate and Vegetation
Normalized mean rainfall, over 50 years of record, for the entire City area is
approximately 13 inches per year. Prolonged rainstorms in this San Diego coastal
plain area of the County are very rare. Precipitation is typically between 8 and 16
inches per annum with 95 percent of rainfall occurring between November and
April. The minimum annual recorded rainfall in the City was 4 inches, back in
1953. The wettest water year on record was in excess of 24 inches, occurring
between October 1, 1977 and September 30, 1978.
Moderate air temperatures prevail throughout the year. Mean annual
temperatures lie between 59 and 63 degrees F. Coastal fog contributes to the
area's humidity for considerable periods, so the loss of soil moisture from
evapotranspiration is reduced significantly, especially during the early summer
months.
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FIGURE 1-1
LAKE CALAVERA LOCATION MAP
Background
Lake Calavera area soils support many annual grasses and brush common to the
region. Prominent bush species include Chamise, scrub oak and sumac. The
most prevalent groundcover plants include wild oats, cheatgrass and flattop
buck.wheat. Plant growth is typically rapid in spring through early June when soil
moisture begins to rapidly dissipate. Organic-carbon content within the soil
surface layer is about 0.7 percent. Several photos of on-site wetland and riparian
vegetation are provided in Appendix D.
Hydrology and Stream Flow
Calavera Creek represents a small northern tributary within the Agua Hedionda
watershed, desigoated Hydrographic Sub-Unit (HSU 4.3). Calavera Dam is
situated about one mile upstream of the confluence of Calavera and Agua
Hedionda Creeks. The Calavera Creek Hydrographic Sub-Area (HSA 4.33) is
separated from the main drainage of Agua Hedionda, which includes Squires Dam
and Los Monos Canyon, by Santa Sinforosa Ridge.
The somewhat Jarger San Marcos Creek -Batiqujtos Lagoon watershed (HSU
4.4), which includes Mahr Reservoir, lies a mile further south past Palomar
Airport Road. The largest drainage system within the entire Carlsbad Unit is the
southernmost Escondido basin (HSU 4.5). To the immediate north of the Agua
Hedionda HSU lies the narrow Buena Vista Creek -Lagoon drainage system
(HSU 4.2) traversed by State Route 78.
Seasonal runoff from the 3.6-square-mile drainage area upstream of the site enters
Lake Calavera via a number of small branch tributaries to upper Calavera Creek,
as shown on Figure 1-1. The drainage extends several miles eastward into
southwest Vista in the vicinity of the Anza Freeway (SR 78). Watershed
elevations are 350-420 feet above mean sea level (amsl) to the northeast (near
Breeze HilJ) and reach 500 feet amsl to the south and southeast of the site along
Santa Sinforosa Ridge. The watershed contains two hills: 513-foot Cerro de la
Calavera, adjacent to the dam; and 525-foot San Francisco Peak, less than a mile
east of the reservoir. About 85 percent of the upstream watershed is outside City
limits. Approximately 2,000 acres contain established residential developments
in the South College -Lake Boulevard. Area of southeast Oceanside, as well as
unincorporated areas along Sunset Drive and Breeze Hill -Melrose Drive
portions of southwest Vista south to Mar Vista.
Nearly all surface runoff within the 2,300-acre drainage area that reaches Lake
Calavera occurs between December and late March. Annual runoff in years of
normal rainfall was estimated in 1990 by L. Burzell (Reference 4) in the range of
100 to 300 AF. As the result of continued upstream residential development,
however, such approximations are considered below current annual volumes
accrued during. average rainfaIJ years. Minimum annual runoff, during very dry
years, may be as low as 100 AF; whereas maximum volumes, anticipated in years
of extreme rainfall (20-24 inches), may amount to 800 AF.
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Background
There are no gauging stations on any of the ephemeral streams found within the
Agua Hedionda HSU, including Calavera Creek. Thus, there are no data on storm
flows, their duration or other specific runoff conditions. Estimates of flow have
been made for this report based on previous HEC-1 storm water modeling results
extrapolated for upper Calavera Creek. These stream flow estimates for storage
and diversion analysis are provided in Chapter 5.
RESERVOIR AND DAM SITE FEATURES
Lake Calavera is an unlined, uncovered water storage reservoir formed by a 65-
foot-fogh, 490-foot-long compacted earth fill dam featuring both upstream and
downstream rock-blanket faces. The dam crest elevation is 223 feet amsl. The
Lake bottom, which is comprised of decomposed granite, was excavated in 1940
to elevation 160 feet amsl just beneath the dam. The maximum pool specified in
the original faciJjty design of 218 feet amsl allowed for additional storm water
retention. The safe yield of the reservoir (maximum to minimum pool elevations)
was calculated at 340 AFY. The minimum operating pool level of 189 feet ams!
was established through placement of the lowest valve port on the outlet tower.
Existing Physical Features
Outflow occurs through a 63-foot high outlet tower located on the reservoir
bottom near the dam's upstream toe, approximate! y 115 feet away from the crest.
The 9-foot 8-incb outside-diameter reinforced-concrete tower contains a grated
cover, and three 18-inch poits with centers at elevations of 208.5, 201.5 and 189.0
feet ams!. A no longer functional steel ladder, which descends to the base at
elevation 160 feet amsl, accessed the interior of the tower. The tower's base is
connected to a 30-foot, 28-inch diameter steel pipe to 30-inch diameter
reinforced-concrete pipeline passing 260 feet below the dam and connecting to a
rectangular concrete box structure at the downstream toe. The key features of the
dam, outlet tower and spillway are presented in Table 1-1. The cable footbridge
abutment and outlet tower structure are shown in Photo 1-6. Additional photos of
the existing structures and specific features are presented in Appendix D.
The effective working storage volume, based on the difference between the
spillway sill (216.5 feet amsl) and minimum operating level (189 feet amsl) is 480
AF. The associated water surface area is approximately 34 acres. Recent water
levels however, have seldom exceeded 208 feet amsl, other than immediately
following storm flows, as the upper 18-inch outlet port is open. The remaining
18-inch valves are in fully closed positions. Those found leaking a number of
years ago were plugged from the tower's exterior with marine caulking by
underwater divers.
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Table 1-1 Existing Lake Calavera Features
Item
Site area (u/s of dam)
Site perimeter
Location
Tributary drainage area
Elevations:
Dam crest
Design maximum ws
Spillway sill
Minimum operating pool
Design minimum ws
Stream bed at u/s toe of dam
Stream bed at dis foot of dam
Dam type
Dam height, crest width, length
Dam volume
Dam u/s and d/s slopes
Reservoir design capacity
Reservoir working storage volume
Water surface area, spillway
Water surface area, minimum
Spillway type
Spillway design flow capacity
Outlet tower:
Size and features
Top, footing base elevations
Upper 18-inch valve and port
Mid 18-inch valve and port
Lower 18-inch valve and port
Emergency 12-inch valve
Outlet pipe diameter and length
Outlet pipe slope
Description/Details
266 acres
Approximate] y 4 miles
Upper Calavera Creek, small northeast sub-basin
within Agua Hedionda watershed (HSU 4.3)
2,300 acres (3.6 sqmi)
223 ft amsl
2 18.0 ft amsl
2 16.5 ft amsl
189 ft ams!
178.0 ft amsl
170 ft amsl
160 ft amsl at outlet box
Earth fill
65 ft, 22 ft, 540 ft
85,000 cu yd
1.5: 1 (upper both), 2.5:1 (lower u/s), 2.25: 1 (lower
dis)
540 AF (I 76 million gallons)
480 AF (156 million gallons)
34 acres (at 216.5 ft arnsl)
5 acres (at 189 ft amsl)
3-in gunite with double #6 Clinton netting and
18-in x 30-in ref. cone. anchors
2,300 cubic feet per second ( cfs)
9-ft 8-.in dia. concrete tower with 4 outlet ports
223 ft, 160 ft ams! (overall height= 63 ft)
208.5 ft amsl at centerline
201 .5 ft amsl at centerline
189.0 ft amsl at centerline
179.0 ft amsl at centerljne
30 ft of 28-in SP plus 230 ft of 30-in RCP
0 .0135 ft/ft (flow line 161.0 tol57.5 ft amsl)
a) u/s = upstream; dis = downstream; ws = water surface.
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Photo 1-6 Spillway Apron, Walkway Abutment and Outlet Tower
Upstream dam face, viewing west from flank of Cerro de la Calavera.
(March 8, 2001)
Reservoir Volume and Area Curves
Figure 1-2 provides computed Lake Calavera storage volume and surface area
curves in relation to water depths. Reservoir design capacity, the volumetric
difference between the design maximum water surface (218.0 feet amsl) and
minimum pool elevation (189 feet ams]) is 540 AF. The associated water surface
area (maximum inundation) is approximately 37 acres. Effective working
storage, as mentioned above, is less than the capacity of Lake Calavera.
General Safety and Operational Considerations
Significant physical changes have occurred at Lake Calavera over the past several
decades. As previously noted, most of the controls and other components of the
outlet tower have deteriorated to the point that they are inoperable and/or non-
functional. The suspension cable walkway leading from the dam to the tower was
dismantled in the late 1980s due to deterioration and the risk of injury. Wood
flooring within the tower has rotted away. The tower's interior access ladder as
well as protective screens have rusted through. With loss of operable valves,
water level through the outlet works can be controlled only by gravity flow
through the open upper port.
CGvL ENGLNEERS IN ASSOCIATION WITH POWELLIPBS&J 1-11
230
220 0 E m
~ 210 ~
,:£
£ 200 m > Cl) w 190
180
230
0 E
220
a,
j 210
c 0 200 ;:
~ Cl)
i,jj 190
180
0
0
Background
Lake Calavera Volume
200 400 600 800 1,000
Volume, acre-feet
Lake Calavera Surface Area
10 20 30 40 50 60
Area, acres
Figure 1-2 Lak e Calavera Volume and Surface Area Curves
CGvL ENGINEERS IN ASSOCIATION WITH P OWELLIPBS&J 1-12
Background
Erosion at the dam near the spillway and along the channel itself necessitates
additional protection measures. Access over the spillway apron and onto the dam
also reql1ires improvements to permit reservoir construction and maintenance
repair eqttipment all-weather use. Lastly, although posted with no trespassing
signs by the City, encroachment of resjdential development over the past decade
has allowed the public greater access to the reservoir and surrounding property.
Recreational activities such as fishing, swimming, motorcycle and bicycle riding,
and hiking are common. Some of these activities pose both a secu1ity and safety
concern for the City that require mitigation. The modifications and repairs
discussed in the next two chapters, involving a proposed set of facility and site
improvements, represent remedial works.
Preliminary investigations have also been implemented for possible use of Lake
Calavera's storage capacity as part of a future expanded RW system. Proposed
CMWD RW syslem expansion projects are discussed in several previous planning
studies and preliminary design reports (References 12, 18, and 19). A number of
future conceptual projects and possible alternatives involving Lake Calavera
storage have been considered, ranging from upstream runoff diversion to runoff
capture and treatment through a constructed wetlands system. A transmission
pipeline connecting the reservoir with the RW system through a downstream
pumping station and the likely need for additional treatment subsequent to storage
have also been evaluated. Such long-term improvements are dependent not only
on the intended ultimate function of the reservoir but also on other possible uses
to which the system and surrounding site may be put. These future storage issues,
alternative concept plans and options are addressed in Chapters 5 and 6 of this
report.
CGvLENGINEERS IN ASSOCIATION Wlnl PoWELLiPBS&J 1-13
Chapter 2
Basis of Evaluation
Study approach as well as planning, preliminary design and cost criteria preserited
in this chapter covec both the remeclial works and conceptual level plans for
proposed future RW conversion facilities. Detailed drawings and specifications
of the recommended remeclial works are not required at the preliminary design
level as a reasonably close approximation of size, location, and cost for these
improvements can be made. It is anticipated, however, tpat some relocation
and/or facility resizing may be required as detailed environmental and engineering
analyses are completed during the next stage of review and design. Conceptual
plans for proposed future facilities have been developed to a sufficient level of
detail to permit sound economic and non-monetary comparisons of alternative
projects and actions.
STUDY APPROACH
Remedial improvements needed to correct existing deficiencies over the next
several years, are those modifications and repair projects deemed critical for
protection and preservation of the Lake Calavera storage system. Absent these
improvements, the City increases its liability and the risk of devaluing and
possibly losing an attractive and useful community asset. The remedial
improvements include:
□ Restore functionality to the inlet/outlet (1/0) works through repair or
replacement of the existing tower with a new I/0 pipeline
□ Repair the spillway and dam face in order to maintain dam safety and protect
public investment
□ Extend and upgrade the existing access road to allow cost-effective
construction of the other remedial projects and improved reservoir
maintenance in the future
□ Install fencing to mitigate present risks regarding lack of adequate site
security and protect new facilities from potential damage
A conceptual plan is also considered for future conversion of the Lake Calavera
storage system for use as an integral part of CMWD's expanding RW system.
Chapters 5 and 6 of this report examine the likely improvement projects and
facilities needed to affect such a conversion and the potential benefits derived
from these actions. The primary considerations of future conversion of Lake
Calavera for RW storage include:
CGvL ENGINEERS IN ASSOCIAllON WITH POWEulPBS&J 2-1
Basis of Evaluation
o Evaluate system connection facilities, including pumping stations and
transmission pipeline
o Evaluate possible reservoir tributary flow diversion structures, partial bypass
of 1'first-flush" flows, or an upstream constructed wetlands for pre-storage
water quality control measures
□ Examine aeratiotJ/destratification, chlorination, micro-filtration and other
likely storage or post-storage tre.atment processes
□ Consider other Lake Calavera site features, including riparian wetlands, trail
systems, open land and aesthetics, fishing, and habitaJ protection in
developing a conceptual R W conversion -plan
Underlying Assumptions
The underlying assumptions associated with addressing specific issues and
concerns regarding Lake Calavera improvements, both remedial and future, are
summarized in Table 2-1. These assumptions were developed in order to alJow
effective internal review and appropriate revisions as project scope and level-of-
effort on specific subtasks were refined during the initial period of study.
Environmental Considerations
Several environmental concerns have been raised regarding CMWD's proposed
remedjal actions to either repair or replace the existing outlet tower at Lake
Calavera. Draining the reservoir was discussed as the most likely low-cost option
to facilitate such work. Concerns by area residents were voiced regarding
potential adverse jmpacts on habitat, aquatic and terrestrial biota, and aesthetics
associated with such draining. These concerns culminated in letters from the
Sierra Club and other environmental groups expressing objections to proceeding
with such actions without thorough environmental documentation and public
review.
One of the objectives of this study is to examine procedures other than draining
that are avaHable in order to make the needed repairs and remedial improvements
of Lake Calavera. The proposed actions presented in Chapters 3 and 4 have been
developed with the underlying premise that maintenance of the dam, reservoir,
and site (in terms of natural assets and the community mosaic) are of great
importance. All feasible means to maintain and protect existing conditions will
be considered in developing mitigations and examining construction techniques.
Planning Considerations
Future conversion of Lake Calavera to RW storage is also closely tied to a
number of important planning considerations and constraints. The City's 266-
acre Lake Calavera property represents one of few remaining large open-space
parcels situated in the northeastern portion of the, City.
CGvL ENGINEERS IN ASSOClATION WITH POWELliPBS&J 2-2
Basis of Evaluation
Table 2-1 Underlying Assumptions
Issue/Concern
Storage analysis
Tributary runoff evaluation
I/0 preliminary design3
Access roadn
Site securicy3
Upstream water quality protection
RW pumping station (RWPS) and
transmission pipeline
Alternative construction
procedures a
Benefit/cost analysis
Planning and preliminary design
report
a) Remedial works phase.
Study Report Assumptions
To satisfy seasonal RW distribution system (RWDS)
requirements under Phase II and Ultimate conditions w/ and w/o
Mahr Reservoir in operation; analyses lo also address seasonal
storage of natural runoff from upper Calavera Creek
Future stream flows based on HEC-1 model results for upstream
catchment areas Cl and C2, per Reference 13
Plan to include remedial works (demolish or modify existing
tower) as well as accommodation of future RW conveyance
under Phase Il and Ultimate hydraulic requirements
Various conceptual design alternatives considered (bridge
strncture over spjlJway, earth-fill w/ and w/out culverts, etc) each
in sufficient detail to permit a comparative cost opinion
Evaluation of the need for fencing in light of other ongojng site
planning efforts related to remedial improvements
Development and costing of both full-flow and partial, or first-
flush, bypass systems; and cost compared with those of a
constructed wetlands system for future conceptual RW
conversion plan
Development of alternative candidate sites for a future proposed
pumping station, including preliminary sjte plan, and
transmission pipeline alignment for connection between
reservoir and RWPS
To include options to reservoir draining, cleaning and re-grading,
with less potential environmental impacts as well as possible
mitigation measures
To include both capital and O&M costs, while benefits
incorporate system storage and comprehensive future potential
site uses
To cover above analyses of both remedial and future reservoir
improvements presented wilh opinion of costs and lime
schedules for project implementation
The City had proposed to include the Lake Calavera property as a public project
mitigation bank as part of their Habitat Management Plan (Reference 16) for
future municipal projects such as the City Golf Course, major roadway extensions
per the Circulation Plan, and other likely public projects. The purpose of the bank
CGvL ENGINEERS IN ASSOCIATJON WITH PoWELI..IPBS&J 2-3
Basis of Evaluation
is mitigation of unavoidable impacts to biological resources resulting from the
construction of such public facilities.
The 266-acre Lake Calavera site is believed to provide nearly 207 acres of
remaining credits to rrutigate impacts of City projects on an acre-for-acre basis,
with the exception of impacts to gnatcatcher-occupied coastal sage scrub,
southern maritime chapairnJ, marjtime succulent scrub and wetlands. Although
the mitigation bank credit concept has not yet. been adopted, the idea may still
bear fruit. Maintaining the open-space Jand surrounding Lake Calavera is of
significant interest and value to the City. It is envisioned that future recreational
activities and opportunities within this area may include extended hiking trails
interconnected with a regional trail system, jogging and bicycling paths, possible
fishing and boating concessions, and a nature interpretive center. The use of Lake
Calavera as an integral component of storage for an expanding RW delivery
system is considered compatible with the long-term open-space land-use planning
concepts expressed by both the City's_Habitat Management and General Plans.
Seasonal storage of RW in Lake Calavera would present a different set of
conditions than does CMWD's proposed storage in Mahr Reservoir. Lake
Calavera, although of larger capacity than Mahr, is situated at a considerably
lower elevation. fts tributary drainage area and associated run-off is also
considerably greater than that of Mahr Reservoir, as discussed in Chapter 5. Lake
Calavera's placement within CMWD's RWDS is presented in the hydraulic
profile schematic for Ultimate conditions, shown on Figure 2-1. Such
characteristics and conditions suggest consideration of several R W conversion
alternatives. These alterhatives are examined in Chapter 6.
FACILlTY PLANNING AND PRELIMINARY DESIGN CRITERIA
Facility sizing is generally based on future RW requirements presented below.
Criteria and standards governing planning of proposed facilities are assumed to
use quality design, materials, and construction. Further, it is assumed that proper
attention will be given to considerations such as appearance, landscaping,
operation and maintenance efficiency, and service reliability. In planning future
facility needs, efforts have been made to effectively use existing components of
the storage system where practical.
The fundamental hydrologic and hydraulic ciiteria used in developing alternative
reservoir improvement projects and determining their costs are presented in Table
2-2. These criteria affect facility sizing for open channel diversion structures,
pipelines, pumping stations, constructed wetland systems as well as the concept
design and layout of the remedial improvements.
CGvL ENGINEERS IN ASSOC IA TlON WITH POWEuiPBS&J 2-4
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HGL 660
Mahr
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660Zone
PS 660 ZONE
HWL 594'
HGL550
550 ZONE 550 ZONE
-------,1--------500
Potable >>------.. Water Meadowlark ul
"D" PS PS Gj
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Meadowlark g
Water Recycling Facility <{
384ZONE
"E"
lANI<
J-------------=-----~--il----Capacity = 3 MGD_ 300 ti:j
HGL264
264ZONE
384Zone Encina PS
Lake
Calavera
w 1.1..
z
z 0 ~ >
200 ~
UJ
To La Costa South
---'£> Golf Course --------+--------------------'~-+-------------100
■
LEGEND
~ l___) RESERVOIR, HWL
a::i PUMPING STATION
"f' PRESSURE REDUCING STATION
UNDER CONSIDERATION
NOTE: HGL'S AND PRESSURE ZONES ARE
BASED ON LOW WATER LEVELS.
CG L In association with 1 ••rnY .. , PQ\VELL/ PBSJ
0
FIGURE 2-1 ULTIMATE RW
DISTRIBUTION SYSTEM
SCHEMATIC
Basis of Evaluation
Table 2-2 H}·drologic and Hydraulic Criteria
Transmission pipelines and ps:
Peak-hour flow
Velocity
Maximum head loss
Rw supply/demand for seasonal storage:
Phase Il system demands
Ultimate system demands
Rainfall:
Mean annual
Dry year (well below average)
Wet year (well above average)
Tributary runoff:
U/s urbanized area
Gross annual coefficient
Coefficient for desi eak storm flow
Remedial Works
4,200 gallons per minute (gpm)
3 feet per second (fps) or less
IO ft/1000 lineal feet (LF)
5,400 AFY (pk mo= 945 AF)
9,800 AFY (pk mo =1,716 AF)
13 inches (95% Nov-Apr)
<8 inches (90% Dec-Mar)
>16 inches
1,500 ac residential+ 800 ac natural/open
0.25 entire area
0.85 entire area
The remedial work projects are associated with repairs or modifications to t he
outlet tower, the spillway and channel, the access road, and site security. A
compilation of general safety and operational requirements for small dam
improvements is presented in Table 2-3. These requirements have been used as
the basis of evaluation.
Table 2-3 Small Dam Safet}' and Operational Requirements
Spillway discharge:
Return period
Minimum freeboard
Minimum residual freeboard at crest
Inlet/outlet works:
Minimum pipeline diameter
Elevation
Mirumum capacity
Blow-off valves
Controls (gates/valves)
Ports
Access road
Securit
Design flood fl ow at 500 or 1,000 yr
4 ft
1.5 ft
12 in
Allow min. 2/3 volume to drain by gravity
Allow 1/2 volume to drain in 7 days
Near up-stream end
All with trash racks/screens
Accommodate peak flow at < 5 fps
All-weather surface
I/0 ort and I/0 control buildin fencino
Two basic 1/0 configurations have been considered: a freestanding tower rising
from the reservoir bottom (per existing structure), and a laid-back structure
CGvL ENGINEERS IN AsSOCIATION WJTH POWELL/PBS&J 2-6
Basis of Evaluation
secured to the upstream face of the dam. The existing free standing tower could
be rehabilitated through an extensive set of facility improvements involving a new
access bridge, new piping and valves, flooring, control mechanisms, and a new
cover. In addition, a much improved security system is needed to protect against
vandalism as well as ensure safe operations. Alternatively, a laid-back structure
could be installed from the foot of the existing outlet tower along the upstream
dam face to the high water level.
Review of conceptual design considerations for the two alternatives indicates that
a laid-back structure will be of comparable cost to that for repair and modification
of the existing facility, while less disruptive of reservoir operations, more
effective in terms of control of pool levels, and aesthetically more pleasing. The
laid-back I/O pipeline concept was determined to be the preferable design
approach.
Spillways are designed to discharge surplus floodwater from a reservoir.
Spillway capacity must accommodate the maximum probable flood when storm
flows from the entire watershed are routed through the reservoir. The original
design incorporated a spillway capacity of 2,300 cfs; however, debris within the
c.hannel as well as some pocket erosion have likely reduced carrying capacity.
The spillway improvements identified in the following two chapters are intended
to restore the facility to its original design capacity. Additionally, if storage
reservoir hydraulic analysis presented in Chapter 5 indicates that greater spillway
capacity may be required for future tributary area storm flow conditions using
cu1rent dam safety criteria, such measures and features will be incorporated as
part of the RW conversion improvements presented in Chapter 6.
Design of access road improvements will allow for all-weather access to the dam
and the proposed I/O control system. Remedial regrading and paving will permit
year-round access for both construction equipment and improved operation and
maintenance activities.
The remedial works will also incorporate security fencing around all new
structures. A laid-back 1/0 pipe and its appurtenances will require special
consideration. The I/O system design presented in subsequent chapters
incorporates both public safety and security features. Protection of the access
road spillway channel and proposed I/O control building would be realized
through construction of gates and fencing.
RW Conversion Facilities
Facilities under consideration for future RW conversion projects include
transmission pipelines, pumping stations, storm flow diversion structures, and
various treatment processes as needed to ensure that the water stored would meet
all RW quality requirements.
CGvL ENGINEERS TN ASSOCIATrON WITH POWELUPBS&J 2-7
Basis of Evaluation
System piping should be evaluated under a range of demand conditions, but
performance assessment is typically most critical under peak-hour demands.
Generally, pipelines 12-inch and greater in diameter are considered transmission
pipelines. Because transmission pipelines impact large areas, they can
accumulate large head losses from long pipe runs. Large pipeline friction losses
associated with high fluid velocities must be evaluated witb respect to system
delivery capacity, their contribution to lowered system pressures, and excessive
energy consumption.
Transmission pipelines are typically considered undersized if water velocities
exceed 3 fps or head losses exceed 10 feet of head per 1,000 LF of pipe.
Distribution pipes are normally considered undersized if velocities exceed 5 fps
and head losses exceed 10 feet of bead per 1,000 LF of pipe. These criteria are,
however, only general guidelines, as higher velocities and head losses may be
tolerable under certain operating conditions such as systero emergencies, and
within short lengths of pumping station or reservoir yard piping where impact on
system pressure is minimal.
A broad range of future RW quality control facilities, features and measures have
b_een identified and evaluated in this report. The pre-storage controls involve
consideration of storm flow diversion structures and constructed wetland systems.
In-storage treatment includes aeration/destratification devices, for improving
water quality within the reservoir itself. Post-storage treatment involves
processes for disinfection and control of possible algae and odor problems. The
downstream treatment processes of primary interest include in-line chlorination
for disinfection and micro-filtration for removal of algae and suspended solids.
As data on Lake Calavera water quality are minimal, in-depth evaluation of these
treatment processes must await further study. A preliminary, reconnaissance-
level survey of present water quality has been made as part of an extension to this
study. The water quality sampling results are presented in Appendix F.
PROJECT COST CRITERIA
Project cost is defined as the total capital investment necessary to complete a
project, including costs for land acquisition, construction, contingencies,
necessary engineering services, and overhead items such as legal and
administrative services, and financing. Construction cost opinions presented in
this report include allowances for contractor administrative expenses as well as
general overhead and profit (OH&P). Total project capHal cost includes an
additional allowance for construction-related contingencies as well as
engineering, environmental documentation and project administration.
CGvL ENGINEERS IN ASSOCIATION WITH POWEuJPBS&J 2 -8
Basis of Evaluation
Construction Costs
Construction cost opinions cover materiats, taxes, labor, mobilization-
demobilization, and services necessary to build proposed facilities. These costs
derive from cun·ent or adjusted historical cost information and are intended to
represent median prices anticipated for each type of work. Cost estimating
guides, previous studies, cost curves, and recent contract bids were used to
develop cost information.
ln an evaluation such as this, cost opinions are considered as defined by the
American Association of Cost Engineers for preliminary design. These are
opinions made without detailed engineering data and have an expected accuracy
range of plus 30 percent to minus 20 percent. Actual project costs wilJ depend on
future labor and material costs, market conditions, project-specific details, and
otber variables. An allowance of 20 percent for contractor OH&P is calculated
from the subtotal of all other construction costs, the addition of which results in
the total construction cost.
Construction Contingencies
A contingency allowance covers uncertainties associated with project design.
Factors such as unusual foundation conditions, special construction methods,
variation in final lengths or average depths of pipeline, and construction adjacent
to existing facilities are just a few of the many items that may increase
construction costs, and for which an allowance is made in preliminary design cost
opinions. The cost of these items can vary greatly depending on the type and
magnitude of project. A 20 percent allowance of total construction cost is
assumed for immediate, remedial improvements to cover such-contingencies. A
30 percent allowance for constrQCtion contingencies has been assumed for
analysis of future, long-term project improvements. The addition for
contingencies results in subtotal project cost.
Engineering and Administration
The cost of engineering services for major construction projects includes some or
all of the following: special investigations, surveys, foundation explorations,
locating interfering uti1ities, detailed design, preparing contract documents,
construction inspection, office engineering, materials testing, final inspection, and
start-up of the-completed project. Depending on the size and complexity of
project, total engineering, Jegal and administrative costs may range from 7 to 40
percent of the contract cost. The lower percentage usually applies to relatively
large projects, simple projects, and those not requiring a large amount of
preliminary investigation. The higher percentage usually applies to smaller
projects, projects requiring a great deal of engineering effort, or those requiring a
relatively large amount of preliminary work. An allowance of 12 percent of
subtotal project cost is assumed for this report.
CGvL ENGlNEERS !N ASSOCIATION Wini POWEuiPBS&J 2-9
Chapter 3
Evaluation of
Remedial Works
The remedial works necessary to protect and preserve Lake Calavera as a viable
public asset and return it to an acceptable level of operation are examined in this
chapter. Existing conctitions and problems are described, followed by an
assessment of alternative actions and measures, with a concluding section
identifying proposed improvements. The remedial improvements cover:
a The outlet tower
□ Spillway apron, channel and small dam repairs
□ An improved, all-weather access road
o Improved site and facility security (fencing and gates)
DESCRIPTION OF PRESENT CONDITIONS
This section describes the current condition of those facilities that CMWD has
identified for remedial improvements.
Outlet Tower
The existing outlet tower and its internal control works are presently in a state of
advanced disrepair. Tbe outlet works are non-functioning due to general
deterioration that has occurred over many decades. All remaining valves are
inoperable (stems broken and valves frozen with rust); several intake ports
intentionally plugged, the interior flooring rotted, the access walkway removed,
and the interior access ladder rusted out. The current state of the outlet pipe
beneath the dam is also unknown. In addition, both the outlet tower and walkway
abutment, as shown in Photos 3-1 and 3-2, provide unsafe attractions, especially
to young people who could be injured attempting to scale or enter these structures.
A field reconnaissance-level video inspection of the outlet tower was performed
in late June 2001 following completion of the draft report. Photos and
observations from that work are presented in Appendix E. Several copies of the
videotape were made fot future reference when undertaking design of the
remedial works and preparing construction contracts.
CGvL ENGINEERS IN ASSOCIATION WITH POWELVPBS&J
I
l
Evaluation of Remedial Works
•
Photo 3-1 Existing Outlet Tower
Viewing north from crest of Calavera Dam, with pool elevation at 213 feet amsl.
(March 8, 2001)
Photo 3-2 Outlet Tower, Rock Blanket and Walkway Abutment
Left to right, viewing east from crest of dam.
CGvL ENGINEERS IN ASSOCIATION WITH POWELUPBS&J 3-2
Evaluation of Remedial Works
Spillway and Channel
The existing spillway facility comprises of two components: the spillway itself
and the channel, as shown iD Photos 3-3 and 3-4. The spillway begins at the
western end of the dam and runs north approximate! y 150 feet. The structure is
comprised of compacted earth with a 3-.lnch gurute surface on both the apron and
the face forming the channel. Apron width ranges from approximately 5 to 25
feet. Tbe spillway sill is at elevation 216.5 feet arnsl.
The spillway channel is approximately 500 feet long and ranges in width from 18
to 26 feet. The lining of the channel is comprised of large boulders, loose dirt,
brush, portions of gunite, bedrock, existing facility materials, and some
construction debris. The western slope is comprised of eroded native earth, brush,
boulders and exposed rock as evidenced in Photo 3-5. Additional features are
presented in Appendix D site photos.
There is some minor cracking on the spillway apron, although it is not considered
as needing immediate attention. Some erosional pockets in the channel bottom
need repair. Racks and other debris must also be removed from the channel floor
to reduce future problems and improve capacity, The areas of greatest concern
regard erosion along the edges of the concrete cutoff structures running across the
channel as well as along the foot of the spillway slope. In some small sections
along the spillway slope the gunite has begun to fatigue.
The open channel immediately downstream of the dam is also in need of repair
and improvement. Debris removal is required to avoid further damage and
deterioration, followed by gunite coating to protect the wall from erosion.
Additional discussion of spillway, channel, and downstream geological conditions
are found in Appendix F.
Access Road
The portion of the existing access road extending 80 LF beyond the paved section
to the northeast corner of the spillway is often impassible following significant
rainfall. Access across the spillway apron and up onto the dam crest bas been
curtailed through trepching and relocating several large rocks, which are moved
when necessary to allow vehicular passage. The crest of the dam itself provides
reasonable access to the east end for equipment and general maintenance;
however, intentionally insufficient road width exists for a turnaround.
The existing unimproved access road reaches the spillway area as shown in
Photos 3-3 and 3-5. Freshwater wetland habitat area extending along the
shoreline of the reservoir begins to the immediate northeast of the existing dirt
track. The existing paved sewer access road from Tamarack Avenue, as shown in
Photo 3-6, leads east then turns south above the spillway channel and heads
CGv L ENGINEERS IN ASSOCIATION WITH PoWELLIPBS&J 3-1
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Evaluation of Remedial Works
Photo 3-3 Spillway Apron and Upstream Channel
Viewing north from west end of dam, with pool elevation at 213 feet amsl.
(May 16, 2001)
Photo 3-4 Spillway Apron and Downstream Channel
Viewing south from upstream end. (May 16, 2001)
CGvL ENGINEERS IN ASSOCIATION WITH POWELLIPBS&J 3-4
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Evaluation of Remedial Works
Photo 3-5 Spillway and Access Road
Viewing northwest from crest of dam, pool with elevation at 213 feet amsl.
(May 16, 2001)
Photo 3-6 Paved Access Road and Dam
Viewing south from entrance gate off Tamarack A venue, Cerro de la Calavera
with quarry in background. American flag and vehicles are at intersection with
unpaved access road to dam. (May 8, 2001)
CGvL ENGINEERS IN ASSOCIATION WITH POWELLIPBS&J 3-5
Evaluation of Remedial Works
downstream of the dam to the lower Calavera Creek drainage area. The existing
access road across the dam, shown in Photo 3-7, is approximately 12 to 15 feet
wide. It is overlaid with compacted decomposed granite along the crest, but
contains several shallow potholes and some small erosional gullies. Additional
photos related to these remedial improvements are presented in Appendix D.
Photo 3-7 Calavera Dam Crest and Outlet Tower
Viewing east from knoll above Tamarack A venue, with lower Calavera Creek
access road in foreground.
Site Security
Present security at the Lake Calavera site entails a locked gate at the paved access
road entrance to the dam and lower Lake Calavera Creek off Tamarack A venue.
Significant portions of the site are open to foot traffic, off-road vehicles, and other
means of uncontrolled passage. Although "No Trespassing" signs are posted at
the site, many have been removed or destroyed in recent years. Efforts to patrol
the entire area have been ineffective.
EVALUATION OF ALTERNATIVES
There are a number of possible options or alternative improvements associated
with each remedial element. This section describes the alternatives and presents
key advantages and disadvantages of each. The intent of this evaluation is to
CGvL ENGCNEERS IN ASSOClA TION WITH POWELIJPBS&J 3-6
Evaluation of Remedial Works
provide the City with a broad range of possibilities in order to support decisions
regarding selection of specific improvements.
Outlet Tower
Three basic options for dealing w.ith the existing outlet tower were considered:
(lA) Demolish the tower by removing all control equipment, seali ng off the
outlet pipe, and dismantling the casing to below the low-water level
(lB) Rehabilitate the tower by replacing the access walkway, ladders,
deteriorated valves, shafts, flooring, and other appurtenances
(lC) RepJace the tower by removing all deteriorated equipment, dismantling to
beJow the Jow-water level and constructing a new laid-back I/0 pipe from
the base of the tower on the face of the dam
Key advantages and disadvantages associated with these three options are
provided in Table 3-1.
Table 3-1 Outlet Tower Improvement Options
lA-Demoli.sh Existing Tower
Advantages:
□ Likely to be least costly solution to present tower problems, 1.e.,
eliminates nuisance, removes risk, and reduces O&M
□ Probably requires least amount of time to execute
□ Offers simple solution for immediate concerns
Disadvantages:
□ Least flexible solution if function of reservoir is modified, e.g., RW
storage, wetlands enhancement, drainage control, etc., all of which would
require new I/0 works
□ Would likely require draining reservoir to permit cost-effective outlet pipe
plugging, tower demolition, and debris removal
□ Precludes use of Lake Calavera for water storage except pumped releases
□ Would not satisfy present dam safety requirements for emergency draining
IB-Rehabilitate Existing Tower
Advantages:
□ Would allow reservoir to serve multiple functions if/as needed, e.g. RW
storage, more effective storm water control, wetlands enhancement, etc.
□ Allows effective use of existing outlet facilities for release of stored water
□ Lake would not necessarily require draining, although construction would
be difficult
Disadvantages:
□ Would require remote access for valve control and maintenance unless
cable bridge were also rebuilt
□ Likely to be as costly to constrnct as Alternative IC
CGvL ENGINEERS IN ASSOCIATION WITH PoWELL/PBS&J '3-7
Evaluation of Remedial Works
Table 3-1 Outlet Tower Improvement Options (continued)
□ Risk of accidents associated with current tower sjtuation would remain,
although mitigatjon possible in form of additional security measures
□ Provides attraction to individuals attempting to scale tower during periods
of elevated water levels
□ Less safe than other alternatives from standpoint of maintenance and
operation
1 C-Replace Existing Tower with New I/0 Facility
Advantages:
□ Also allows reservoir to serve multiple functions as needed, e.g.1 RW
storage1 more effective storm water control, wetlands enhanoement, etc.
□ Utilizes ex..isting footing and lower portion of existing tower, as well as
outlet pipeline
□ Offers a number of options to extent of draining and method of
replacement, e.g., cofferdam, caisson, collar/coupling, underwater
installation, etc.
Disadvantages:
□ As future function of reservoir is yet undetermined, alternative may
involve some marginal costs (in excess of demoJition/repair) not
attributable to present needs
□ May be somewhat more complex, from construction standpoint, than
Alternatives IA or lB
Spillway and Channel
Three basic options for dealing with spillway and channel protection were
considered:
(2A) Do nothing and allow continued deterioration of facility
(2B) Repair apron, existing channel, and downstream channel
(2C) Remove and replace existing works with new concrete apron and spillway
Key advantages and disadvantages associated with these three options are
provided in Table 3-2.
Table 3-2 Spillway and Channel Improvement Options
2A-No Action
Advantages:
□ Least cost
□ Simple and easy
Disadvantages:
□ Would most likely not allow facility to meet current dam safety criteria for
spillway operation
CGvL ENGrNEERS IN ASSOClATION WITH POWELIJPBS&J 3-8
Evaluation of Remedial Works
Table 3-2 Spillway and Channel Improvement Options (continued)
2B-Repair Existing Features
Advantages:
o Permits dam to meet operational criteria
□ Likely to be most cost-effective of three alternatives
□ Easy to implement
□ Ensures prolonged service life of the facility
Disadvantages:
o As future use/function of reservoir is yet indeterminate, option may
represent premature commitment to preservation of historic system
2C-Replace Existing Features with New Ones
Advantages:
□ Ensures extended service life of structure
Disadvantages:
□ Most costly of the three alternatives
□ Difficult to implement and least flexible solution
□ Major commitment of capital when ultimate use/function of reservoir is
not yet determined
Access Road
The lower portion of the existing access road, extending 80 to 100 feet from the
paved section to the northeast corner of the spillway, is paved and impassible
following storms. At present, vehicle access across the spillway apron and onto
the dam crest is curtailed through trenching and placement of several large rocks,
which are relocated when necessary to allow maintenance vehicle passage. The
crest of the dam itself provides reasonable access for cleaning equipment and
general maintenance; however, there is, by intention, insufficient space at the far
end for turning a vehicle around.
Three basic options for dealing with the access road were considered:
(3A) Do nothing and continue current restrictions
(3B) Upgrade current access through an improved spillway apron with ramp to
dam crest
(3C) Replace current access with a new structure that bridges the spillway
channel to the dam crest
Key advantages and disadvantages associated with these options are provided in
Table 3-3.
CGvL ENGlNEERS IN ASSOClA TlON WITH POV{ELLIPBS&J 3-9
Evaluation of Remedial Works
3A-No Action
Advantages:
Table 3-3 Access Road Improvement Options
□ Minimum environmental impact
□ Least cost and easy
Disadvantages:
o Allows for continued erosion and deterioration of upper channel and dam
o Restricts year-round maintenance and operation of the facilities
3B-Upgrade via Spillway Apron
Advantages:
a Offers a number of options regarding methods and future developments
□ Can be phased with other improvements
□ Reduces runoff/erosion problems associated with existing access road
Disadvantages:
□ Potentially opens area up to increased traffic unless additional security
features are installed
3C-Replace With New Structure Bridging Spillway Channel
Advantages:
□ Would likely allow greater security at site
□ Would permit larger vehicles somewhat better access for future
construction/operations
□ Would support future development to south side of the reservoir
Disadvantages:
□ Most costly
□ Large capital commitment when future functions/use of site are not yet
defined
□ Greatest long-term environmental consequences, under the assumption
that easier (better) access indirectly leads to greater impacts throughout the
site
□ Likely most difficult to implement
□ Likely to be least compatible with cunent land use plans and policies
regarding open space commitments, under same assumption as two bullets
above
Site Security
Three fundamental approaches to site security were evaluated:
( 4A) Do nothing and continue current security problems
(4B) Fence the entire site
(4C) Fence key facilities only
CGvL ENGINEERS IN ASSOCIATION WlTB POWELLIPBS&J 3-10
Evaluation of Remedial Works
Key advantages and disadvantages associated with these three options are
provided in Table 3.4.
4A-No Action
Advantages:
Table 3-4 Site Security Improvement Options
□ Minimal cost
o Easy
Disadvantages:
□ Perpetuates high risk of accidents occurring on site
o Likely to be unacceptable from a public safety standpoint, without
extensive reposting or other mitigation and/or enforcement measures
□ Likely to be found incompatible with General Use Plan andHMP
4B-Feoce Entire Property
Advantages:
□ Comprehensive
Disadvantages:
□ Most costly to build and maintain
□ Likely to be in-effective in keeping individuals out of sensitive areas
o Likely to represent negative visual/aesthetic impacts that would be
clifficult to mitigate
□ Incompatible with adjacent land uses to east and south
4C-Fence Operational Facilities Only
Advantages:
□ Likely to be a cost-effective solution to existing public safety problems
□ Can be implemented as other remedial improvements are completed
o Greater flexibility to future changing needs
□ Provides security to those facilities of greatest concern
Disadvantages:
□ Would likely present some negative aesthetic/visual impacts compared
with approach 4A
RECOMMENDED ALTERNATIVE IMPROVEMENTS
The following set of recommended remedial improvement options was provided
at mid-conrse of project study execution. Based on review by the City at that
time, preliminary design of the proposed remedial works, as covered in the next
chapter, was initiated.
o Outlet Tower-Subject to preliminary site investigations, pursue tower
improvement Option 1 C, replacing the existing tower with a new 1/0 facility
o Spillway and Channel-Pursue improvement Option 2B, repairing existing
features
CGvL ENGINEERS 1N ASSOCIATION WITH PoWEuJPBS&J 3-11
Evaluation of Remedial Works
o Access Road-Pursue improvement Option 3B, upgrading access via the
spillway apron
o Site Security-Implement a localized facility fencing and gate plan per
Option 4C, as needed for protection of site operations and maintenance
activities
CGvL ENGINEERS IN ASSOCfATION WITH POWELLiPBS&J 3-12
Chapter 4
Preliminary Design of
Remedial Works
Preliminary design of the proposed remedial works for Lake Calavera covers four
elements: I/O works improvements, spillway channel repairs, access road
upgrade, and facility fencing for site security. Each of these elements is discussed
and an opinion of construction cost provided in this chapter.
1/0 WORKS IMPROVEMENTS
An improved 1/0 structure would have multiple ports similar to the existing three
outlet tower ports, in addition to an emergency outlet, equally spaced and
approximately 6 feet apart. This vertical spacing would allow selective water
withdrawal from the stratum having the best water quality, e.g., avoiding near-
surface algae layers that seldom extend below 5-10 feet of depth, as well as
avoiding near-bottom chemically reduced waters or bottom sediments.
Objective and Approach
There are two common I/O works configurations: a free-standing tower rising
from the reservoir bottom, and a laid-back structure secured to the upstream dam
face. Another free-standing tower could, in concept, be constructed above the
base of the existing outlet tower. Altematively, a laid-back structure could be
connected between the existing tower base and the old walkway abutment on the
upstream dam face. Review of conceptual design considerations for the two
configurations indicates a laid-back alternative would be Jess disruptive, less
costly to maintain, and preferable from both environmental and engineering
standpoints. Any modification to the existing structure will require review by the
State of California, Division of Safety of Dams (DSOD). The primary
consideration by DSOD regards maintaining adequate and controllable reservoir
drainage capability under emergency situations.
Results
The location of the proposed laid-back J/O pipe with respect to the existing outlet
tower and other site features is shown on Figure 4-1. A preliminary design profile
drawing for the 24-inch pipeline and riser is shown on Figure 4-2. Three 18-incb
J/O ports would be provided for selecting the best quality water stratum at any
time. An additional 16-inch slide gate valve would isolate the existing tower from
the new pipeline. Tb.is gate, normally closed, would be opened either manually or
CGvL ENGINEERS IN ASSOCIATION WITHPOWELUPBS&J 4-1
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IN ASSOCIATION WITH
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PROPOSED 1/0 WORKS PROFILE
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Preliminary Design of Remedial Works
by hydraulic actuator as a fourth regular outlet port and to satisfy darn emergency
reservoir drainage requirements.
Based on new valve placement shown on Figure 4-2, the conservatively proposed
new maximum and minimum operating levels are elevations 214 and 192 feet
amsl, respectively. The new effective working volume~ based on the difference
between those elevations, is approximately 380 AF.
Preliminary sizing of the proposed 1/0 works was based on hydraulic network
analyses taken from the May 2000 CMWD RWDS expansion report, Encina
Basin Recycled Water Distributlon System Study (Reference 19). Although water
volumes associated with Lake Calavera's operational storage function would be
relatively small compared with those of seasonal storage, peak-hour hydraulic
requirements for operational storage were used as a conservative basis to size I/0
pipes, ports, and valves. Table 4-1 lists peak-hour withdrawal rates estimated in
the above-noted work for the Phase Il and Ultimate system expansions. As
additional RW production capacity and operational storage volumes elsewhere are
developed, the peak-hour demand on storage decreases from Phase Il to Ultimate
conditions. Hence, the estimated Phase II peak-hour withdrawal rate is higher
than the Ultimate rate, and the Phase II rate is used for preliminary 1/0 works
sizing.
Table 4-1 Lake Calavera 1/0 Hydraulic Parameters
Milestone
Parameter Units Phase II Ultimate
Peak-hour flow gpm 3,000 4,200
1/0 pipeline/port diameter3
:
Pipe velocity at 20 inches fps 3.2 4.3
Pipe velocity at 18 inches fps 3.8 5.2
Pipe velocjty at 16 inches fps 5.0 6.8
a) Using a friction factor of C = 120.
Because the total headless difference between a 20-inch and 18-inch valve is
relatively small, but the relative cost difference. greater, 18-incb valves are
assumed for the proposed new 1/0 port controls. Each 1/0 port would be
protected from coarse suspended material by appropriate stainless steel screens.
The arrangement of these screens is highlighted on Figure 4-2. A photograph of
similar 1/0 ports and screens at Upper Oso Reservoir, owned and operated by
Santa Margarita Water District (SMWD), is shown on Photo 4-1. All valves
would be hydrauUcally operated with control lines terminating in a proposed
operations control building located near the west end of the dam, as shown on
Figure 4-1.
CGvL ENGINEERS IN ASSOCIATION WITH PoWEuJPBS&I 4-4
Preliminary Design of Remedial Works
Photo 4-1 Upper Oso Reservoir 1/0 Ports
With screens (lower center) and air/vacuum valve (lower right), viewing east from
dam crest.
A range of control procedures for managing reservoir water levels during
construction of the Lake Calavera remedial modifications has been considered.
The four water level control techniques evaluated include:
(A) Complete draining of the reservoir for the period of construction
(B) Near-complete draining of the reservoir, except a small upstream portion
to be diked-off for storage of runoff and protection of aquatic biota during
construction, with upstream impoundment reverting to wetlands created
by permanent dikes (elevation 210 and 214 feet amsl) constructed on
upper Calavera Creek near reservoir inlet
(C) Partial draw-down of the reservoir to minimum operational water level
(elevation 189 feet amsl), with construction of a small temporary
cofferdam encompassing the existing outlet tower
(D) Underwater construction of the I/O modifications to preserve present pool
levels (elevation 208 feet amsl), maintaining full storage capacity and
minimizing disruption to existing features
Comparison of resultant characteristics, costs and non-monetary attributes
associated with these alternative water level control procedures are presented in
Table 4-2.
CGvL ENGINEERS IN ASSOCIATION WITH POWELL/PBS&] 4-5
Preliminary Design of Remedial Works
Table 4-2 Water Level Control Alternatives for 1/0 Tower Construction
A B C
Water Level Full Drain Drain with Drawdown/
Control Feature of Reservoir u/sDikes Cofferdam
Pool elevation, ft amsl <176 <176 [210-218] 189
Surface area, acres <1.0 <1.0 [6] 5-6
Storage capacity, AF <5 <5 [30-40] 50-60
Muck removal, CY 1000-1200 1600-1800 500-600
Capital cost, $ 83,000 225,000 200,000
Implementation a Easiest Difficult Moderate
Environmental impactb Greatest Consequential .Moderate
Level of complexiti Least Moderate Moderate
Agency approvalsd Difficult Difficult Moderate
Overall rank.int 4th 2nd 1st
a} Relative ease of implementing the alternative measure.
b) Potential for both short-and long-term negative environmental consequences.
c} Considering both technical and administrative issues.
d) For meeting anticipated requirements, permits and other conditions.
e} Considering both economic and non-monetary factors, as rated by consultant.
D
Underwater
Construction
208
18-21
160-200
0
855,000
Difficult
Least
GJ"eatesr
Easiest
3rd
Lowering the reservoir to its historic minimum operational poo] level (elevation
189 feet amsl) and proceeding with construction of a 10-25 feet high cofferdam
on the upstream submerged face to encompass the existing outlet tower is the
recommended procedural alternative. Thi.s procedure is dee01ed to be much less
environmentally disruptive than draining Lake Calavera as weJl as involving
significantly lower costs than those associated with alternative underwater
demolition and construction procedures.
Constructing a laid-back I/0 pipeline on the upstream face of the dam and
connecting to the existing 28-inch steel I/0 pipe and adjacent to the existing tower
base involves construction of a temporary cofferdam as shown on Figure 4-L
With draw-down to minimum pool, the sheet pilings forming the cofferdam walls
need be approximately 25 to 30 feet long as water depths would range from O to a
maximum of 20 feet upstream of the tower. The two walls of the cofferdam
would be approximate1y 12 feet apart and comprise a total length of 120 feet.
A special study assessing the potential biological impacts on aquatic biota and
shoreline habitat plus appropriate mitigation measures associated with temporary
draw-down and cofferdam construction has been proposed. This study could be
carried out during the initial agency review process in fall 2001 to obtain
information that can help determine the full extent and scope of mitigation
measures for the reservoir water level control procedures during construction.
CGvL ENGINEERS .IN ASSOCIATION WITHPOWEulPBS&J 4-6
Preliminary Design of Remedial Works
The general construction steps that would likely be involved with the proposed
VO modifications ar~. in order, as follows:
(1) Mobilize and assemble a construction barge on Lake Calavera
(2) Breach the lower 18-inch valve/inlet port on tower, allowing drawdown
(3) Remove rock blanket and erect sheet piles on upstream dam face from
barge as pool level drops toward elevation 189 feet amsl
(4) Remove remaining rock blanket below water at depths up to 15 feet in the
vicinity of tower and on face of dam, driving remaining sheet piles from
barge
(5) Provide internal support of cofferdam and extract interior water
(6) Dismantle and remove upper 40 feet of existing tower from barge
(7) Install new 16-inch emergency control slide gate at upper end of outlet
pipe within tower base
(8) Inspect existing 260 feet of outlet pipe below dam and correct any
deficiencies
(9) Sink 4-foot well shaft in compacted earth fill of upstream dam face and
excavate to existing 28-inch steel outlet pipe
(10) Install new 28-inch couplings, tee and 24-inch riser pipe in shaft
(11) Erect new cover with screens on tower
( 12) Construct I/0 pipe anchors in compacted earth fiH of upstream dam and
replace 3-foot thick rock blanket
(13) Install 24-incb laid-back I/0 pipeline, ports, valve assemblies, controls,
and protection equipment
(14) Remove piling tops to waterline, flood cofferdam and allow reservoir to
refill
In addition to removal of the upper portion of the existing outlet tower and
construction of a laid back I/0 pipeline, a bydraulic accumulator system for
remote operation of the 1/0 valves will be needed. The system would consist of
the hydraulic control lines extending from the I/0 valves to a small I/0 control
building housing the accumulator, electrical controls and 1nstrumentation. A
small windowless I/0 control building, with a single door, erected on a 10-foot-
square concrete pad to be situated at the west end of the dam is recommended.
The building site location is shown on Figure 4-1; a recent site view is presented
in Photo 4-2.
A cost opinion of the 1/0 works improvements is provided in Table 4-3. The
improvements entail a cost of approximately $530,000 for subtotal construction,
exclusive of contractor OH&P, contingencies, an.d engineering and
administration. Total project costs are presented in the remedial improvements
summary at the end of this chapter.
CGvL ENGINEERS IN ASSOCIATlON WITH POWELIJPBS&J 4-7
f
I
Preliminary Design of Remedial Works
-
Photo 4-2 Proposed Control Building Site
Located at west end of Calavera Dam. (May 16, 1999)
Table 4-3 Cost Opinion for 1/0 Works Improvements
Material Cost, Labor Cost,
Ouantitv dollarsa dollars3
Item No. Unit Unit Extended Unit Extended
Draw-down 65 MG -2,000 -6,100
Temporary cofferdam 200 LF 135 27,000 165 33,000
Muck removal 400 CY 5 2,000 5 2,000
Tower demolition 1 LS 5,000 5,000 15,000 15,000
Debris/pilings removal 300 EA 75 22,500 75 22,500
Subtotal
Shoring 4 EA 600 2,400 360 1,440
Excavation 20 CY 40 800 20 400
New tower cap 5 CY 200 1,000 400 2,000
24" steel pipe 92 LF 115 10,580 105 9,660
Welding joints 20 EA 315 6,300 35 700
24x24x18 tee 3 EA 900 2,700 1,000 3,000
24" 90 elbow 1 EA 950 950 770 770
28x28x24tee l EA 1,990 1,990 1,126 1,126
Flex coupling 2 EA 500 1,000 650 1,300
16" gate valve 1 LS 7,055 7,055 3,000 3,000
CGvL ENGINEERS IN ASSOCIATION WITH POWELL/PBS&J
Total Cost,
dollarsb
8,325
61,664
4,1 11
20,555
46,248
140,903
3,946
1,233
3,186
20,801
7,194
5,858
1,768
3,202
2,364
10,334
4-8
Preliminary Design of Remedial Works
Table 4-3 Cost Opinion for 1/0 Works Improvements (continued)
Material Cost, Labor Cost,
Quantitv dollars2 dollarsa Total Cost,
Item No. Unit Unit Extended Unit Extended dollarsb
Pipe supports 8 EA 250 2,000 500 4,000 6,166
18" butterfly valve 3 EA 5,000 15,000 2,250 6,750 22,353
18" SS wire screen 3 EA 3,500 10,500 1,500 4,500 15,416
Subtotal 103,822
OP Repairs 260 LF 72 18,720 100 26,000 45,960
Hydraulic Accumulator Sys. I LS 32,000 32,000 41,000 41 ,000 75,024
I/0 Control Building 150 SF 100 15,000 250 37,500 53,956
E/Iwork I LS 12,000 12,000 5,900 5,900 18,396
Metal work 1 LS 3,500 3,500 1,600 l,600 5,241
Subtotal 198,578
Sales tax 7 .50 percent 15,807
Mobi]jzation/Demobilization 3 percent 13,524
Allowances" Varies 57,400
Subtotal Construction 530,033
a) Year 2000 construction pase cost.s atENRCCI = 6130.
b) Current costs adjusted to ENRCCI = 6300, estimated for mid-2001.
c) lncludes allowances for miscellaneous items and activities.
SPILLWAY AND CHANNEL IMPROVEMENTS
The spillway channel is in immedia_te need of being cleared, cleaned and repaired
to fill in erosion pockets, protect the exposed cutoff structures and patch any
evident cracks, flakes and fissures. As the spillway apron is also used for access
on to the dam, there is a clear need to coordinate all repairs to the spillway,
channel, and downstream bed with other remedial improvements.
Objective and Approach
The City identified two initial objectives. First was to identify and research any
required improvements to the spillway facility resulting from the addition of an
access road to the dam. Second was to investigate the integrity of the spillway
channel and to determine any improvements necessary.
Based on discussions with the City after preliminary findings, the initial objective
was redefined to detennine required modifications to the spillway in order to
utilize the spillway apron for maintenance vehicle access to the dam crest and I/O
structure (see following section on Access Road Improvements).
CGvL ENGINEERS IN ASSOCIATION WlTHPOWEuJPBS&J 4-9
Preliminary Design of Remedial Works
The spillway channel was analyzed to determine improvements necessary to
increase flow characteristics, as well as increase the life expectancy and safety of
the spillway. DSOD requirements were considered for all investigations.
Results
A cost opinion was prepared for recommended improvements to the existing
spillway facility, excluding cost assoeiated with the access road improvements.
The costs of recommended improvements included excavation and removal of
debris in the spillway channel, reinforced gunite lining of the channe~ and
overlaying the spillway face. The cost opinion for subtotal construction of these
improvements is approximately $47,000.
Improvements to the spillway apron are discussed in the following sectjon of this
report. Improvements to the spillway channel itself are recommended to decrease
the effects of erosion and possible future damage to tbe spillway structure and
dam. Based on preliminary analyses of the existing channel and DSOD
requirements, the entire channel should be lined with either reinforced concrete or
gunite. Prior to lining, all loose materials (rocks, dirt, brush, trash, etc.) within the
channel should be removed. The existing east slope (face of spiJlway structure)
should be rehabilitated with an overlay of reinforced gunite that will prolong the
life of the structure. The existing west slope (eroded native earth and rock) may
need further investigation during design to determine overall stability. Portions of
tbe downstream channel may also require lining with reinforced gunite if erosion
is found to be extensive. The three horizontal rows of 2-inch weep holes
irregularly spaced along the spillway slope should also be cleared to remain open.
ACCESS ROAD IMPROVEMENTS
The initial objective for access road improvements was to determine two
alternatives to cross the spillway facility. The two alternatives proposed were a
bridge structure and an earthen fill over large diameter culverts. This would
provide access to the dam for maintenance personnel and others as required.
Objective and Approach
Based on discussions with the City following preliminary findings, the initial
objective was modified to investigate proposed remedial works at the preliminary
design level. It was determined that the remedial improvements were to include
access to the I/0 works and dam crest, as well as to a proposed control building
site located near the dam. The City proposed utilizing the spillway apron as a
means of access to the dam. The City desired that the access road be designed to
provjde adequate access and safety for a small utility vehicle to traverse the
spillway apron, transition to the dam crest, and turn around at its eastern end.
CGvL ENG1NEERS IN .ASSOCIAT!ON WITH POWELL/PBS&J 4-JO
Preliminary Design of Remedial Works
Initial investigations of possible aocess roads across the spillway and dam crest to
a then-proposed shooling range on the east side included the use of a bridge aod
-arch culvert. The bridge would traverse the spillway channel from the dam crest
to a point directly west across the channel. The concrete arch culvert bridge
would also traverse the spillway channel at a similar location. Modifications for
tie-ins to the dam and west side bank of the spillway channel would be required
for both alternatives. Preliminary costs ranging from $500,000 to $700,000 were
developed for the bridge and culvert options. This investigation included
improving the spillway channel in conjunction wjth upgrading the existing road.
Results
Cost opinions were prepared for all three alternatives investigated. All three
opinions included costs for improvements to the access road across the top of the
dam. The cost opinion for the bridge crossing is approximately $670,000. The
cost opinion for the arch culvert is approximately $560,000.
The cost opinion for access utilizing the spillway apron included the following:
o Excavation for the spillway extension to the north
□ Construction of the extended spillway
□ Improvements to the spillway apron
o Construction of the transition ramp to the top of the dam
□ Construction of the turnaround at the east end of the dam
□ Improvements to the dam crest
The cost opinion for subtotal construction of this third alternative is
approximately $96,000. Detailed costs for the three alternatives are presented in
Appendix C.
Based on initial. findings of the two proposed spillway channel crossings (bridge
and arch culvert)1 it was determined that the use of these two structures is feasible.
Due to the recent elimination of access to a proposed shooting range, however,
neither of these structures is recommended as r:emedial improvements.
The existing spillway apron and dam crest are recommended as means of
immediate access to the outlet tower, the dam crest, and the south face of the dam.
A turnaround for maintenance vehicles is also recommended at the eastern end of
the dam, the location of which is shown in Photo 4-3. The acces~ road across the
spillway apron will require an extension of the spillway as well as a transition
ramp to the top of the dam. An all-weather maintenance road consisting of a
single 12-foot wide lane will need to be constructed from the southern portion of
the spillway apron (elevation 216.5 to 214.5 feet amsl) to the dam crest (elevation
223 feet amsl). The transition roadway should be constructed of eartbeh fill with
a concrete overlay. A conceptual plan and profile of the upgraded access roadway
improvements are provided on Figures 4-3 and 4-4, respectively.
CGvL ENGTNEERS IN ASSOCIATION WITH POWELIJPBS&J 4-11
Preliminary Design of Remedial Works
Photo 4-3 East End of Calavera Dam
For upgraded access road above turnaround is proposed
The transition roadway will eliminate portions of the spillway apron at its
southern edge. The spillway facility (both structure and channel) may need to be
increased by the same length lost in constructing the transition road from the
apron to the dam crest. The extended spillway structure should consist of earthen
fill with concrete overlay, while the extended spillway channel should be overlaid
with reinforced concrete gunite. The transition area is shown in Photo 4-4.
The existing spillway apron should be overlaid with reinforced concrete that will
be able to both handle light traffic loads, as well as reduce the roughness of the
existing gunite surface. This overlay will need to maintain a minimal thickness in
order to not exceed the present spillway crest elevation of 216.5 feet amsl.
Minor improvements to the dam are also required for completion of the access
road to the eastern end of the dam. Shallow potholes on the crest and some
erosional gullies and minor fissures need to be repaired. Following repair, a new
layer of decomposed granite should be placed on the crest to avoid future
indentations and cracks.
An adequate space for maintenance vehicle turnaround is also needed at the east
end of the dam. In order to construct this turnaround, minor grading will be
required. The turnaround should also be overlaid with decomposed granite.
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PROFILE OF ACCESS ROAD IMPROVEMENTS
Preliminary Design of Remedial Works
Photo 4-4 Proposed Access Road Transition Ramp Area
Leading from spillway apron onto dam crest. (September 12, 2001)
SITE SECURITY IMPROVEMENTS
Objective and Approach
Present site security consists of a locked gate installed across the paved access
road west of the entrance to the dam site off Tamarack A venue. There are also a
number of "No Trespassing" signs posted at strategic places along the property
boundary. The high cost, difficulty, and lack of aesthetics associated with fencing
the entire 266-acre site combined with the need to protect specific remedial
facilities indicate that fencing of several key facilities is the most viable and
economical option to pursue.
Results
A standard 7-foot-high chain-link security fence supporting a gated 12-foot
opening facing the dam and access road is recommended for protection of the
proposed I/0 control building. Approximately 80 feet of fence work including
two outward swinging gates would be required. Additional security fencing is
recommended for placement around the proposed upper I/0 air/vacuum valve to
ensure protection from vandals and animals. The hydraulic control lines, housed
CGvL ENGINEERS IN ASSOCIATION WITH POWEUiPBS&J 4-15
Preliminary Design of Remedial Works
within conduit, would be buried in a shallow trench running along the new access
road on the dam crest extending from the control building to the 1/0 port valves.
An additional double-wide gated security fence js recommended for placement
across the upgraded access road at its intersection with the. existing paved section
extending south from Tamarack A venue and a dirt road learung east onto the Lake
Calavera properly as shown on Figure 4-1. This gate would provide a barrier to
motor vehicles but allow pedestrian traffic passage across the spillway and dam.
The cost opinion for subtotal construction of remedial fencing is approximately
$26,000.
Site security regarding future RW conversion facilities has also been considered
in context with the remedial fencing improvements. The planning concept of a
future interpretive trail system through the property, possibly developed in
conjunction with a manned fishing and boating concession at the Lake shore,
might offer a more realistic means of controlling site access and maintaining
security than attempts to fence and patrol the entire property. A substantially
similar approach has prov.en reasonably successful under comparable
circumstances at SMWD's Upper Oso Reservoir.
REMEDIAL WORKS SUMMARY
A summary construction cost opinion for the proposed remedial works at Lake
Calavera is presented in Table 4-4. The total project cost, including design and
administration, is $1,203,100, expressed in current dollars.
Table 4-4 Cost Opinion for Remedial Works
Item Cost, dollarsa
Partial mobilization, draw-down and temp. cofferdam 97,300
Tower demolition, new cap, muck/debris removal 95,500
New laid-back 1/0 pipeline and ports 115,000
1/0 control system and building 222,200
I/O Works Improvement Subtotal 530,000
Other mobilization 15,100
Spillway, channel and dam repairs 47,300
Access road extension and upgrade 95,500
Fencing, gates and demobilization 26,200
Subtotal Construction 714,100
Contractor OH&P 20 percent 142,800
Total Construction 856,900
Contingencies 20 percent 171,400
Subtotal Project 1,028,300
Engineering and administration 17 percent 174,800
Total Project 1,203,100
a) Costs al ENRCCI = 6300.
CGvL ENGINEERS IN ASSOCIATION WlTHPOWELllPBS&J 4-16
Chapter 5
Seasonal
Storage Analysis
Lake Calavera offers, in the future, the potential to provide both additional supply
through impounding upstream runoff and augmented .seasonal storage for
CMWD's expanding RW system. These RW storage concepts are analyzed in
this chapter. Operational and emergency storage analysis are part of ongoing
CMWD related distribution system work, but outside the scope of this study.
Results of the following seasonal storage analyses are used in sizing the facility
improvements presented in Chapter 6.
COMPARISON WITH OTHER STORAGE RESERVOIRS
As a basis for comparison, this srudy reviewed some of the important features and
operating histories of other reservoirs in the region with storage volumes both less
than and greater than Lake Calavera. The storage systems examined included
other RW storage reservoirs in California, several comparably sized reservoirs in
San Diego County, and some local area reservoirs used for multi-purposes.
AW Storage Reservoirs in California
Relatively few seasonal RW storage reservoirs exist in California. Three such
seasonal impoundment systems are located in Orange County. Sand Canyon and
Rattlesnake Reservoirs are owned and operated by Irvine Ranch Water District
(IRWD), and contain total volumes of 800 AF and 1,200 AF, respectively.
SMWD's Upper Oso Reservoir has a total voJume of 4,000 AF. All three
reservoirs have been in RW service for over 21 years.
The City of Santa Rosa, in northern California, owns and operates several RW
storage reservoirs. The largest has a volume of 2,000 AF and has been in service
for approximately 17 years. Their next two largest reservoirs have volumes of
1,100 AF and 700 AF, respectively, and have been in service for approximateJy
23 years. All three reservoirs have relatively flat bottoms, with an average water
depth, when full, of 24 to 25 feet. AJJ three reservoirs are surrounded by man-
made berms, with virtually no tributary drainage area.
In discussing design and operation of these reservoirs with respective agency
staff, several features emerge for possible application at Lake Calavera:
□ Relative size and watershed management of upstream tributary area
CGv L ENGINEERS IN ASSOC IA TIQN WITH POWELrlPBS&J 5-1
Seasonal Storage Analysis
□ Average water depth of full reservoir
□ Combination of treated wastewater with other water supplies
□ Nutrient removal from treated wastewater
□ Use of multiple-port I/O works
□ Use of an aeration/destratffication system
□ Chlorination of reservoir outflow
□ Treatment of reservoir outflow for algae and other nuisance problems
□ Use of basin lining and covering
Table 5-1 presents a matrix of these features, listed in the same order, and their
involvement at the above-noted, existing seasonal RW storage reservoirs. One of
the most significant features to emerge in tbis evaluation appears to be the relative
size and watershed management of upstream tributary area. By far the most
problematic in this regard of the three reservoirs that have significant tributary
watershed area is Sand Canyon. Runoff from a large upstream tributary area
carries in fine, colloidal material and nutrients, both difficult to treat in reservoir
outflow. Upper Oso appears least problematic in this regard of the three. The
ratio of tributary area to total reservoir capacity for Sand Canyon is approximately
30 times larger than Upper Oso Reservoir1 s ratio. Lake Calavera, similar in this
regard to Sand Canyon, presents a tributary area to total capacity ratio of 4.42: 1.
The other significant feature to emerge in this evaluation appears to be the
average water depth of a reservoir when full. Santa Rosa staff reported no
significant algae growth or other depth-related water quality problems when water
depths were predominantly greater than about 8 feet. Their three largest
reservoirs only suffered problems on occasions when they were drained to within
several feet of bottom. Two of their smaller reservoirs (not noted above), with
volumes of approximately 200 to 300 AF and average depths of about 4 feet, have
been regularly troubled with algal growth and related water quality problems.
Santa Rosa has employed algae harvesters and ban-el filters to mitigate these
problems. with moderate success after considerable cost and effort. Lake
Calavera's average. water depth is greater than 15 feet, while planned minimum
operat,ional pool depth is in excess of 12 feet.
Application of the above considerations is explicitly made for proposed Lake
Calavera improvements in Chapter 6 of1his report.
CGvL ENGINEERS IN ASSOCIATION WITHPOWELllPBS~ 5-2
Seasonal Storage Analysis
Sand Canyon Rattlesnake u erOso Santa Rosa
Tributary area, acres 4,330 1,290 723 32
Capacity, AF 800 1,200 4,000 3,800
Tributary area/ capacity ratio, 1/ft 5.41: 1 l.08:1 0.18:1 0.01:1
Average water depth, ft 15a 15a 30 24-25
Combined with other soufces No No Yes No No
Nutrient removal at WRPs No Minorb Minoi No Minorc
Multiple port 1/0 works No Yes Yes Yes Yes/Nod
Aeration/destratification No Yef Nof Yes No
Chlorination of outflow No Yes& Yesg No No
Other treatment Yes Yesh Noi Noi No
Basin lining and covering No No No No No
Yesi Yesk No No No
Estimated values.
Partial nitrification/denitrification practiced at IRWD's Michelson Water Reclamation PJant, but not primarily
for reservoir water quality.
c) Partial nitrificatioo/denilrification practiced at SRWRP, primarily motivated by regulatory requirement for
winter discharge to river.
d) Some turbidity problems with single port and seasonally low water levels.
e) System installed in 1999 with successful performance.
f) Water quality tends to be good without aeration, but installation under re-evaluation.
g) Initially practiced for chemical oxidation of sulfides; later continued partially to maintain chlorine residual in
distribution system.
h) Several relatively expensive filtration systems have been tried, witb varied success.
i) Have occasionally used Adams strainers.
j) Suspected high algal counts and odor problems to be rectified with. improvements.
k) High turbidity and algal counts.
l) Represents aggregate of their three largest reservoirs.
Comparable Capacity Reservoirs in San Diego County
In addition to considering current operations at other RW seasonal storage
reservoirs, the fact that Lake Calavera may in the future be used for
supplementing supply to the expanding RWDS merits comparison with other
comparable capacity reservoirs within San Diego County. The gene.ral physical
properties of four of these impoundment systems and Lake Calavera are presented
in Table 5-2.
Other North County Reservoirs
There are, in addition to those listed above, several other multi-purpose water
storage reservoirs situated in the North County coastal zone. The three principal
CGvL ENGINEERS IN ASSOCIATtON WITHPOWEu.JPBS&J 5-3
Seasonal Storage Analysis
Table 5-2 Comparison with Comparable Size San Diego County Reservoirs
San Marcos Lake US Silica FW
Reservoir Name South Corte Madera Calavera Ponds Palo Verde
Location San Marcos Corte Madera Carlsbad Oceanside Palo Verde
Owner VWD Rancho CM Inc. City US Silica PV Ranch HOA
Type Open, potable Runoff Open, runoff Off-stream
Water source Maggy Creek P ine Vly Creek Calavera Creek Loma Alta Crk. Sweetwater R.
Tributary area, acres 282 1,600 2,300 130 34,600
Capacity, AF 320 325 520 700 730
Surface area. acres 14 69 35 46 39
Elevation, ft ams! 830 3,920 210 230 1,800
23 5 15 15 19 Mean depth, ft
Dam volume, CY 131,780 earth 3,500 concrete 85,000 earth 192,300 earth 75,000 concrete
Dam H/L, ft 85/400 16/200 67/490 76/?? 67/410
impoundments are listed in Table 5-3, and are currently used for potable water
storage.
San Diegito Reservoir, although over twice the size of Lake Calavera, is located
at comparable elevation. Lake San Marcos has an equivalent storage capacity to
Lake Calavera, but its water surface elevation is much higher. San Marcos Creek
runoff into the reservoir has not presented a quality pr9blem. Maerkle Reservoir
is a major treated water storage facility (asphalt-lined and covered in 1998) for the
City with an operational capacity slightly larger than Lake Calavera's.
Table 5-3 Comparison with Other Nearby North County Reservoirs
Maerkle Reservoir Lake San Dieguito
Name (aka Suuires Darn) San Marcos Reservoir
Location Aqua Hedionda Ck Sao Marcos Creek Rancho Santa Fe
Owner CMWD Citizens DC SFID/SDWCD
Type Covered, potable Open, imported Open, irrigation
Supply source Imported Water• SD Aqueduct b San Diegnito Riverc
Tributary area, acres 13 1,860 770
Capacity, AF 600 480 1,128
Surface area, acres 14 54 56
Elevation, ft amsl 505 500 250
Mean depth, ft 43 9 20
Dam volume, CY 479 ;500 earthfill 131,780 2,435 concrete
DamH/L, ft 165/800 52/290 51/650
Water quality problems No No No
a) lnfluent supply from SDCW A Second San Diego Aqueduct, no local runoff.
b) Small amounts of local runoff also captured from San Marcos Creek.
c) Most influent conveyed from Lake Hodges; however small volume of runoff also captured from
immediate upstream drainage area.
CGvL ENGINEERS IN ASSOCIATION WITH POWELLIPBS&J 5-4
Seasonal Storage Analysis
TRIBUTARY RUNOFF DIVERSION
As discussed in the previous section, reservoir water quality can be substantially
affected by tributary drainage. Accordingly, this section of the report presents
hydrological assumptions, conceptual facilities and cost opinions associated with
diverting or bypassing a portion of upper Calavera Creek storm flows around
Lake Calavera. Such structures might constitute an essential component of a
future system to ensure protection of water quality in the reservoir should it be
conve1ted to RW storage.
Hydrology
The tributary drainage area to Lake Calavera is approximately 3.6 square miles.
The watershed extends to just east of Highway 78. The general hydrologic
features of the watershed tributary to Lake Calavera are presented in Table 5-4.
a Table 5-4 Upper Calavera Creek Hydrology
Average Extreme
Item DrvYear Year Wet Year Year
Annual rainfall, inches-8 13 18 22
Runoff, AFY 100-300 500 700 850
Max month, AF 100 150 200 250
24-hr, Mgal 85 100 130 160
Storm event Low-flowb 2-yr 100-yr 1000-yr
Inflow, cfs 1-20 600 1,900 3,800
Overflow, cfsc 0 90 1,400 3,600
a) Anticipated under future conditions within u:ibutary area upstream of dam.
b) typical, recurrent storm with 0.25 -0.5 inch ofrainfall.
c) Spillway flow assuming pre-storm pool el.= 209.0 ft ams!.
Rick Engineering performed hydrology calculations using HEC-1 for this area as
reported in June 30, 1998 (Reference 13). The report focused on the 100-year
discharge. In order to compute smaller events, the HEC-1 model was reproduced
for the two basins (Cl and C2) tributary to Lake Calavera. After duplicating the
results of Rick Engineering's 100-year run, a range of 24-hour rainfall events
obtained from NOAA rainfall map "isopluvials" were run in the model
representing the 2-, 5-, 10-, 25-, and 50-year events. The results are shown in
Table 5-5.
A separate HEC-1 model was run for each precipitation event to compute
discharge. The discharges presented in Table 5-5 were next extrapolated to a
1-year and extreme (1,000-year) event. The 1-year event, which corresponds to
about l.2 inches of rainfall, was computed at 180 cfs, which represents a large
flow for diversion. The design extreme flow for a 1,000-year event by
extrapolation was 3,800 cfs.
CGvL ENGINEERS IN ASSOClATlON WITH PoWELUPBS&J 5-5
Seasonal Storage Analysis
Table 5-5 HEC-1 Computed Discharge Results
Rainfall Depth, HEC-1 Discharge,
Storm Event inches cfs
2-year 2.2-2.3 595
5-year 3.0-3.2 930
10-year 3.4-3.6 1,096
25-year 4.2-5.0 1,431
50-year 4.7 -5.0 1,648
100-year 5.3-5.5 1,890
Flows smaller than the 1-year event were then run in HEC-1 to represent a
probable first-flush event. The reason for focusing on a first-flush low flow is
that the first flush typically bears a disproportionately large share of undesirable
constituents with respect to a relatively small, and therefore more manageable,
water volume. While many agencies and cities still have varying definitions of
what comprises a fust-tlush event, a standard is developing in southern CaJifornia
to define the first-flush event as the flow resulting from 0.1 -0.5 inches of
rainfall. At Lake Calavera, flow resulting from 0.25 inches of rain would be
approximately 1 cfs, and the flow resulting from 0.5 inches of rain is
approximately 20 cfs. A flow of 5 cfs was adopted as the low-flow diversion
design flow, which corresponds to a mid-range rainfall event within the first-flush
definition.
Development of Alternatives
CMWD initially requested investigating both a partial and total diversion of
tributary flow around Lake Calavera, with the goal of improving water quality in
the reservoir. The total diversion option was quickly dismissed after reviewing
the topographical features around the· Lake as well as the hydrology. Large
conveyance facilities would be restrictively expensive. Therefore·, CMWD
directed effort to a concept for low-flow diversion. One concept reviewed was
using the nearby sewer system to discharge first-flush flows, but this concept was
found to be infeasible following a brief review of the existing sewage collection
facilities capability of accommodating a flow of 5 cfs.
After further discussions with the City, three alternatives were investigated for a
low-flow diversion:
(1) Forcemain/open channel around north side of Lake to spillway channel
(2) Forcemain/pipeline around north side of Lake to spillway cbanneJ
(3) Anchored, gravity pipeline along bottom of Lake to existing outlet tower
Alternatives 1 and 2 focus on diverting low flows along the north side of the Lake
to the spillway channel, because the spjllway is located on that side. The
CGv L ENGINEERS IN ASSOCIATION WITH PowELrJPB S&J 5-6
Seasonal Storage Analysis
diversion structure would be located sUghtly upstream of the high-water elevation
of the Lake, as shown on Figure 5-1. The structure wouJd extend across the
channel with a side-flow weir to djvert low flows to a sump. As there is high
ground between the east end of the Lake and the spillway, a pump would be
required to convey water by pipeline to a high point, and from there a gravity flow
channel would convey water to the east end of the spillway channel. A small
tributary exists between the high point where gravity flow is possible and the
spillway, and the assumption was made that an open channel around the tributary
would be feasible. This concept is labeled Alternative 1.
A second alternative, Alternative 2, is very similar to Alternative 1 except that the
open channel would be replaced with a buried pipeline. This alternative may be
more desirable for aesthetic and safety considerations.
Alternative 3 is a concept in which a pipe from the diversion structure would be
placed along the bottom of the Lake connecting to the outlet tower near the
upstream toe of the dam. Alternative 3 eliminates the need for a pumping station,
which is anticipated to require considerable maintenance, but it would add
operational complexities at the outlet tower. Figure 5-1 provides the plan view
alignments of each alternative.
Cost Analysis and Results
A summary of alternative costs is presented below and key assumptions presented
in Table 5-6.
Table 5-6 Cost Opinion for Diversion Facilities
Cost,
Alternative Features $xl.0008
Alternative 1 1,400
0 Pumping station cost opiruon based on accepted standards and
relevant experience of similar pumping stations
□ Pumping station cost approximately $700,000 for a flow of 5 cfs
0 App.roxjmately 500 feet of 12-inch fotcemain, 4,200 feet of a
SDRSD D-75 type channel
□ Diversion structure cost approximately $100,000
Alternative 2 1,700
□ 16-inch pipe used in place of gravity channel
□ Other features same as for Alternative 1
Alternative 3 1,200
□ 36-inch polyethylene pipe from diversion structure to outlet tower
□ Pipe anchors assumed every 25 feet at $1,000 each
□ Outlet tower modification cost approximately $50,000
a) Costs at ENRCCI = 6300, exclusive of engineering and admjnistration.
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Seasonal Storage Analysis
The three alternatives described above are relatively close in cost and each
deserves further consideration if the City were to decide to bypass upstream
flows. Alternatives I and 2 require pumping, and Alternative 3 involves pipe
anchoring and outlet tower operational complexities. Based on costs alone,
Alternative 3 appears to be the best alternative of the three, although creating a
stable foundation for the pipe on the Lake bottom may require reservoir draining,
which imposes an environmental issue and cost. Results of this concept level
investigation suggested the need to evaluate other methods of pre-and post-
storage treatment, such as constructed wetlands, disinfection, and micro-filtration,
depending on future impounded water quality. These water quality control
concepts are evaluated in Chapter 6.
SEASONAL STORAGE POTENTIAL
An analysis of seasonal storage potential is needed in order to determine the value
of converting Lake Calavera for future storage of recycled water. Two expansion
milestones were selected at which to assess the reservoir's seasonal benefit to
CMWD's planned RWDS expansion:
(II) Completion of Phase II, representing an annual system demand of
approximate1y 5,400 AFY, with an associated seasonal dry-weather peak-
day demand of 11 million gallons per day (MGD)
(U) Ultimate expansion, representing an annual system demand of
approxjmately 9,800 AFY, with an associated seasonaJ dry-weather peak-
day demand of 10 MGD
Three CMWD system scenarios were selected to quantify benefits at each of these
two milestones:
(A) System supply/demand fully balanced with seasonal storage capacity
(hypothetical storage concept for comparative analysis purposes)
(B) System supply/demand balanced with only Mahr Reservoir working
storage (equivalent analysis as provided under Scenario C in May 2000
evaluation of Mahr Reservoir [Reference 18])
(C) System supply/demand balanced with both Mahr Reservoir and Lake
Calavera working storage on-line
Demand Analysis
Monthly demands are used to determine seasonal supply and storage needs for the
RW system. The ratio of peak-month to average-month demand, or peak-month
factor,. is used in detennining pumping and operational storage capacities.
Hourly demands are directly used in determining pumping, operational storage,
and pipeline capacities, and are determined by average-day use during the peak
month, multiplied by the ratio of 24 hours over the length of the regular daily
CGvL ENGINEERS IN AsSOCIA TION WITH POWELLIPBS&J 5-9
Seasonal Storage Analysis
irngation period expressed in hours. For example, in calculating peak-hour
demands, the peak-month factor would be multiplied by two if a 12-hour
irrigation period is assumed, or multiplied by three if an 8-hour irrigation period is
assumed.
All scenarios used the same RW demand hydrograph, which was developed from
the past six years ( 1995-2000) of actual CMWD metered demand. A listing of
monthly demand values and related statistics for these years is provided in
Appendix A. Because the months in which peak and minimum demands occur
are not the same from year to year, a simple average of each month, as shown in
the second-to-last row of the table in Appendix A, does not result in
representative factors for accurately modeling and projecting system demand
variations. Rather, it tends to reduce peak demands and increase minimum
demands. Therefore, a simple average was adjusted by an algorithm to preserve
the true average peak-month and minimum-month factors, more representative of
historical seasonal fluctuations. This adjusted average is shown in the last row of
the same table. The resulting adjusted peak-month factor of 2.05 is used for
subsequent facility analysis.
A unit hydrograph was developed for monthly irrigation demands based on this
adjusted six-year system average. Figure 5-2 is a graphical representation of the
adjusted hydrograph. Based on these adjusted factors, July has the representative
peak-month. demand and February bas the representative minimum-month
demand. This bydrograph is typical of RW monthly demand variations and
reflects typical southern California irrigation cycles.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Figure 5-2 CMWD Six-Year RW Demand Hydrograph
CGvL ENGINEERS IN ASSOCIATION WITH POWEUJPBS&J 5-10
Seasonal Storage Analysis
Supply Analysis
Existing and planned RW supply sources for the CMWD service area include the
following:
o Carlsbad Advanced Wastewater Treatment (AWT) facility, to be constructed
by CMWD at the Eocina Water Pollution Control Facility (WPCF), owned
and operated by the Encina Water Authority
□ Meadowlark Water Recycling Facility (WRF), owned and operated by the
Vallecitos Water District (VWD)
o Gafner Water Reclamation Plant (WRP), owned and operated by Leucadia
County Water District (LCWD)
For this evaluation, it is assumed that production capacities of these plants would
be used in the order listed above. Estimated available peak-month plant supply
capacities in MGD and acre-feet per month (AFM) for each of the two milestones
are listed in Table 5-7. Calculated plant supply capacities required for each
scenario, which are sometimes less, are discussed below.
Table 5-7 CMWD Recycled Water Supply Availability
Potential Peak-Month Supply
Phase II Ultimate
Supply Source MGD AFM MGD AFM
Carlsbad A WT 4.00 373 15.0 1,400
Meadowlark WRF 3.00 281 3.0 281
GafnerWRP 1.00 93 2.0 187
Total 8.00 747 20.0 1,868
Seasonal Balancing
A computerized spreadsheet model of CMWD's RW system was developed to
test monthly supply/demand balances, and the resulting use of seasonal storage.
The model was applied to each of the two scenarios at each of the three
milestones. For those analyses using Mahr Reservoir as seasonal storage,
reservoir filling was assumed to occur in January and February, the two lowest
demand months. Copies of these analyses are found in Append.ix B and labeled
by Milestone II or U and Scenario A, B, or C.
For evaluation purposes, a future ntiniroum pool level was set at 192 feet amsl for
Lake Calavera in order to allow for continued submergence of a future
aeration/destrat.ification system, avoidance of water quality problems associated
with shallow depths, and preservation of a visually attractive, expansive water
surface. The assumed minimum pool level would ensure a water depth of 12-15
feet near the outlet tower with a water surface area of approximately 7 acres.
CGvL ENGINEERS IN ASSOCIATION WITH POWELUPBS&J 5-11
Seasonal Storage Analysis
A critical test for seasonal supply/demand balancing is satisfying peak-month
demand, either directly from one or more supply sources, or from a combination
of dir-ect supply and water returned from seasonal storage (reservoir outflow).
Peak-month volume results expressed in AF for the analyses are summarized in
Table 5-8. Scenario C was evaluated over a range of annual rainfall assumptions
to assess sensitivity to that parameter.
Table 5-8 CMWD Peak-Month11 Supply/Demand Balance
Peak-Month volume. AF Storage
Required Supply From Volume,
Milestone/Scenario Demand Carlsbad Meadow. Gafner Otherh Storagec AF
Phase TI
A -Fully Bala□ced 922 373 77 0 0 472 1,721
B -Mahronly 922 373 281 93 148 27 151
C -Plus Lake Calavera:
Dry-year 983 373 281 93 0 236 379
Average-year 922 373 281 62 0 206 502
Wet-vear 834 373 250 0 0 211 521
Ultimate
A -Fully Balanced 1,673 817 0 0 0 875 3,124
B-Mabronly 1,673 1,400 153 0 0 120
C -Plus Lake Calavera:
Dry-year 1,801 1,400 85 0 0 316
Average-year 1,673 1,400 36 0 0 237
Wet-vear 1,513 1,289 0 0 0 224
a) Peak month assumed to be July, with a peak-to-average-month ratio of 2.05, based on Figure 5-2.
b) Other supply capacity assumed robe supplemented potable water.
c) Includes Mahr Reservoir plus Lake Calavera volumes, where applicable.
Because of production limitations in planned Phase Il Meadowlark WRF and
Carlsbad A WT expansions, 148 AF from other supply sources (most likely
potable water), in addition to Mahr Reservoir's storage, would be needed to
balance peak-month demands under Scenario IlB.
In assessing Lake Calavera's seasonal storage benefit to CMWD's system, it is
helpful to compare the reservoir wjtb an equivalent peak-month supply source,
both in volume delivered (AF) and equivalent production rate (MGD). The
estimated volume delivered from storage by Mahr Reservoir and Lake Calavera is
shown in the second-to-last column for Scenario C under each of the two
milestones in Table 5-8. It is also a useful perspective to see what fraction Lake
Calavera's storage would represent of the total seasonal storage needed to fully
balance the RW system for the two milestones. These values are summarized in
Table 5-9.
CGvLENGINEERS IN ASSOCJATION WITH POWELIJPBS&J 5-1 2
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Seasonal Storage Analysis
Table 5-9 Lake Calavera's Seasonal Storage Benefit to CMWD
Equivalent Peak-Fraction of Fully-
Scenario C Peak-Month Supp)y, Month Production Balanced Storage,
Milestone/Condition AF Rate, MGD oercent
Pbasell
Dry-year 133 1.43 28
Average-year 206 2.22 44
Wet-year 182 1.96 39
Ultimate
Dry-year 165 1.77 19
A verage--year 230 2.47 27
Wet-vear 103 1.11 12
Using 206 AF of Lake Calavera storage capacity, under the Phase II demand
condition with average annual rainfall, would reduce peak-month supply
requirements by 2.22 MGD and represent 44 percent of fully-balanced storage.
Likewise, using 230 AF of Lake Calavera storage capacity, under the Ultimate
demand condition with average annual rainfall, would result in a 2.47 MGD
reduction in the peak-month RW production rate and represent 27 percent of
fully-balanced storage. In years of well below and well above average rainfall,
reduction in peak production rates would be slightly lower than in years of
average rainfall under both Phase II and Ultimate conditions, as peak month
supply/demand ratios are less.
Other Storage Considerations
Lake Calavera's emergency storage benefit to CMWD's RW system will depend
on total reclaimed water production capacity available, demand on the distribution
system, and volume of water in the reservoir, all at the time of the emergency, and
time of year.
If water were stored in the Lake-beyond minimum operating pool volumes over
more of the year, say startin g in the fall, emergency supply would be available for
more months. To maintain the full seasonal benefit discussed in the previous
section, however, no emergency storage would be available from May through
September. It is important to correctly condition emergency storage availability,
so as not to inappropriately ''double-count'' Lake Calavera storage for both
seasonal and emergency purposes.
CGvL ENGINEE~S IN ASSOCIATION WITH POWELL/PBS&! S-J 3
Chapter 6
Recycled Water
Conversion Facilities
Lake Calavera' s potential future RW system benefits accrue from both its
seasonal storage value and capture of runoff as analyzed in the previous chapter.
To realize this value, a number of facility improvements would be required.
These improvements could occur at the reservoir, or at other locations affecting
water quality of reservoir inflow and outflow. Long-term RW conversion facility
concepts covered in this chapter include:
o Reducing sediment, algal nutrients and other potential problem constituents
from reservoir inflow through either bypassing of tributary runoff (partial
diversion) or, alternatively, constructing an upstream wetlands treatment
system
o Constructing an improved 550 Calavera RWPS and a RW transmission
pipeline between the proposed downstream RWPS and the improved .I/O
works
a Adding an aeration/destratification system within the reservoir
o Adding a chlorination system for disinfectioning reservoir outflow at the
proposed RWPS
o Adding a micro-filtration system to remove algae and other suspended
materials from reservoir outflow at the proposed R WPS
FUTURE CONVERSION FOR RW STORAGE
General system schematic diagrams of overalJ facility concepts and layout
involved with conversion of Lake Calavera for either RW seasonal storage,
involving bypass (diversion) of first-flush storm flows, or supplemental RW
supply, involving alternative storm water quality control measures, are presented
on Figures 6-1 and 6-2, respectively. An evaluation of the facilities, costs and
non-monetary issues associated with these two alternative concepts as well as
comparison with a no-action plan, i.e., no conversion of Lake Calavera for use
with the RW system, js covered in the following sections of this chapter.
Existing RW Piping and Pumping Facilities
Currently, RW transmission pipelines are located throughout the City. RW
service is planned for the areas near Lake Calavera in the near future. Many of
the newer subdivisions near the reservoir have RW piping systems that currently
CGvL ENGINEERS IN ASSOClA TION WITH POWELLlPBS&J 6-1
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RW SUPPLY -WETLANDS CONCEPT
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POWELL / PBSJ
Recycled Water Conversion Facilities
ilistribute potable water. This includes a 12-inch, 550-Zone line in Tamarack
A venue just west of Lake Calavera.
The 550 Calavera RWPS js proposed to be located approximately 5,000 feet
southwest of Lake Calavera along the future extension of College A venue within
a proposed subdivision referred to as McMmin Village. This pumping station
will boost pressure from the 384-Zone to the 550-Zone.
Additionally, an abandoned sewage lift station site also exists approximately
2,000 feet south of the dam adjacent to lower Calavera Creek. According to the
City, this site is available for use as an alternative location for a RWPS.
Investigation of Future RW Piping and Pumping Facilities
The initial objective of CMWD was to evaluate two alternative sites for a RWPS
downstream of Lake Calavera. This objective also included determining a
proposed alignment for interconnection with the planned 384-Zone RWDS.
Initial locations for the pumping station included two sites with ilisturbed areas
that have minimal habitat issues.
In subsequent discussions, the City also requested investigating the possibility of
not only transmitting water from Lake Calavera to the 550 Calavera Pump
Station, but also transmitting water through an existing non-utilized sewage
forcemain located in Tamarack Avenue west of Lake Calavera, which would be
connected with existing Calavera 550-Zone piping. While this idea wouJd not
provide a long-term fit with the Ultimate RWDS plan, it may be practical to
.initially puml? from the reservoir to the Calavera 550-Zone. Later, as the RWDS
was built out to the Lake Calavera area, the pumping station could be converted
back to pumping to the 384-Zone. Ultimately, the 384-Zone pumping station
would be required, Although the evaluations focus on siting the 384-Zone
pumping station, piping for connection to the 550-Zone is also included.
Two pumping station sites were investigated: Option A, south of the Lake on the
west end of the dam (shown in Photo 6-1), and Option B, the abandoned sewage
lift station site several thousand feet downstream (shown in Photo 6-2). These
sites are also presented on Figure 6-3.
The pumping station will provide approximately one third of the maximum-day
ultimate demand for the 384-Zone and all of the peak-hour ultimate demand for
th.e Calavera 550-Zone. The required capacity of the pumping station is 4,200
gpm with a total dynamic head ranging from 200 to 275 feet, thus requiring the
range of 300 to 400 horsepower (hp).
Two new transmission main alignments were investigated for each pumping
station site. One transmission main connects to the 384-Zone piping to the south
and the other connects to 550-Zone piping as shown on Figure 6-3.
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Photo 6-1 Candidate RWPS Site A
Viewing west from crest of dam. (May 16, 2001)
Photo 6-2 Candidate RWPS Site B
Viewing northwest from downstream of dam. (May 16, 2001)
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TRANSMISSION PIPELINE ALI GNMENTS
AND PUMPING STATION SITES
Recycled Water Conversion Facilities
A cost opinion was prepared for the new RWPS. The subtotal construction cost
for these improvements is approximately $1.1 million dollars. This figure
includes the cost for both the 384-Zone interconnect transmission pipeline and the
550-Zone connection piping.
Based on preli.mmary hydraulic calculations, both pumping station sites
investigated were feasible. The new RWPS is required to boost the hydraulic
grade line (HGL) of the water from Lake Calavera (minimum HGL 204.5) to the
384-Zone. The two recommended transmission pipelines would transmit flow
from the pumping station to either a tie-in to the existing 550-Zone pipeline in
Calavera Heights, or to tbe proposed 384-Zone piping south of the 550 Calavera
RWPS.
Costs for the two site options are comparable at this level of detail; however,
Option B, the abandoned sewage lift station site offers a number of advantages
over Option A. These advantages are summarized as follows:
□ The site is flat and already cleared of vegetation; while grading and rock
excavation is anticipated for Option A
o The City already owns the site
o Suction conditions from the reservoir are improved when compared with those
for Option A, resulting in a wider range of operating levels likely available
with Option B
For these reasons, it is recommended that CMWD consider Option B as the best
location for the RWPS to the 384-Zone.
Constructed Wetlands for Runoff Quality Control
A free water surface constructed wetlands has been proposed to improve the
quality of runoff that could be captured and added to the non-potable supply in
Lake Calavera. Originally proposed for nutrient removal from RW tertiary
effluent, a constructed wetlands might also serve equally well in pretreating storm
water runoff. The original constructed wetlands concept for treatment of RW
stored at Lake Calavera was considered for location on a disturbed portion of the
site to the northwest of the reservoir. The concept was examiJled in a report
prepared by Brown & Caldwell in 1999 (Reference 14), as a candidate method
providing additional treatment for nutrient reduction of recycled water prior to
storage in the reservoir.
The revised concept approach would be to allow upper Calavera Creek runoff tu
pass through a series of 3 to 4 gravity-flow wetlands cells located entirely within
the 100-year flood zone, with the majority of the cell area within the high-water
elevation of the Lake. The existing flood zone, just upstream of the reservoir
constitutes a combination of freshwater wetlands and heavily vegetated riparian
scrub and woodland as shown in Photo 6-3. The constructed wetlands facilities
would permit controlled application of runoff from upper Calavera Creek via a
CGvL ENGINEERS IN AsSOCIATION WITH Powm . .UPBS&J 6-7
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Recycled Water Conversion Facilities
terraced series of shallow ponds as well as incorporate recirculated water from the
reservoir. The cells would be partially vegetated to filter the runoff and partially
open to allow for solids settling and uniform flow distribution. A general
layout/site plan for an up-to 10-acre, 4-cell, terraced wetlands system is presented
on Figure 6-4.
Photo 6-3 Inlet Area to Lake Calavera
Showing existing wetlands and riparian woodlands. (September 12, 2001)
A wetlands treatment system would serve to reduce settleable solids, dissolved
organics, and nutrients in storm water runoff from the upstream area. Treated
runoff with much-reduced solids and organic loads would present a higher-value
resource for addition to the RW supply. Additionally, the constructed wetlands
would better preserve water quality of the Lake as an enhanced visual asset.
The vegetation in the planted areas would consist primarily of hardstem bulrush.
The water levels would range from 1 to 2 feet in depth. It is anticipated that 100
to 300 AF of runoff would pass through the wetlands during the annual rainy
season. In the dry season, a small pump could be used to recirculate Lake water
through the wetlands to keep them growing and to avoid stagnant water. The
recirculation will also remove additional nutrients from the Lake water. Mosquito
control would be accomplished by using mosquitofish. An hydraulic profile for
the constructed terraced wetlands concept is shown on Figure 6-5.
Costs for construction of the upstream terraced wetlands would include site
grading, wetlands earthwork, piping and valving, recirculation pumping, and
CGvL ENGINEERS IN ASSOCIATION WITH POWEUJPBS&J 6-8
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WETLANDS HYDRAULIC PROFILE
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FIGURE 6-6 AERATION/DESTRATIFICATION
SYSTEM CONCEPT
Recycled Wa1er Conversion Facilities
place, approximately parallel to the reservoir bottom, by a series of anchors that
resist the pipeline's tendency to rise when charged with air.
This type system has been operating at SMWD's Upper Oso Reservoir for over
ten years. While other aeration/destratification systems are feasible, a cost
opinion for the one described here, with costs adjusted from SMWD' s experience,
is presented in Appenrux C. The subtotal construction cost for this system is
about $398,000. Annual operational cost is relatively low ($9,000/year), as the
system is expected to be only activated for approximately half the year.
Post-Storage Treatment Processes
Open seasonal storage generally degrades bacteriological water quality below
those levels specified by Title 22, California Code of Regulations, for disinfected
tertiary effluent at a production source. The extent of degradation typically
depends on the size of the drainage area tributary to the reservoir and the
development characteristics within the drainage area. While not currently
required by regulatory agencies, chlorination of reservoir outflow could be
installed to mitigate potential degradation. A unit subtotal construction cost range
of $150-180 per gpm of capacity is assumed for this post-storage treatment
component.
Standby micro-filtration for algae removal may also be necessary as a post-
storage treatment step. A unit subtotal construction cost range of $1,100-1,250
per gpm of capacity is assumed for this component. Operational costs are
expected to be comparable to those assumed for chlorination.
COMPARISON OF ALTERNATIVE FACILITY CONCEPTS
Three Lake Calavera conceptual storage facility alternatives have been identified:
(A) Converting Lake Calavera for seasonal storage of RW similar co the Mahr
Reservoir proposal
(B) Using Lake Calavera for seasonal storage of storm water that would be
used to supplement the RW system
(C) No conversion-not using Lake Calavera storage or supplemental supply
in the future RW system
Selecting the best combination of facility improvements affects the costs and the
decision of whether or not to convert the reservoir for use in the expanding RW
system. To make a fair comparison, if the Lake is not to be used, equivalent
seasonal and operational supply components must be considered. These include
additional peak-month supply capacity as weJJ as ao additional above-ground
operational storage reservoir. These alternatives and their associated cost
opinions are presented below.
CGvL ENGINEERS IN ASSOClA TION WJTH POWELUPBS&J 6-13
Recycled Water Conversion Facilities
The long-term history of other deeper-water RW seasonal storage reservoirs,
discussed in Chapter 5, argues against an absolute need for pre-treating Lake
Calavera inflow. The relatively large size of the Lake's upstream catchment area
with respect to reservoir volume, also discussed in Chapter 5, however, prompts
concern for inflow water quality issues. The combination of these two properties
suggests that diversion of first-flush storm flows might represent a feasible option
for seasonal storage. Given the relatively large cost of post treatment, various
combinations of future conversion facility improvements have been considered.
The first facility combination, Alternative A. involves the following key
components:
D Construction of an upstream diversion structure to allow bypass (around the
reservoir) of first-flush storm flows from upper Calavera Creek
o Connection of the reservoir to the RWDS to permit conveyance of excess RW
for storage during low demand periods of the year
a Constmction of an aeration/destratification system within the reservoir
□ lnstallation of post-storage (outflow) water quality control systems, most
likely incorporating both chlorination and micro-filtration processing to allow
return of the supply to the RWDS during stimmer peak-demand periods
The second facility combination, Alternative B, involves the following key
components:
□ Construction of an upstream terraced wetlands treatment system for hydraulic
and quality control of upper Calavera Creek storm water runoff
□ Construction of an aeration/destratification system within the reservoir
□ Installation of post-storage (outflow) water quality control systen1s, most
likely incorporating both chlorination and micro-filtration processing to
permit delivery of the supplemental supply to the RWDS during summer
peak-demand periods
The third conceptual alternative, Alternative C, involves no conversion. Lake
Calavera would remain unused for storage, and additional RW supply processing
and storage capacity would be provided elsewhere in the system.
Alternative Conversion Improvement Cost Comparison
Several variations involving the extent and degree of processing for these
conceptual facility alternatives were examined in order to establish a range of
costs, from low to high, with each. The low-cost options for Alternatives A and B
represent limited treatment under the assumption that the more extensive water
quality control measures associated with the high-cost options would not be
needed. The low-cost option for Alternative C, involves purchase of potable
water as a supplemental supply in-lieu of seasonal storage. The high-cost option
for Alternate C represents construction of additional water reclamation plant
processing and storage capacity. The cost comparisons are provided in Table 6-1.
CGvL ENGINEERS IN ASSOCIATION WITH POWELUPBS&J 6-14
Recycled Water Conversion Facilities
Table 6-1 Alternative Conversion Cost Comparison
Alternative A Alternative B
Conversion for Seasonal Conversion as Alternativt C
RW Stora2e Sunn)emental Supply No Conversion
Low Hieh Low Hh?h Low• Hi2hb
Project cost, $xl,000 6,510 8,600 4,620 6,670 1,490 6,240
O&M cost, $xl,000/yr 220 280 175 250 310 220
Present worth, $M 5.05 6.62 3.69 5.31 2.77 4.88
Unit cost, $/AFY 860 1,130 630 905 475 830
Overall cost ranking 4th 6th 2nd 5th 1st 3rd
a) Potable water purchase.
b) WRP and storage capacity.
Based on the unit costs shown in the second-last line of Table 6-1, the alternatives
ranked in order of ascending cost are as follows:
o Alternative C Low-No Conversion, with potable water purchased (if
available) to supplement storage
o Alternative B Low-Conversion as supplemental RW supply, with restricted
constructed wetlands (5 acres) an.d limited additional treatment
o Alternatjye C High-No conversion, with construction of additional water
reclamation processing and storage capacity
a Alternative A Low-Conversion for seasonal RW storage, with limited
additional treatment
a Alternative B High-Conversion as supplemental RW supply, with full
constructed wetlands (10 acres) and complete additional treatment
a Alternative A High-Conversion for seasonal RW storage, with complete
additional treatment
Non-monetary Comparison
Along with a cost evaluation, a set of non-monetary factors has been used to
compare the three conceptual alternatives. These factors are subjective. The
evaluation includes a broad assessment of the operational, functional and
environmental issues listed jn Table 6-2.
A numerical rating was used in comparing these alternatives, as presented in
Table 6-3. Alternative B, Supplemental Supply, ranked somewhat higher overall
than the other two concepts. This subjective ranking was carried out by the
consultants as prut of the project evaluation effort, and as such does not
necessarily represent the final judgment or position of the City.
CGvL ENGINEERS IN ASSOC1A TrON WITH PoWE.UJPBS&J 6-15,
Recycled Water Conversion Facilities
Table 6-2 Non-monetary Factors and Issues
Factor Project Issues
Implementation o Can be rapidly implemented from institutional and construction
standpoints
□ Can be expected to ·encounter minimum legal, financial, and
logistical obstacles
□ Appears likely to receive public and local government
acceptance/support
Flexibility □ Sensitivity of cost and perfoJmance to changing patterns of
urban development/land use
□ Adaptability to technological changes/advances
□ Ability to meet anticipated water quality objectives/requirements
Reliability □ Assurance that performance meets expectations
□ Acceptable resolution of possible system failures/upsets due to
natural disasters/catastrophes
Compatibility □ Compatibility with existing water and wastewater plans and
programs
□ Minimum conflict with other local and regional plans
□ Compliance with water quality control requirements
o Consistency with established regulatory agency policies
Environmental □ Minimum potential adverse/negative impacts on natural and
cultural resources
□ Effects on socio-economic development
□ Protection of smface and groundwater
Overall □ Relative ratio of expected performance to total cost burden
Effectiveness
Table 6-3 Alternative Non-monetary (Subjective) Comparison
Alternative A Alternative B
Conversion for Conversion as Alternative C
Seasonal RW Storaee Suoolemental Sunolv No Conversion
Factor Verbal Numericala Verbal Numerical" Verbal Numerical"
Implementation Good 3 Very Good 4 Excellent 5
Flexibility Very Poor l Good 3 Very Good 4
Reliability Good 3 Very Good 4 Very Poor l
Compatibility Very Good 4 Very Good 4 Poor 2
Environmental Good 3 Very Good 4 Poor 2
Overall effectiveness Good 3 Very Good 4 Very Poor ]
Summary-Average score 3.00 3.83 2.50
a) I-Very poor or inferior to all others; 2-Poor or below average; 3-Good, moderate or average; 4-Very good or above
average; 5-Ex.ceUent or superior to all others.
CGvL ENGINEERS IN ASSOCIA TlON WITH POWELllPBS&J 6-16
Recycled Water Conversion Facilities
Conclusions
Based on comparison of costs and the non-monetary issues, Alternative B,
involving treatment and storage of upper Calavera Creek stream flows for
supplemental use in the RW system, appears to represent the best overall
conceptual approach. An opinion of capital and operational costs associated with
this proposed conceptual R W conversion plan is presented in Table 6-4.
Table 6-4 Cost Opinion for Future RW Conversion Facilities"
Cost, O&M,
Improvement Size $xl,000 $:d,000/yr
RWPS 1,400 gpm 799 19
Transmission pipeline 2,200LF@18-in 345 7
Aeration/destratification works 450AF 398 9
Chlorination 2,100 gpm 335 22
Micro-filtration 1,700 gpm 1,894 33
Constructed wetlands 5 acres 181 17
Subtotal Construction 3,952 -
Contractor OH&P 20 percent 791 .
Total Construction 4,743 .
Contingencies 30 percent 1,423 .
Subtotal Project 6,166 -
Engineering and administration 17 percent 1,048 .
Total Project 7,214 107
a) Costs at ENRCCI = 6,300.
CGvLENGINEERS IN AssoCJATI0N WITHPOWELIJPBS&J 6-17
Chapter 7
Report
Recommendations
This chapter covers the study's recommendations regarding both remedial works and
future RW conversion facilities identified and evaluated in previous chapters.
REMEDIAL WORKS
Project Costs
A set of remedial works for Lake Calavera has been identified and a cost opinion for their
design and construction determined. These remedial improvements are needed to recover,
protect and enhance the intrinsic value as well as functionality of Lake Calavera.
The remedial improvements, which were detailed in Chapters 3 and 4, are as follows:
□ Construction of a new I/O pipeline and control building, which will require the
temporary drawdown of the reservoir water surface, construction of a temporary
cofferdam on the upstream dam face and demolition of the upper portion of the
existing outlet tower
□ Repairs to existing spillway, channel, and downstream bed
□ Upgrade of the existing access roadway
□ Facility fencing for security _purposes
Cost opinions for these improvements are presented in Table 7-1 (same as Table 4-4).
Some opinions are highly dependent on field survey results. It is anticipated that as
additional field data are collected and analyzed, further cost refinements during detailed
design of the improvements can proceed.
Reconnaissance-Level Surveys and Initial Agency Review
A set of preliminary field inspection/surveys was found necessary in order to better
identify extent of repair work and refine project cost opinions for the remedial
improvements. The reconnaissance-level surveys were carried out during summer 2001
and the results provided in Appendices E and F of this report. An initial review of the
proposed plan and projects by City departments and various agencies with responsibility
CGvL ENGINEERS IN ASSOCIATION WfTH POWELL/PBS&} 7-1
Report Recommendations
Table 7-1 Cost Opinion for Remedial Works
Item Cost, dollarsa
Partial mobilization, draw-down and temp. cofferdam 97,300
Tower demolition, new cap, muck/debris removal 95,500
New laid-back I/O pipeline and ports 115,000
I/O control system and building 222,200
1/0 Works Improvement Subtotal 530,000
Other mobilization 15,100
Spillway, channel and dam repairs 47,300
Access road extension and upgrade 95,500
fencing, gates and demobilization 26,200
Subtotal Construction 714,100
Contractor OH&P 20 percent 142,800
Total Construction 856,900
Contingencies 20 percent 171,400
Subtotal Project 1,028,300
Engineering and administration 17 percent 174,800
Total Proiect 1,203,100
a) Costs at ENRCCI = 6300.
for approval and permitting is expected to proceed over the next few months following
this report's completion. The reconnaissance-level surveys included the following:
□ Video survey of existing, tower to ascertain status of internal structure, valves, other
appurtenances, debris, etc. (planned coincidental video survey of existing I/O pipeline
was precluded and will be performed in a later phase)
□ Survey of reservoir bottom for current depth and physical characteristics of
accumulated sediment
□ Water quality analysis for physical, chemical and biological characterization
Planned City department and agency review activities include the following:
□ Environmental constraints assessment (fatal flaw analysis)
□ Initial City department review
□ Initial agency review, e.g., with DSOD and California Department of Fish and Game
Implementation
A proposed list of action items for implementation and completion of remedial works
project activities is presented in Table 7-2. If the improvement project is approved and
design is initiated by May 2002, it is anticipated that construction of the remedial
improvements can be completed by November 2003.
CGv L ENGINEERS IN ASS OCTA Tl ON WlTH PoWELL/PBS&J 7-2
Report Recommendations
Table 7-2 Lake Calavera Remedial Works Action Items
Action Item Comments/Notes
Field surveysla?,ency review:
Video inspectiona Video survey of outlet works
Environmental reconnaissance3 Reservoir WQ/depth survey/sampling
Geological/soils reconnaissancea Site soils/sediment testing/analysis
Biological studies Site-specific review of biota/habitat
Internal review City planning and other departments
Resource agency reviewb Fatal flaw analysis
DSOD concept review Remedial works focus
Environmental Review:
Environmental assessment Determination of project impacts
Environmental approvat
Desi~n & bid documentation:
Project Design Design, cost and specifications
Final agency review Remedial projects approval
Prepare bid oackage(s)
Bid/contract process:
Advertise/accept
Review /selection
Negotiate/award contract(s)
Pro_iect Construction:
Mobilization/draw-down Set up and release to min. pool level
Tower cofferdam Removal of rock blanket, drive sheet piles,
install supports/shoring
Dredging/demolition Mucking, excavation for riser and removal
of tower top from within cofferdam
New laid-back I/0 pipeline Anchor supports, 1/0 pipe installation and
connections to outlet pipe
Spillway/channel repairs lncludes dam and dis bed
1/0 control building Includes 1/0 connections and turnaround
Access road/upgrade All weather surf ace plus dam repairs
Fencing and miscellaneous Includes security gate o n access road
Testinilstart-up
a) Completed tasks; results are provided in this report (Appendix E and F).
b) Initial review to include California Department of Fish and Game, possibly U.S. Fish and
Wildlife Service, Army Corps of Engineers, and others.
The proposed Lake Calavera remedial works implementation schedule is presented on
Figure 7-1.
CGvL ENGINEERS IN ASSOCIATION WITH P OWELLIPBS&J 7-3
Year 2001 2002 2003
Monlh 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jut Aua Seo Oct Nov Dec
Draft PDR Delivered Late May
1. Site Recon/Prelim Review tmonths
1.1 -Field Studies/Sampling 90da s
1.2 • Prepare Final PDR llO.da~s
1.3 -Biological Studies iro davs
1.4 • Citv Departmental Review ,90 da-/s
1.5 -Initial Aaencv Review 90da\S
2. Environmental Documentation 6 months
2, 1 • Impact Assessment! 120 davs _
2.2 -Envir. Review/APProval 90 da~s
3. Desian/Bid Documents 6 months
3.1 • Proiect Desion 150.davs
3.2 • Final Agency Review 60 cfavs
3.3 -Prepare Bid Package(s) 60.davs
4. Bid/Con. Contracts Process 4 monihs
4.1 -Advertise/Aocept Bids 45 davJ,
4.2 -Review/Select 45davs
4.3 • Neaotiate/Award 45davs
5. Construction 9•months
5.1 • Mobilization & Drawdown 60davs
5.2 -Cofferdam 60 days
5.3 -Tower Demolition 60 davs
5.4 • Laid-back 1/0 Pioe 9'0da1s
5.5 • Spillway & Dam Repairs 60 davs
5.6 -1/0 Building & Access Rd 60 davs
5.7 . Fencino & Clean U1 60 davs
6. Testina/Start-Uo 1' 2monlhs
Figure 7-1 Implementation Schedule for Remedial Improvements
M:\Proieots\Carisbad.224\LakeCalaPDA.001\Dlvrable\Flg 7-17-2 -Fig 7-1
Report Recommendations
RW CONVERSION FACILITIES'
Economic Assessment
An economic assessment of the costs and benefits associated with future RW conversion
facilities is provided below, Table 7-3 presents an economic "snapshot" of the future
facilities under Phase II RW supply and demand conditions. Table 7 ~4 presents the same
assessment under the projected Ultimate RW supply and demand conditions.
As expressed in Table 7-3, approximately $4.0 million in capital improvements and
anticipated operational costs yield $476,000 in annual expenditures. Subtracting projected
annual revenues of $245,000 and avoided costs of $233,000 results in a net annual
revenue of $1,000, i.e., an economically viable but marginal endeavor under Phase 11
conditions.
As expressed in Table 7-4, $7.1 million in total capital improvements and anticipated
operational costs yield $767,000 in annual expenditures. Subtracting projected annual
revenues of $245,000 and avoided costs of $560,000 results in a net annual revenue of
$38,000, i.e., an economically viable endeavor under Ultimate conditions.
Implementation
A proposed project .implementation schedule for conversion of Lake Calavera to RW
storage and supply is presented in Figure 7-2. These conceptual facility plan activities
have been keyed to the proposed Phase Il expansion of the RW distribution system.
In light of the foregoing evaluatfon and related ongoing preliminary design of the City's
RW system expansions, the following recommendations are made regarding future
conversion of Lake Calavera for RW storage:
□ Once the remedial works are in service, sample and test the reservoir's performance
and water quality in context of the need for future RW storage, specifically for the
degree and extent of treatment
□ Upon further analysis as to the extent, degree, and cost of pre-storage treatment
(constructed wetlands) and post-storage treatment (disinfection and micro-filtration),
phase the future conversion facilities with the proposed Phase Il RWDS expansion
O Likely phasing of the improvements would involve staging construction of the RW
transmission pipeline. pumping station and installation of an aeration/destratification
system before proceeding with other pre-and post-storage water quality control
measures
CGvL ENGINEBRS IN ASSOCIATION WltH POWELLIPBS&J 7-5
Report Recommendations
Table 7-3 Economic Assessment of RW Conversion at Phase II Conditions
Item Quantity $xl,000
Capital Cost
RW forcemain connection 2,200 LF@18-in 345
RWPS expansion 700 gpm 399
Water quality control features:
Constructed u/s wetlands (runoff) 2.5 acres 90
Aeration/destratification Lump sum 398
Chlorination at RWPS 1,050 gpm 186
Micro-filtration at RWPS 850 gpm 1,029
Subtotal Construction, $xl,000 2,448
Contractor OH&P 20percent 490
Contingencies 30 percent 881
Engineerinl! and administration 15 percent 573
Total Project Cost, $xl"'000 4,392
Annual Cost
RWPS expansion O&M 17
WQ controls (chlorination/micro-filtration) 32
Reservoir/wetlands maintenance and security 27
Allowances and other 19
Amortized capital 6 percent over 20 yrs 382
Total Annual Cost, $xl,O00/vr 476
Annual Revenue
RW sales 352 AFY@$660/AF (232)
Wetlands restoration/enhancement 0
Recreational proceeds (fishing, boating, etc.) Visitor fees@$2.50/d (13)
Total Annual Revenue, $xl,000/yr (245)
Annual A voided Costs
Purchase cost of potable water 290 AF@$700/AF (204)
Amortized capital for WRP expansion Not applicable 0
Amortized capital for RW oper. storage 0.2 Mga1@$140K (12)
Variable O&M for WRP expansion Not applicable 0
Variable O&M for RWPS 55 kwb@$ 0.1/kwh (6)
Amortized capital for alt. wetlands mitigation 2.5 ac@$500 K (11)
Total A voided Cost, $xl,000/yr (233)
Net Annual Cost/(Revenue), $xl,OOO/vr (1)
COvLENGINEERS IN ASSOCIATION WITH POWELUPBS&J 7-6
Report Recommendations
Table 7-4 Economic Assessment of R\iV Conversion at lJltimate Conditions
Item Quantity $xl,000
Capital Cost
RW forcemain connection 2,200LF@18-in 345
R WPS expansion 1,400 gpm 799
Water quality control features:
Constructed u/s wetlands (runoff) 5.0 acres 181
Aeration/destratification Lump sum 398
Chlorination at RWPS 2,100 gpm 335
Micro-filtration at RWPS 1,700 gpm 1,894
Subtotal Construction, $xl,000 3,952
Contractor OH&P 20 percent 790
Contingencies 30 percent 1,423
Engineering and administration 15 percent 925
Total Project Cost, $xl.00O 7,089
Annual Cost
RWPS expansion O&M 26
WQ controls (chlorination/micro-fiJttation) 64
Reservoir/wetlands maintenance and security 30
Allowances and other 30
Amortized capital 6 percent over 20 vrs 617
Total Annual Cost, $xl,000/vr 767
Annual Revenue
RW sales 352 AFY@$660/AF (232)
Wetlands restoration/enhancement 0
Recreational proceeds (fishing, boating, etc.) Visitor fees@$2.50/d (13)
Total Annual Revenue, $xl,000/vr (245)
Annual A voided Costs
Amortized capital for WRP expansion 2.5 MGD@$3.8M (431)
Amortized capital for RW storage 0.75 Mgal@$0.5M (46)
Variable O&M for WRP expansion 2.5MGD (47)
Variable O&M for RWPS 155 kwh@$ 0.1/kwh (16)
Amortized capital for alt. wetlands mitigation 5.0 ac@$500 K (22)
Total Avoided Cost, $xl,000/yr (560)
Net Annual CosU(Revenue), $xl.000/vr (38)
CGvL ENGINEERS IN ASSOCIATION WITH POWELl./PBS&J 7-7
Month 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48
Start Phase II RWDS Expansion
1. AW Conversion Proieci Plannin J 14,mohths·
1. 1 -Proj Plan/Facility Report 12mos·"'
1.2 -Environmental Review .-1z mos
2. Constructed Wetlands 34(110S
2.1 -Desian/Bid 10 mos
2.2 -Construction 12mos
2.3 -Start-Uo 1411'\0S
3. Aeration/Destralification 16 mo_s
3.1 -Oesian/Bid 6 mos
3.2 -Construction a.mos
3.3 -Start-Up 2 mos
4. Transmission Pipeline/Box 24mos
4.1 -Deslon/Bid 8mos
4.2 -Construction 14 mos
4.3 • Start-Up 4'mos
5. Calavera RWPS ·34 mos• coordinate with Phase ll'RWOS Exoansfoo schedule
5.1 -Phase II Hvdraulic Mods Desian 6mos_
5.2 -Micro-filtration Svstem Deslan 6'mos
5.3 -Chlorination System Oesian 611'\0S
5.4 -384 Zone PS & PAV Desi< n .6mos
5.5 -Phase II Bid 2 mos·
5.6 -Construction 1Bmos
5.7 • Start-Up 4mos
Figure 7-2 RW Conversion Facilities Design and Construction Schedule
M:\Profe<:ts\Carisbad.224\LakeCelaPOR.001\0lvrable\F',g 7-17-2 • Fig 7-2
Report Recommendations
WATER QUALITY MONITORING PROGRAM
Pre-Conversion
To test potential performance of the Lake Calavera storage system, a water quality
monitoring program should be initiated. It .is recommended that such a monitoring
program be implemented in 20021 to establish an accurate and reliable database for future
operations and management decisions. This program should continue until the reservofr is
converted to use in the RW system.
Table 7-5 illustrates a pre-conversion water quality monitoring program, with samples
collected in the water column near the existing outlet tower. The program requires use of
a small boat for sample acquisition as well as use of a portable analyzer to measure
common limnetic parameters at various depths. At the program's onset, several additional
samples should be collected at other locations within the Lake, to verify that the
recommended sample location is adeqt1ately representative of the entire water body.
Parameter, units Fre uenc
Dissolved oxygen, mg/L Analyzer Profilen Quarterly
Temperature, degrees F Analyzer Profile3 Quarterly
pH Analyzer Profilea Quarterly
Electrical conductivity, µmhos/cm Analyzer Profilea Quarterly
Oxidation-reduction potential, m V Analyzer Profilea Quarterly
Turbidity, NTU Analyzer Profile3 Quarterly
Total coliform, MPN/ 100ml Grab Near surface Quarterly
Apparent color1 CU Grab Near surface Quarterly
Algae count, organisms/ml Grab Near surface Quarterly
TOC,rng/L Grab Mid-depth Quarterly
General mineral, m IL Grab Mid-de th Quarterly
a) Every 5 feet from surface to near bottom.
Post-Conversion
Table 7-6 provjdes an expanded monitoring program for future storage operations
subsequent to RW conversion. Daily sample timing would depend on specific operating
times of the proposed aeration/destratification system as well as any specific regulatory
requirements. It is suggested that additional samples be collected on an infrequent basis
elsewhere within the reservoir, with consideration especially for the upstream end.
CGvL ENGINEERS IN ASSOCIATION WITH PoWEuJPBS&J 7-9
Report Recommendations
Table 7-6 Post Conversion Lake Calavera Monitoring Program
Parameter, units Method Depth Frequency
Dissolved oxygen, mg/L Analyzer Profilea Monthly°
Temperature, degrees F Analyzer Profilea Monthl/
pH Analyzer Profilea Monthl/
Electrical conductivity, µmhos/cm Analyzer ProfiJea Monthll
Oxidation-reduction potential, m V Analyzer Profilea Monthll
Turbidity, NTU Analyzer Profilea Monthll
Total coliform, MPN/lO0ml Grab Near surface Month!/
Apparent color, CU Grab Near surface Quarterly
Algae count, organisms/ml Grab Near surface Quarterly
TOC,mg/L Grab Top, mid, bottom Quarterly
General miner~ mg/L Grnb Top, mid, bottom Quarterly
a) Every 5 feet from surface to near bottom.
b) April through October, otherwise quarterly.
CGvL ENGINEERS IN AsSOCIA TlON WITH POWELIJPBS&J 7-10
REFERENCES
Reports:
1. A History of Dams & Water Supply of Westem San Diego County, by LJoyd
C. Fowler, 1952
2. Gibraltar Dam Strengthening Project, Final EIR/EA City of Santa Barbara,
February 1988
3. Natural Systems for Waste Management and Treatment, Reed, Middlebrooks
& Crites, McGraw-Hill, 1988
4. Report on Water Supply for Lake Calavera Golf Course, L. Burzell, August
27, 1990
5. Preliminary Siting Study for the Surface Storage of Reclaimed Water, CWP
for Greater San Diego, November 1992
6. The Cost of Water Reclamation in Califomia, Richard, Asano &
Tchobanoglous, UC Davis, November 1992
7. Guidelines for Water Reuse, BP A/USAID Technology Transfer Manual,
September 1992
8. Master Drainage and Storm Water Quality Management Plan, City
Engineering Department, (Fraser & Cooper Engineering JV), March 1994
9. Sand Canyon Reservoir Micro.filtration DemonstraJion Study, Akiyoshi &
Kalinsky, IR WD, August 1995
10. Reservoir Management Strategies: Development and Implementation,
Spangenberg, Horne & Quinlan, IRWD Reclaimed Storage Seminar, Water
Reuse 96, May 1996
11. Protecting Natural Wetlands -A Guide to Stonn Water Best Management
Practices, USEPA Office of Water, October 1996
12. Reclaimed Water Master Plan Update, Carlsbad Municipal Water District,
(Corrollo Engineers), November 1997
13. Rancho Carlsbad Channel & Basin Project, City, (Rick Engineering), June
30, 1998
14. Lake Calavera Constructed Wetlands, CMWD, (Brown and Caldwell, Ron
Crites), January 1999
15. Sand Canyon Reservoir Filter Media Replacement Pilot Study, Kalinsky &
Spangenberg, IRWD, April 1999
16. Habitat Management Plan for Natural Communities in the City of Carlsbad,
City, December 1999
17. City of Carlsbad Receiving Water Quality Sampling Program, City, (D-max
Engineering), May 2000
18. Preliminary Design for the Encina Basin Phase 11 Recycled Water
Distribution System -Mahr Reservoir Evaluation, Carlsbad Municipal Water
District, (CGvL with Powe11 & Associates), May 2000
19. Encina Basin Recycled Water Distribution System Study, Carlsbad Municipal
Water District, (Powell & Associates with CGvL), May 2000
20. Conceptual Mitigation Plan, South Carlsbad Village Stonn Drain/Sewer
Line, City, May 2000
21. City of Carlsbad Public Opinion Survey Report, City, January 2001
22. Draft Natural Habitat Mitigation and Monitoring Plan, South Carlsbad
Village Storm Drain/Sewer Line, City, February 2001
CGvLENGINEERS IN ASSOCIATION WITHPOWEU/PBS&J R-1
References
Maps, Drawings and Other Sources of Information:
23. Drainage Master Plans l"-1,000', 1,2 of 4 sheets (City Engineering
Department drawings# 296-5)
24. Area Orthophoto with topo l"-100' 1 15,24,25 of 225 sheets (Frazier &
Cooper), 1988
25. Shooting Range and Access Road draft plan drawing l '-100'
26. Lake Calavera Golf Course, l" -200' proposed plan & conceptual layout
27. Rancho Carlsbad Detention Basin BIB at Cannon Rd. & College Blvd. 11' -
50' with flood map, May 2000
28. CalaveraHillsArea Vegetation Map, l "-200'
29. Soil Survey Map, USGS Quad #22
30. Calavera Hills Village T, 1"-200' (Hunsaker & Assoc.) w/planned sewage
lift station
31. Calavera Hills Village Q, Landscape
32. Detention Basin BIB, 'l"-50', Rancho Carlsbad, (Rick Engineering
Company)
33. Rancho Carlsbad Channel & Basin Project, 1 "-100'
34. Flood Insurance Rate Map, panel 768 of 2375
35. GIS aerial image file of Northeast Carlsbad, City of Carlsbad, April 2001
36. Water, Sewer, RW pipelines, parcel lines, and 5 feet contours for above area,
City of Carlsbad, April 2001
37. Dams Under the Jurisdiction of the State of California, California Divfaion
of Safety of Dams, The Resources Agency, Department of Water Resources,
<www.dsod.water.ca.gov/bJtn 17>
38. Inspection of Dam and Reservoir in Certified Status, California Division of
Safety of Dams, The Resources Agency, Department of Water Resources,
Inspection Field Sheets, 12/8/98, 5/31/00 and 5/4/01
39. North County Times-The Californian NET, <www.nctimes.com/news>:
17 A) Dirty Creek Soils Moonlight Beach, 12/3/00
17B) Conservation Plan Targeted/or Volcanic Hill, 12117/00
17C) Group Aims to Save More Calavera Land from Development, 2118101
17D) Carlsbad Kids Take to Lagoons, Creek, Looking for Pollution, 417101
17E) Sierra Club Challenging City Over Calavera Environmental Program,
4/20101
17F) La.ke Calavera to be Drained for Repair, 5/11/01
17G) Lake Study to Include Options for City Use, 5112/01
40. Preserve Calavera-lnfo/Habitat/lssues, <www. preservecala vera. org>
41. Redesigned Wetlands Water Supply Project, Irvine Ranch Water District
Project Overview Fact Sheet, <www.irwd.com/environment/wwspfact>
42. Constructed Wetlands for Treatment of Storm Water Runoff, Department of
Soil Science, North Carolina State University, <www.soil.ncsu.edu/Broome>
43. Constructed Wetlands for Treatment of Non-Point Source Pollution, NFESC
Environmental Department, 1997
<http://enviro.nfesc.navy.mil/wetlands/index>
44. Conceptual Open Space & Conservation Map, Cjty of Carlsbad, June 1994
45. Calavera Nature Preserve Draft 2, November 2000
CGvL ENGINEERS IN ASSOCIATIONWITRPOWEJ...LJ'PBS&J R-2
Appendix A
RECYCLED WATER DEMAND ANALYSIS
CGvL ENGINEERS IN ASSOCIATION WITH PoWEuJPBS&J
CMWD Recycled Water System
Historical Monthly Recycled Water Demands3 (acre-feet), 1995-2000
Factorsc
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals Average PIA MIA
Use 18.26 10.65 9.54 42.04 89.83 127.00 149.24 193.48 181.99 128.61 78.10 62.08 1,090.82 90.90 1995 Ratiob I• 0.20 0.12 0.10 0.46 0.99 1.40 1.64 .2,.13 , 2.00 1.41 0.86 0.68 2.13 0.10
Use 33.93 12.11 16.70 89.48 152.55 223.57 198.31 203.14 158.07 130.26 29.78 l0.93 1,258.83 104.90 1996 Ratiob 0.32 0.12 0.85 1.45 ~.13 1.24 0.28 0.10 0.16 1.89 1.94 1.51 2.13 0.10
Use 11.24 34.59 108.29 132.47 181.82 215.65 179.32 171.35 152.62 110.35 24.06 26.26 1,348.01 112.33 1997 Ratiob 0.10 0.31 0.96 1.18 1.62 1.9.2 1.60 1.53 1.36 0.98 0.21 0.23 1.92 0.10
Use 14.22 22.29 50.91 90.73 161.27 228.75 191.74 208.43 158.65 103.86 33.23 68.39 1,332.46 J 11.04 1998 -
Ratiob 0.13 0.20 0.46 0.82 1.45 .2,06 1.73 1.88 1.43 0.94 0.30 0.62 2.06 0.13
Use 15.00 55.38 64.71 143.92 204.23 190.64 332.49 183.97 188.02 146.19 100.79 136.37 1,761.71 146.81 1999 1--,-,.
Ratiob 0.10 0.38 0.44 0.98 l.39 1.30 1, '2.26 1.25 1.28 1.00 0.69 0.93 2.26 0.10
Use 136.61 56.91 17.06 166.47 142.32 254.36 278.75 248.47 191.98 177.58 91.95 106.77 1,869.24 155.77 2000 Ratiob 0.88 0.37 0.11 1.07 0.91 1.63 1.79 1.60 1.23 1.14 0.59 0.69 l.79 0.11
Simple 0.29 0.25 0.37 0.89 1.30 1.74 1.82 1.72 1.47 1.12 0.49 0.54 1,443.51 120.29 2.05 0.11 Average Adjustedd 0.15 0.11 0.25 0.84 1.30 1.94 '~.05. 1.91 1.54 1.09 0.38 0.44 2.05 0.11
a) Based on actual CMWD metered demands.
b) Annual monthly demand variation expressed as a ratio of actual monthly demand divided by the average monthly demand for that year.
c) Demand factors include peak-to-average (PIA) month and minimum-to-average (MIA) month.
d) See report text for explanation.
M :\Projeots\Carlsbad.224\LakeCalaPDR.001 \Data\LkCMoSDS4 -Demands
Appendix B
SEASONAL STORAGE MODEL RUNS
CGvL ENGINEERS IN ASSOClA TION WITH POWEuJPBS&J
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements -CMWD Recycled Water System Expansion Analysis
SCENARIO 2A: Phase II with Unlimited Seasonal Storage
SUPPLY: RW=4.82 mgd; Other=0 mgd
DEMAND: Phase II @ 5,400 ac-ft/yr
STORAGE: o ac-ft existing seasonal storage, 1,644 ac-ft required seasonal storage
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec ~----------
TOTAL
a)
b)
c)
d)
e)
f)
g)
iii .!!
-~ " .. .,
E ::,
0 >
Seasonal Variation Ratlo Project Other
Min Max Avg Demand, Demand,
ac-ft" ac-ft
0.10 0.10 0.15 70
0.20 0.20 0.11 49
0.40 0.40 0.25 113
1.00 1.00 0,84 378
1.50 1.40 1.30 586
1.70 1.70 1.94 871
1.95 2.10 2.05 -922
1.85 1.80 L91 857
1.50 1.30 1.54 693
1.10 1.00 1.09 492
0.40 0.50 0.38 172
0.30 0.50 0.44 199 -------·-------···----------·--
12.00 I 12.00 I 12.00 5,400
INPUT
n/a "'-effective/total precipitation ratlo (no units)
n/a = irrigation efficiency (no units)
0
0
0
0
0
0
0
0
0
0
0
0
0
5,400 = annual project irrigation demand (ac-fVyr)
8.00 = maximum recycled water supply available (mgd).
0.00 = maximum other water supply available (mgd)
8.00 = maximum reservoir lnflow allowed (mgd)
1,000
900
800
700
600
500
400
300
200
100
0
8.00 = maximum reservoir outflow allowed (mgd)
2,000 = maximum reservoir wori<ing storage available (ac-ft)
Monthly Supply / Oemand
r, ~DDemand~ ...... ...... ■Supply
f-----
L---
' f--......
i ---
----) --
-, --
--------f j r -1
Jan Fell Mar Apr May Jun Jul ,O.Vg &lp Oct Nos Dec
Month
F;\Pro;ects\Powell.207\C<!(lsbad Ph ll.001\Reseivolr\LkCMoSOS4 • 2A·Phll(FS)
Total
Demand,
ac-ft
70
49
113
378
586
871
922
857
693
492
i72
199 ----------
5,400
RW Other Total Reser. Reser. Unused
Supply, Supply, Supply, Flow, Storage, RW Supp.,
ac-ft 0 ac-ft e ac-ft ac•ft' ac-ftg ac-ft
450 0 450 380 910 297
450 0 450 401 1,31 i 297
450 0 450 337 1,649 297
450 0 450 72 1,721 297
450 0 450 (136) i ,585 297
450 0 450 (421 ) 1,165 297
450 0 450 (472) 692 297
450 0 450 (407) 285 297
450 0 450 (243) 42 297
450 0 450 (42) 0 297
450 0 450 278 278 297
450 0 450 251 530 297 ----------------- --------·-------------·--------------------·-
5,400
.;
i ::, .. .,
12 ::,
0 >
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
2,000
1,600
1,600
1,400
1,200
1,000
800
600
400
200
0 5,400 0
OUTPUT
2.05 = peak month factor (no units)
n/a "'irrigatfon application rate (ft/yr)
5,400 = annual total demand (ac•ft/yr)
1.00 =total supply/demand ratio (no units)
Jul = maximum lrrlg!ltion demand month
Jan =-minimum irrigation demand month
4.82 = maximum RW supply used (mgd,)
3,565
o.oo = maximum other supply used (mgd)
4.30 = maximum reservoir inflow used (mgd)
5.05 = maximum reservoir outflow used (mgd)
1,721 = maximum reservoir working storage used (ac-ft)
Monthly Reservoir/ Unused RW Supply
--Reser.
----------------------,-&-Unused -
Jan Fab Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
5/31100
I
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements -CMWD Recycled Water System Expansion Analysis
SCENARIO 2B: Phase II w/ Mahr Seasonal Storage only
SUPPL V: RW=8.00 mgd; Other=2.12 mgd
DEMAND: Phase II @ 5,400 ac-ft/yr
STORAGE: 0 ac-ft existing seasonal storag.e, 151 ac-ft required seasonal storage
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec ----------
TOTAL
a)
b)
c)
d)
e)
f)
g)
iii
"*-! u .. t :,
0 >
Seasonal Variation Ratio Project Other
Min Max Avg Demand, Demand,
ac-ft 0
0.10 0.10 0.15 70
0.20 0.20 0.11 49
0.40 0.40 0.25 113
1.00 1.00 0.84 378
1.50 1.40 1.30 586
1.70 1.70 1.94 871
1.95 2.10 2.05 922
1.85 1.80 1.91 857
1.50 1.30 1.54 693
1.10 1.00 1.09 492.
0.40 0.50 0.38 172
0,30 0.50 0.44 199 -----·• ----------
12.00 I 12.00 I 12.00 5,400
INPUT
n/a = effective/total precipitation ratio (no units)
n/a = irrigation efficiency (no units)
ac-tt
0
0
0
0
0
0
0
0
0
0
0
0 --·-
0
5,400 = annual project irrigation demand (ac-ft/yr)
8.00 = maximum recycled water supply available (mgd)
2.00 = maximum other water supply available (mgd)
1.00 = maximum reservoir inflow allowed (mgd)
1,000
900
BOO
700
600
500
400
300
200
100
0
1.50 = maximum reservoir outflow allowed (mgd)
151 = maximum reservoir working storage available (ac-ft)
Monthly Supply I Demand
1DDemandL
~ LJ ■svpply --
~ -'-
---
--'
-- --
• --. '-11-f!I r1 r-l l 0I ---
I I
Jan Feb Mar Apr May Jon Jul AUg Sep Oct Nov Dec
Month
F:\Projects\Powe0.207\Carlsbad Ph ll.001\ReseNoirllkCMoSOS4 • 2B·Phll(MAO)
Total
Demand,
ac-ft
70
49
113
378
586
871
922
857
693
492
172
199
5,400
RW Other Total System Reser. Unused
Supply, Supply, Supply, Flow, Storage, RW Supp.,
ac-ft a ac-ft • ac-ft ac-ft ' ac-ft 9 ac-ft
145 0 145 76 76 602
124 0 124 76 151 623
113 0 113 0 151 635
378 0 378 0 151 370
586 0 586 0 151 161
747 0 747 {124) 27 0
747 148 895 (27) 0 0
747 110 857 (0) 0 0
693 0 693 0 0 54
492 0 492 0 0 255
172 0 172 0 0 575
199 0 199 0 0 549 --------------·---·-----------·-·-····-----
5,142
... .,
4! !! u ..
oj
E :, g
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
500
400
300
200
100
258 5,400 0
OUTPUT
2.05 = peak month factor (no units)
n/a : Irrigation application rate (ftlyr)
5,400 = annual total demand (ac-ft/yr)
1.00 = total supply/demand ratio (no units)
Jul = .maximum irrigation demand month
Jan = minimum irrigation demand month
8.00 = maximum RW supply used (mgd)
1.58 = maximum other supply used (mgd)
0.81 "' maximum reservoir inflow used (mgd)
1.32 = maximum reservoir outflow used (mgd)
3,823
151 = maximum reservoir working storage used (ac-ft)
Monthly Reservoir/ Unused RW Supply
Jan Feb Mar Apr May Jun Jul />/Jg Sep Ocr Nov Dec
Month
5131/00
Analysts of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements -CMWD Recycled Water System Expansion Analysi~
SCENARIO 2C: With Lk Calavera Seasonal Storage, dry yr. precip.
SUPPLY: RW=B.00 mgd; Other:0.66 mgd
DEMAND: Phase II @ 5,400 ac-fVyr
STORAGE: 161 ac-ftexistlng seasonal storage, 352 '!IC-ft required seasonal storage
Other Total RW Other Total MahrResv. Runott Lk Calavr. Calavera Seasonal VariaJlon Ratio Pro]ect System Unused I Month
Min Ory Avg Oemand, Demand, Demand, Supply, Supply, Supply, Flow, Storage Retained Storage, Elev AW Supp.,
ac-ft • ac-ft ac-ft ac•tt• ac-fl • ac-ft ac-ft' ac-ft g ac-ft ac-ft h ft ac-ft
I
I
l
Jan
Feb
Mar
,V,r
May
Jun
Jul
Aug
Sep
Ocl
Nov
Dec
TOTAL
'i i Ii ..
i :, 0 >
a)
b)
c)
d)
e)
f)
g)
h)
1,200
1,000
800
600
400
20(1
0.10
0.20
0.40
1.00
1.50
1.70
1.9&
1.85
1.50
1.10
0.40
0.30
12.00 I
INPUT
D w
0.10
0.20
0.40
1.00
HO
1.70
-2.10
1.80
1.30
1.00
0.50
0.50
12.00 I
0.15 47
0.11 94
025 187
0.84 468
1.30 655
1.94 798
2.05 983
1.91 842
1.54 608
1.09 468
0.38 234
0.44 234
12.00 5,616
5,616 = amual profecl lmgatioo demand (ac-lt/ylj
0
0
0
0
0
0
0
0
0
0
0
0
0
8.00 = maiclmum recycled water supply availabls (mgd)
2.00 = maximum other wa,ter supply available (mgd)
8.00 = maximum reservoir Inflow allowed {mgd)
8.00 = maximum reservoir ouillow allowed (mgd)
47
94
187
468
655
796
983
842
608
4Q8
234
234
5,616
151 = m.u<imum reservoir working storage ava1able (ac•fl) at Ma.ht
350 = maximum re,e!VOif working sto,age avalfabl1 (ac-11) at Calavera
Monthly Supply/ Demand
Jan ,,_, Mo, A"1 May Jun Jul A.lo Sap Oct -Ooc
Monlh
122
169
18'7
468
655
747
747
747
608
468
234
234
5,388
f ; • t :,
?
1)
2)
3)
4)
5)
6)
7)
8}
9)
10)
11)
7IICI
600
500
,oo
300
200
100
• ~.
0 122 76 76 72 160 204 625
0 169 76 151 72 232 207 578
0 187 0 151 29 261 209 560
0 468 0 151 14 274 209 279
0 655 0 151 0 274 209 92
0 747 (48) 103 0 274 209 0
0 747 (236) (133) 0 141 202 0
0 747 (95) 0 0 46 194 0
0 608 0 0 0 50 195 139
0 468 0 0 3 53 195 279
0 234 0 0 12 65 197 513
0 234 0 0 23 88 199 513
0 5,388 (228) 224 228 15 3,578
160 203
Curve: Depth (ft)= (10,593 • Volume (AF)) A 0.4195
2.10 = peak month fader (no un,11)
n/a = irrigation applicalioo rare (l\lyll
5,816 = amual total demand (ao-tt,yr)
1.00 = total supply/demand ratio (no untts)
Jul " mal<lmum Irrigation demand mont~
Jan = minimum Irrigation demand month
8.00 : maximum RW supply used (mgd)
0.00 : maximum other supply used (rngd)
0,81 =-max!n-,m reseNOir inflow u$l!cl (rngd)
2.52 = maidmum rese,voir out.flow used (mgd)
204 = maximum resef\loir working sto,age used (ac-11)
QJlQ typjded WRP capaciy
Monthly Reservoir I Unused RW Supply
-+-~Hr,
------------------------------&--Unu.od ----------
fob -.... Oct Nov
Month
S/31100
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements -CMWD Recycled Water System Expansion Analysi~
SCENARIO 2C: With Lk CalaveraSeasonal Storage, avg. yr. precip. w/diversion
SUPPLY: RW=B.00 mgd; Other=0.66 mgd
DEMAND: Phase ii @ 5,400 ac-ft/yr
STORAGE: 151 ac-fl existing seasonal storage, 352 ac-11 required seasonal stol'89e
Seasonal Variation Ratio Project other Total RW Other Total System MatrrResv.
Min Max Avg Demand, Demand, Demand, Supply, Supply, Supply, Flow, Storage
Month ac-ft 0 ac-ft ac-ft ac-ft • ac-ft • ac-ft ac-ft' ac-tt g
Jan 0.10 0.10 0.15 70 0 70 145 0 145 76 76
Feb 0,20 0.20 0.11 49 0 49 124 0 124 76 151
Mar 0,40 0.40 0.25 113 0 i 13 113 0 113 0 151
Apr 1.00 ;,oo 0.84 378 0 378 378 0 378 0 151
M~y 1.50 1.40 1.30 588 0 586 586 0 586 0 151
Jun 1.70 1,70 1.94 871 0 871 716 0 716 (154) (3)
Jul 1.95 2.10 2.05 922 0 922 716 0 716 (206) 0
Aug 1.85 1,80 1.91 857 0 857 716 0 716 (141) 0
Sep 1,50 1.30 1,54 693 0 693 693 0 693 0 0
Oct 1.10 1.00 1.09 492 0 492 492 0 492 0 0
Nov 0.40 0.50 0.38 172 0 172 172 0 172 0 0
Dec 0.30 0.50 0.44 199 0 199 199 0 199 0 0 ---..
TOTAL 12.00 I 12.00 I 12.00 5,4-00 0 5,400 5,050 0 5,050 (350)
Runoff Lk Calavr. Calavera Unused
Retained Storage, Elev RW Supp,,
ao-ft ac-ft h ft ac·ft
124 205 20o 571
107 312 211 592
89 401 214 604
0 401 214 339
0 401 214 130
0 397 214 0
0 192 205 0
0 51 195 0
0 50 195 23
.0 so 195 224
0 50 195 545
31 81 198 518
351 351 19 3,547
216 205
INPUT
0 w
Curve: Depth (fl)= (10,593 • Volume (AF})" 0,4195
.;
t ,; E ::,
0 >
a)
b)
c)
d)
e)
f)
g)
h)
1iOr;JO
900
600
700
EOO
600
400
300
200
100
0
5,400 = annual project Irrigation, demand (ao-11/yr; 7.67 = maximum recycled water supply available (mgd)
2.00 = maximum other water ·supply available {mgd)
8.00 = maximum reservoir innow allowed (mgd)
8.00 = maximum reservoir outflow allowed (mgd)
151 = maximum reservoir working storage available (ac-ft) at Mahr
350 = max[mum reservoir working stora_ge available (ac-ft) at Calavera
Monthly Supply/ Demand
Jan Fob Mar p.,,, May J~ Juf AUQ Sop Oct Nov Dae
Month
F:'\Pro/eet&\Powell.207\Carl!.bad F'tl tl.OOt\Re:sflN041\LkCMoSOS4 -2C•Phll(•vo)
1)
2)
S)
4)
5)
6)
7)
8)
9)
10)
11)
2.05 = peak month factor (no units)
n/a : irrigalion applicafion rate (!Vyr]
5,400 : annllal total demand (ac-!Vyr)
1.00 = total supply/demand ratio (no units)
Jul = maximum Irrigation demand m9ntt
Jan = minimum Irrigation demand mon1h
7.67 = maximum RW supply used (mgd)
0.00 = maximum other supply used (mgd)
0,81 = maidmum reservoir Inflow used ("1Qd)
2:20 = maximum reservoir outflow used (mgd)
331 = maxlmum reservoir working storage used (ac-11)
Monthly Reservoir/ Unused RW Supply
Q...aa avoided WRP capac;y
700 r------------------------------~
800
Jan Jun Aug Sep OcJ Nov
Mo,nlh
Analysis o1 Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements• CMWD Recycled Water System Expansion Analysi~
SCENARIO 2C: Wllh Lk Calavera Seasonal Stora.ge, avg. yr. precip. w/diversion
SUPPLY; RW=8.00 mgd; Other=0.66 mgd
DEMAND: Phase II @ 5,400 ac-fttyr
STORAGE: 151 ac-ft exlstlng seasonal storage, 352 ao-ft required seasonal storage
Month
Ja.n
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
TOTAL
a)
b)
c)
cl)
8)
f)
Seasonal V,ulatlon Ratio
Wet
0.10
0.20
0.40
1.00
1.50
1,70
1.95
1.85
1.50
1. 10
0.40
0,30
12.00 I
llif.l.!.!
0 w
Max
0.10
020
0.40
1.00
1.40
1.70
2.10
1.80
1.30
1.00
0.50
0.50
12.00
Avg
0.15
0.11
0.25
0.84
1.30
1.94
2.05
1.91
1.54
1.09
0.38
0.44
I 12.00
Project Other
Demand, Demand,
ac•ft 0 BC·ft
43 0
86 0
171 0
428 0
641 0
727 0
834 0
791 0
641 0
470 0
171 0
128 0
5,130 0
5.130 = annual profect irrigation demand (ac-ftlyr;
6.67 = maldmum recycled water supply avaUable (mgd)
2.00 = maximum Dlher water supply available (mgd)
8.00 = maximum reservoir inflow allowed (mgd)
8.00 = maximum reservoir otJtfiow allowed (mgd)
Total
Demand,
ac-ft
43
88
171
428
641
127
834
791
641
470
171
128
5,130
g)
h)
151 = maximum reservoirworidng storllge avaUable (ac-tt) at Mahr
350 = maximum reservoir working s10tage avaDable (ac-11) at Calaoera
Monthly Supply/ Demand
900 ~-------------------,
•oa +----------<1-----r.a~o~"""'-~-:-,....~
700 +----------f ■supply
i:+-------ft t 400 -!------t
~ 300 +------t
.looFe1,MarJA,,,""1' .... Jul""96opOetNovO..
Month
AW
Supply,
ac-ft0
118
161
171
428
623
623
623
623
623
470
171
128
4,762
..
i .;
E :, 0 >
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
....
500 -
300
200
100
O1.her Total System MahrAesv. Aunott UcCal;ivr. Calavera Unused
Supply, Supply, Flow, Storage Retained Storage, Elev AW Supp.,
ac•ft • ac-ft ac-tt' ac-ft g ac-tt ac-ft h ft ac-tt
0 118 76 76 144 344 212 505
0 161 76 151 106 420 215 462
0 171 0 151 0 420 215 452
0 428 0 151 0 420 215 195
0 623 (18) 133 0 420 215 0
0 623 (104) 29 0 420 215 0
0 623 (211) (182) 0 238 208 0
0 623 (168) 0 0 70 197 0
0 623 (18} 0 0 62 195 0
0 470 0 0 0 so 195 153
0 171 0 0 93 143 203 452
0 128 0 0 58 200 206 495
0 4,762 (368) 400 370 20 2,713
266 207
Curve: Depth (ft)~ (10,593 • Volume (AF)) A 0.4195
1.95 = peak monlh factor (no units)
n/a = imgation app&cation rate (ftlyr)
5,130 = aMUal total demand (ac•ftlyr)
1.01 = total supply/demand ratio (no units)
jul = maximum Irrigation demand montt
Jan = minimum lrrlgallon demand month
6.67 = maximum RW supply used (mgd)
0.00 = maximum other supply uaed (mgd)
0,81 =maxmum reservoir lnflow used (mgd)
2.26 = maximum reservoir outllow used (mgd)
350 = maximum reservoir wor1dng storage used (ac-fl)
Monthly Reservoir/ Unused RW Supply
u.a iiYC/lded WRP capacjy
_____________________________ j:::=::.i ~--------
Fob Jon --Month
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements• CMWD Recycled Water System Expansion Analysis
SCENARIO 3A: Ultimate with Unlimited Seasonal Storage
SUPPLY: RW=8.74 mgd; Other=O n,gd
DEMAND: Ultimate @ 9,800 .ac-ft/yr
STORAGE: O ao-ft existing seasonal storage, 2,983 ac-ft required seasonal storage
Seasonal Variation Ratio Project Other Total
Min Max Avg Demand, Demand, Demand,
Month ao-ft • ac-ft ac-ft
Jan 0.10 0.10 0.15 126 0 126
Feb 0.20 0.20 0.11 88 0 88
Mar 0.40 0.40 0.25 204 0 204
Apr 1.00 1.00 0.84 685 0 685
May 1.50 1.40 1.30 1,063 0 1,063
Jun 1.70 1,70 1.94 1,580 0 1,580
Jul 1.95 2.10 2.05 1,673 0 1,673
Aug 1.85 1.80 1.91 1,556 0 1,556
Sep 1.50 1.30 1.54 1,258 0 1,258
Oct 1.10 1.00 1.09 893 0 893
Nov 0.40 0.50 0.38 311 0 311
Dec-0.30 0.50 0.44 360 0 360 1--------·---,-------------·--------·-----.. ---------·-------------------··---·'"'---· ·--
TOTAL
ii ~ f " "' t ::,
0 >
a)
b)
c)
d)
e)
f)
g)
1,800
1,600
1,400
1.200
1,000
800
600
400
200
0
12.00 I 12.00 I 12.00 9,800 0
r
nla = effective/total precipitation ratio (no units)
n/a = Irrigation efficiency (no units)
9,800 = annual project lrrigatfon demand (ao-ft/yt)
20.00 = maximum recycled water supply available (mgd)
0.00 = maximum other water supply available (mgd)
12.00 = maximum reservoir inflow allowed (mgd)
12.00 = maximum reservoir outflow allowed (mgd)
3,125 = maximum reservoir working storage available (ac,ft)
Monthly Supply/ Demand
~
,-' ~ !DDemand~
--i ■supply .
~ ---~
I,
1,· ---1,
--· ----
" --------'-'-'-'-{ -I " 1,
f ~
Jan Feb Mar Apr May Jun Jul Aug Sep Oct r,Jov Dec
Month
F:IProfects\Powell.207\Ca~sbad Ph ll.001\ReservolillkCMoSDS4 -SA-Ult(FS)
9,800
AW
Supply,
ac-ft a
817
817
817
817
817
817
817
817
817
817
817
817
9,800
ii .,
"; e u .. t ::, g
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
3,500
3,000
2,500
2,000
1,500
1.000
500
Other Total Reser. Reser. Unused
Supply, Supply, Flow, Storage, RWSupp.,
ac-ft • ac-ft ac-ft' ac-ft 9 ac-ft
0 817 690 1,652 1,051
0 817 728 2,380 1,051
0 817 612 2,992 1,051
0 817 131 3,124 1,051
0 817 (247) 2,877 1,051
0 817 (764) 2,113 1,051
0 817 (857) 1,257 1,051
0 8H (739) 518 1,051
0 817 (441) 76 1,051
0 817 (76) 0 1,051
0 817 505 505 1,051
0 817 456 961 1,051 ------·---·----·---·----L----------------·-·----
0 9,800 0
OUTPUT
2.05 = peak month factor·(no units)
n/a = irrigation applicatlon rate (ft/yr)
9,800 = annual total demand (ac-ft/yr)
1.00 =total supply/demand ratio (no units)
Jul = maximum Irrigation demand month
Jan = minimum irrigation demand month
8.74 = maximum AW supply used (mgd)
0.00 = maximum other supply used (mgd)
7.80 = maximum reservotr inflow used (mgd)
9.17 = maximum reservoir outflow used (mgd)
12,613
3,124 = maximum reservoir working s\orage used (ac-ft)
Monthly Reservoir / Unused RW Supply
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
5131/00
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements -CMWD Recycled Water System Expansion Analysis
SCENARIO 38: Ultimate w/ Mahr Seasonal Storage only
SUPPL V: AW:18.37 mgd; Other=0 mgd
DEMAND: Ultimate @ 9,800 ac-ft/yr
STORAGE: O ac-tt existing seasonal storage, 151 ac-tt required seasonal storage
Seasonal Variation Ratio Project Other
Min Max Avg Demand, Demand,
Month ac-ft c ac-ft
Jan 0.10 0.10 0.15 126 0
Feb 0.20 0.20 0.11 88 0
Mar 0.40 0.40 0.25 204 0
Apr 1.00 1.00 0.84 685 0
May 1.50 1.40 1.30 1,063 0
Jun 1.70 1.70 1.94 1,580 0
Jul 1.95 2.10 2.05 1,673 0
Aug 1.85 1.80 1.91 1,556 0
Sep 1.50 1.30 1.54 1,258 0
Oct 1.10 1.00 1.09 893 0
Nov 0.40 0.50 0.38 311 0
Dec 0.30 0.50 0.44 360 0 --·------·------·-·-----···-
TOTAL 12.00 I 12.00 I 12.00 9,800 0
a)
b)
c)
d)
e)
I)
g)
1,800
1,600
1,400
.:; ~ 1.200 e " .. 1,000
t 800
::, 0 > 600
.400
200
0
INPUT
n/a =-effecllve/1otal precipitation ratio (no units)
n/a = irrigation efficiency (no units)
9,800 = annual project Irrigation demand (ac-ft/yr)
16.75 = maximum recycled water supply available (mgd)
0.00 = maximum other water supply available (mgd)
1.00 = maximum reservoir inflow allowed (mgd)
1.50 ; maximum reservoir outflow allowed (mgd)
151 = maximum reservoir working storage available (ac-ft)
Monthly Supply/ Demand
+--------....--t t--c:------1 D Demand r----i
■Sopply
Jan Feb Mar /<pl May Jun Jul Auo Sep Oct Nov Dec
Month
F;\Pn,Jects\Powell.207\Cai1sbad PN ILOOI\ReselVOfr\LkCMoSDS4 -'3B·Ull(MRO)
Total
Demand,
ac-ft
126
88
204
685
1,063
1,580
1,673
1,556
1,258
893
311
360
9,800
AW
Supply,
ac-ft a
202
164
204
685
1,063
1,553
1,553
1,552
1,258
893
311
360
9,800
1 " "' r 0 >
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
1,600
1,400
1200
1,000
800
600
400
200
Other Total Reser. Reser. Unused
Supply, Supply, Flow, Storage, RW Supp.,
ac•ft • ac-ft ac-ft' ac-ft 9
0 202 76 76
0 164 76 151
0 204 0 151
0 685 0 151
0 1,063 0 151
0 1,553 (27) 124
0 1,553 (120) 4
0 1,552 (4) 0
0 1,258 0 0
0 893 0 0
0 311 0 0
0 360 0 0 ... -··
0 9,800 0
OUTPUT
2.05 = peak month factor (no units)
n/a = irrigation appltcauon rate (fl/yr)
9,800 = annual total demand (ac-fl/yr)
1.00 =total supply/demand ratio (no units)
Jul = maximum irrigation demand month
Jan = minimum irrigation demand month
16.63 = maximum AW supply used (mgcl)
ac-ft
1,362
1,400
1,360
879
501
11
11
12
306
671
1,253
1,204
8,971
0.00 = maximum other suppfy used (m,gd)
0.81 = maxlmum reservoir inflow used (mgd)
1.28 = maximum reservoir outflow used (mgd)
151 = maximum reservoir working storage used (ac-ft)
Monthly Reservoir/ Unused RW Supply
=------=·. _. ___________ ~Reser. ____ _
-e-unused
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
5f3Ml0
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements • CMWO Recycled Water System Expansion Analysis
SCENARIO 3C: With Lk Calavera Seasonal Storage, dry yr. precip.
SUPPLY: AW=16.76 mgd; Other=0 mgd
DEMAND: Ultimate @ 9,800 ao-ft/yr
STORAGE: 151 ac-lt existing seasonal storage, 352 ac-11 required seasonal storage
Seasonal Variation Ratio Project Other Total RW Other Total I System MaMResv.
Min Ory Avg Demand, Demand, Demand, Supply, Supply, Supply, Flow, Storage
Month ac-lt • ac-lt ac-ft ac-ft • ac-ft. ac-ft ac•ft' ac•ft
Jan 0.10 0.10 0.15 86 0 86 161 0 161 76 76
Feb 0.20 0.20 0.11 172 0 172 247 0 247 76 151
Mar 0.40 0.40 0.26 343 0 343 343 0 343 0 151
Apr 1.00 1.00 0.84 858 0 858 858 0 858 0 151
May 1.50 1.40 1.30 1,201 0 1,201 1,201 0 1,201 0 151
Jun 1.70 1.70 1.94 1,458 0 1,458 1,458 0 1,458 0 151
Jul 1.95 2.10 2.05 1,801 0 1,801 1,485 0 1,485 (316) (165)
Aug i.85 1.80 1.91 1,544 0 1.544 1,485 0 1,485 (59) 0
Sep 1.50 1.30 1.54 1,115 0 1,115 1,115 0 1,115
I
0 0
001 1.10 1.00 1.09 858 0 858 858 0 858 0 0
Nov 0.40 0.50 0.38 429 0 429 429 0 429 0 0
Dec 0.30 0.50 0.44 429 0 429 429 0 429 0 0
TOTAL 12.ClO I 12.00 I 12.00 10,290 0 10,290 10,067 0 10.067 (223)
Runoff Lk Calavr. Calavera Unused
Retained Storage, Elev RW Supp.,
ac-ft ao-ft9 ft ac-lt
72 160 204 1.324
72 232 207 1,238
29 261 209 1,142
14 274 209 627
0 274 209 284
0 274 209 27
0 109 200 0
0 51 195 0
0 50 195 370
3 53 195 627
12 65 197 1,056
23 88 199 1,056
224 224 14 7,752
158 202.
Curve: Depth (ft)= (10.593 • Volume {AF))" 0.4195
a)
b)
C)
d)
e)
I)
W : rrinlffllm variance kl seasonal Oamands {Wei yrJ
O =· maxfmum varlance lo seasonal demands (dry yr)
10,290 • annual project lrrigallon demand (ac•fl/yr)
15.90 ~ maximum reoycied waler supply provided (mod)
0.00 ~ ma,dmum other waler wppty available (mod)
8.00 , maid,oom reservoir ltlflow allowed (mgd)
8.00 : malCimum ,eservolrOUCflow atlowed (mgd)
1)
2)
3)
WARNINGl4)
5)
6)
7)
2.10 = peal(month factor (no unilS)
n/a ~ Jrrigadon appllcallon rate (ft/yf)
10,290 = annual fOlal demand (ac-ft/yr)
1.00 =total supply/demand ratio (no units)
Jul "ma,rlmum lrrl{Ptlo,i demand-month
Jan ~ minimum lrrigallon demand month
151 : maximum reseivoir wori<ing storage 1111;,ilable (ac-fl) at Mahr
352 = maximum reseivolr wori<tng storage available (ae•fl) at Cala\lerr
6)
9)
10)
15.90 ~ maxfmum AW supply used (mgd)
0.00 ~ maximum other supply used (ri,od)
0,81 " max1mum Inflow used (rngd}
Monthly Supply/ Demand
1.000 -,-------------------,
).1100 +--------------1
1,IIOO +----------f..1-~-t
1.«>0 +-------~fa--UH,a-------1
,.-+--------nrl
1,000 t-------llH--••....1•-------1
800 -1------l'W---llll--l a-t-■H ;■-1 ■'"I ■f-----1
!IOl)-t-----
400 -t---.....,,,~-••-,.1..-. ... l■H.la-l ■-f7--ra-l
200 -t-=-s--f
3.38 = maximum outflow used (mgd)
11) 204 " maximum WO<klng storage used (a,;-ft) at LI< Calavere
Monthly Reservoir/ Unused RW Supply
1,400 ~----------------~
i.200 -------------1===~1------
t,000
lU!§ Ayolded WRP Cagatjry
I
I
Analysts of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements• CMWD Recycled Water System Expansion Analysl£
SCENARIO 3C: With Lk Calavera Seasonal Storage, avg. yr. preclp.
SUPPLY: AW=16.76 mgd; Other=O mgd
DEMAND: Ultimate @ 9,800 ac,JVyr
STORAGE: 151 ao-lt existing seasonal storage, 352 ao-h required seasonal storage
Seasonal Variation Ratio Project Other iotal RW Other Total System MahrResv,
Min Max Avg Demand, Demand, Demand, Supply, Supply, Supply, I Flow, Storage
Month ac-tt • ac-tt ac-ft ac•tt • ao-rt • ac--ft ae-ft' ac•ft
J.an 0,10 0.10 0.15 126 0 126 202 0 202 76 76
Feb 0.20 0.20 0.11 88 0 88 164 0 164 76 151
Mar 0.40 0.40 0.25 204 0 204 204 0 204 0 151
/1,f,r 1.(JO 1.00 0.84 685 0 685 685 0 685 0 151
May 1,50 1.40 1.30 1,063 0 1,063 1,063 0 1,063 0 151
Jun 1,70 1.70 1.94 1,580 0 1,580 1,436 0 1,436 (144) 7
Jul 1.95 2.10 2.05 1,673 0 1,673 1,436 0 1,436 I (237) (230)
Auo 1.85 1 80 1.91 1,656 0 1,556 1,436 0 1,436 I (120) 0
Sep 1.50 1.30 1.54 1,258 0 1,258 1,256 0 1,258 0 0
OC! 1, 10 1.00 1.09 693 0 893 893 0 893 0 0
Nov 0.40 a.so 0.38 311 0 311 311 0 311 0 0
Dec-0.30 0.50 0.44 360 0 360 360 0 360 0 0
Runoff -LkCalavr. Calavera Unused
Retained Stora_ge, Elev AW Supp.,
ac-ft ao-ft9 ft ac-ft
124 205 206 1,234
107 312 211 1,273
89 401 214 1,232
0 401 214 751
0 401 214 373
0 401 214 0
0 171 204 0
0 51 195 0
0 50 195 178
0 so 195 643
0 50 195 1,125
31 81 198 1,076
lrorAL 12.00 I 12.00 I 12.00 9,800 0 9,800 9,451 I 9,4S1 0 I (350) 351 351 19 7,785
a)
b)
C)
d)
e)
f)
g)
h)
INPUT
W = rrinln.mi variance In seasonal demaods {wel yr)
D = maiomum variance'" seasonal demands (dry yr)
9,800 ; annual project lrrigaUon demand (ac-fVyr)
1 s.ae ~ maximum recycled water supply provided (mod)
o.oo = ma>clmum other wataf supply available (mgd)
8.00 ~ maximum res.eivolr Inflow allowed {rngd)
!LOO = maximum reservoir Olllflow allowed (mgd)
t 51 = maximum resowolr wori<lng storage available (ac-11) at Mahr
352 2 maxfmum reservoir wo(king storage available (ac.-h) at Calave11
Monthly Supply I Demand
,.-~------------------.
1,111>0 +---------,..--i
1,.00 +--------
j 1,200 +--------.. ~ 1.000 +--------111-ij .. -llH
{ 800
g eoo +-----
"°° +-----
..... Feb Ma, ~ Mai J.., "" Jo.Jg Sep 0d ,,.,, Cloe -
i I ..
f I
214 205
Curve: Depth (ft)• (10.593 • Volume (AF))" 0.4195
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
1,400
1,ZlO
1,000
1!01)
GOO
<00
200
2.05 ~ peak month lac-tor (no units)
n/a ~ lmgadon application mta (ftly1
9,800 = annual total demand (ac-11/yr)
1.00 ., total supply/demand ratio (no units)
Jul .. maximum Irrigation clemand,monlh
Jan = minimum lrrigatloo demand month
15-38 = maidmum AW supply Used (mgd)
0.00 = maximum other supply used (rngd)
0.81 = maximum inflow used (mod)
2.54 = maximum outtlow used (mgd)
331 = maximum wOlkina storage usad (GC'•fl) at Lk Oalavera
Monthly Reservoir/ Unused RW Supply
---------1::::::::r1------
o L......,_-+---~-~:::t:~~::::r
.Ion Ftb Mar ~· May Jew, Ju "'iv Sep Cid ,.., Dec
Month
~ Ayojded WRP Qapacfly
51.31100
I
Analysls of Monthly Supply/Demand/Storage Requirements
PROJECT: Lake Calavera Improvements • CMWD Recycled Water System Expansion Analysis
SCENARIO 3C: With Lk Calavera Seasonal Storage, wet yr. precip.
SUPPLY: AW:16.76 mgd; Otl)er;{) mgd
DEMAND: Ultimate @ 9,800 ac-tt/yr
STORAGE: 161 ac-ft existing seasonal storage, 352 ac-ft required seasonal storage
Seasonal Variation Ratio Project Other Total RW Oth@r Total System MahrResv.
Min Max Avg Demand, Demand, Demand, Supply, Supply, Supply, Flow, Storage
Month ac-ft • ac-11 ac-ft ac-11 • ac•ft • ac,ft ac-ft ' ac-tt
Jan 0.10 0.10 0.15 78 0 78 153 0 153 76 76
Feb 0.20 0.20 0.11 155 0 155 231 0 231 76 151
Mar 0.40 0.40 0.25 310 0 310 310 0 310 0 151
Apr 1.00 1.00 0.84 ns 0 ns ns 0 ns 0 151
May 1.50 1.40 1.30 1,164 0 1,164 1,164 0 1,164 0 151
Jun 1,70 1.70 1.94 1,319 0 1,319 1,289 0 1,289 (30) 121
J11I 1.95 2.10 2.05 1,513 0 1,513 1.289 0 1,289 (224) (103)
Aug 1.85 1.00 1.91 1.435 0 1,435 1,289 0 1,289 (147) 0
Sep t.50 1.30 1.54 1,164 0 1,164 1,164 0 1,164 0 0
Oct 1.10 1.00 1.09 853 0 853 853 0 853 0 0
Nov 0.40 0.60 0.38 310 0 310 310 0 310 0 0
Dec 0.30 0.50 0.44 233 0 233 233 0 233 0 0
TOTAL 12.00 I 12.00 I 12.00 9,310 0 9,310 9,060 0 9,060 I (250)
Runoff Lk CaJavr. Calavera Unused
Retained Storage, Etev RWSupp.,
ac,tt ac-tt • fl ac-tt
144 344 212 1,136
106 422 215 1,058
0 422 215 978
0 422 216 513
0 422 215 125
0 422 215 0
0 319 211 0
0 172 204 0
0 so 195 125
0 50 195 435
93 143 203 978
58 200 206 1,056
400 372 20 6,405
282 208
Curve: Depth (ft) • (10.593 • Volume (AF)) "0.4195
a)
bl
cl d)
&)
f)
g)
h)
W ~ minimum variance in seasonal demands (we1 y(
O s maxlmum variance in seaaonal demands (dry y(
9,310 -aMUal project lrrigatioo demand (ac-11/Y(,
13.80 = ma>irnJm recycled waler sUJ)ply provided (mo<f
0.00 -maxmJIJI D1hM water supply available (mgd'
8.00 • maximum reservoir Inflow allowad (mg<(
8.00 = maximum reservoir outflow allowed (mgcf,
151 • maxi,,..,m reservoir wor11fng storage avallable (ac•fl) a1 Mahi
352 • maximum reservoir w0!1<1ng storage available (ac•ft) al Calaver.
Monlhly Supply I Demand
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
1.95 • peak monlh lactor (no unilS)
n/a • Irrigation appllcatlO/'I rate (ltlyt)
9,310 -amual tOlal domand (ac-fllyr)
1.02 • Iola) supply/demand ratio (!10 units)
Jul =maximum lrrlg~Uon demand month
Jan = minimum lrrigallon demand montr
13.80 • maximum RW supply used ( rTQd)
0.00 • maximum o1her supply used (mgd!
0.81 • maxlmum inllow used (mgd)
2.40 -maximumoutllow used (mgd)
352 • maxifT'IJm WOll<ing storage usod (ac-ft) al Lk Cftlava,a
Monthly Reservoir I Unused RW Supply
1,200 ~----------------~
1,000 ---------~====~~ ---
llOO
''" foo ""'' ,..,, May .kin Jul A"9 s'I' o,, -0oo
2Jl6 Ayo/dad WRP CaOjlchy
ff.WOO
Appendix C
PROJECT COST OPINIONS
CGvL ENGINEERS IN ASSOCIATION WlTH POWELLIPBS&J
Table C-1 Opinion of 1/0 Modification Costs 6130 6300 ENRCCI
Quantity Material Labor Jan-00 mid'01
Item no unit unit cost,$ unit cost,$ Total Cost,$
A2 Drawdown 65 Mgal 8,100 8,325
A3 Cofferdam 200 LF 135 27,000 165 33,000 60,000 61,664
A4 Muck Removal 400 CY 5 2,000 5 2,000 4,000 4,111
AS Tower Demolition 1 LS 10,000 10,000 20,000 20,555
A6 Db/CD Removal 300 CY 75 22,500 75 22,500 45,000 46.248
140,902 31.8%
81 Shoring 4 ton 600 2,400 360 1,440 3,840 3,946
81 Excavation 20 cy 40 800 20 400 1,200 1,233
81 New Tower Cap 5 cy 215 1,075 405 2,025 3,100 3,186
82 24" Stee·I Pipes 92 ft 115 10,680 105 9,660 20,240 20,801
B2 Welded Joints 20 each 315 6,300 35 7QO 7,000 7,194
82 24x24x 18 Tee 3 900 2,700 1,000 3,000 5,700 5,858
82 24-tn 90 Elbow 1 950 950 770 no 1,720 1,768
82 28x28x24Tee 1 each 1,990 1,990 1,126 1,126 3,116 3,202
B2 Flex Coupling 2 500 1,000 650 1,300 2,300 2,364
B2 16" EGate Valve 1 LS 7,055 7,055 3,000 3,000 10,055 10,334 w/manual accua1or
B2 Pipe Supports 8 each 250 2,000 500 4,000 6,000 6,166
82 18" BF Valve 3 each 5,000 15,000 2,250 6,750 21,750 22,353
82 18" SS Wire Screen 3 each 3,500 10,500 1,500 4,500 15,000 15,416
103,822 23.4%
84 Outlet Pipe Repairs 260 ft 72 18,720 100 26,000 44,720 45,960 su~ject to inspection/
83 Hydrlc Accurn Systen 1 LS 32,000 32,000 41,000 41,000 73,000 75,024
B3 Controls Bldg 150 SF 100 15,000 250 37,500 52,500 53,956
B3 E/1 1 LS 12,000 12,000 5,900 5,900 17,900 18,396
83 Metalworks 1 LS 3,500 3,500 1,600 1,600 5,100 5,241
198,578 44.8%
Sales tax 7 .50% 205,070 15,380 15,807
MobiVDernobl 3% 13. 159 13,524
Allowances 10% 57,400
Subtotal -Construction 459,879 530,000 530,033
Contractor OH&P 20% 106,000
Construction 636,000
Contingencies 20% 127,200
Sub-total 763,200
Eng/Envr/ Admin 17% 129,744
Total VO Project 892,944
Table C-2 Opinion of Spillway and Access Road Repair Costs
Costs
Lake Calavera Remedial Improvements
Description Unit Qt.
Access Road ltnprovments (Across Spillway Apron)
Excavation (Spillway Extension) CY
Export Excess Excavation CY
Fill (Transition Ramp, Turn Around Region) CY
Reinforced Concrete Overlay (Spillway Apron) CY
Reinforced Concrete Overlay (Transition Ratnp) CY
Reinforeed Gunite Overlay (Spillway Extension) CY
Decomposecl Granite (Dam Crest) CY
Unit Cost
300
150
150
110
30
40
125
Sub-total:
Contingency @ 30%
Sub-total:
100
30
40
280
280
62
27
Contractor Overhead & Profit @ 15°/c
Spillway/Channel Repairs
Excavation (Spillway Channel) CY
Reinforced Gunite Overlay (Spillway Channel) CY
30
250
Access Road Total:
250
112
Sub-total:
Contingency @ 30%
Sub-total:
Cost Basis
$30,000 -2
$4,500 -2
$6,000 -2
$30,800 -2
$8,400 -2
$2,480 -2
$3,375 -2
$85,555
$25,667
$111,222
i16,683
$130,000
$7,500 (2,3)
$28,000 -2
$35,500
$10,650
$46,150
Contractor Overhead & Profit @ 15% $6,923
Spillway/Channel Total: $50,000
Spillway and Access Road Total $180,000
Al
A'l
A3
A4
AS
AS
A7
81
82
83
84
86
A2
A3
A4
AS
A6
Bl
82
83
84
C1
C2
C3
C4
C6
CB
c,
C2
C3
C4 cs
C6
Table C-3 Remedial lmprov~ments Cost Summary
/ram
Mobllizatlon
DrawOOwn lo min. pool elev.
E'recl, Cottarcfam a, T <:Nver
Muck Removal
Demolilion of Upper Tower
Oellris/Calreroam Removal
Allowances/olher Items
subtotal A
New Submer:god Top Cap
Size
2,50% LS
65 MQal
1 LS
400OV
1 LS
300CV
f6%
New 1/0 Works pipe/valves/tees
Adcfnl 1/0 Controls for AW future RW Ops
outlet Pipe/Bo~ Ropair 260!1· 28 In
Allowances/other ilems l!l'll,
.sublolal B
Spillway Repalre & Extn
Dam Repairs (minor)
Access Road Improvements
Fencing (site securily)
Allowanceslotner Items
Demoblllzatjoo/Clean Up
sobtota:1 C
Total Projecl Cost
Eng, /EnvJAdmin
Total C'apilal Incl. 'EDIVA
allowances/other hems
2.00CV
1 LS
1200 LF
600 LF
10%
1% LS
17'¾.
10%
Con bass Mid o,
$/·
124
10
150
159
71
20
Jan-oo Mld'01 1.64
Base,$ Project.$ ProjQOI,$
26,000 38,478
8,100 12.467
60.000 92,348
4,000 6,157 A)
20,000 30,763
45,000 69,261
2.4 315 37 424
186,415 266,917
a. 140 12.s2e
92.881 142,955
146,500 228.561
4.4,720 68.8,0
29.~24 ~
323,665 498,163
31,749 49,865
8,000 12,1313
84,836 130,573
10.000 16,391
1 S,468 20,714
12.llQJl .1Uil
158,043 243,249
668,122 1,028,328
113.W .lli&tii
781,7031,203,144
103,426
Mld'01
assumes lower gate valve openetl "I/release lhroo_gh outlet pJpa
subjoct to del11iled <Ile survay and environmental review
assuma$ on-site disposal of muck;
removal or upper 40 fl soolioas
truck-haul of conslruclion debri•
assumes· extensive repair of plpefine may be needed
gunlle weal wall. dis channel-and clearing floor
grOUllriu astwhere required
Costs from 'IOWo,~s·
Iru-!rno l/0 Works
:i,840 20.240
1,200 7fJOO
~ 5,700
8,140 1,720
3,116
2.:ioo
10,056
fully paved from road, ap;on, e<esI and tum-around at easI and
now ace,,.. rd gale alld enclosure of 1/0 controls bullding
6,000
2.l,750
.wlQQ
92,881
8-u/o Berm
15,000 Access Rd
Controls
73,000
52,500
17,900
?.,.lilQ
148,500•
Ot1IIP.l
44,720
llem
Mobilizallon
Dmwdown ,to min, pool elev.
Erecl 'Cofferdam at Tower
Muck Removal
wm OHP Con plus OHP
2.6,700 32,100
8,700 10.-400
Pro/sci Coor, :
38,500
12.500
92,300 64. 100 77,000 97,300
SLnl'lS
99,500
167,BOO 116,528
A:!2ta!oB ~ ~ P•Vn~erw•••r
20,025 40.050 26.700 80100
10,320 10,320 6,600 0 a 103,889 04, too o
10,000 Claa,InglGtubblng
56,669 Berms/dikes ~ Control s1ructures/e<i1Jlpment
100.sag
Demolitioo of Upper Tower
OeM•ICoffordam Reniolllil
Allowances/other Items
subtotal A
Now Submetged Top Cap
Newl/OWorf<s
Acldnl 1/0 ContrOls for AW
Outlet !'{pa/Box Repair
Allowa,ice&lolher ilems
subtotal B
Spillway Repairs & Extn
Oam Repoira (mlror)
Acee&& Road trnprovemanls
Fencing (site security)
Allowanceslolher
Oemobillzalion/Clean Up
sublolalC
Tolal Project Cos!
Cootlngency @ 2.0%
E11g. IEJwJAdmin
Total Capltal· lacl. EDIVA
OHIP@ 20%
Conllngency @ 20%
ED/lJA@ 17%
Total Oa~ll•I Cos\
4,300 5,100
21,400 25,700
48,100 57.700 95,500
~ au.@
199,200 239.100 199,250
B,700 10.400
99.300 119.100 115,000
168. 700 190,500
47,800 57,400 222,200
aMJlQ fililQ
345,900 415,100 345,917
33,900 40,700
8,600 10,300
90,700 1 08,800
10,700 12,800
14,400 17,300
~ ~
47,300
95,500
26,200
168,900 202,700 168,917
714.100 856.900 •
•~2.eoo
.1ZM.Q2
1,028,300
1WillQ_
1,203,100
illAQQ'
1,028,300 .!1ilQQ.
1,203,100..
6.200
30,800
69;500
~ 286,000
'12,500
143,000
228,600
68,800
.4ilQQ
498,200
48,900
12,300
130,600
192,800
337,200 630,000
42,'iOO
90,700
11,500 17.000 4,300 0
21,400 2.1,40!) 21,400 0
3,000 3,000 48,100
1Mfil ~ ~
82,806 225,008 199,200
530033
15,400
20,700
1Mllll
243.200
·JS.800 Sacurily plus damotll & alfow
184,100
714,100 714,100
1,028,300 1,028,300
lli.§llQ 17%
1,203,100
20%0HP
20%CC
harm Is a pennanenl slruutu,e
$80,000 e~pendarum ror RW conversion
ooffe10am is terr,porary strvctur~
$ n 0,000 expeodatum for 1em,x,t31Y Works
AppendixD
ADDITIONAL SITE PHOTOS
CGvL ENGINEERS IN ASSOCIATION WITH POWELLJPBS&J
f
~
f
f
' l
f
l
\
l
\
t
I
(
1
l
Additional Site Photos
D1 ENVIRONMENTAL SETTING
D1-1 Shoreline Vegetation Upstream of Spillway
D1-2 Shallow Water Vegetation Viewing Upstream from Spillway Apron
CGvL ENGINEERS IN ASSOCIATION WlTH POWELiJPBS&J D-1
f
{
1
f
1
l
\
f
I
l
{
l
l
t
I
{
l
l
Additional Site Photos
Dl-3 Mid Lake Calavera Shoreline from Dam
D 1-4 Lake Calavera Inlet Area
CGvL ENGINEERS IN ASSOCIATION WITH POWELLIPBS&J D-2
i
{
l
t
\
l
I
\
{
(
1
{
l
{
l
Additional Site Photos
Dl-5 West Granitic Wall of Spillway Channel
D 1-6 Wetland and Disturbed Areas West of Lake from Access Road
CGv L ENGINEERS IN ASSOCIATION WITH POWELUPBS&J D-3
Additional Site Photos
D2 FACILITY DETERIORATION
l
f
f
{ D2-1 Exposed Spillway Channel Anchors
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D2-3 Spillway Channel Walls
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D2-4 Access Road Erosion North of Spillway
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D2-5 Bed Debris below Spillway Channel
D2-6 Construction Debris below Spillway Channel
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D2-7 Dam Face Erosion and Control Trenching
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D3 CALAVERA DAM AND SPILLWAY FEATURES
D3-l Downstream Face from Outlet Box at Foot of Dam
D3-2 Upstream Face and Crest from Spillway Apron
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D3-3 Rock Blanket on Upstream Face
D3-4 Flotsam/Debris at Dam
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D3-5 Walkway Abutment and Tower
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04 ACCESS ROAD
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D4-1 Security Gate at Entrance to Paved Access Road
D4-2 Spillway/Dam Access Road Turnout
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D4-3 Spillway Apron to Dam Transition Area
D4-4 Barrier Rocks on Apron/Dam Face
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05 SITES FOR FUTURE RW FACILITIES
D5-1 Calavera RWPS Site A
D5-2 CalaveraRWPS Site Bl
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D5-3 Calavera RWPS Site B2
D5-4 I/O Control Building/Candidate RWPS Site A Viewing East Towards Darn
Crest
CGvL ENGINEERS IN ASSOCIATION WITH POWELL/PBS&J D-14
Appendix E
OUTLET TOWER VIDEO SURVEY
CGvL ENGINEERS IN ASSOCIATION WITH POWELUPBS&J
Appendix E
Outlet Tower Video Survey
Date: Jane 28, 2001
Survey Crew: Everest V1T Technicians (C. Harke and J. Petty), City
maintenance personnel (2), CGvL Engineers (J. Kennedy)
Procedure & Results: Meet at City Maintenance Yard 7 AM to pick up boat,
trailer, access ladder and operations/maintenance crew. Launch boat and access
top of tower with secured ladder and safety equipment (8 -9 AM). Set up video
equipment/control and power connections between tower and dam (9 -10 AM).
EVIT technician Petty on tower to lower/retrieve camera, and EVIT technician
Harke in truck on dam to operate camera tilt/focus/swing and record video (10
AM-12:30). Remove equipment, repack, and demobilize (12:30 - 2 PM).
Taoe Count Camera Attitude and Observations
First run down interior of tower (approx. start 10:15 AM)
0-3.8 360 pan from below safety grate on top platform (el. 219.5) 3x6-in
redwood planks all intact, 3 wheel housings intact, small amount of
concrete ac·cretion/chipping on platform. Camera tilt angle varies during
the double pan (twice around interior) from 0 (straight down) past 90
(horizontal) to about130 up toward top edge of tower (el. 223), .interior
ladder intact above platform opening. Air temp. 88 F.
3.8-5.2 Camera lowered below top platform to el. 218-216 approx. Interior ladder
rungs, bars and support brackets heavily corroded, valve shafts and
support brackets heavily corroded, 6-in iron I-beams intact. ·
5.2-7.9 Check light (on/off) and camera lowered approx. el. 212 wl 360 pan of
walls, ladder and shafts ( also up/down tilt). Concrete walls look to be in
good condition but metal work highly corroded. Air temp. 90 F.
7.9-8.7 Camera lowered another foot or two. Interior ladder broken at approx. el.
210, just above upper most 18-in gate valve, redwood platform (el. 207)
almost entirely gone, 6-in iron I-beams supporting several rotted redwood
planks from above. Absent/open gate valve at el. 208' permits direct
inflow from reservoir surface level. Estimated flow of 10-20 gpm ( 100-
200 cf./hr) pouring onto a 6-in I-beam and cascading in droplets 40-45 fl
below.
8.7 -9.9 Viewing down toward mid-and lower valves/platforms below. View
somewhat obscured by cascading inflow from top portal. Ladder gone,
only some supports remain in wall. Bent ladder bars can be seen below.
Air temp. 82F.
10.0-16.2 Slow lowering of camera and close up of ladder parts and valves at
approx. el. 200. Camera lowered another 20-30 ft past mid (eJ. 201) and
lower (el.189) valves. No evidence of leakage below water line. On full
tilt, several wood planks floating on water surface below.
16.2 -20.9 Camera slowly lowered to water surface (el. 165 approx.). Several near
Outlet Tower Video Survey
water-logged wood planks from upper platforms floating on surface.
20.9-23.2 Camera submerged in 2-3 feet of standing water. Considerable amount of
slime-covered debris, presumed planking/ metal parts/other possible
components, on floor of tower (between el.160-163 approx.). Small fish
( est. 1-3-in length) observed in debris. Attempts at guiding camera into
28-in steel outlet pipe unsuccessful. Underwater pan and tilt. Water riled
up
Water temp. 78 F.
23.2-26.2 Camera brouRht back(uo) to water surface (el. 165 approx.) and shut off
Second run with bung (safety cone) inserted from boat in upper intake port (approx.
time 10:45 AM)
26.2-27.3 Camera lowered down tower interior wall adjacent to ladder. Bung plug
unsuccessful in stemming inflow. No new observations during rapid 50 ft
descent
27. -28.4 Camera reaches water level (approx. el. 165) and submerRed.
28.4 -30.2 Camera pan and tilt below water level. Extensive slime growth on debris,
fisb and other aquatic organisms, some slime on camera lens.
30.2-0.8 Stir up sediment, focus difficult. Camera pulled back up to lowet 18-in
inlet £ate valve (el. 189). View and orient toward valve.
30.8-34.8 Maneuver camera lens onto face of lower 18-in gate valve flange. Seal
looks tight, no indication of Jeaka2e. Some corrosion evident on face.
34.8-35.2 Camera up to middle 18-in inlet gate valve (el. 201). Also looks tight
with no indication of leaka2e.
35.2 -36.0 Camera uo to uooer-most 18-in ooen Rate valve oort ( el. 208).
36.0-36.6 Quick shot of bung from inside of open port, ineffectual as plug, can be
seen folded over in inlet port. More rigid bung to fit port opening required
to close inlet.
View exterior tower walls from top (approx. start 11:20AM)
36.6-37.0 Lower camera down south side tower fa ce to water line (el. 226 to 208)
37.3 -38.2 Lower camera to bottom (el. 208 to 182 approx.). Poor view of wall due
to aquatic growth in uooer 10-12ft zone and sediment at bottom,
38.2-39.2 Close up of wall on. ascent (el. 185-190 approx.) Exterior concrete waIJ
looks in good condition. Water temp 74 F.
39.2-40.4 Camera up to surface (el. 208), Abundant weed growth, unable to view
tower wall. Water temp 78 F
40.5 -40.9 Surface to below water line (el. 208) on north side, no view, extensive
weeds .end tape
Concrete Outlet Box: Submerged 8 x 5 ft concrete outlet box at downstream toe
of dam el. 158 ft (bottom) -162.5 ft (top) filled with rocks, aquatic vegetation and
small fish. Video camera entry into 30-in reinf. cone. outlet pipe below dam not
possible without removal of barrier rocks, special setup for underwater remote
control robotic camera transp01t device and effective plugging of the upper port
on the outlet tower. Outflow from box to Calavera Creek estimated at between
CGvL ENGINEERS IN ASSOCIATION WITH POWELLIPBS&J E-2
Outlet Tower Video Survey
10-20 gpm based on rough measurements of water depth and velocity over 4-inch
lip of box.
It is recommended that the outlet box be cleared of rocks and debris during
forthcoming remedial improvements to the outlet works once a cofferdam is in
place so that the outlet pipe below the dam can be drained and thoroughly
inspected for structural integrity and possible leakage.
Principal Findings:
□ 16-in concrete walls of outlet tower seem to be in reasonably good condition,
as there is little or no inctication of deterioration. Base of tower is also
presumed to yet be structuraUy sound. No indication of leakage around
plugged ports or at joints.
□ Extensive deterioration of all interior iron work (ladderj shafts, housing,
supports, eye bolts, etc. with exception of 6-in pJatform support I-beams.
□ 6-in I-cross beams look to be in good condition (extensive corrosion not
evident)
□ Nearly complete deterioration of all 3 x 6-in redwood flooring on all but top
(el. 212 ft) platform.
□ Interior access ladder missing between el. 210 ft and 195 ft due to
deterioration of 3/8 x 3-in rails, 3/8 x 18-in rungs and 3/8x 6-in (exposed)
support brackets.
o Vee 30-in diam. 1/2-in mesh exterior intake screens on below water ports are
presumed deteriorated, missing or removed.
o 18-in gate valves are presumed non-operable due to extensive corrosion of 1
1/2-in shafts, brackets and wheel housings.
□ Control wheel on lowest 12-in gate valve (el. 179 ft) is also presumed in-
operable due to coJTosion and lack of access (deteriorated ladder).
□ Extensive amounts of debris within tower base precluded direct access of
remote video equipment into 28-in steel outlet pipe below dam.
□ Presence of fish and other smalJ aquatic life forms, however, indicates
relatively open access along 260 ft outlet pipe from the downstream outlet box
□ Large rocks and other debris filling the outlet box precluded video access of
the 30-in RC outlet pipe from the downstream end.
□ Presence of small inflow/outflow through outlet tower/pipeline in late June
indicates likely hood of some irrigation-related runoff tributary from upstream
drainage area occurring throughout considerable portions of the dry weather
period.
□ Post-Inspection Finding: The outlet box was observed to have dried out
during the month of August. As no leakage was detected at the mouth of the
30-in outlet pipe into the box on September 12, the outlet pipe and joints are
believed to be in reasonably sound condition.
Video Review: Jeremy Clemmons, Powell/PBSJ; Dave Roohk and John
Kennedy, CGvL Engineers (August/September 2001)
Photo Files Following:
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OUTLET TOWER VIDEO SURVEY-JUNE 28, 2001
E-1 Video Technicians and Crew on Outlet Tower
E-2 Video Equipment Setup on Dam
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E-4 Rusted Valve Stem Housing and Broken Wheel below I-Beam (el. 222 ft)
E-5 Base of Valve Stem Housing on Top Floor with Rotted Wood Planks
(el. 219 ft)
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E-6 Remaining Wood Floor Plank with Water Entering through Top Inlet onto
I-Beam (el. 208 ft)
E-7 Same Floor Level as E-6, Viewing Toward Other Side with Rusty Stem to
Lower-Level Valve (on left)
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E-8 Viewing Down from Upper Level (el. 208 ft) to Mid-Level Plank and I-
Beam and Lower Valve, Floor Plank and I-Beam
E-9 Viewing Down Deteriorated Inside Ladder (from el. 216 ft) to Mid-Level
Valve and Remaining Planks (stems to lower valves on right)
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E-10 Viewing Down (from el. 204 ft) to 15-ft Section of Collapsed Inside Ladder
(twisted rails on left)
E-11 Interior Tower Water Surface (el. 165 ft) with Floating Wood Planks and
Other Debris.
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E-12 Broken Valve Stem (to left) and Fish (center) Near Bottom of Tower
(el.162ft)
E-13 Collapsed Flooring, Stems, and Other Debris with Fish (lower right) Near
Bottom of Tower (el. 162 ft)
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E-14 Over-flowing Outlet Box at Downstream Toe of Dam
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CGvL ENGINEERS IN ASSOCIATION WITH POWEuJPBS&J E-11
Appendix F
GEOTECHNICAL AND ENVIRONMENTAL
SERVICES
CGvLENGINEERS IN AsSOCIATION wm-iPOWELilPBS&J
PREDESIGN GEOTECHNICAL
AND ENVIRONMENTAL SERVICES
LAKE CALAVERA IMPROVEMENTS
CARLSBAD, CALIFORNIA
PREPARED FOR:
CGvL Engineers
6 Hughes, Suite 100
Irvine, California 92618
PREPARED BY:
Ninyo & Moore Geotechnical and Environmental Sciences Consultants
5710 Ruffin Road
San Diego, California 92123
September 7, 2001
ProjectNo. 104468001
571 o Ruffin Road • San Diego. California 92123 • Phone (858) 576-1000 • Fax (85B/ 57 6-9600
San Diego • Irvine • Ontario • Los Angeles • Oakland • Las Vegas • Salt Lake City • Phoenix
$if£Jr,i;;i,i~~7~B,;JV!!J7Nf) &~~ffi\W:lt:ci\ ~;-"'•~:~.1f,;.;;--___ .... · · -~ ,f<,),· · .,~ ,, "~ ·"" · ---. -'IJJ/6/i ~ 1~'l!.IU \2S jt---~~ --~"• ., ~--:r,; ~~---~ ---
~ =LW ;µ; ZF. CS.z:G ...j •
Geotecnnfcal and Envrronrnemal Sciences Consuli;;ncs
Mr. Dave Roohk
CGv L Engineers
6 Hughes, Suite 100
Irvine, California 92618
September 7, 2001
Project No. 104468001
Subject: Predesign Geotechnical and Environmental Services
Lake Calavera Improvements
Carlsbad, California
Dear Mr. Roohk:
In accordance with your request, we have prepared a predesign geotechnical and environmental
evaluation of the Lake Calavera site. Transmitted herewith is our report that presents our find-
ings, conclusions, and recommendations regarding the proposed improvements.
We appreciate the opportunity to be of service. If you have any questions or comments pertaining
this rep01i, please contact the undersigned at (858) 576-1000.
Respectfully submitted,
NINYO & MOORE
Nathan A. Ash
Senior Staff Geologist
NAA/RJ/kmf
~~
Randal L. Irwin, C.E.G.
Chief Engineering Geo lo gist
57 IO Ruffin Road • San Diego, California 921 23 • Phone /858) 57 6· 1000 • Fax /858} 57 6-9600
San Diego • Irvine • Ontario • Los Angeles • Oakland • Las Vegas • Salt Lake Oty • Phoenix
CGvL Engineers
Lake Calavera Improvements, Carlsbad
APPENDIXF
TABLE OF CONTENTS
September 7, 200 I
Project No. 104468001
Page
1. INTRODUCTION .................................................................................................................... 1
2. SCOPE OF SERVICES ............................................................................................................ 1
3. GEOLOGIC RECONNAISSANCE AND SOIL SAMPLING ................................................ 1
4. GENERAL SITE CONDITIONS ............................................................................................. 2
5. BACKGROUND AND PROPOSED IMPROVEMENTS ...................................................... 3
6. GEOLOGIC RECONNAISSANCE AND SOIL SAMPLING ................................................ 4
6.1 . Earth Materials .............................................................................................................. 4
6.1.1. Artificial Fill ....................................................................................................... 4
6.1.2. Marsh Deposits .................................................................................................... 5
6.1.3. Granitic Rock ...................................................................................................... 5
6.1.4. Santiago Formation ............................................................................................. 5
6.2. Laboratory Testing ........................................................................................................ 6
6.3. Groundwater and Reservoir Water ............................................................................... 6
6.4. Faulting and Seismicity ................................................................................................ 6
7. ENVIR.ONMENTAL EVALUATION ..................................................................................... ?
7 .1. Water Sampling and Water Column Profiling ................................................. , ............ 7
7. 1. 1. Water Sampling and Laboratory Analysis .......................................................... 7
7.1.2. Water Column Profiling ...................................................................................... 9
7.2. Environmental Sediment Sampling ............................................................................... 9
7.3. Reservoir Bottom Profiling ........................................................................................... 9
8. · DISCUSSION, CONCLUSIONS, AND RECOMMENDATIONS ...................................... 10
8.1. I/0 Controls Building ................................................................................................. 10
8.2. Spillway Cbannel ......................................................................................................... 10
8.3. Access Road ................................................................................................................ 11
8.4. Outlet Tower Cofferdam and I/O Pipeline ................................................................. 12
8.5. Constructed Wetlands .................................................................................................. 12
8.6. Environmental and Water Quality Assessment .......................................................... 13
9. LIMITATIONS ....................................................................................................................... 14
10. SELECTED REFERE'NCES .................................................................................................. 15
Tables
Table 7-1 -Water Quality Test Data ................................................................................................ 8
Table 7-2 -Water Column Profile Field Data ................................................................................. 9
Illustrations
Figure 1 -Site Location Map
Figure 2 -Site Plan
Figure 3 -Topographic Map
l(ln901scl(t.oo~e
CGv L Engineers
Lake Calavera Improvements, Carlsbad
September 7, 2001
Project No. 104468001
Attachments
Attachment FA
Attachment FB
Soil Sample Laboratory Testing Results
Water and Sediment Sample Laboratory Testing Results
II
CGvL Engineers
Lake Calavera Improvements, Carlsbad
1. INTRODUCTION
September 7, 2001
Project No_ 104468001
In response to your firm's request, we are pleased to submit this predesign geotecbnical and envi-
ronmental evaluation report for the subject project. The purpose of our study is to assess the
general geological and geotecbnical conditions in the Lake Calavera area as well as perform a
limited environmental assessment related to both remedial and proposed future improvements at
the site.
We understand that the remedial projects will involve construction of a temporary cofferdam to
facilitate modifications to the existing outlet tower, construction of a new laid-back inlet/outlet
(I/O) pipeline and abutments on the upstream dam face, construction of a 150 square-foot I/O
controls building on the downstream terrace edge of the earthfill dam, repair of and improve-
ments to the spillway channel, access road improvements, utilities installation, and fencing. An
initial environmental assessment of water and sediment samples collected from the reservoir and
creek mouth was also made. Proposed future projects at Lake Ca1avera might include an up-
stream constructed wetlands, a reservoir re-aeration-destratification system, and post-storage,
downstream treatment facilities.
2. SCOPE OF SERVICES
Based on our discussions with your fum and our Proposal No. P-5150, dated June 13, 2001, we
performed.the following scope of services:
3. GEOLOGIC RECONNAISSANCE AND SOIL SAMPLING
• Review of background information including available geotechnical reports, geologic and
topographic maps, and stereoscopic aerial photographs.
• Geologic field reconnaissance of the site with emphasis on the areas of the proposed I/0
control building, tower cofferdam and pipeline abutments, spillway channel improvements,
access .road and utilities, as well as possible future facilities at the upstream end of the reser-
voir.
• Co1lection of soil samples (2 bulk samples) at selected locations in the areas of the proposed
control building and upstream constructed wetlands for preliminary geoteclmical testing.
Testing included sieve analysis, Atterberg limits, and Expansjon Index. Samples were col-
lected with hand equipment by geologists from Ninyo & Moore.
'146!•Rlr.doc. 1
CGvL Engineers
Lake Calavera Improvements, Carlsbad
September 7, 2001
Project No. 104468001
• Depth profiling at selected locations, from the outlet tower to the upstream end of the reser-
voir and back using an electronic depth finder and manual soundings. Access was gained
using a small watercraft. Depths were measured to the nearest foot from water surface to
bottom (Figure 2).
• Collection of three water quality samples, for designated analytical laboratory analyses.
Samples were obtained at depths of 3, 12, and 22 feet below the water surface adjacent to the
outlet tower.
• Analytical profiling of the water column near the outlet tower with respect to dissolved oxy-
gen (DO), temperature, pH, electrical conductivity (EC), and total dissolved solids (TDS).
Readings for the profile were takep at approximately 5-foot increments from surface to bot-
tom. The results of the profiling are presented in Section 7.1.2.
• Collection of a sediment sample from the upstream end of the reservoir, for designated
chemical analysis. The test results are discussed in Section 7 .2.
• Preparation of this predesign geotechnical and environmental evaluation report, which pro-
vides our :findings and preliminary conclusions and recommendations regarding the proposed
improvements. The report addresses geotechnical issues such as general geologic conditions,
potential geologic hazards, and a preliminary assessment of the suitability of on-site earth
materials for the construction of the proposed improvements. Also included are the results of
a limited initial environmental assessment.
4. GENERAL SITE CONDITIONS
The project site is located at Lake Calavera, a dam and reservoir storage system situated in
northeastern Carlsbad, San Diego County, California. The site includes Calavera Dam, the reser-
voir, dam spillway, tributary lands immediately upstream, and access roads (Figure 2). The
-earthfill dam is 65 feet high~ 20 feet wide at the crest, and 490 feet in length. It has historically
been used for capture and storage of surface water runoff. A dirt access road extends across the
axis of the darn and connects with a paved road l 00 feet west of the dam. The dam was con-
structed of compacted earth fi]l with rock blankets placed on both the upstream and downstream
faces.
The spil1way is located on the west side of the dam and extends roughly 500 feet in a north-south
orientation. The spillway elevation at the crest is 216.5 feet relative to mean sea level (MSL).
The east wall of the spillway is a roughly 1.5:l (horizontal:vertical) slope that has been coated
with gunite from the north end roughly 250 feet south. The remainder of the east wall is native
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CGvL Engineers
Lake Calavera Improvements, Carlsbad
September 7, 2001
Project No. 104468001
rock. The west wall of the spillway is an approximately 1:1 (horizontal:vertical) slope composed
of native rock. The base of the spillway is gently to moderately sloping toward the south and is
composed ,of granitic rock. A 63-foot tall reinforced concrete tower structure is located on the
north end of the submerged dam slope and is connected to an outlet pipe that passes below the
base of the dam. The pipe outlets into a concrete box located at the downstream base of the dam
(Figure 2).
Lake Calavera constitutes an unlined, uncovered, reservoir created upstream (northeast) of
Calavera Dam. The reservoir currently has approximately 28 feet of depth with a surface area of
20 acres. When full; it ha.s a maximum depth of 36 feet with a water surface area of 26 acres
(CGvL, 2001). The upstream end of the reservoir terminates in a marshy area at the mouth of upper
Calavera Creek. The dam crest elevation is 223 feet MSL and the maximum operating pool is 220
feet MSL. The water surface elevations typically range between 206 and 216 feet MSL (CGvL,
2001) and was measured during the fieldwork for this study at 208 feet MSL, using the top of the
outlet tower as a reference point.
5. BACKGROUND AND PROPOSED IMPROVEMENTS
Calavera Dam was built in the early 1940's by the Carlsbad Mutual Water Company to capture
surface runoff from the upper Calavera Creek watershed for storage in a 520 (acre-feet) AF res-
ervoir. The water was originally used for delivery to the Company's coastal service area. The
delivery system included several water supply wells, a pipeline system, and a water treatment
plant. The transmjssion system and water treatment plant have not been in use since their aban-
donment in the 1960's. Lake Calavera has since been used for limited stormwater protection,
flood control, and passive recreational pursuits.
It is our understanding that the proposed remedial improvements at the reservoir include con-
struction of a 150 square-foot I/0 control building located on the downstream terrace edge of the
dan1, construction of a cofferdam to facilitate repair of the existing outlet tower and new I/0
pipeline and abutments, repairs and improvements to tbe spillway, construction of an access road
connecting with the paved access road to the west of the dam and extendi,ng along the crest of the
darn (Figure 2), and fencing portions of the site for improved security
3
CGvL Engineers September 7, 2001
Project No. 104468001 Lake Calavera Improvements, Carlsbad
In addition, several future improvements related to conversion of the reservoir for reclaimed
water use have also been considered. These include a possible constructed wetlands system up-
stream of the reservoir and new water quality control facilities in the vicinity of the existing
outlet tower.
6. GEOLOGIC RECONNAISSANCE AND SOIL SAMPLING
Geologic reconnaissance of the dam was performed by a geologist from our firm and included
review of background information including available geotechnical reports, geologic and topo-
graphic maps, stereoscopic aerial photographs and a limited field reconnaissance. The
reconnaissance was performed in the area of the spillway, upstream and downs.tream dam faces,
and upstream. Bulk soil samples were taken in the area of the proposed I/0 control building and
near the mouth of Calavera Creek, upstream of the reservoir, for designated laboratory testing.
Laboratory tests performed on the samples included sieve analysis, Atterberg limits, and Expan-
sion Index.
6.1. Earth Materials
Earth materials encountered during our geologic reconnaissance and mapped by Tan and
Kennedy (1996) include artificial fill1 marsh deposits, weathered and decomposed granitic
·rock assigned to the Green Valley Tona:Iite, and Santiago Formation. Generalized descrip-
tions of the units are provided below. The soil samples were classified in accordance with the
Unified Soil Classification System (USCS).
4-'61-Rlt,dac
6,1 .1. Artificial Fill
Artificial fill material was encountered in the area to the north and west of the dirt ac-
cess road where it meets the paved road (Figure 2). Thickness of fill in these areas is on
the order of several feet and may not have been placed as compacted fill. A fill berm has
been constructed at the north end of the spjllway that is approximately 4 feet high. In gen-
eral, fill material consists of brown, damp to moist, silty and clayey sand with gr<!vel
These fills are likely improperJy compacted and unsuitable for the support of structures
or compacted fill.
4
CGvL Engineers September 7, 2001
Project No. 104468001 Lake Calavera Improvements, Car1sbad
4~6S-R..1r,Joc
The dam structure also consists of compacted fill material containing upstream and
downstream face rock blankets (CGvL, 2001). The dam was not observed to exhibit any
noticeable seepage, piping, or major settlement and the fill used for dam construction
' has performed well for its intended purpose. Several minor erosion features were ob-
served, mainly on the upstream crest of the dam, and are likely related to the presence
of the access road along the crest of the dam. The limits of darn fill above the water line
are presented on Figure 2.
6.1.2. Marsh Deposits
Marsh deposits were encountered in the vicinity of the mouth of Calavera Creek in
boring HB-2. Marsh deposits consist of dark grayish brown to nearly black organic clay
and organic clayey sand and contain abundant roots and organic debris. Marsh deposits
are wet to saturated and very soft or very loose. Marsh deposits in their present condi-
tion have very limited suitability for the support of compacted fill, structures, or use as
compacted fil1.
6.1.3. Granitic Rock
Granitic rock assigned by Tan and Kennedy (1996) to the Cretaceous-age Green Valley
Tonalite was encountered and/or is mapped as underlying the majority of the site in-
cluding the areas of the spillway, dam, access road, and portions of the reservoir.
Granitic rock ranges from relatively unweathered to decomposed. Decomposed granitic
rock is composed of brown to slightly reddish brown, dry to damp, loose to dense, silty
fine sand. The decomposed granite was observed to be locally highly erodable in some
areas of the spillway. In general, the less weathered granitic rock was more resistant to
erosion, however, the rock may have difficult rippability. In general, the granitic rock is
suitable for the support of structures and compacted fill.
6.1.4. Santiago Formation
Fonnational sediments assigned by Tan and Kennedy (1996) to the Tertiary-age Santi-
ago Formation are mapped north of the dirt access road and as underlying the majority
of the reservoir and upstream areas at depth. Tan and Kennedy (1996) descrih~ the San-
5
CGvL Engineers
Lake Calavera Improvements, Carlsbad
September 7, 2001
Project No. 104468001
tiago Formation as light-colored, poorly-bedded, poorly-indurated, fine-to medium-
grained sandstone interbedded with siltstone and claystone.
6.2. Laboratory Testing
Soil samples were collected during our field exploration using hand tools in the location of
the proposed I/0 control building, and upstream of the reservoir, near the mouth of Upper
Calaveras Creek. (Figure 2). Laboratory tests performed by Ninyo & Moore included sieve
analysis, Expansion Index, and Atterberg limits. The results of these geotechnical engineer-
ing tests are provided in Attachment FA.
6.3. Groundwater and Reservoir Water
Groundwater was en.countered near the surface in boring HB-2 excavated for this study and
was not observed in HB-1. Groundwater levels may be expected to fluctuate due to seasonal
variations, water usage, and other factors. Proposed drainage or draw down of portions of the
reservoir may affect 'the groundwater conditions in the immediate vicinity of the water con-
trol structures.
Reservoir surface water levels fluctuate due to increases or decreases in runoff fr.om the wa-
_tershed. Reservoir water levels (especially exceptionally high levels) may effect access to
the proposed improvements or create hazardous condit1ons. Evidern;:e of seepage or piping
was not observed in the vicinity of the earthen dam.
6.4. Faulting and Seismicity
Based on our field observations, and review of pertinent geologic data and stereoscopic aer-
ial photographs, mapped faults are not located on or in the near vicinity of the site. The
closest known active faults are the Rose Canyon fault zone, located approximately 6 miles
west of the site, the Elsinore fault zone, located about 22 miles east of the site, and the
Coronado Bank fault, located 25 miles west of the site (Jennings, 1994). Portions of the
Rose Canyon fault zone are mapped as being within State of California Earthquake Fault
Zones. The Lake Calavera site is not located in an Earthquake Fault Zone.
t46&·RJr.doc 6
CGvL Engineers September 7, 2001
Project No. 104468001 Lake Calayera Improvements, Carlsbad
The most significant seismic event likely to affect the proposed facilities would be a maxi-
mum moment magnitude 6.9 earthquake along the Rose Canyon fault zone (Califonria
Division of Mines and Geology [CDMGJ. 1998). According to the 1997 Uniform Building
Code (UBC) (International Conference of Building Officials [ICBO), 1997) and the CDMG
(1998), the Rose Canyon fault zone is classified as a "B" seismic source type. The site is lo-
cated within UBC Seismic Zone 4, but is not located within a UBC Near-Source Zone for
active faults.
Based on a Probabilistic Seismic Hazard Assessment for the Western United States, issued
by the United States Geological Survey (USGS) (1999), the project site is located in a zone
where the horizontal peak ground acceleration having a 10 percent probability of exceed-
ance in 50 years :is 0.27g (27 percent of the acceleration of gravity) and a 5 percent
probability of exceedance in 50 years is 0.4 l g. The requirements of the governing jurisdic-
tions and the practices of the Structural Engineers Association shou1d be considered in the
design of the structure.
7. ENVIRONMENTAL EVALUATION
Water samples were collected near the outlet tower for laboratory water quality analysis (Fig-
ure 7). A water column profile was also performed near the outlet tower. A -sediment sample
from upstream was collected for designated chemical analysis.
7.1. ,vater Sampling and Water Column Profiling
Specific laboratory analyses of the water, and sediment samples collected at the site are pre-
sented below and laboratory data are presented in Attachment FB.
4468-R.lr.doc
7.1.1. Water Sampling and Laboratory Analysis
Water samples were collected in the vicinity of the out1et tower at depths of 3, 12, and 22
feet below the water surface using a submersible sample pump. Laboratory analysis in-
cluded tests for chemical oxygen demand, tota1 phosphate, nitrogen (Kjeldahl), nitrogen
(nitrate), total dissolved solids, total alkalinity, hydroxide alkalinity, carbonate alkalinity, bi-
carbonate alkalinity, stdfate, chloride, calcium, magnesium, sodium, potassium, turbidity,
7
CGvL Engineers September 7, 2001
Project No. 104468001 Lake Calavera Improvements, Carlsbad
4(68-RIT,doc.
total coliform count, fecal colifonn count, and color. Laboratory test results are summarized
in Table 7-1.
Table 7-1 -Water Quality Test Data
Test Run: Sample3 Result Sample 12 Result Sample Result
(m2'f) (~l!fl) 22 (mg/£)
Chemical Oxygen Demand 42.8 53.2 75.8
Phosphate, Total 0.23 2.48 3.43
Nitrogen, Kjeldabl 1.17 1.54 15.3
10.4 as 12.2 as
Nitrogen, Nitrate ND
NO3 NO3
Total Dissolved Solids, IDS 2570 3190 3190
Alkalirnty, Total 219 248 268
Alkalinity, Hydroxide 0 0 0
Alkalinity, Carbonate 0 0 0
Alkalinity, Bicarbonate 267.2 302.6 327
Sulfate 537 634 556
Chloride 969 1234.3 1275.1
Calcium 297 365 365
Magnesium 119 145 147
Sodium 404 500 499
Potassium 17.1 22.7 23.2
Turbidity (NTU) 11.3 34 40
Coliform, Fecal 8 4 2
(MPN/100ml)
Coliform, Total 300 50 13
I (MPN/1 OOm])
Color Test pH Dominant Wave-Luminescence Purity
lenlrth (%) (%)
Sample 3 8.3 553 99.1 10
7.6 553 98.7 10
Sample 12 7.8 540 98.8 10
7.6 540 98.7 10
Sample 22 8.1 700 92.1 10
7.6 700 92.5 10
8
l(in9o&l(loore
CGvL Engineers September 7, 2001
Project No. 104468001 Lake Calavera .Improvements, Carlsbad
7.1.2. Water Column Profiling
A profile of the water column was performed in the vicinity of the outlet tower using a
Horiba™ U22 instrument at 5-foot depth increments from the water surface to near the
bottom. Parameters measured included dissolved oxygen, temperature, pH, electrical
conductivity, and total dissolved solids. A summary of field data collected with this in-
strument is presented in Table 7-2.
Table 7-2 -Water Column Profile Field Data
Water Dissolved Oxygen Temperature pH Conductivity T.D.S.
Depth (m!!/l} (°C) (Siem) (elf)
25 0.00 13.2 7.23 4.71 3.2
20 0.00 13.3 7.23 4.95 3.2
15 0.12 14.8 7.19 5.02 3.2
10 0.65 21.7 7.25 4.85 3.0
5 8.73 24.5 8.07 4.04 2.6
0 10.43 25.0 8.19 3.98 2.5
7.2. Environmental Sediment Sampling
Sediment samples were collected, for designated environmental laboratory analysis, in boring
HA-2 using a hand auger. Laboratory tests performed on the sediment sample included Ti-
·ue 22 metals, EPA 8081&8082 (PCBs/Pesticides), EPA 8260B (volatile organics), and EPA
8270C (semi volatile organics). Laboratory test results indicate that the con~entrations of harm-
ful po Uutants in the soil in the marsh sediments at the mouth of upper Calavera Creek, where
observed, were either below detectable limits or in innocuous concentrations. Laboratory re-
sults are presented in Attachment FB.
7.3. Reservoir Bottom Profiling
Reservoir water depths were measured from the water surface to the bottom using an elec-
tronic depth finder and manual soundings. Depth measurements were performed at various
locations throughout the reservoir. Depths ranged from 3 to 28 feet, with the deepest por-
tions of the reservoir in the vicinity of the outlet tower. Depth measurements are presented
on Figure 2.
4 ~ 68-R l r,doc 9
CGvL Engineers
Lake Calavera Improvements, Carlsbad
8. DISCUSSION, CONCLUSIONS, AND RECOMMENDATIONS
September 7, 2001
Project No. 104468001
Based on our review of background information, limited geologic reconnaissance, water, soil,
and sediment laboratory analysis, field data collection, and our understanding of the project~ we
present the following conclusions and recommendations. Specific grading plans for the proposed
remedial works were not available at the time of this report. Comments regarding observations
made during our geologic field reconnaissance are presented in Figure 3.
8.1. 1/0 Controls Building
The area of the proposed VO controls building is mapped by Tan and Kennedy (1996) as
being underlain by granitic rock. Limited subsurface evaluation from boring HB-1 and geo-
logic reconnaissance indicate that there is likely a few feet_ of poorly developed topsoil grading
into decomposed and weathered granitic rock. Laboratory testing from boring HB-1 indicates
that the topsoil is composed of silty sand that is loose to medium dense3 non-plastic, and has
an Expansion Index of very low (approximately zero). Plans showing the exact proposed lo-
cation of the new bu-ilding were not available at the time of this report. A portion of the area
may be underlain by fill materials associated with dam construction. Fill material may not be
suitable for the support of the structure and shou]d be evaluated along with more detailed
subsurface analysis of the building site during the design phase of the project. Remedial
. grading for the topsoil will also be needed.
8._2. Spillway Channel
The area of the existing spillway channel is mapped by Tan and Kennedy (1996) as being
underlain by granitic rock. A detailed description of the condition of the spillway is pre-
sented on Figure 3. Field reconnaissance and "As-Constructed" building plans for the dam
(Carlsbad Mutual Water Company, 1941) indicates that the east wall of the spillway chan-
nel is coated with 3 inches of gunite reinforced with double 4" x 4" #6 netting. The gunite
section of the east spillway wall extends for approximately 240 feet and has a slope of 1: 1
(horizontal:vertica1). Visual inspection of the gunite slope indicates that the gunite is in
relatively good condition and is functioning to protect the channel wall as intended. The
gunite terminates roughly 55 feet south of the projected dam access. The east wall south of
446S•Rlr.doc 10
CGvL Engineers
Lake CaJavera Improvements, Carlsbad
September 7, 2001
Project No. 104468001
the gunite area is composed of intensely weathered to decomposed granitic rock with slopes
ranging from 1:1 to 1/2:1 (horizontaJ:vertical). The east wall has been eroded around the
gunite in the area of the gunite/native transition and void space exists behind 1he gunite. The
east wall continues south of the gunite area for roughly 260 feet. The wall is locally highly
eroded and shows indications of sloughing and backcutting.
The bottom of the spillway channel is composed of moderately weathered to decomposed
granitic rock. The rock is jointed in some areas and joints are locally nearly vertically ori-
ented. The spillway channel is crossed by two 1.5 foot by 2.5 foot concrete cutoffs. The roc)c
has been eroded around the cutoffs and void space exists below the cutoffs. Erosion gullies
have formed in several locations along the spillway channel indicating that the bottom of the
spillway channel is locally highly susceptible to continued erosion. Several areas of the
spillway channel are partially blocked with piles of construction debris.
The west wall of the spillway channel is composed of moderately to intensely weathered and
eroded granitic rock. The wall was originally constructed as a 1/2:1 (horizontal:vertical)
slope, but erosion has oversteepened portions and cut back others. Proposed improvements
to the spillway channel may extend as far as from 300 feet south of the centerline of the dam
to the convergence of the spillway and Calavera Creek. Granitic rock along this stretch of
. the spillway is moderately to intensely weathered or decomposed and can be highly
erodable. Erosion gullies and bank cutbacks were observed, especially along the east wall of
the channel. The channel also contains thick vegetation and debris in some areas. The spill-
way channel should be further evaluated to provide recommendations for repair and erosion
mitigation.
8.3. Access Road
The existing dirt access road extends from the asphalt road west of the dam, southward
across the spillway then continues east along the dam crest (Figure 2). The northernmost
portion of the dirt road, near the intersection with the asphalt road, is likely underlain by
several feet of undocumented fill material (Figure 3). This fill may not be suitable for sup-
port of the proposed new access road and should be further evaluated. The pro.posed location
11
CGvL Engineers
Lake Calavera hnprovements, Carlsbad
September 7, 2001
Project No. 104468001
of the new access road is plotted as extending onto the crest of the dam and extending to the
east, terminating with a turnaround at the east end of the dam. The approach to the dam from
the existing dirt road is mapped as being underlain be granitic rock and may be suitable for
placing fill or retaining walls for a dam access ramp. The majority of the road will be un-
derlain by the fill material composing the dam. These areas should also be further evaluated
as part of the design phase.
8.4. Outlet Tower Cofferdam and 1/0 Pipeline
Proposed pipeline improvements include construction of a new 24-inch steel I/0 pipeline
extending from the base of the existing outlet tower to approximately 2/3 of the way up the
north dam face. The pipeline will likely be constructed with typical pipe abutments. Toe face
of the dam is underlain by an existing 3-foot thick rock blanket with rocks ranging in size up
to approximately 2 -3 feet in diameter. The rock blanket m its present condition could be pro-
hibitive to construction and measures for its removal/replacement should be evaluated.
Proposed I/0 improvements may be facilitated by the construction of a coffer dam, or series
of coffer dams in the vicinity of the existing outlet tower. Constraints to construction may
include the existence of the rock blanket beneath at least a portion of the proposed location,
possible significant thicknesses of soft, unstable lake depositsi and possible hard underlying
granitic bedrock, as well as access and environmental issues. Further evaluation of the pro-
posed coffer dam location is recommended during design.
8.5. Constructed Wetlands
A series of wetland cells have been considered as part of a future recycled water conserva-
tion concept plan; extending for approximately 1,700 feet to the northeast immediately
upstream of the existing reservoir. Laboratory testing of samples taken from this upstream
area indicate that the soil, in its present condition_, is not suitable for the support of structures
or compacted fill and has limited suitability for use as compacted fill. Construction of
berms, levees, etc. would likely involve the import of significant quantities of fiil material.
-446S.-Jt"Jrdoc 12
CGv L Engineers
Lake Calavera Improvements, Carlsbad
8.6. Environmental and Water Quality Assessment
September 7, 200 l
Project No. 104468001
The water quality data collected provide some general information regarding reservoir water
quality characteristics. However, the conclusions that can be drawn from these data are in-
herently limited due to sampling and analysis uncertainties (e.g. accuracy and precision),
interpretation of water quality objectives, and the fact Lake Calavera is a dynamic system
that constantly reacts to changes in the physical, chemical, and biological environment. A
much better understanding of reservoir water quality would be provided br a more rigorous
and extensive sampling and analysis program that addresses seasonal variations as well as
sampling locations. The sampling and analysis of sediment and upland soil should also be a
part of additional studies regarding water quality or the preparation of a water quality man-
agement plan for the reservoir, if necessary.
The following general comments are based on a comparison with various water quality pa-
rameters and objectives for inland surface waters as presented in the Water Quality Control
Plan, San Diego Basin (9), prepared by the California Regional Water Quality Control
Board, San Diego Region (1994). The Basin Plan presents beneficial uses and water quality
objectives intended to be protective of those uses,
The presence of dissolved oxygen (DO) is essential in maintaining aquatic life and aesthetic
-qualities of the lake water. Thus, DO is an important indicator of overall water quality. The
lack of DO near the bottom of the reservoir is likely due to oxygen consumption at the sedi-
ment water interface associated with bacterial decomposition of organic matter and elevated
coocentrations of mineral and organic nutrients. Anaerobic decomposition of organic matter
:is also supported by the presence of a strong noxious odor (hydrogen sulfide?) noted during
collection of the bottom water samples. The mineral and organic nutrients are likely con-
tributors to the elevated turbidity and total dissolved solids found in the water samples. Due
in part to the thermal stratification of the reservoir, as evidenced by the significant decrease
in temperature between 10 to 15 feet beneath the lake surface, oxygen replenishment is
minimal. Thus, anoxic conditions will likely continue until thermal stratification breaks
down in the cooler Autt.imn months.
446S-Rlr,doc 13
CGvL Engineers
Lake Calavera Improvements, Carlsbad
Septembe; 7, 2001
Project No. 104468001
Elevated total phosphate in the water samples suggests that control of phosphate may be a
major concern in managing the water quality of the reservoir. Excess phosphate can stimu-
late plant growth in nuisance quantities.
The range in pH of the water indicates neutral to slightly alkaline conditions. These condi-
tions are supported by the alkalinity values of the samples, which indicate that the water has
adequate neutralizing capacity that wou1d act as a buffer against large variations in pH.
Total and fecal coliform concentrations do not indicate a significant contribution of bacteria
from natural sources, stonnwater pollution or sewage spills.
9. LIMITATIONS
All of the data and conclusions obtained are preliminary and related to a limited scope of field
reconnaissance and laboratory analyses. Additional studies will be necessary to provide geotech-
nical design parameters and possible environmental mitigation measures concerning the
recommended remedial improvements for Lake Calavera
H68-R.I r.doc. 14
CGvL Engineers
Lake Calavera Improvements, Carlsbad
10. SELECTED REFERENCES
September 7, 2001
Project No. 104468001
California Division of Mines and Geology (CDMG), 1998, Maps of Known Active Fault Near-
Source Zones in California and Adj acent Portions of Nevada: International Conference of
Building Officials.
California Regional Water Quality Control Board, San Diego Region, 1994, Water Quality Con-
trol Plan San Diego Basin (9): dated September 8.
Car1sbad Mutual Water Company, 1941, "As Constructed" Lake Calavera Dam Plans: dated
September.
CGvL Engineers,2001, Lake Calavera Improvements Preliminary Design Report: draft dated
May.
County of San Diego, 1958, Topographic Survey, Sheet 214-1773: scale 1'' = 200': dated July.
County of San Diego, 1973, Ortbotopographic Survey, Sheet 214-1773: scale l'' = 200': dated
June 14.
Iotemational Conference of Building Officials (ICBO)~ 1997, Uniform Building Code: Whittier, Cali-
fornia
Tan,· S.S., and Kennedy, M.P.,. 1996, Geologic Map of the Oceanside, San Luis Rey, and San
Marcos 7.51 Quadrangles, San Diego County, California: California Division of Mines.
and Geology Open-File Report 96-02.
AERIAL PHOTOGRAPHS
. Source Date Flight Numbers ScaJe
USDA I 4/14/53 I AXN-9M I 158 & 159 I 1:20,000
15
l
N
1900 0 1900 3800
Approximate Scale in Feet
REFERENCE: 2001 THOMAS GUIDE FOR SAN DIEGO COUNTY, STREET GUIDE AND DIRECTORY A
SITE LOCATION MAP
LAKE CALAVERA IMPROVEMENTS
CARLSBAD, CALIFORNIA
_P_A_O_J E_C_T_N_O_.---+-__ D_AT_E_----1 (
104468001 8/01 ,
FIGURE
1 )
l
(
' [
\
{
4468001ph
BASE: FUTURE AERATION/OE-STRATIFICATION SYSTEM CONCEPT. CGVL ENGINEERS, CITY OF CARLS8AD, UNDATED
0
~HB-2
015
LEGEND
Location of Ninyo & Moore
hand borings
Sounding Location with
depth to bottom below waler
surface (208')
Limits of Existing Dam, fill
above water line
N
A
200 400
Approximate Scala in Feat
SITE PLAN
... -M/nua& ~oo .. e._.... LAKE cALAVERA IMPRovEMENrs I,. ii" • J • -CARLSBAD, CALIFORNIA ;::::======--==~ PROJECT NO.___ DATE ( FIG
2
URE )
104468001 8/01 _ _
0 "-,g
f8 ,.,, ...
zzs-+-----Kgr
af
Qal
QI
Tsa
Kgr
Artificial RII
Quaternary Alluvium
Quaternary Lake Deposits
Tertiary Santiago Formation
Cretaceous Granitic Rock
r
Kgr
LEGEND
----Approximate geologic contacts ••••••
• • • • Approximate limits of erosional features .. ,.
7la._ Strike and dip of bedrock jointing
H B-1 0 Location of hand boring
22b • Original soil boring locations
-
BASE: CALAVERA DAM, CARLSBAD MUTUAL WATER COMPANY, DATED SEPT. 1941
" r TOPOGRAPHIC MAP
0 80 160
Jfln90&1ft1111--re LAKE CALAVERA IMPROVEMENTS
CARLSBAD, CALIFORNIA ... ~--Approximate Scale in Feet
( PROJECT NO. DATE JC FIGURE
\.. ~ \ 104468001 8/01 3
El.
...
~
)
Figure 4 Lake Calavera Depth Profile 210 -,--------------------------,
U)
~ 195 ~-------------------------------~
;:t=
c
0 += ~ 190--+-+--------~~---------------------i
(l)
w
175 -+--------,.----..-------.-----~----,--------l
0 500 1,000 1,500 2,000 3,000
Distance U/S of Dam, ft
Figure 5 Lake Calavera Water Quality Profile
(/) @ 198 --i---71f---~-------tl~-----ffi-----------------7'!f------;
;t=
c
0 += 0 a; 193 -ir---~~-....,_---m-------------g...--------------t
LLJ
~Temp
--&-pH
188 -4------------1E----lfr----------H-l-------,__------------j -6.-EC
--¾--TDS
_,._DO
183 -~--~~-A-,----fll----,-------e-----,----------.------------;
0 5 10 15 20 25
Water Quality Parameter Value, units
CGvL Engineers
Lake Calavera Improvements, Carlsbad
ATTACHMENT FA
September 7, 2001
Project No. 104468001
SOIL SAMPLE LABORATORY TESTING RESULTS
Classification
Soils were visually and texturally classified in accordance with the Unified Soil Classification
System (USCS) as described in ASTM D2488-93.
Gradation Analysis
Gradation analysis tests were performed on selected soil samples in general accordance with
ASTM D 422-63. The grain-size distribution curves are shown on Figure F-1 and F-2. The test
results were utilized in evaluating the soil classifications in accordance with the Unified Soil
Classification System.
Ex_pansion Index Tests
The expansion index of selected materials was evaluated in general accordance with U.B.C.
Standard No. 18-2. Specimens were molded under a specified compactive energy at approxi-
mately 50 percent saturation (plus or minus I percent). The prepared 1-incb thick by 4-inch
diameter specimens were loaded with a surcharge of 144 pounds per square foot and were inun-
dated with tap water. Readings of volumetric swell were made for a period of 24 hours. The
results of these tests are presented on Figure F-3.
Atterberg Limits
Tests were perfonned on selected fine-grained soil samples to evaluate the liquid limit, plastic
limit, and plasticity index in general accordance with ASTM D 4318-95. These test results were
utihzed to evaluate the soil classification in accordance with the Unified Soil Classification Sys-
tem. The test results and classifications are shown on Figure F-4.
4468-R I do<:
GRAVEL SAND FINES
Coarse Fine Coarse Medium Fine Silt Clay
U.S. STANDARD SIEVE NUMBERS HYDROMETER
3' 1-112· 1· 314• 1/2" 318' 4 8 16 30 50 100 200
100
90
80
I I T I T I -~ I I I
I I ' ' '
I I I I I I I 1\1 I I
I I I 1' I I
I I I I I I I I I I
I-70 :c Cl UJ 60 ~ > a,
Cl'. 50 w z u:
'z 40 w Ll Cl'. w 30 C.
II I I l I ~~ I I
I I I I I I I I I I I
I I I I I I I I I r-... I I
:1 I I I I I ' I I
I I I I I I I I I '\ I I
I I I I I I
I I I I I I I I I ' I
I I I I I I
I I I I I I I I I I I
20 I I I I I I
10 I I I I I I I I I I I
I I I I I I I I I I I
0 I I I I I
100 10 0.1 0,01 0.001
GRAIN SIZE IN MILLIMETERS
Symbol Hole No. Depth Liquid Plastic Plasticity
(ft) Limit Limit Index
• HB-1 0-1.0 ---
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422-63
JVln9o&l(toore
SVH8-1A@<>1.o.,1s
D10 D30 Dso Cu Cc
Passing
U.S.C.S No.200
/%)
-.. ---28 SM
GRADATION TEST RESULTS
LAKE CALAVERA IMPROVEMENTS
CARLSBAD, CALIFORNIA
PROJECT NO. DATE
104468001 9/01
0.0001
GRAVEL SAND FINES
Coarse Fine Coarse Medium Fine Silt Clay
U.S. STANDARD SIEVE NUMBERS HYDROMETER
3" 1-112" 1" 314• 112· 3/8' 4 8 16 30 50 100 200
100
90
80
--
I I T I I I I T T ... I--, I I
I 1 I I I ' I
I I I I I I I I I \ I I
I I ' I ' I I
f-70 :,:
(!) w 60 ~ >-a,
~ 50 w z G:
f-40 z w
ffi 30 I>.
I I I I I I I I I I I
I I I I ~ I I I I I I I I I I
I I I I I I I I I I'\ I
II I I I I I I
I I I I I I I I I I
II I I I I I I
I I I I I I I I I I I
I 1 I I I I I
I I I I I I I I I I I
20 I I I I I T I I
10 I I I I I I I I I I I
I I I I I I I I I I I
0 I I II I I I
100 10 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
Symbol Hole No. Depth Liquid Plastic Plasticity
(ft) Limit Limit Index
• HB-2 0-1.0 38 19 19
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422-63
r
SVHS.2@~1.0.>il;
010 0 30 Dso c., Cc
Passing u.s.c.s No. 200
1%)
- ----48 CL
GRADATION TEST RESULTS
LAKE CALAVERAIMPROVEMENTS
CARLSBAD, CALIFORNIA
PROJECT NO. DATE
104468001 9/01
0.0001
...
EXPANSION INDEX TEST RESULTS
SAMPLE SAMPLE INITIAL COMPACTED FINAL VOLUMETRIC EXPANSION EXPANSION
LOCATION DEPTH MOISTURE DRY DENSITY MOISTURE SWELL INDEX POTENTIAL
IFTI (%) IPCFl (%) (IN)
HB-1 (B) 0-1.0 7.5 117.9 14.6 -0.0027 0 Very Low
PERFORMED IN GENERAL ACCORDANCE WITH UBC STANDARD 18°2
EIHB1@0-1,0,xls
EXPANSION INDEX TEST RESULTS
LAKE CALAVERA IMPROVEMENTS
CARLSBAD, CALIFORNIA
PROJECT NO. DATE C;:)
1----------+----I 3 104468001 9/01
U.S.C.S.
SYMBOL LOCATION DEPTH LL (¾) PL(%) Pl (%) CLASSIACA TION U.S.C.S.
(FT) (Minus No. 40 (Entire Sample)
Sieve Fraction)
• HB-2 0-1.0 38 19 19 CL CL
■ HB-1 (B) 0-1 .0 NP NP
•
0
□
!!,.
X
+
NP -Indicates non-plastic
70
:,!! 60 0 -~ 50 >< w Q 40 ~ t ()
i=
30
• 1/)
:3 20
a.
10
0
AT~l!Lxls
V
V ~7
V CH ./ V
V I/'
I/ CL V MH&OH
I/ • V
./
----:.
I ., II/IL,' ML&OL ~
0 10 20 30 40 50 60 70 80 90 100
LIQUID LIMIT (LL), %
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318-98
'ATTERBERG LIMITS TEST RESULTS~
LAKECALAVERA IMPROVEMENTS
CARLSBAD, CALIFORNIA
PROJECT NO. DATE ~ ------+-----4 104468001 9/01
CGvL Engineers
Lake Calavera Improvements, Carlsbad
ATTACHMENT FB
September 7, 2001
Project No. I 04468001
WATER AND SEDIMENT SAMPLE LABORATORY TESTING RESULTS
~468-R I doc
Environmental Engineering Laboratory
3538 Hancock Street
NINYO & MOORE
5710 RUFFIN RD
SAN DIEGO, CA
92123
San Diego, CA 92110
(619) 298-6131
ELAP certificate number l738
Comment ATTN:NATHAN ASH
07/20/01 M
07/20/01 04:30 PM
(LAKE CALAVERA/104468001)
Sampled
Received
Coliform, Fecal I I Coliform, Total
:========= ========----==--------=============~======== ====--===-===========
C..JVL-3 / 10:50
107072so 11 300 a
. ---------++----------------------+----------------------+---------------------
( fVL -12 '; 11:00 l I
10707251 11 so 4
----------++----------------------+----------------------+---------------------~ ·VL-22 / ll:55 I I
10707252 11 13 2
-----------++----------------------+----------------------+---------------------
Coliform results are in MPN/100 mi using Multiple Tube Fermentation
Reported by Robert L. Chambers M.S, Michael M. Chambers M.S., P.S.
07/25/01
Michael Harris Plu) Date
Environmental Engineering Laboratory
3538 Hanc6ck Street
NINYO & MOORE
5710 RUFFIN RD
SAN DIEGO, CA
92123
San Diego, CA 92110
(619} 298-6131
ELAP certificate number 1738
Customer#
Reference
Sampled
Received
Comment
1331 Sample# 10707253
Date Started 07/20/01
CVGL-3 /LK. CA.LAVERA
07/20/01 10 :50AM
07/20/01 04:30PM P.O. #
ATN:N.ASH
104468001 Date Completed: 07/31/01
Test Run:
Chemical Oxygen Demand
Phosphate, Total
Nitrogen, Kjeldahl
Nitrogen, Nitrate
Solids, Dissolved
Alkalinity -Total
Alkalinity -Hyd~oxide
Alkalinity -Carbonate
Alkalinity -Bicarbonate
sulfate -
Chloride
Calcium
Magnesium
Sodium
Potassium
Turbidity
Additional Test
Dominant Wavelength
Luminance
Purity
ND ~ None Detected DL s Detection ~imit
=
Result:
42 .-a mg/L
-0.23 mg/L
1.17 mg/L
10.4 AS N03 mg/L
2570 mg/L
219.0 mg/L
0.0 mg/L
0.0 mg/L
267.2 mg/L
537 mg/L
969.0 mg/L
297.0 mg/L
119 mg/L
404 mg/t.
17.1 mg/L
11..3 NTU
SEE COLOR
pH 8.3 553
99 .1%
10 %
Reported by Robert L. Chambers M,S. Michael M. Chambers M.S., P.E.
MCL DL Method:
6 SM5220C
0.05 SM4500
0.10 SM4500C
0.18 SM4S00H
10 SM24SOC
0.2 SM2320B
0.2 SM2320B
0.2 SM2320B
0.2 SM2320B
1 SM4500
0.2 SM4500B
l.0 SM3120B
1 SM3120B
1 SM3120B
1 SM31208
0.10 SM2130B
pH 7.6 553
98.7%
10 %
08/01/0.l
Michael Harris PhD Date
Environmental Engineering Laboratory
3538 Hancock Street
NINYO & MOORE
5710 RUFFIN RD
SAN DIEGO, CA
92123
San Diego, CA 92110
(619) 298-6131
ELAP certificate number 1738
Customer#
Reference
Sampled
Received
Comment
1331 Sample# 10707254
CGVL-12/LK.CALAVERA
Date Started 07/20/01
Test Run:
07/20/01 11:00AM
07/20/01 04:30PM
ATTN: NATHAN ASH
Chemical Oxygen Demand
Phosphate, Total
Nitr::ogen, K]"eldahl
Nitrogen, Nitrate -
Solids, Dissolved
Alkalinity -Total
Alkalinity -Hydroxide
Alkalinity -Carbonate
Alkalinity Bicarbonate
Sulfate
Chloride
Calcium
Magnesium
Sodium
Potassium
Turbidity
Additional Test
Dominant Wavelength
Lunlinance
Purity
ND -None Detected DL ~ Detection Limit
P.O. # Date Completed : 07/31/01
(LAKE CALAVEA/104468001}
Result: MCL DL Method:
53.2 mg/L 6 SM5220C
2.48 mg/L 0.05 SM4500
1.54 mg/L O.lO SM4SOOC
12.2 AS N03 mg/L O.lB SM4SOOH
3190 mg/L 10 SM24SOC
248. 0 mg/L 0.2 SM2320B
0.0 mg/L Q.2 SM2320B
0.0 mg/L 0.2 SM2320B
302.6 mg/L 0.2 SM2320B
634 mg/L 1 SM4SOO
1234.3 mg/L 0.2 SM4500B
365.0 mg/L 1.0 SM3120B
145 mg/L l SM3120B
500 mg/L 1 SM3120B
22 .7 mg/L 1 SM3l20B
34 NTU 0.10 SM2130B
SEE COLOR
pH 7.8 pH 7.6
540 540
98.8%. 98 .7%
10 % 10 %
Reported by Robert L . Chambers M.S. Michael M. Chambers M.S., P-~-
08/01/01
Michael lfarris PhD Dat:e
Environmental Engineering Laboratory
3538 Hancock Street
NINYO & MOORE
5710 RUFFIN RD
SAN DIEGO I CA
9·2123
San Diego, CA 92110
(619) 298-6131
ELAP certificate number 1738
Customer#
Reference
Sampled
Received
Comment
1331 Sample# 10707255
CGVL-22/LK.CALAVERA
07/20/01 11:30AM
07/20/01 04:30PM P.O . #
ATN : NATHAN ASH
Test Run:
Chemical Oxygen Demand
Phosphate, Total
Nitrogen, Kjeldahl
Nitrogen, Nitrate
Solids, Dissolved
Alka.linity -Total
Alkalinity -Hydroxide
Alkalinity -Carbonate
Alkalinity -Bicarbonate
sulfate
Chloride
Calcium
Magnesium
S6dium
Potassium
Turbidity
Additional Test
Dominant Wavelength
Luminance
Purity
ND a None DetecGed DL; Detection Limit
Result:
75.8 mg/L
3 .43 mg/L
15.3 mg/L
ND mg/L
3190 mg/L
268.0 mg/L
0.0 mg/L
o·. o mg/L
327.0 mg/L
556 mg/L
1275.1 mg/L
365.0 mg/L
147 mg/L
499 mg/L
23 .2 mg/L
40
SEE COLOR
pH 8.09
700
92 .1%
10 %
Repor:ed by Robert L. Chambers M.S. MicJ1,ael M. Chambers M.S., ·P.E.
Date Started 07/20/0l
Date Completed: 07/31/0l
MCL DL Method:
6 SM5220C
0.05 SM4500
0. 10 SM4500C
0.04 SM4500H
10 SM24S0C
0.2 SM2320B
0 .2 SM2320B
0.2 SM2320B
0.2 SM2320B
l SM4500
0.2 SM4500B
l. 0 SM3120B
1. SM3120B
1 SM31205
1 SM3120B
0. 1.0 SM2130B
pH 7.6
700
92.5%
10 %
08/01/01
Michael Barris PhD Date
NINYO & MOORE
5710 RUFFIN RD
SAN DIEGO, CA
92123
Customer#
Reference
Sampled
Received
Comment
Test. Run:
Addit.ional Test
P..ntimony
Arsenic
Barium
Beryllium
Cadmium
Cobalt
Chromium, Tot.al
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Environmental Engineering Laboratory
3538 Hancock Street
San Diego, CA 92110
(619) 298-6131
ELAP certificate number 1.738
1331
CGVL-SEDIMENT.
07/20/01 11:30AM
07/20/01 04:30PM
ATTN; NATHAN ASH
8081/8260/8270
Sample# 10707256
Date Started : 07/20/01
P.O.# Date Completed: 08/14/01
(LAKE CALAVERA/104468001) ADD.REPORTS:
Result: MCL DL Method:
SEE REPORTS
ND mg/Kg 1.0 SM3120B
3.2 mg/Kg 1. 0 SM3120B
69.4 mg/Kg 1.0 SM3120B
ND mg/Kg 1.0 SM3120B
ND mg/L 0.01 SM3J.20B
4.7 mg/Kg-1.0 SM3120B
8.9 mg/Kg 1.0 SM3120B
17.5 mg/L 1. 0 SM3120B
2.0 mg/Kg 1.0 SM3113B
ND mg/Kg 0.1 SM3112B
ND mg/Kg 1.0 SM3120B
5.5 mg/Kg 1.0 SM3120B
ND mg/Kg 1.0 SM3120B
ND mg/Kg 1.0 SM3120B
ND mg/Kg 1.0 SM3120B
26.2 mg/Kg 1.. 0 SM3120B
44 .5 mg/Kg 1. 0 SM3120B
ND ~ None D-et:ecced DL = Oet:eccion Limit. MCL =
Repo,ted by Robe.re L. Cha~hers M.S. MiChpel M. Chambers M.S., P.E,
08/20/01
Mi chael Harris PhD Date
vo, .i.(,-&._VV.1.. rn1. .&."I: .. VJ rt'1.A ..)Jt1't-OVUt1JJ D.:JJ:\ ~--1..0~
. ~--·s-·-:.·K·: .A .N.A.1 ·v:·r •.1 ·e .AL B.;. · -L' ~ 'ti ·o: .. Tb . "'-;~:~J1r1·.-E·_.-~ , .... . . ·... . ~ D .. --~1%:.11-·J. .. ~ ~ , . . -1.t ~ r ··•·--··-&7 .. -,,. .... ------······r ...... , ...... f --cr··;v+ ✓--.. 7-•·1
~like Chambers
Environmental Engineering Laboratory
3538 Hancock Street
San Diego, CA 92110
BSK Submissioi;. #: 2001071118
BSK Sample ID#: ll8342
Project ID: PrQjectDcsc:
Submissl:on Comments:
Sample Type: Solid
Samp1e Description: 7256
Sample Comments:
Organics
Analyte Method Reault Utii13
.\,4'-DDD EPA808l ND mg'Xg
4,4'-DDE EPA8081 ND mg/Kg
4,4'-DDT EPA8081 ND mg/Kg
&.•BHC EPA808l ND mg/Kg
Aldrin EPA 8081 ND mg/Kg
b-BHC EPA 808) ND mg/Kg
Ch!ordm; EI'A 8081 ND mg/.Kg
d-BHC SPA 8081 ND .mg/Kg
Dield."'in l.:l'A8081 ND mef.!Cg
Endosul:an I EPA 8081 ND mliKg
tmdo,ulmn n [j!IA!0,21 ND ~
.En.dosulf.e.n s\!lfau E.PA &-081 ND m&OCg
~ndrin ~AllOil ND mg.,'.Kg
Endrin aldehyde E?A 8081 ND ~g
g-BHC E'PA 8081 ND m§"Kg
He-ptACh!'Clr EPA80U ND m&'Xg
Hcptachlor epoxide EPA SCSI ND mg.!Kg
Methoxychlor EPA 8081 ND mg/Kg
'l'oxaphcce EPA 8081 ND mg/Kg
-Arochlor 1016 EPA8082 ND mg/Kg
Arochlor 1221 EPA 5082 ND mg/Kg -
Arocblor 1232 EPA801!2 ND mef.Kg
Arochlor 1242 EPASO!l ND mg,'.Kj
,A..rochlcr l:Z48 EPA8C82 ND mdX-g
ArPcblor )254 EPA 800 ND mg,Xg
Arochlor 1260 EPA8082 ND mg/.Kg
l,1,1,2-Tctru:hlol"C-(\hane E!'A 8260 ND µg/Kg
't, 1,1-Trlchloroethane EPA8260 ND µg/Kg
1, l.2,2• T etrachlor.>c!lh2lle E:PA8260 ND µg,](g
: , l ,2-Trichlorociliw-.e EPA 8260 ND µg,Xg
1, t-Dicbloro-2-propt!I!cne EPA 8260 .ND µg;Kg
mg/L: Milligrams/Liter (ppm)
mg/Kg: Milligranw'Kilogram (ppm}
µg/L: Micrograr:u/1..iter (ppb)
PQL: Prectical Quantita:tion limir
DLR: Detection Limit for Repor:ing
: PQL JC Dilution
µg/Kg; Micrograms/Kilognun (ppb)
%Rec: Pcn:cntRecoycted (~WTogates)
ND: None Detected atDL~
R:pon Ai:tl,~eatit::1 cc-&:: IIIIHIUHll~qf lJ IIHllffll II IIH!m Hlli!U
Qi vv:.1 •,u,
Certificate of Analysis
EL.AP Certificsfe #1180
Report ls&ic Date: 08/17/2001
Den= Sampled: 07/20!2001
TiI::ie Sa.'llplcd: 1130
Dstc Received: 07/24/2001
Prep Analym
PQL Dilution DLR Date Date
0.05
0.v5
0,05
0.05
0.-02
0.0.5
0.05
o.os
0.02
0.05
0.0!
0.01
0.05
0.05
0.(1~
0.05
0.0:5
0.05
0.4
0.1
0.1
O.l
0.1
0.1
O.l
0.1
5.0
5.0
5.C,
s.o
25
1 0.fJS 07/30/2001
O.vS 07/30/2001
0.(t:5 07/3(;/2001
1 0.05 07/.lQ/20Ql
o.oz 07/30/2001
0.05 07/30/2001
1 0.0:S 07/300001
l 0.05 07/30/2001
] 0.02 Oi/30/2001
1 0.05 07/30/2001
1 0.05 07/l0/2001
0.0$ 07/30/2001
1 o.cs 07/30/2001
I 0,U5 07/30.12001
1 0.05 07/30/2001
0.IJ5 07/30/2001
0.05 07/30/20Gi
l 0.0S 07/30/2001
1 0.4 07/30/2001
1 0.1 07/30/2001
I 0.1 07/30120()1
l 0.1 07/30/2001
0,l 07/J0/2001
0.1 07/30/2001
0.1 07/30/'2001
0.1 07/30/2001
I 5 08/01/2001
1 s 08/01/2001
1 ~ 08/01/2001
5 08/Q1/2001
1 25 08/0U2001
H; Alla1yzed ol!'.sicie of bold time
P: Ptclii.-ninazy 1esuh
08/01/2001
08/01/2001
08/01/2001
08/01/2001
08/01/2001
08/01/2001
08/0 lf.?00 l
08/01/2001
08/01/2001
08/01aoo1
08/01/2001
08/01/2001
08/01/2001
08/01/2001
08/01/2001
08/01/2001
08/01/2001
08/011"-001
08/01/2001
08/01/2001
08/01/2001
08/01/2001
08i0ll2001
08/01/2001
08/011'2001
0&/01/2001
08/01/2001
08/01/2001
0&/01/2001
08/01/2001
08/01/2001
S: Suspect result See Cov~ Lcrte-r for wromeofs.
E; • .\na.J:·sis p('rfu:med by Exteml!l ll\boT111ory.
S.e..! Extern~ Labora\Ory Report ~e:its.
Page 2 of7
Mike Chambers Certificate of Analysis
Environmental Engineering Laboratory ELAP Certificate #1180
3538 Hancock Street Report Issue Date: 08/17/2001
San Diego, CA 92110
BSK Submission#: 2001071118
BSK Sample ID #: 128342
Project ID: Project .Desc:
Sublll.Wi.:.u ColJ.iJJ.ieo~:
Sample Type: Solid Da!eSampled: 07/20/2001
Sample Description: 72j6 Time SBinpled: 1130
Sample Comments: Date Received: 07/24/2001
Organics Prep Analyais
A_nalyte Mithod Result Unita PQL Dilution DLR Datil Date
1, 1-Dichlorocthanc EPA 8260 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
l,1-Dlohlorocticoc EPAS260 rm µg/Kg s.o 5 08/01/2001 08/01/2001
I, 1-Dichloropropcne EPA8260 ND µg/Kg 5.0 s 08/01/2001 08.'0112001
1.2,3-T richlorobenunc EPA&260 ND µg/Kg 5.0 s 08/0lt2001 08/01/2001
l_.2,3-Tr:ichloropropB!l.C EPA8260 1'-.1) µg/Kg s.o 1 5 08/01/2001 08/01/2001
l.,2,+'1',;..11.,,.,1,.,..., .. .,... D'A62(;Q ND !-'~ s.o I -' 08/01/1001 08/01/2001
1,2,4-Trimethylbenzene EPA&:Z60 ND µg/Kg s.o l 5 08/01/2001 08/01/2001
l ,2-Dlbro%1lc-3-cblorcpro:,ane (DBCP) EPA8260 ND µg/Kg s.o 1 5 os·,0112001 08/01/2001
1,2-Dibromoetha.nc EPA8260 1'1) µg/Kg 5.0 l 5 08i01/2001 08/01/2001
1,2-Dichlorobenzene EPA8260 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
1,2 •Dichloroethane EP.A8260 'ND µg/Xg 5.0 1 s 08/01/2001 08/01/2001
l.l•Dichloropropane EPA8260 ND µg/Kg 5.0 1 5 08/01/2.001 08/01/2001
1,3,S-Tl'imethylbenzeoc EPA8260 ND µgt'"Jeg s.o l 5 08/01/2001 08/01/2001
l,3•Dichlorobcnzene EPA&260 :rm µg,'Kg 5.0 1 5 08/01/2.001 08i0l/2001
1,3 OichlQroptopllllj EPAil60 !-11) µg/Kg S-.0 1 j 08/01/2001 08/01/2001
1,4-Diehlorobenzene EPA&260 ND µg/Kg 5.0 l ~ 08/01/2001 08/01/2001
1-Chlorobutane EPA 8260 !"11) µg/Kg s.o 1 5 08/01/200] 08/01/2001
2,2-Dichloropropane EPA8260 ND µg/Kg .s.o 1 5 08/01/2001 08/01/2001
2d3µtaDOne EPA-8260 ND µg/Kg 25 25 08/01/2001 08/01/2001
2-cllloratohiene EPA8260 ND µg.'Kg 5.0 s 08/01/2001 08/01/2001
2-Hcxmonc EPA8260 ND µef"q 25 1 25 08/01/2001 08/01/2001
3-chloropropeoe EPAS260 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
4-Chlorotolucn c EPA 8260 ND µgt'.Kg 5.0 ' j 5 08/01/2001 08/01/2001
4-Methyl-2-pent.enone EPA8260 :ND µg/Kg 25 1 25 08/01/2001 08/01/2001
Acetone EPA 8260 ND µg/Xg 25 1 25 08/01/2001 08/01/2001
Benzene EPA8260 :rm µglKg 5.0 1 5 08/01/2001 08/0i/200)
Bromobenzime EPA8260 ND µg!Kg 5.0 1 5 08/01/2001 08/01/2001
Brcmochlcl'OlllC'dwle EPA8260 ND µg/Kg s.-0 1 5 08/01/2001 08/01/2001
Bromodichlorom,:th1111e EPA 8260 ND µg!Kg 5.C 1 5 08/01/2001 08/01/2001
Bromoform EPA8260 ND µg/Kg 5.0 1 5 08/Gl/2001 08/01/2001
Brorncmcthanc EPA8260 ND µg/Kg s.o 5 08/01/2001 08/01/2001
mg/L: Milligrams/Liter (ppm)
mg/Kg: Milligrams/Kilogram (ppm)
PQL: Practical Quantitatior.: Limit
DLR: Detection Limit for Repo:tiag
H: Analyzed. ott.side of hold time
P: P~liminary result
µg/L: MiQl'Ogramf.'Lit.:r (ppb) : PQL x Dilution S: Suspect result See C0ver Letter for co!Dlilents.
fl~ Micrograms/Kifogram (_ppb) ND: None Detected at DLR E: Analysis performed by E>:tcroal laboratory.
%Rec: Percent R...--covercd (surrogaics) See Exteroal Laboratory Report attachments.
•-•••-,. , .. •-••1t•~••-t•••-.-i-w•■IMII t., WW': WIIU.'Tltll
'1111001 :..n 111 :07 :i.U 5504W560'Hi il>ll L~i" @OOd 100,
Mike Chambers Certificate of _Analysis
Environmental Engineering Laboratory ELM Certificate #1180
3538 Hancock Street Report Issue Date: 08/17/2001
San Diego, CA 92110
BSK Submission#: 2001071118
BSK Sample ID#: 128342
Project ID: Project Deso:
Submission Comments:
Sample Type: Solid Date Sampled: 07/20/2001
Sample !kscription: 7256 Time Sampled: l 130
Sample Comments: Date Received: 07/24/2001
Organics Prep Analysis
Anslyte Method Result Units PQL Dilution DLR Due Date
Carbo11 Disulfide EPA8260 ND µg/Kg 5.0 1 5 08/01/200] 0&/01/2001
~ttiieh!oiitle EPA8260 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
Chlcrobenzene .EPA8260 ND µg;Kg 5.0 1 s 08/01/2001 08/01/2001
Chloroethane EPA8260 ND µg/Kg 5.0 1 5 08/01/2001 08/01.12001
Cblotofur.n EPA 8260 ND µg/Kg. 5.0 s 08/01/2001 08/01/2001
C"a!oromcthanc EPA8260 ND µ~ j_Q 1 s 08/01/2001 08/01/2001
~l,2-Dicbloroethene EPA.8260 ND µg/Kg 5.0 1 5 OS/01/2001 08/01/2001
c:..s-J ,3-Dichlc.ro;>ror,eoe EPA8260 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
Dtbrolll\.~orome:..'w!c EPA826-0 ND µg/Kg s.o 1 s 08/01/2001 08/01/2001
Dibrow..mr.ttll~~ EPA8250 ND fig/Kg 5.0 1 5 08/01/2001 OS/01/2001
Dichlorodifluoromethe.ne-EPA&260 ND µg;Xg 5.0 1 s OS/01/2001 08/0 l /2001
Di,:m;•I ether EPA8260 ND µg/Kg 5.0 1 s 08/01/2001 08/0l/2001
Ethyl!ielli'.tne EPA8260 ND µg/Kg 5.0 l s 08/01/2001 0&/0,l/2001
Etl:!ylmetht:.ciyla~ EPA8260 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
Haach!ofl?buted.ieue EPA8260 ND µg/Kg_ 5.0 1 5 08/01/2001 08,01/2001
HC"Xacbloro:tbme EPA8260 J'ljl) µgiKg 5.0 5 08/01/2001 08/01/2001
Iodomcihaoe EPA8260 ND µg.,X.g 5.0 1 .s 08/01/2001 08/01/2001
Isopropylbenr.:ne E!:'A8260 .rm µg!Kg 5.0 1 5 08/01/2001 08/01/2001
...,.i,-.K-1I<.,...,• rPAS2GO ND µ~ 3.0 1 s 08/01)2001 08/0 I/200 l
Mroiylar.rylat:= EPA8260 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
MC'Ji;>-lcne Chloride EPA8260 ~1) µr/Kg 25 1 2-5 08/01/2001 08/01/2001
MethylmetJ:iacrylgj:e EPA8260 ''.ND µg,'l(g 5,0 1 s 08/0li2001 08/0l/200i
M~thyl-t-Butyl Ether EPA8260 ND µg/Kg 10 l 10 08/01/2001 08/01.'2001
Naphthalene EPA8260 ND µg,'4 5.0 1 s 08/01/2001 08/01/2001
n-Butylbeu.cne EPA8260 ND µg/Kg 5.0 1 .s 08/01/2001 08/0li2001
Nurobc=r EPA8:!60 ND µg/Kg 25 1 25 08/01/2001 08/01/2001
n•PropyUw...zene EPA8260 ND µg/Kg 5.0 ] s 08/01/2001 08/01/2001
o-X)·lcll( .EPA8260 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
• Pentl!ch!oroeth,a.'1<! EPA8260 ND µg/Kg s.o 1 5 08/01/2001 08/01/ZOOl
p--lsopropylt.:ilucnc EPA8260 ND µg/Kg 5,0 5 08/01/2001 08/01/2001
sec-Butylbenz= EPA 8260 .ND µg/Kg 5.0 5 08/01/2001 08/01/2001
mg/L: Milligrams/Liter (ppm) PQL: Pracdcal Qwntitation Limit H: Analyzed outside of hold time
mg!Kg: .Milligra.mstKilogram (ppm) DLR: Dclection Limit for Reporting P: Frdiminary result
µyL: MicrogramY.Liter {ppb) : PQL x Dilution S: S~--pect rc.>-ult. See Cover Letter for comments.
µg/Kg: Microgmns,'Kilogram (ppb) ND: None Deu:ctcd at DLR I: Analysis perfo.rmed by External laborato:-y.
%Rec: Percent Recvvered (surrcga±es) See External Laboratory Report attachments.
•~~Jrt::Jt:e9:tl!llc:i~1ill11Ctti?.:fflllt~ff;i~Dl~Wt.Ol
08/ l i/2001 JiilI 141 08 FAX o504&6S0Zii nsi LAUS @006/007
'B,· s· .. ;·K,· .; -A ·N AL··v JT•I ;CIA "L, ·, . ·. , · ... _ ·s:,. ---,-... . . "O ... ·tt·, ·1· E ...... . i. . .; L 11. . "'·1!); ,A 1' . •; • • • . • . . .. __ :., .. · ·:__ ·, ... ·~_.-o, ... ,,-;,:~~I-" -,. _,.. ___ £
1 1
Mike Chambers Certificate of Analysis
Environmental Engineering Laboratory EI.AP Certificate #1180
3538 Hancock Street lleportlssae Date; 08/17/2001
San Diego, CA 92110
mm: Sabll.\U~iOD ;;: 2001071118
BSK Sample ID #: 128342
Project JD: Pmjcr:t~·
Submission Co=ents:
SM\ple l'ype: Solid D~e Sampkd: 07/20/200 I
Sample .Description: 7256 Time Sampled: 1130
SwnplG Cumuu;ub;; D~ R~theu; 01i14/2001
Organic..\.._ Prep Amiy~is
Ans}yte Method Result Unit, PQL Dilution DLR Date Date
Styrene £PA8260 ND µg/Kg 5.0 1 5 OK!Ol/2001 08/01/2001
ten•Butylbemcne EPA826Q ND 1,1i,'Kg s.o 1 s 08/01/2001 08/01/2001
Tetrachloroetbenc (PCB) .EPA Sl60 ND µg/Kg 5.0 t 5 OSiOl/2001 08/01/2001
Tolu.coe EPA8250 ND µg/Kg 5.0 1 5 08/01/2001 08/01/2001
trens-1,2-Dichloroe!b:ne EPA8260 ND µg,'Kg 5.0 1 s 08i0li20()1 08/01/2001
trans-1,3-Dichlorcprop.:lle EPA8260 ND µg(.l{g s.o l 5 08/01/2001 08/01/2001
Trfohloroethene (TCE) EPA 8260 I-t'D µwKg 5.0 1 5 08/01/2001 08/01/2001
Trichlorofiourom...4:h~e EPA8260 ND µg..-'.Kg s.o 1 5 08/0i/2001 08/01/2001
Vinyl Chloridt EPA8260 ND µg!Kg 5.0 5 08/01/2001 08/01/2001
1,2,4-T richlorobc!lzenc EPAB270 ND mvKg 0.33 10 3.3 08102/2001 08/14/2001
1,?•Diailorob=cne EPAS270 ND mg/Xg 0.33 10 3.3 08/02/2001 08/14/2001
1,3-Dichlorobcnu.ne EPAll270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14,'2001
V-Dicblorob=Uc EPA8270 l'll'"D mgllCg 0.33 10 3.3 08/02/2001 08/14/2001
2,4,6-Trii:Sloropbcool EPA8270 ND :mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
2,4-Dlchlorophencl EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
2,4-Dimethylphen,:,J EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
2,4-Dinitrophcnol EPA8270 ND mg/Kg 3.3 10 33 08/02/2001 08/14/2001
2,4-Dinitrotoluenc EPA8270 ND ~ 1.3 10 13 08/0212001 08/14/2001
2,6-Dinitrotoluene EPA8270 ND mg/Xg 1.3 10 13 08/02/2001 08/14/2001
2-<:hloronap.bthalenc EPA 8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
2-CbloropbCDDl EPA8270 ND mg/Kg 0.33 10 3.3 08/02i2001 08/14/2001
2°Ni'iiopbcnol EPA8210 ND mgOCg 0.33 10 3.3 0&/(:2/2001 08/14/2001
3',3-Dichlorcbeozidine EPA8270 ND mg/Kg 0.65 10 6.5 08/02,'2001 08/14/2001
4,4'-DDD EPA 8270 ND Il!g/Kg 0.33 10 l.3 08/02/2001 0&!14/2001
4,4'-DDB EPA827D .l'cl) mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
4,4'-DDT EPA 8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
4,6-Dinitro-2-mctbylphmiol EPA8270 ND mg/Kg 1.6S 10 15.5 08/02/2001 08/14/2001
4-Bromopher:,ylphen;yl roier EPA8270 l\iD mg/Kg 0.33 10 33 08/02/2001 08/14/2001
4-Cbloro-3-Jn!!thy 1:, benol -EPA8270 ND mg/Kg 0.65 10 6.5 08/0212001 08/14/2001
4-Cblorophcnylphcn)'I ~er EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
4-Nitropbenol EPA 8270 ND mg/Kg 1.65 10 16.5 08/02/2001 08/14/2001
rng/L: Milligrams/'.wter (ppm) PQL: Practical Quantitation Limit H: Analyzed outside of hold ti:ne
mg/Kg: MilligramsllG]ogram (ppm) DLR: Detection Limit for Reporting P: Prelmrina:ry result
µg/L: Micrograms/Liter (ppb) : PQL x .Dilution S: Suspect result See Cover Letter for comments..
~g/Kg: Mlcrogram9/K.ilogram (ppb) ND: None Det~ted at DLR E: Analysis perfonned by Extems1. laboratory.
%Rec: Pe.roent Recovered (surrogates) See Exicrnal Laborator/ Repc~ artachmen+s.
-·----..--.. ---.. ---i-,•·~-------•11r-.,.1:w
.... --........ -------ll
Mike Chambers Certificate of Analysis
Environmental Engineering Laboratory ELAP Certificate #1180
3538 Hancock Street Report Issue Date: 08/17/2001
San Diego, CA 92110
BSK Scbmission #: 2001071118
BSK Sample ID #: 128342
ProjcQtID: Piojtct Desc:
Subm.bsion Co m.menls:
·Sample Typ,:: Solid Dare Sampled: 07/20:'2001
Sample Description: 7256 Time Sampled: 1130
Sample Comm.cots; Date Receh·ed: 07.f24f.2001
·organic! Prep Analysis
Analyte Method Result Units PQL Dilution DLR Date Date
a-BHC EPA827-0 ffi) mg/Kg 0.33 10 3.3 08/021200i 08/14/2001
A~htl=ic EPA 8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
Accnaphthylcr.c EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
Aldrin EPA8270 ND mg/Kg 0.33 10 3.3 08/01/ZOOl 0&114/2001
Alllhraceoe EPA8270 ND mg/Kg 0.33 10 3.3 08/01./2001 08i14/2001
Benzo( a)anthrsce;ic EPA8270 ND mg,'.Kg 0.33 10 3.3 08/02/2001 08/14/2001
Bomo(n)pyreoe EPA8270 ND mg/Kg 0.33 10 3.3 08/021200] 0&/14/2001
Bcm<>(b )fluoraolhene EPA&270 ND mg/Kg 0.33 10 3.3 08/02/2001 OS/14/2001
Bw:o(glu)p-ttylcoc EPA 8270 ND mg/Kg 0.33 lU 33 08/02/2001 08/1412001
Bi:nzo(k)fiuowrtl:cnc EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
bis(2-Chloro:'.n0xy) m.ed:um~ EPA 8270 ND mg/Kg 033 10 3.3 08/02/2001 08/14/2001
bi!(2-ChloroctbyO c:lb::r EPA8270 ND mg/Kg 1.65 10 16.5 08/02/2001 08/1412001
bis(2.Cblorojso;,ropyl) ciher EPA8270 ND mg/Kg 3,3 10 33 08/02/2001 08/14C001
bis(2-EtbylhcxyJ) phlhe.Lut .EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
Butyl beoiyl pll!halw EPA8270 ND mg/"i(g 0.33 JO 33 08102/2001 . 0&/14/2001
Cluyscne EPA8270 r,cl) mg/Kg 0.33 10 33 08/02/2001 0&/14/2001
d-BHC EPA8270 ND mg/Kg 033 10 3.3 08/02/2001 08/14/2001
Dibenz(a,h)arrthraow.e El'A8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
Dieldrin EPA 8270 ND mg/Kg 0.33 10 3.3 08/0212001· 0&114/2001
Die-thyl pbth!lme EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
Dimethyl-phlbalm EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 081'14/2001
Di-o•butyl pht.1111.Jlllt: EPA 8270 ND mg,'Kg 0,33 10 3.3 08/02/2001 08/14/2001
Di-o-octyl phthels EPA8270 rm mgrXg 0.33 HI 3.3 08/02/2001 08/14/2001
Endosulfan I EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14.1.2001
Endosulfan ll EPA8:i70 ND mg/Kg 0.33 iO 3.3 08/02/2001 08/14/lOOJ
Endosulfen ttl.fm EPA~270 ND mg/Kg 0.33 10 ·3.3 08/02/2001 08/14/2001
Eadrln EPA&270 ND mg/Kg 1.3 10 13 08/02/2001 08/1412001
Eodrin aldehyde EPA827IJ ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
fluorenthene EPA8270 ND mg/Kg 0.33 10 3.3 08/02/2001 08/14/2001
Fluomie EPA82i0 ND m.ef.Kg 0.33 10 3.3 08/02/2001 08/14/2001
g-Bl:!C EPA8270 · ND mg/Kg 0.33 10 3.3 O&!OZ/2001 08/14/2001
mg/L: Milligra.mr,/Lftcr Ci-,pro) PQL~ Pra..-tlcal Quantitstiou Limit H: Analyzed out.side of hold time
mg/Kg: Milligrams/Kilogram (ppm) DLR: Detection Limitfor Reportmg P: Prel!mina:y result
µg/L: Micrograms/Liter. (ppb) : PQL x Dilation S: Suspect result. See Cover Lener for commeols.
µwl(g: Micrograu..s!Kilogra;n (ppb) ?-i"D: None Detected at DLR E: Ar.alysi.s performed by External l1iliv.ratory.
%Rec: Percent Rxov~d (surrogai:s) s~ Extern.al. Laboratory Report attachments.
Mike Cham hers
En vitonmtsnlal Engin~~ring Labon1lury
3538 H.ancock Street
San Diego, CA 92110
BSK Submission #: 2001071118
BSK Sample ID #: 128342
Project ID: Project DCSI!:
Subm.issiOD Comments:
88.I!lpk Type! Solid
Sample Description: 7256
Sample Comments:
Organics
ldl nn u nrn
Certificate of Analysis
ELAP Certiflcate #1180
Report l~ue Date: 08/17/2001
Date Sampled: 07i20/2001
Yuue Sampled: 1130
Date Received: 07124/200 l
Prep AD~sis
AUSlytt-Mi-thod Be,ult ll.nlt-L-.I>l)L Dilntlo:1 Dl.B fu.tt Tuite
Heptacblor
Heptachlor cpo;ode
HcX11Cblorobenune
H::xachlorobutt.di:n~
Hcxai:bloroctha:::e
Iodono(l,2,3-td)pyrc:ne
Isophotonc
Nepbthalcn:
n-Nitrosodi-n-propylamine
n-Ni-.rosodiphet.ylamillc
Pcntachloroph~oo1(PCP)
Phenm:lhn:0t
Phenol
Pyrene
Surrogate
Tctre.:hloro-m•xyl=
Bromo:fluorobcnzene
Dloromol:luorometh!llle
Totucne-c!8
2,4,6-Tribromopb~aol
2-Fluorobiphenyl
2-Fluotophenol
4-Terph..--nyl-d 14
Nitrobcnz.cnc-d5
Phcnol-d5
mg/L: Milligrams/Liter (ppm)
mg/Kg: Milligrani~c/Kilogram (ppm}
µg/L; Micro~Uter (ppl:)
µg/Kg: Microgran::s/Kilogram (ppb)
%Rec: Percent Recovered (su.vrogates)
.EYA8270 ND mg/Kg
EPAll2?0 'ND mg/Kg
EPA&270 ND mg/Kg
EPAS270 ND mg/Kg
EPA82i0 ND mg/Kg
EPAS270 ND mwKg
EPA8270 ND mg/'4
EPA 8270 ND mg,'K.g
EPA&2i0 ND mg/Kg
E?A8270 ND mg/Kg
EPA82i0 ND mg/Kg
EPA8270 ND" mg.f".(g
EPA8270 Ni) mg/Kg
EPA8270 ND mg/Kg
EPA 8081 150 % R...sc
EPA 8260 89 %Rec-
EPA8260 toz %Rec
EPA8260 8S %Rec
EPA&270 69 %Rec
EPAB270 71 %Rec
EPAS270 61 %Rec
EPA8270 58 %Rec
· EPA8270 78 %Rec
EPA8270 75 %Rec
PQL: Practi~al Q,;entitaeion Limit
DLR: Detection Limit for Reporting.
: PQL x Dilution
ND: None De~ectctl at DLR
0.33
0.33
0.33
0.33
0.33-
0.33
0.33
(\,33
1.65
033
l.65
0.6.S
0.65
033
.
-.
.
-.
.
.
.
10 3.3 08/02/2001
10 3.3 08/02/.2001
10 3J 0S/02/2001
10 3.3 08/02/2001
rn :;.3 08/02/2001
10 3.3 08/02/2001
10 3,3 08/0li2001
10 3.3 08/02/2001
10 16.5 08/0i/2001
10 3.3 08i02/2001
10 16.S 08/02/2001
10 6.5 08/02/2001
10 6.5 08/02/2001
10 3.3 08/02'2001
l NIA 07/30/2001
1 NIA 08/01i2001
1 NIA 08/01/2001
l NIA 08/01/2001
IO NIA 08/02'2001
10 NIA:.. 08/02/2001
10 NIA 08/02/2001
10 NIA 0&'02/2001
10 NIA 08/02/2001
10 NIA 08/02/2001
H: Analyzed outside ofho1d time
P: Pretimina.-y result
08/14/2001
08/14/2001
()8/14/2001
0&/14/2001
08/14/2001
08/14/2001
08/14/2001
08/14,'2001
GS/14/2001
G8/14/200J
08/14/2001
08/14/2001· ·
0&114/2001
08/14i2001
08/01/200!
08/01/2001
08/01/2001
08/01/2001
08/14/2001
C,g/14/2001
08/14/2001
08ii4/2001
08i14/200l
08/14/2001
S: Suspect result. See Cover Letter for CO!w!l'!Ois.
E: A.o.81';s~ perfonned b) fa.ieroal la!xlratOI)'.
Se.:-.Extemal Lebmatozy R..jJ•.lrt a~hments.