HomeMy WebLinkAboutHMPP 06-03; AGUA HEDIONDA CREEK EMERGENCY DREDGE PROJECT; CLOSE-OUT REPORT - ENVIRONMENTAL COMPLIANCE MONITORING; 2006-06-01I
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TABLE OF CONTENTS
Section
I. PROJECT BACKGROUND .............................................................................................. 1
II. PRECONSTRUCTION ACTIVITIES ............................................................................... 2
Biological Services .............................................................................................................. 2
III. TURBIDITY MONITORING ............................................................................................ 2
IV. DREDGING ACTIVITIES ................................................................................................. 5
V. COMPLIANCE MONITORING ........................................................................................ 6
APPENDICES
Appendix A Biological Resources Survey Results
-Bird Nesting Survey Report
-Field Survey Report for Light-Footed Clapper Rail
Appendix B Data Reporting and Results
Attachment 1 -Ambient Turbidity Measurements
Attachment 2 -Hourly Turbidity Measurements
Attachment 3 -Comparison ofUpstream and Downstream Turbidity
Measurements during Emergency Dredging
Attachment 4 -Ambient Turbidity and Creek Level in Agua Hedionda Creek
Appendix C RWQCB Correspondence and Photo Documentation
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I. PROJECT BACKGROUND
The City of Carlsbad (City) obtained expedited permit approvals from vanous regulatory
agencies to conduct emergency dredging activities within Agua Hedionda Creek and portions of
Calavera Creek. Channel dredging within Agua Hedionda and Calavera creeks was conducted
under emergency circumstances to maintain adequate flood protection for the adjacent residential
community of Rancho Carlsbad. Rancho Carlsbad is an existing residential mobile home
community located east of El Camino Real and south of Cannon Road, in the northeastern
section of Carlsbad, California (Figure 1 ). Because over 50 percent of the homes in Rancho
Carlsbad are located within the existing limits of the 100-year floodplain and are subject to
flooding during major storm events, emergency channel dredging was deemed necessary to
regain appropriate interim flood protection while ongoing channel designs are completed.
Channel dredging activities were deemed necessary if the channel capacity was not regained.
Channel dredging occurred between the downstream edge of the Rancho Carlsbad Bridge to the
upstream edge of the Cannon Road Bridge (Figure 1 ).
Agua Hedionda and Calavera creeks are earthen channel watercourses that have historically been
subject to significant sedimentation. Due to increased peak discharge from development within
the watershed and the accumulation of up to 6 feet of sediment in the channel, the creeks were
dredged to avoid flooding hazards and improve public safety in the event of a significant storm
event.
The regulatory authorizations that were issued by the U.S. Army Corps of Engineers (ACOE),
the Regional Water Quality Control Board (RWQCB), and the California Department of Fish
and Game (CDFG) to allow the emergency dredging activities to occur included:
• ACOE Section 404 permit (200600151-KJC)
• RWQCB Clean Water Act (CWA) Section 401 Water Quality Certification (06C-007)
• CDFG Streambed Alteration Agreement (1600-2006-0060-RS)
To assist the City during implementation of the dredging activities, EDA W, Inc. (EDA W) was
retained to provide general environmental compliance monitoring, including turbidity and water
quality monitoring per the conditions outlined in the issued permits. The EDA W team also
included the services of Konecny Biological Services to address monitoring efforts for the
light-footed clapper rail and to conduct a general preconstruction biological survey. This report
summarizes these monitoring efforts from the initiation of the project on March 4, 2006, through
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completion of dredging activities on March 25, 2006. Copies of the survey results are included
in Appendix A.
II. PRECONSTRUCTION ACTIVITIES
Biologi'cal Services
Biological monitonng services were provided by wildlife biologist John Konecny of Konecny
Biological Services and EDA W's environmental monitor, Jeff Warner. Biological monitoring
occurred between March 3 and March 9, 2006, during vegetation removal and dredging activities
between the Cannon Road and El Camino Real bridges. Results of the biological surveys are
included in Appendix A of this report and summarized below.
In accordance with the ACOE 404 Permit (200600151-KJC) Special Condition la, and CDFG
Streambed Alteration Agreement (1600-2006-0060-R5) Condition 14, a biological monitor
conducted a preconstruction survey of the project alignment prior to the beginning of vegetation
removal between the Cannon Road and El Camino Real bridges. The survey was conducted on
March 3, 2006. No active bird nests were detected at the site. The biological monitor was
present during vegetation removal between the bridge structures on the morning of March 4,
2006. Biological monitoring continued during vegetation removal and dredging activities that
occurred between the bridge structures through March 9, 2006. Exclusionary fencing was
provided near the edge of the Cannon Road Bridge to prevent dredging activities from extending
outside the project limits and into the environmentally sensitive area downstream of Cannon
Road Bridge (Figure 1 ). The fencing also served as a buffer to keep the clapper rails from
entering the active construction site.
Although the City was permitted to conduct dredging and vegetation clearing to the downstream
portion of Cannon Road Bridge, no actual disturbance occurred in this area. No vegetation
removal occurred on the south side of the banks between the two bridges.
III. TURBIDITY MONITORING
In accordance with the requirements of the CW A Section 401 Water Quality Certification ( 401
Certification), EDA W conducted the following turbidity and water quality monitoring services:
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• Turbidity Control Plan (TCP)-per Condition B.l of the 401 Certification, EDAW prepared
a turbidity monitoring plan that described the dredging process, the turbidity control best
management practices (BMPs ), and the turbidity monitoring approach.
• Turbidity Compliance Monitoring -turbidity monitoring was conducted throughout the
emergency dredging process, including:
o Collection of water samples within the active flow to measure turbidity levels,
o Measurement of creek velocity at the point of measurement, and
o Recording of visual observations.
IV. DREDGING ACTIVITIES
To document ambient water quality prior to dredging, turbidity measurements were taken at 10
locations along the creek alignment. Ambient Turbidity monitoring locations are shown in
Figure 1 and the field measurements are shown in Appendix B (Attachment 1 ).
Prior to dredging activities, vegetation removal began on March 4, 2006, between Cannon Road
Bridge and El Camino Real Bridge. In accordance with the TCP, a series of gravel-bag check
dam structures were constructed under the Cannon Road Bridge to create stilling pools for
capturing sediment and controlling turbidity downstream of the project limits. Dredging
activities commenced on March 6, 2006, but were limited to the area between the Cannon Road
Bridge and El Camino Real Bridge. Dredging between the Cannon Road Bridge and El Camino
Real Bridge was isolated from the active stream flow via a diversion channel created along the
northeast side of Agua Hedionda Creek. At the upstream edge of the Cannon Road Bridge
where the diversion channel terminated, a desilting basin was created to promote sediment
settling and capture prior to coming in contact with the gravel-bag check dams downstream.
The creation of the diversion channel and desilting basin provided an isolated and relatively dry
earthen platform from which dredging was conducted. The dredging crew carefully removed
sediment within the perimeter of the earthen platform, leaving approximately 1 to 2 feet of
natural creekbed in place as a protective berm between the active creek flow and dredging
operations.
Dredging activities between the bridge structures were completed ahead of schedule. Permit
conditions required that work be completed between the Cannon Road Bridge and El Camino
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Real Bridge by March 15, 2006 (to avoid the active nesting season). Work activities at this
location were completed on March 9, 2006.
Following a temporary work stoppage due to a storm event, creek dredging was reinitiated on
March 14, 2006, upstream of El Camino Real Bridge, beginning with the construction of a
similar desilting basin at the upstream edge of the b~dge and a diversion channel along the
southwestern edge of the creek. The diversion channel was overexcavated (to an approximate
depth of 6 feet) to provide extra capacity for capturing additional sediment traveling
downstream. By isolating the creek within the diversion channel, the remaining creekbed was
accessible ~or dredging equipment.
A roadway was created along the northeastern edge of the creek to allow the dredging excavator
and dump trucks to travel the length of the creek without disturbing water quality. A stream
crossing, consisting of a 50-foot steel pipe was placed in Calaveras Creek at the junction with
Agua Hedionda Creek and covered with creekbed sand to create a water quality bypass
underneath the access route to Agua Hedionda Creek. Emergency dredging in Agua Hedionda
Creek upstream of the El Camino Real Bridge was completed by March 25, 2006.
Dredging underneath the south side El Camino Real Bridge began on March 27, 2006. The 50-
foot section of pipe used for the Calaveras Creek bypass was used to divert the creek's
watercourse and allow the creation of an access road across the creek. Once the material from
the south side of El Camino Real Bridge was removed and the area settled from the disturbance,
flow was returned to the south side such that work under the central and north sections could
take place. With dredging completed, dredging equipment was demobilized and gravel-bag
check dams were .removed on March 28, 2006.
V. COMPLIANCE MONITORING
As required in Condition B.2.d of the 401 Certification, any exceedances of turbidity limits that
occurred during emergency dredging were to be reported to the RWQCB within 48 hours and
immediate action was taken to reduce turbidity downstream to the maximum extent practicable.
Throughout the emergency dredging in Agua Hedionda Creek, there were a number of occasions
when downstream turbidity levels "spiked" due to inadvertent berm sloughing, leakage, and
failures that exceeded permit" limitations. As these conditions occurred, they were communicated
to the RWQCB within 48 hours and, when applicable, BMPs were adjusted to improve turbidity
controls and water quality downstream. Turbidity monitoring data and data histograms are
provided in Appendix B (Attachments 1, 2, 3, and 4), and project correspondence to the
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RWQCB and photo documentation are provided m Appendix C. Additional photo
documentation is available upon request.
The emergency dredging activities were completed ahead of schedule, under extreme rainy
conditions. The implementation ofBMPs was conducted in accordance with the project's Storm
Water Pollution Prevention Plan, which was amended when necessary (Section 207). All BMPs
required by the TCP were implemented and were adjusted to adapt to the morphology of Agua
Hedionda Creek.
It should be noted that throughout dredging operations, water quality controls were monitored
and modified to achieve the best practicable water quality conditions at the downstream
monitoring location. As shown by the hourly monitoring data (Appendix B -Attachments 2 and
3), there were short episodes of elevated measurements. Overall, the ranges of turbidity
measurement statistics were not notably different among upstream and downstream monitoring
locations (Table 1 ).
Table 1
Turbidity Measurement Statistics, Agua Hedionda Creek
Emergency Dredging, March 2006
Upstream Downstream
Min 6 9
Mean 28 48
Max 398 462
Median 14 20
Its important to note that observations made and measurements taken during the course of the
emergency dredging also indicated that upstream turbidity was periodically higher than
downstream values. This was particularly true following rainfall and subsequent runoff events.
To demonstrate the effects of storm water runoff, turbidity data from the Agua Hedionda Creek
Monitoring Project (Pacific REMS), as measured at the El Camino Real Bridge, shows that
significant turbidity effects can be caused by natural conditions (Appendix A -Attachment 4).
As shown in Appendix B (Attachment 4), Pacific REMS turbidity data recorded during a storm
event in early January 2006 shows in-creek turbidity reaching 3,000 NTUs (nephelometric
turbidity units) on two occasions. Average turbidity during this record of measurement was 333
NTUs. As illustrated in Appendix B (Attachment 4), the rise in creek level from local runoff
significantly affects water clarity in the creek and substantially exceeds any levels that were
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measured during the emergency dredging project (which also experienced rainfall on two
occasions).
Overall, the BMPs installed were effective in controlling turbidity. Flocculent was also proposed
(and approved by the RWQCB) for use on this project to supplement the physical BMPs
installed but was not used because the project finished ahead of schedule. In lieu of the very
stringent turbidity limits set by the 401 Certification and the documentation of hourly turbidity at
upstream and downstream monitoring locations, water quality was controlled to the maximum
extent practicable aild was maintained we.ll below conditions that have been documented to
occur naturally.
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BIRD NESTING SURVEY REPORT
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FIELD SURVEY REPORT FOR
LIGHT-FOOTED CLAPPER RAIL
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Ko11oe11y 8iol!o1Jiet11! So,vieos
Biological Consulting, Research, Conservation
April 30, 2006
06-01-A
EDAW,Inc.
1420 Kettner Blvd.
San Diego, California, 92101
Attn: Teresa Wilkinson, Senior Project Manager
Re: Results of a Focused Field Survey for the Light-footed Clapper Rail at the Agua Hedionda Creek
Emergency Dredge Work, San Diego County, California, 2005.
Dear Ms. Wilkinson
This letter report presents the results of focused field surveys for the light-footed clapper rail (Rallus
longirostris levipes), for the Agua Hedionda Creek Emergency Dredge Work in coastal San Diego
County, California. The light-footed clapper rail is listed as an endangered species by the U.S. Fish and
Wildlife Service (USFWS) and the California Department of Fish and Game (CDFG).
Surveys for the light-footed clapper rail were conducted by wildlife biologist John Konecny, following
methodology formulated by Konecny Biological Services (KBS) in consultation with light-footed clapper
rail principal investigator Richard Zembal, and approved by the USFWS. This activity is authorized by
KBS's USFWS section l0(a) permit number TE837308-3, and a CDFG Memorandum of Understanding.
INTRODUCTION
The light-footed clapper rail is a slender, tawny-breasted bird with grayish edges on brown centered back
feathers, olive wing coverts, vertical white bars on the flanks, a white stripe over the eye, and a partially
orange bill. Light-footed clapper rail occurred historically along the coast of southern California from
Carpinteria Marsh in Santa Barbara County south to San Quintin, Baja California, Mexico (Grinnell and
Miller 1944, USFWS 1994).
The light-footed clapper rail is a permanent resident of coastal salt marsh traversed by tidal sloughs,
usually characterized by cordgrass (Spartinafoliosa) and pickleweed (Salicornia spp.)(Grinnell and
Miller 1944, USFWS 1994). Light-footed clapper rails have also nested in freshwater marsh
characterized by cattails (Typha sp.) and bulrush (Scirpus sp.) at Buena Vista, Agua Hedionda, Batiquitos,
San Elijo, and San Dieguito Lagoons in San Diego County (Zembal et al 2005); and in spiny rush (Juncus
acutus) at Naval Air Station (NAS) Point Mugu. There is very limited evidence for inter-marsh
movement by light-footed clapper rails.
Populations oflight-footed clapper rails have undergone decline in the United States due to the rail's
limited distribution and destruction and degradation of coastal salt marsh habitat. The statewide breeding
rail population in 2005 was reported to be 360 pairs in 16 marshes (Zembal et al 2005), the largest
number of rails in recent history since the statewide census began in 1980. Seventy-three percent of these
pairs were found in two coastal salt marsh complexes at Upper Newport Bay and the Tijuana Marsh
National Wildlife Refuge.
Zembal and Massey (1986) have shown that paired light-footed clapper rails can be detected "clappering"
throughout the year, but have a bimodal peak in vocalizing during mid-February to mid-April and again
1501 East Grand Avenue #2403, Escondido, California, 92027
Tel (760) 489-5276 E-mail jkonecny@nethere.com
Ms. Teresa Wilkinson Page2
in September to October. The initial peak in vocalizing corresponds to the onset of breeding season. In
contrast to "clappering", single male and female "keking" is highly seasonal, almost exclusively
occurring between February and June.
PROJECT LOCATION
The Agua Hedionda Creek Emergency Dredge project site is located in Agua Hedionda Creek,
approximately two miles (3 .4 kilometers) east of Agua Hedionda Lagoon in the City of Carlsbad, coastal
San Diego County, Californa (Figure 1). The project is located mostly upstream of El Camino Real and ·
south of Cannon Road, extending approximately 3,000 feet (910 meters) eastward up Agua Hedionda
Creek, and approximately 4,000 feet (1,212 meters) northward up Calavera Creek. Portions of Agua
Hedionda Creek, including the area between Cannon Road and El Camino Real bridges, needed to be
dredged on an emergency basis. No dredging was done along Agua Hedionda creek, downstream of
Cannon Road Bridge and west of El Camino Real.
The light-footed clapper rail survey area extended for 500 feet (151 meters) from all of the area that
needed to be dredged. Specifically, the Agua Hedionda Creek Emergency Dredge Project site is located
within Township 12 South, Range 4 West, and in a numbered section of the U.S. Geological Survey San
Luis Rey, CA. 7.5-minute quadrangle.
PROJECT SITE DESCRIPTION
Much of the area of the Agua Hedionda Creek watershed in the Calavera Hills area, including the portion
of the creek that extends through the Rancho Carlsbad residential community has been highly disturbed in
the recent past by channelization and converted to residential housing. Very little native vegetation exists
upstream of the confluence of Agua Hedionda Creek and Calavera Creek, and between the confluence
and El Camino Real in the project area. The creeks are basically a denuded sandy bottom with non-native
ornamentals on the side slopes. No light-footed clapper rail habitat is present in these two reaches of the
project site.
The area upstream of the existing weir wall on Calavera Creek near the intersection of College Boulevard
and Cannon Road has been channelized and a detention basin is present to its immediate north. The
vegetation present here is riparian woodland and a disturbed mule-fat scrub. No light-footed clapper rail
habitat is present in this area.
The area west and downstream of El Camino Real consists of three distinct segments. The southern-most
segment, southeast of the dirt access road is considered "open space" by the City of Carlsbad, and
consists of freshwater marsh characterized by extensive cattails with emergent willows, mule-fat
(Baccharis sa/icifolia), and Eucalyptus.
Emergency dredge work commenced in the middle and smallest segment, located between the access road
and Cannon Road. Additional dredging was conducted upstream through the Rancho Carlsbad residential
community. The area between the two bridge structures consists ofrip-rapped sides and has a mature
overstory of willow riparian woodland, characterized by black willow (Salix goodengii), arroyo willow
(S. lasiolepis), sandbar willow (S. hindsiana), and mule-fat. The understory is poorly developed. Light-
footed clapper rail habitat is not present in this reach.
The third area, located outside the project work limits and downstream of the Cannon Road Bridge and
west of El Camino Real is a mosaic of freshwater marsh and willow riparian woodland, with scattered
Eucalyptus. This reach of habitat continues downstream and is continuous with Agua Hedionda Lagoon
u
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Ms. Teresa Wilkinson Page3
proper. Elevation of the Agua Hedionda Creek Emergency Dredging project site is approximately 60 feet
(18 meters) to 100 feet (30 meters) above mean sea level.
METHODS
At this time, the USFWS does not have a survey protocol for the light-footed clapper rail. Surveys were
conducted following a methodology formulated by KBS in consultation with light-footed clapper rail
principal investigator Richard Zembal, and approved by the USFWS.
Five focused light-footed clapper rail surveys were conducted at least seven days apart between February
13 th and March 141\ 2006. Dusk surveys were conducted on February 131\ March 71\ and March 141\
2006. Dawn surveys were conducted on February 20th and February 2i\ 2006. Each dawn and dusk
survey lasted approximately two-hours. Dawn surveys were conducted from pre-dawn to no later than
two-hours after sunrise. Dusk surveys were conducted between sunset and no more than two-hours prior
to sunset. A summary of the environmental conditions on the five survey dates is provided in Table 1.
The surveys were conducted by stopping at stations approximately 50-feet (17-meters) apart along the
perimeter of the survey area and listening for vocalizing light-footed clapper rails. If rails were not
detected passively, a call-prompt or tape-recorded vocalization of the light-footed clapper rail "dueting"
was played at 15-second intervals alternating with 15 seconds oflistening. A response was listened for in
the final three minutes before proceeding to the next survey station.
All potential clapper rail habitat within 500 feet of the dredge area was surveyed. An orange mesh
construction fence was erected on the upstream side of the Cannon Road Bridge over Agua Hedionda
Creek to prevent rails and other wildlife species from wandering into the Emergency Dredge area during
the clearing activity. The fence was removed on March 10, 2006, as soon as the Emergency Dredge area
had been cleared and excavated.
RESULTS
Two pairs of light-footed clapper rails were detected in the freshwater marsh north of Cannon Road, and
west and downstream of El Camino Real. No rails were detected in the freshwater marsh south of
Cannon Road and west of El Camino Real. One rail was initially detected on February 131\ near the
Eucalyptus grove immediately west of El Camino Real and north of Cannon Road. No rails were
detected on the morning of February 20th. Two pairs of"dueting" light-footed clapper rails were detected
the morning of February 271\ and subsequently relocated during the dusk surveys of March ih and 14th.
The light-footed clapper rail locations are shown in Figure 2. No other endangered or threatened species
were detected.
DISCUSSION
Described as "formerly common in all coastal marshes" by Grinnell and Miller (1944), the light-footed
clapper rail has never been a common bird species at Agua Hedionda Lagoon in recent history. The rail
population has vacillated between two and five pairs between 2000 and 2005, and has been at one or less
from 1997 and before (Zembal et al 2005). During 2005, one pair of clapper rails was present in the
freshwater marsh west of El Camino Real and a second pair was present farther downstream, well beyond
the 500 foot buffer area.
The short-term direct impacts of the project did not affect the light-footed clapper rails in the area, as rails
were detected in the same areas after the emergency dredging, that they were present in before the
activity. Temporary measures to minimize potential downstream sediment buildup should be considered
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Ms. Teresa Wilkinson Page 5
REFERENCES CITED
Grinnell, J., and A.H. Miller. 1944. The Distribution of the Birds of California. Cooper Ornithological
Club. Berkeley, California.
U.S. Fish and Wildlife Service. 1994. Light-footed Clapper Rail. Unpublished two-page pamphlet,
prepared by R. Zembal.
Zembal, R., S. Hoffman, and J. Konecny. 2005. Light-footed Clapper Rail Management, Study, and
Translocation, 2004. Report to Naval Base Ventura County, Point Mugu; U.S. Fish and Wildlife
Service; and California Department of Fish and Game, for California State University, Long
Beach Foundation and El Dorado Audubon Society.
Zembal, R. and B. W. Massey. 1986. Seasonality of Vocalizations by Light-footed Clapper Rails. J.
Field Ornithol., 58(1):41-48.
Table 1. Summary of Weather Conditions During Five Light-footed Clapper Rail Surveys at the
Agua Hedionda Dredging and Improvement Site, 2006.
Survey# Date Surveyor (Species) Time Weather Conditions
1 02/13/06 JK(LFCR) 1310-1650 20% overcast, 60-58F, wind 4-7 mph
2 02/20/06 JK(LFCR) 0630-0845 100% overcast, 44-46F, wind 1-3 mph
3 02/27/06 JK(LFCR) 0640-0850 100% overcast, 52-55F, wind 1-3 mph
4 03/07/06 JK(LFCR) 1505-1700 70% overcast, 62-60F, wind l-3mph
5 03/14/06 JK(LFCR) 1510-0715 60% overcast, 64-66F, wind 3-5 mph
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APPENDIXB
Data Reporting and Results
Agua Hedionda Creek
Emergency Dredging
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ATTACHMENT 1
AMBIENT TURBIDITY MEASUREMENTS
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Attachment 1.
Ambient Turbidity Measurements, Agua HediQnda Creek Emergency Dredging, 2006.
Sunday, March 05, 2006
Turbidity Turbidity
Time (NTU) Time (NTU)
Station 1 1242 42 1400 16
Station 2 1236 27 1414 15
Station 3 1227 14 1420 12
Station 4 1219 32 1425 15
Station 5 1213 17 1436 16
Station 6 1200 30 1443 16
Station 7 1147 26 1450 19
Station 8 1136 14 1455 14
Station 9 1128 51 1505 15
Station 10 1118 26 1512 15
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ATTACHMENT 2
HOURLY TURBIDITY MEASUREMENTS
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Attachment 2.
Hourly Turbidity Measurements, Agua Hedionda Creek Emergency Dredging, 2006.
Monday Upstream
Turbidity
3/6/2006 Time (NTU) Flow
1532 14 1.42
1625 15 1.21
Tuesday Upstream
Turbidity
3/7/2006 Time (NTU) Flow
0740 212 2.3
0835 182 2.11
0935 158 2.17
1030 132 1.83
1130 89 2.41
1235 61 1.79
1330 58 1.86
1435 47 1.91
Wednesday Upstream
Turbidity
3/8/2006 Time (NTU) Flow
0730 15 1.46
0830 12 1.32
930 11 1.7
1026 11 1.83
1132 32 1.33
1235 32 1.41
1325 39 1.38
1425 53 1.32
1532 53 1.39
1635 42 1.23
Thursday Upstream
Turbidity
3/9/2006 Time (NTU) Flow
0730 12 1.6
835 37 1.21
935 47 1.12
1030 64 1.32
1135 41 1.22
1232 25 1.09
1330 17 0.93
1430 12 1.23
1530 12 0.73
1630 14 1.09
Friday Upstream
Turbidity
3/10/2006 Time (NTU) Flow
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
06080058.01 Agua Hedionda Closeout Rpt_Attachment I, 2, & 3.xls
Downstream
Turbidity
Time (NTU)
1500 102
1600 32
Downstream
Turbidity
Time (NTU)
0700 142
0800 152
0900 108
1000 98
1100 69
1210 46
1300 37
1400 36
Downstream
Turbidity
Time (NTU)
700 11
800 10
900 13
1000 10
1110 24
1205 33
1300 21
1400 16
1500 21
1600 29
Downstream
Turbidity
Time (NTU)
700 10
800 14
900 11
1005 24
1100 36
1200 29
1300 19
1400 11
1500 14
1600 17
Downstream
Turbidity
Time (NTU)
NA NA
NA NA
NA NA
NA NA
NA NA
NA NA
NA NA
NA NA
NA NA
NA NA
Flow
1.17
1.42
Flow
1.82
1.78
1.61
2.08
2.33
2.08
1.81
1.76
Flow
1.62
1.66
1.78
1.94
1.81
1.82
1.77
1.96
2.21
1.61
Flow
1.64
1.12
1.53
1.84
1.87
1.42
1.87
2.03
1.84
2.26
Flow
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Initial setup and rain forecasted for tomorrow.
Crews (~30 people) installing BMPs
Measurements taken~ 20-30 minutes after crew leaving
Approximately 0.1 -0.2" rain the night before; runoff creating turbid
creek flow throughout length
Light rainfall overnight ( ~0. !Oinches ).
Visually more cloudy at upstream station; water level higher
Visually more cloudy at upstream station; water level higher
Visually more cloudy at upstream station; water level higher
Visually more cloudy at upstream station; water level higher
Visually more cloudy at upstream station; water level higher
Storm event forecasted for Friday-Sunday with 0. 70 inches.
Crews begin to remove sand/gravel bags from desilting basin.
No work activities because of storm event forecasted for Fri-Sunday.
Attachment 2. I Hourly Turbidity Measurements, Agua Hedionda Creek Emergency Dredging, 2006.
Monday Uostream Downstream No work occurred,Monday due,to the amount of rainfall over the Turbidity Turbidity weekend (---0.79inch). I 3/13/2006 Time (NTU) Flow Time (NTU) Flow
i NA NA NA NA NA NA
NA NA NA NA NA NA
NA NA NA NA NA NA I NA NA NA NA NA NA
NA NA NA NA NA NA
NA NA NA NA NA NA I NA NA NA NA NA NA
NA NA NA NA NA NA
NA NA NA NA NA NA
I Tuesday Upstream Downstream Water level was high due to the storm event(---0,65 inch). Initial work Turbidity Turbidity started on north side of El Camino Real Bridge. 3/14/2006 Time (NTU) Flow Time (NTU) Flow
0735 11 1.19 0700 12 1.85 Workers reinstalling gravel.bags for desilting,basin,prior to working. I 0835 12 1.47 0805 13 1.78
0930 13 1.04 0900 11 1.73
1030 10 0.79 10()5 12 L51
1135 12 1.15 1105 15 1.64 Pilot channel for upstream work beginning I 1235 16 0.56 1200 89 1.53 Water is visually cloudy downstream.
1335 14 0.73 1305 188 1.83
1430 13 0.83 1405 127 1.63 Added additional gravel bags downstream.
1530 17 1.01 1504 101 1.47 Rearranged ·chevrons downstream. I 1630 15 1.11 1605 172 1.98 Rearranged chevrons downstream.
Wednesday Upstream Downstream No work today, all efforts are to reposition chevrons and strengthen Turbidity Turbidity desilting berms. I 3/15/2006 Time (NTU) Flow Time (NTU) Flow
1140 13 1.11 1115 16 1.23 Sample taken downstream ofBMPs.
NA NA NA 1200 ' 9 0.53 Sample taken under Cannon Road Bridge behind second,row.
"I NA NA NA 1210 13 0.98 Sample taken in front of all.BMPs.
NA NA NA NA NA NA
NA NA NA NA NA NA
NA NA NA NA NA NA I NA NA NA NA NA NA
NA NA NA NA NA NA
NA NA NA NA NA NA
NA NA NA NA NA NA I Thursday Upstream Downstream
Turbidity Turbidity Storm forecasted for Friday/Saturday,
3/16/2006 Time (NTU) Flow Time (NTU) Flow I 0735 10 1.44 0700 11 1.83
0835 9 1.49 0805 13 1.96 Construction began upstream outside of pilot channel.
0930 11 1.53 0905 14 2.13 Material slumped into pilot channel.
1030 13 1.13 1000 41 2.22 I 1130 11 1.29 1100 89 1.91 All work is outside of pilot channel-visually see turbidity.
1230 10 0.84 1200 142 1.83
1330 12 1.05 1300 49 1.76 Visually see water clarity,
1430 15 0.79 1400 27 1.94 I 1530 12 1.01 1500 17 1.54
1630 11 0.92 1600 15 1.58
I Friday Upstream Downstream Storm event'forecasted, for Friday afternoon through Saturday
Turbidity Turbidity (---0.82inches). Work is to stop at 1600 to remove gravel bag berms, so·
3/17/2006 Time (NTU) Flow Time (NTU) Flow· that they don't wash downstream.
0735 9 0.78 0700 11 1.62 I 0835 10 0.64 0800 12 1.89 Construction began upstream outside of pilot channel.
0930 10 0.68 0900 11 1.73
1030 11 0.73 1000 12 1.52
1130 9 1.14 1100 12 2.07 Sand berm slumped into pilot channel. I 1230 9 0.91 1200 10 2.14
1330 10 0.84 1300 12 2.09
1430 9 0.77 1400 21 1.93
06080058,01 Agua Hedionda Closeout Rpt_Attachment I, 2, & 3.xls I
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1535
Monday
3/20/2006 Time
0730
NA
NA
NA
NA
NA
NA
NA
NA
Tuesday
3/21/2006 Time
0705
NA
NA
NA
NA
NA
NA
NA
NA
NA
Wednesday
3/22/2006 Time
0730
0830
0930
1030
1130
1230
1330
1430
1530
1630
Thursday
3/23/2006 Time
0730
0830
0930
1030
1130
1230
1330
1433
1530
1635
Friday
3/24/2006 Time
0730
0830
0930
1030
1130
1230
1330
Attachment 2.
Hourly Turbidity Measurements, Agua Hedionda Creek Emergency Dredging, 2006.
11 0.98 j j 1500 17 1.69 I Work activities stopped to prepare for storm event.
Upstream
Turbidity
(NTU) Flow Time
22 1.56 0700
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
Upstream
Turbidity
(NTU) Flow Time
398 3.63 0640
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
NA NA NA
Upstream
Turbidity
(NTU) Flow Time
18 1.36 0700
20 1.41 0800
21 1.74 0900
24 1.7 1000
22 1.81 1100
17 1.46 1200
17 1.51 1300
14 1.6 1400
13 1.43 1500
15 1.56 1600
Upstream
Turbidity
(NTU) Flow Time
10 1.09 0700
13 1.04 0800
12 1.11 0900
13 1.17 1000
12 1.25 1100
23 0.78 1200
21 1.03 1300
18 1.01 1400
16 1.61 1500
21 1.52 1600
Upstream
Turbidity
(NTU) Flow Time
23 0.71 0700
18 0.86 0800
15 0.93 0900
16 0.68 1000
14 0.76 1100
11 0.83 1200
16 0.7 1300
Downstream
Turbidity
(NTU)
20
NA
NA
NA
NA
NA
NA
NA
NA
Downstream
Turbidity
(NTU)
462
NA
NA
NA
NA
NA
NA
NA
NA
NA
Downstream
Turbidity
(NTU)
20
21
96
37
26
21
19
16
15
74
Downstream
Turbidity
(NTU)
12
16
121
56
255
120
38
78
137
64
Downstream
Turbidity
(NTU)
16
15
16
13
11
309
204
Flow
1.79
NA
NA
NA
NA
NA
NA
NA
NA
Flow
2.81
NA
NA
NA
NA
NA
NA
NA
NA
NA
Flow
1.13
1.47
1.9
1.79
1.39
1.9
2.03
1.9
2.3
2.07
Flow
2.13
2.17
2.3
2.19
2.36
2.14
1.26
2.06
1.58
1.95
Flow
1.86
1.79
1.61
1.72
1.27
1.68
1.49
No work activities because of storm event over the weekend.
No work activities because of rainfall overnight.
Water slightly turbid from previous rainfall.
Resetting gravel bags under Cannon Road, sample taken in front ofBMPs.
Benn collapsed into pilot channel.
Visually see water clearing up.
Upstream berm slumped into pilot channel.
No storms forecasted, work activities began at 0730.
At 0840 material slumped into the pilot channel upstream.
At 1015 discharge from Calaveras Creek from up the watershed.
At 1345 two sections of pilot channel slumped.
Visually see the turbidity lessen.
Work activities began at 0740 upstream, all work should be outside of
pilot channel.
Water is cloudy between the bridges.
At 101 O material slumped into the pilot channel.
Added additional chevron downstream eastside.
06080058.0l Agua Hedionda Closeout Rpt_Attachment I, 2, & 3.xls
Saturday
3/25/2006
Monday
3/27/2006
Tuesday
3/28/2006
1430
1530
1625
Time
0730
0830
0930
1030
1130
1230
NA
NA
NA
NA
Time
0730
0830
0930
1030
1130
1230
1330
1430
1530
1630
Time
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Attachment 2.
Hourly Turbidity Measurements, Agua Hedionda Creek-Emergency Dredging, 2006.
18 1.53 1400 96 2.14
16 1.09 1500 64 l.89 Wateris visually clearer frotn previous samples.
21 1.01 1550 42 1.96
Upstream Downstream
Turbidity Turbidity All work occurred upstream and ceased at 1215.
(NTU) Flow Time (NTU) Flow
8 1.21 0700 18 1.4
13 0.79 0800 28 1.32
6 1.07 0900 14 1.06
6 1.07 1000 11 1.52
18 0.92 1100 13 1.35
20 1.03 1200 30 1.35
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
Upstream Downstream
Turbidity Turbidity Work activities occurring under El Camino Real Bridge.
(NTU) Flow Time (NTU) Flow
9 ·0.79 0700 10 1.42
10 0.74 0800 11 1.51 50-foot steel pipe laid to divert flow.
13 0.89 0900 83 1.82
11 0.85 1000 41 1.85
12 0.76 1100 22 1.73
9 0.64 1200 23 1.62
16 0.9 1300 24 l.76
14 0.88 1400 13 1.81
9 0.83 1500 q 1.86 BMP gravel bags removed for,storm event.
11 0.72 1600 14 l.71
Uostream Downstream
Turbidity Turbidity Demobilization Day
(NTU) Flow Time (NTU) Flow
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
NA NA NA NA NA
06080058.0J Agua Hedionda Closeout Rpt_Attachment I, 2, & 3.xls
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ATTACHMENT 3
COMPARISON OF UPSTREAM AND DOWNSTREAM
TURBIDITY MEASUREMENTS DURING
EMERGENCY DREDGING
I Attachment 3.
Comparison of Upstream and Downstream Turbidity Measurements During Emergency Dredging, Aqua Hedionda Creek, March 2006.
I
I I
Turbidity in Agua Hedionda Creek During Emergency Dredging
-Upstream -Downstream I
500
I 450
I 400
350
I 300
I
;:, 250 I-z
200
I 150
100
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50 I\. -A \ \
~ -j \.._ ~, ,~~ _,... ... ~ ~,~ 0 r-n ,-
3/7 /06 3/8/06 3/10/06 3/14/06 3/16/06 3/20/06 3/22/06 3/24/06 3/27/06
I Turbidity in Agua Hedionda Creek During Emergency Dredging
(rescaled to ambient data scale shown in Attachment 4)
I I -Upstream -Downstream I
3500
I 3000
I 2500
I 2000
;:,
I-z
1500
I
1000
I 500
I ~ -M A A Ah~ A. 0
3/7/06 3/8/06 3/10/06 3/14/06 3/16/06 3/20/06 3/22/06 3/24/06 3/27/06
I 06080058.01 Agua Hedionda Closeout Rpt_Attachmcnt I, 2, & 3.xls
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ATTACHMENT 4
AMBIENT TURBIDITY AND CREEK LEVEL
IN AGUA HEDIONDA CREEK
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APPENDIXC
RWQCB Correspondence
and Photo Documentation
Agua Hedionda Creek
Emergency Dredging
EDAW Page2
Turbidity levels on March 7, 2006 were notably higher due to storm water runoff from a small
storm (approximately 0.1 -0.2 inch ofrainfall) occurring the night before. During this first full
day of active dredging (March 7, 2006), turbidity levels were generally higher at the upstream
monitoring location than immediately downstream of the dredge. By isolating the dredging
activity within a small berm-protected footprint between the Cannon Road and El Camino Real
bridges, there was no disturbance within the creek occurred (see Attachment 3). This approach
was supplemental to the BMP .approaches detailed in the TCP and it proved to protect water
quality and meet the goals of the 401 Certification for controlling downstream turbidity.
EXPECTATIONS
Local forecasts (Attachment 4) ·are predicting approximately 1 inch of rainfall or more between
this Friday night (March 10, 2006) and Sunday (March 12, 2006). The creek flows observed
during the light rain last Monday night are expected to be significantly higher for this storm
event.
As a safety and water quality precaution, no dredging will be conducted during this upcoming
rainfall. Dredging work is expected to be suspended until Monday, March 13, 2006 at the
earliest.
To keep BMPs from being transported downstream, sand bags, gravel bags, fiber rolls, and
other BMP materials will be removed from. the creekbed and staged on the banks nearby. Once
precipitation has abated and creek flow is low enough, BMPs will be reinstalled. Dredging will
be reactivated once. conditions are safe and BMPs are in place.
As demonstrated by the data collected to date, turbidity has been controlled. Following the
completion of emergency dredging activities, a compliance monitoring report will be provided
to the RWQCB that summarizes daily activities (i.e., turbidity monitoring, biological
monitoring, and general housekeeping measures).
We look forward to working with you and providing you with any additional data or
documentation prior to and during your field visit. If you have any questions regarding this
memorandum, please call me at (619) 233-1454.
Respectfully,
::~~;:.
Senior Environmental Scientist
06080{)58 Means Memo
DESIGN, PLANNING AND ENVIRONMENTS WORLDWIDE
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Attachment 1
Ambient, Pre-dredge Turbidity Monitoring
Agua Hedionda Emergency Dredging Project
5-Mar-06 Time Turbidity
(NTU)
Station 1 1242 42
Station 2 1236 27
Station 3 1227 14
Station 4 1219 32
Station 5 1213 17
Station 6 1200 30
Station 7 1147 26
Station 8 1136 14
Station 9 1128 51
Station 10 1118 26
Station 1 1400 16
Station 2 1414 15
Station 3 1420 12
Station 4 1425 15
Station 5 1436 16
Station 6 1443 16
Station 7 1450 19
Station 8 1455 14
Station 9 1505 15
Station 10 1512 15
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MEMO
Date: March 17, 2006
Project: Agua Hedionda Channel Dredging Project
Reference: File No. 06C-007
To: Christopher Means, Environmental Scientist
California Regional Water Quality Control Board, San Diego Region
9174 Sky Park Court, Suite 100
San Diego, CA 92123
Copy: Kari Coler, U.S. Army Corps of Engineers
From:
Via:
Subject:
Tamara Spear, California Dept. of Fish and Game
David Hauser, Deputy City Engineer
Glen K. Van Peski, Consultant Project Engineer, City of Carlsbad
email
Notification of Exceedence of Turbidity Criteria,
Water Quality Certification 0GC-007
This memorandum is to notify the Regional Water Quality Control Board (RWQCB) that turbidity
limitations mandated for the Agua Hedionda Creek Emergency Dredging Project (Certification
06C-007, § B2.d) were periodically exceeded.
On March 16, 2006, dredging of the main channel of Agua Hedionda Creek commenced at the
upstream end of the project. It was anticipated (see previous memo dated March 15, 2006) that
being the main channel containing coarse sand, being far upstream of the turbidity control
works, and having a diversion channel in place would allow operations to meet the turbidity
criteria of the Water Quality Certification. The excavator left a segment of sand on the upstream
side of the channel, and excavated a section from the 'dry' side first (see 7:52 am photo). The
last removal for that section was the area adjacent to the diversion channel (see 8:12 am
photo). This caused water to flow into the excavated area, but once it was equalized with the
water level in the diversion channel, water continued to flow by the excavated area with very
little of the disturbed water flowing downstream (see 8:15 am photo). Turbidity measurements
downstream from 7:00 am to 9:00 am ranged from 11 to 14 NTU.
As the excavated area lengthened, the water from the diversion channel started to mix more
with the dredged area water, and at 10:00, the turbidity measurements downstream were 41
NTU. At that time, the contractor was notified to modify the dredging operations to leave sand
between the dredging area and the diversion channel flows. Water still seeped through the
sand, but the physical sand barrier prevented the turbid water from joining stream flows (see
11 :29 am photo). By this time, turbidity already in the water worked it's way downstream,
resulting in downstream turbidity measurements that peaked at 142 NTU at 12:00 pm. By 1 :00,
the results of the changed dredging operations were having an effect downstream, and the
measurements dropped to 49 NTU. Measurements continued to drop the remainder of the day,
to 15 NTU at 4:00 pm.
As work progressed, the sand dike separating the dredged area from the stream flows breached
at one point. The contractor then created another containment dike to isolate that dredged
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MEMO
Date: March 25, 2006
Project: Agua Hedionda Channel Dredging Project
Reference: File No. 06C-007
To: Christopher Means, Environmental Scientist
California Regional Water Quality Control Board, San Diego Region
9174 Sky Park Court, Suite 100
San Diego, CA 92123
Copy: Kari Coler, U.S. Army Corps of Engineers
From:
Via:
Subject:
Tamara Spear, California Dept. of Fish and Game
David Hauser, Deputy City Engineer
Glen K. Van Peski, Consultant Project Engineer, City of Carlsbad
email
Notification of Exceedence of Turbidity Criteria,
Water Quality Certification 06C-007
This memorandum is to notify the Regional Water Quality Control Board (RWQCB) that turbidity
limitations mandated for the Agua Hedionda Creek Emergency Dredging Project (Certification 06C-
007, § 82.d) were periodically exceeded.
On March 23, 2006, at 10:40 a.m., the discharge from Calavera Creek was noted to be turbid,
though the emergency dredging project is doing no work upstream on Calavera Creek. The
construction manager walked up Calavera Creek to try and identify the source of the dirty water, but
it was already clearing. No explanation was found for the turbidity in Calavera Creek. It appears
that the tubidity from Calavera Creek affected the turbidity readings downstream in Agua Hedionda
Creek.
Also on this day, there were troubles with the side berm in the excavation area, collapsing and
letting the stream flow from the diversion channel into the dredge area. Depending on a number of
factors, this generally released very little turbidity, as once the water level equalized, the stream
continued to flow past the dredged basin. However, in one instance both the side berm and the
rear berm collapsed, which resulted in water entering the dredge basin at the upstream end, and
pushing the silty water out the lower end, into the stream. This created a spike in turbidity readings.
Action taken included adding a gravel bag chevron under Cannon Road. Also, contractor was told
to leave the rear berms higher and wider to prevent their collapse.
On Friday, March 24, work was proceeding well using the method of dredging within contained
basins, with wider rear berms. The contractor noted that the side berm collapses were because of
the higher water level in the adjacent diversion channel compared to the lower water level in the
dredging basin area. Water was seeping through from the diversion channel into the basin, and in
the process, creating weak spots in the side berms that then collapsed. The contractor figured that
if he opened the end berm, it would allow some water into the basin to equalize the water level with
that of the diversion channel, and help keep the side berm intact. As it turned out, after he opened
the previous end berm, the water level in the basin rose until it was above the diversion channel,
creating the same problem as before but in reverse. The swelling basin water threatened to break
the terminal berm and flood the current work area, so the excavator operator was told to put a break
in the side berm to relieve the pressure. Unfortunately, this meant that the complete flow was now
-traveling through the morning work area, flushing all the turbid water. This created a spike in the
noon measurement, but the turbidity decreased steadily to the end of the day. Contractor was
instructed to leave wider side berms.
On Saturday, March 25, the wider side berm held intact for the entire day.
Please see attached turbidity monitoring log from EDAW for this period. You will still receive the
final summary monitoring report at the conclusion of the project, this excerpt was provided solely for
the purpose of this notification.
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