HomeMy WebLinkAbout2006-01-18; Planning Commission; Resolution 58901 PLANNING COMMISSION RESOLUTION NO. 5890
2 A RESOLUTION OF THE PLANNING COMMISSION OF THE
3 CITY OF CARLSBAD, CALIFORNIA, ADOPTING A
MITIGATED NEGATIVE DECLARATION FOR REPAIRS TO
4 THE EXISTING LAKE CALAVERA RESERVOIR INTAKE
AND OUTLET WORKS, SPILLWAY AND ACCESS ROAD,
AND OUTLET PIPING AND THE CONSTRUCTION OF A
6 NEW DAM OPERATIONS CONTROL BUILDING, LOCATED
APPROXIMATELY 900 TO 1,200 FEET SOUTH OF THE
7 INTERSECTION OF TAMARACK AVENUE AND
KNOLLWOOD DRIVE, IN LOCAL FACILITIES
8 MANAGEMENT ZONE 7.
9 CASE NAME: LAKE CALAVERA RESERVOIR
REMEDIAL IMPROVEMENTS
10 CASE NO.: CUP 04-11
1! WHEREAS, Carlsbad Municipal Water District, "Developer/Owner," has filed
12 a verified application with the City of Carlsbad regarding property described as
13
A portion of Lots D and L of Rancho Agua Hedionda,
14 according to Map No. 823, filed in the Office of the County
Recorder of San Diego County on May 1, 1915, in the City of
15 Carlsbad, County of San Diego, State of California
16 ("the Property"); and
17
WHEREAS, a Mitigated Negative Declaration was prepared in conjunction with
18
said project; and
20 WHEREAS, the Planning Commission did on the 18th day of January 2006,
21 hold a duly noticed public hearing as prescribed by law to consider said request; and
22 WHEREAS, at said public hearing, upon hearing and considering all testimony
23 and arguments, examining the initial study, analyzing the information submitted by staff, and
24
considering any written comments received, the Planning Commission considered all factors
25
relating to the Mitigated Negative Declaration; and26
27 WHEREAS, the Lake Calavera Reservoir Remedial Improvements project site is
28 located within the boundaries of the City of Carlsbad Habitat Management Plan and North San
Diego County Multiple Habitat Conservation Plan, both of which contain technical information
related to the identification and protection of conservation areas and the impact assessment and
2 mitigation measures for the incidental take of habitats and species of concern within the plan
3
areas; and
4
, WHEREAS, all relevant information contained in the City of Carlsbad Habitat
6 Management Plan and North San Diego County Multiple Habitat Conservation Plan, on file in
7 the Planning Department and incorporated by reference herein, has been analyzed and
o considered in the environmental determination.
9 NOW, THEREFORE, BE IT HEREBY RESOLVED by the Planning
10
Commission as follows:
11
A) That the foregoing recitations are true and correct.
13 B) That based on the evidence presented at the public hearing, the Planning
Commission hereby ADOPTS the Mitigated Negative Declaration, Exhibit "ND,"
14 dated January 18, 2006 according to Exhibits "NOI" dated December 12, 2005,
and "PII" dated November 30, 2005, attached hereto and made a part hereof,
15 based on the following findings:
16 Findings:
17
1. The Planning Commission of the City of Carlsbad does hereby find:
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a. it has reviewed, analyzed and considered the Mitigated Negative Declaration and
the environmental impacts therein identified for this project and any comments
2Q thereon prior to APPROVING the project; and
21 b. the Mitigated Negative Declaration has been prepared in accordance with
requirements of the California Environmental Quality Act, the State Guidelines
22 and the Environmental Protection Procedures of the City of Carlsbad; and
23 c. it reflects the independent judgment of the Planning Commission of the City of
24 Carlsbad; and
25 d. based on the EIA Part II and comments thereon, there is no substantial evidence
the project will have a significant effect on the environment.
26 Conditions:
27 1. As a condition of this approval, applicant must comply with the requirements of all
28 regulatory agencies having jurisdiction over the project and any mitigation requirements
of the environmental documents for the project.
PCRESONO. 5890 -2-
2. Developer shall implement, or cause the implementation of, the Lake Calavera
2 Reservoir Remedial Improvement Project Mitigation Monitoring and Reporting
Program.
3
PASSED, APPROVED AND ADOPTED at a regular meeting of the Planning4
, Commission of the City of Carlsbad, California, held on the 18th day of January 2006, by the
6 following vote, to wit:
7 AYES: Chairperson Montgomery, Commissioners Baker, Cardosa,
Dominguez, Heineman, Segall and Whitton8
9 NOES:
10 ABSENT:
11 ABSTAIN:
12
13
14 M
MARTELL B. MONTGOMERY, Chairperson
15 CARLSBAD PLANNING COMMISSION
16
17 AJTEST:
18
19 DONNEU
2Q Assistant Planning Director
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24
25
26
27
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PCRESONO. 5890 -3-
City of Carlsbad
CASE NAME:
CASE NO:
PROJECT LOCATION:
Planning Department
MITIGATED NEGATIVE DECLARATION
Lake Calavera Reservoir Remedial Improvements
CUP 04-11/HMP 05-03
In and around the Lake Calavera Reservoir, approximately 900 to 1.200 feet
south of the intersection of Tamarack Avenue and Knollwood Drive. City of
Carlsbad. County of San Diego.
PROJECT DESCRIPTION: Repairs to the existing Lake Calavera Reservoir intake and outlet works,
spillway and access road, and outlet piping; construction of a new dam operations control building and
security fencing. Repairs will require the controlled drawdown of approximately 77 million gallons of
impounded water within the reservoir over a four to six week period. Once repaired, the normal operations
of the reservoir will result in water level fluctuations between 190 and 208 feet in accordance with an
overall water management program.
DETERMINATION: The City of Carlsbad has conducted an environmental review of the above described
project pursuant to the Guidelines for Implementation of the California Environmental Quality Act and the
Environmental Protection Ordinance of the City of Carlsbad. As a result of said review, the initial study
(EIA Part 2) identified potentially significant effects on the environment, and the City of Carlsbad finds as
follows:
^ Although the proposed project could have a significant effect on the environment, there will not be a
significant effect in this case because the mitigation measures described on an attached sheet have
been added to the project.
CD The proposed project MAY have "potentially significant impact(s)" on the environment, but at least
one potentially significant impact 1) has been adequately analyzed in an earlier document pursuant
to applicable legal standards, and 2) has been addressed by mitigation measures based on the earlier
analysis as described on attached sheets. (Mitigated Negative Declaration applies only to the effects
that remained to be addressed).
CD Although the proposed project could have a significant effect on the environment, there WILL NOT
be a significant effect in this case because all potentially significant effects (a) have been analyzed
adequately in an earlier ENVIRONMENTAL IMPACT REPORT or NEGATIVE DECLARATION
pursuant to applicable standards and (b) have been avoided or mitigated pursuant to that earlier
ENVIRONMENTAL IMPACT REPORT or NEGATIVE DECLARATION, including revisions or
mitigation measures that are imposed upon the proposed project. Therefore, nothing further is
required.
A copy of the initial study (EIA Part 2) documenting reasons to support the Negative Declaration is on file
in the Planning Department, 1635 Faraday Avenue, Carlsbad, California 92008.
ADOPTED: January 18. 2006. pursuant to Planning Commission Resolution No.5890
ATTEST:
DON NEU
Assistant Planning Director
1635 Faraday Avenue • Carlsbad, CA 92008-7314 • (760) 602-4600 • FAX (760) 602-8559 • www.ci.carlsbad.ca.us
City of Carlsbad
Planning Department
CASE NAME:
CASE NO:
PROJECT LOCATION:
NOTICE OF INTENT TO ADOPT A
MITIGATED NEGATIVE DECLARATION
Lake Calavera Reservoir Remedial Improvements
CUP 04-11/HMPP 05-03
In and around the Lake Calavera Reservoir, approximately 900 to
1.200 feet south of the intersection of Tamarack Avenue and
Knollwood Drive, City of Carlsbad. County of San Diego.
PROJECT DESCRIPTION: Repairs to the existing Lake Calavera Reservoir intake and outlet
works, spillway and access road, and outlet piping; construction of a new dam operations control
building and security fencing. Repairs will require utilization of a small temporary water-tight
structure with an inflatable gasket which will be placed around the upper section of the existing tower in
order to pump out the water between this tower and the temporary structure for demolition and
construction access. Once repaired, the normal operations of the reservoir will result in water level
fluctuations between 190 and 208 feet elevation in accordance with an overall water management
program.
PROPOSED DETERMINATION: The City of Carlsbad has conducted an environmental review
of the above described project pursuant to the Guidelines for Implementation of the California
Environmental Quality Act and the Environmental Protection Ordinance of the City of Carlsbad. As
a result of said review, the initial study (EIA Part 2) identified potentially significant effects on the
environment, but (1) revisions in the project plans or proposals made by, or agreed to by, the
applicant before the proposed negative declaration and initial study are released for public review
would avoid the effects or mitigate the effects to a point where clearly no significant effect on the
environment would occur, and (2) there is no substantial evidence in light of the whole record before
the City that the project "as revised" may have a significant effect on the environment. Therefore, a
Mitigated Negative Declaration will be recommended for adoption by the City of Carlsbad
Planning Commission.
A copy of the initial study (EIA Part 2) documenting reasons to support the proposed Mitigated
Negative Declaration are on file in the Planning Department, 1635 Faraday Avenue, Carlsbad,
California 92008. Comments from the public are invited. Please submit comments in writing to the
Planning Department within 30 days of the date of this notice.
The proposed project and revised Mitigated Negative Declaration are subject to review and
approval/adoption by the City of Carlsbad Planning Commission and City Council. Additional
public notices will be issued when those public hearings are scheduled. If you have any questions,
please call Michael Grim in the Planning Department at (760) 602-4623.
PUBLIC REVIEW PERIOD
PUBLISH DATE
December 12. 2005 through January 11. 2006
December 12. 2005
1635 Faraday Avenue • Carlsbad, CA 92008-7314 • (760) 602-4600 • FAX (760) 602-8559 • www.ci.carlsbad.ca.us
ENVIRONMENTAL IMPACT ASSESSMENT FORM - PART II
(TO BE COMPLETED BY THE PLANNING DEPARTMENT)
CASE NO: CUP 04- 11/HMPP 05-03
DATE: November 30. 2005
BACKGROUND
1. CASE NAME: Lake Calavera Reservoir Remedial Improvements
2. LEAD AGENCY NAME AND ADDRESS: City of Carlsbad
3. CONTACT PERSON AND PHONE NUMBER: Christopher Muehlbacher (760) 602-2736
4. PROJECT LOCATION: In and around the Lake Calavera Reservoir. Approximately 900-1.200
linear feet south of the intersection of Tamarack Avenue and Knollwood Drive in the
northeast quadrant of Carlsbad.
5. PROJECT SPONSOR'S NAME AND ADDRESS: Carlsbad Municipal Water District. 1635
Faraday Ave.. Carlsbad. CA 92008
6. GENERAL PLAN DESIGNATION: Open Space (OS)
7. ZONING: Open Space (Q-S)
8. OTHER PUBLIC AGENCIES WHOSE APPROVAL IS REQUIRED (i.e., permits, financing
approval or participation agreements): U.S. Army Corps of Engineers (USAGE), California
Dept. of Fish & Game (CDFG). San Diego Regional Water Resources Control Board (RWQCB)
California Dept. of Safety of Dams (DSOD).
9. PROJECT DESCRIPTION/ ENVIRONMENTAL SETTING AND SURROUNDING LAND
USES:
Background. The Carlsbad Municipal Water District (CMWD) proposes to construct repairs to
the existing Lake Calavera Reservoir intake/outlet works, to the spillway and access road,
conduct repairs to the existing outlet piping using slip-lining methods, construct a control
building, and to install fencing for improved site security around the dam operations. Much of
the existing operational features and apparatus are inoperable, having failed or been destroyed
over years of maintenance neglect. The dam intake tower and walkway abutment now constitute
undesirable and unsafe attractions to the public. The outlet pipeline, partially clogged with debris
at the tower base, is requiring remediation. In addition, structural and operational deficiencies
have also been detected at the outlet box structure, spillway apron, spillway channel, access road
and security fencing. All of these aspects of the existing facility are proposed for improvement
and upgrade.
The primary function of the Lake Calavera Reservoir is stormwater retention for flood control.
The water level in the reservoir is presently regulated solely by the elevation (approximately 208
ft. MSL) of the highest of three inoperable (rusted) outflow control valves on the intake tower.
The lower two valves have been permanently sealed with marine caulk in order that a medium-
high water level (and thus a visually attractive reservoir) can be maintained. This highest (208 ft)
Rev. 07/03/04
valve is rusted in a permanently open position. Upon completion of the proposed remedial
improvements, ongoing management of a functional dam operations system will result in water
level fluctuation between 194-214 feet elevation in accordance with an overall water management
program. The designed extreme high water level of the reservoir is 220 feet elevation.
As a result of the inoperable nature of the outflow valves, the existing dam facilities are not in
compliance with the requirements of the Division of Safety of Dams (a division of the California
Dept. of Water Resources). DSOD emergency regulations dictate that dam managers shall have
the ability to draw-down at least 50% of the volume of the reservoir water within seven (7) days.
While the Calavera Dam does not presently have this ability, implementation of the proposed
remedial improvements would allow function and control of the dam which would allow it to
comply with the requirement. This project will allow the reservoir to return to a natural in-flow,
out-flow hydrological regime that can be managed to maximize its visual, biological and storm
water control benefits.
Environmental Setting. The subject repairs will take place on and around Calavera Dam, which
is located on an existing 288 acre parcel encompassing Lake Calavera Reservoir and associated
surrounding open spaces. This parcel is owned by the City of Carlsbad. The dam and related
facilities are operated and maintained by CMWD. The surface area of the reservoir, when full,
approximates 21 acres in size. Its maximum storage capacity is approximately 540 acre-feet of
water. The average depth of the reservoir is between 12 to 16 feet and has a maximum water
depth of 54 feet. Over the past thirty years the water surface level has ranged from 196-ft amsl to
217-ft amsl. The water level fluctuates naturally in response to rainfall and drought conditions,
which results in variation of the surface area depending upon time of year, climatic conditions,
evaporation rates and water saturation of soil in the watershed.
The Lake Calavera reservoir impoundment is formed by the compacted earth-fill dam containing
rock blankets on both upstream and downstream faces. The decomposed granite base was
excavated and the dam and spillway structures were completed in 1941. The maximum operating
reservoir height (extreme high water) is specified at elevation 220 feet (the elevation of the
spillway) to allow for maximum storm water retention. The minimum operating reservoir level is
established by the existing outlet lowest gate valve (elevation 189 ft.).
The existing controlled water outflow occurs through a vertical, 63-foot tall reinforced concrete
outlet tower located within the body of the reservoir, near the lake-side toe of the dam, and
approximately 115 feet from the crest of the dam. The existing tower has an approximate 10-
foot exterior diameter, and includes a grated cover, three 18 inch gate valves and ports, spaced at
approximate 7 foot intervals, and a 12 inch emergency release valve. The base of the tower
connects to a steel outlet pipe which is encased in reinforced concrete that transitions to concrete
pipe which extends through the base of the dam to an outlet box situated at the downstream toe of
the dam. The upper 26 feet (cut at elev. 199 ft.) of this vertical tower will be removed.
Surrounding Land Uses. The subject property is identified as a future mitigation bank in the
City of Carlsbad adopted Habitat Management Plan (HMP). Final execution of a mitigation bank
agreement with the Wildlife Agencies however has not yet taken place. Surrounding land uses in
the immediate vicinity of the proposed project and the Lake Calavera Mitigation Bank lands are
all open space. Further to the west are newer single-family residential neighborhoods of
Sheffield, Nantucket and Capistrano. An older, existing single family neighborhood, located
within the city limits of Oceanside, exists over % mile northerly of the site. The volcanic core of
ancient Calavera Mountain exists south of, and supports the southern portion of the Lake
Calavera Reservoir.
Rev. 07/03/04
Intake/Outlet Pipeline Repairs. The major aspect of the proposed improvements involves the
modification to the Intake/Outlet (I/O) pipeline system. This activity includes demolition of the
upper 26-foot portion of the existing tower, and construction of a new laid-back outlet pipe along
the upstream face of the dam equipped with intake points, including hydraulically and
pneumatically actuated valves, and fish screens. The new laid-back pipe will be installed on the
lake side of the face of the dam, with piping juncture to the existing tower above the historical
minimum operating pool level, which is approximately elevation 189 feet.
The outlet apparatus will be replaced with a laid-back pipeline secured to the lake-side face of the
existing dam through a series of three saddle-pipe supports placed on the dam. This laid-back
pipeline is proposed with multiple intake ports. This would allow for both ease of operation and
selective water withdrawal from the stratum having the seasonally best water quality, avoiding
both near-surface algae layers and also intake of bottom sediments. Each port will be protected
from coarse suspended material by appropriate stainless steel screens and protective cages. The
valves will be hydraulically operated with lines terminating at an operations control building to be
situated at the dam's west end. The project will include construction of intake/outlet (I/O)
controls to replace the existing manually operated devices. The new controls will be remotely
operated through a pneumatic and hydraulic driver located in a small I/O control building located
near the western terminus of the dam. An override pneumatic system for manually operating the
valves under emergency conditions will be part of the control program. This pneumatic system
will store energy to operate the valves numerous times under emergency conditions such as
during power outages.
Intake/Outlet Construction Method. In order to avoid environmental damage that could occur
from draw-down of the reservoir level for construction, the project proposes a construction
method which does not necessitate raising or lowering of the existing reservoir water level. This
construction will be accomplished through utilization of a small temporary structure which will
encompass the existing outlet tower during the tower work process. The tower removal and laid-
back pipe replacement construction method avoids the need for reservoir draw-down by placing
an inflatable gasket and a water-tight temporary structure around the upper section of the existing
tower and pumping out the water between this tower and the temporary structure. The existing
tower will be then sawed and replaced by a new outlet pipe which is connected to the horizontal
outlet pipe under the dam (upon completion of slip-line repairs to this pipe). The temporary
structure can then be removed and the laid-back pipe connected to both the inside face of the dam
and the new outlet flange located near the top of the new vertical outlet pipe. The
hydraulic/pneumatic controls are then connected to this new apparatus.
The above methodology of I/O apparatus replacement will not necessitate any modification of
reservoir level.
Outlet Pipe Slip-line Repairs. The existing 28-inch steel outlet pipe fixed to the bottom of the
existing outlet tower and the 30-inch concrete pipe located through the bottom of the dam also
require remediation. To repair these existing outlet pipes, the 28-inch steel pipe will be removed
and the entire reach of pipeline will be repaired using a 28-inch diameter high density
polyethylene slip-liner. These improvements will necessitate the cutting of a temporary trail from
the downstream end of the spillway to the outlet box. This trail will be restored in appropriate
upland and riparian vegetation upon completion of the construction activities.
Spillway Apron and Channel Repairs. Proposed repairs to the dam spillway apron and channel
involve demolition and restoration of the existing gunite surface on the spillway apron; and
Rev. 07/03/04
clearing, grading and restoration of the spillway channel surface are also proposed. The gunite
surface of the spillway apron is presently in disrepair and debris within the spillway channel as
well as some floor erosion has reduced the present carrying capacity and functionality of the
channel. The repairs involve removal of approximately 7,500 sq. ft. of existing gunite spillway
apron and channel wall, and replacement with reinforced gunite and concrete lining on the upper
half, and Armorloc (an articulated concrete block revetment system of interlocking keys with
open cells in which grasses and small shrubs can grow) on the lower portion. These
improvements will restore the apron and channel to their original runoff transport design capacity.
A slight revision to the dam crest approach ramp is also proposed at the spillway apron, which a
will result in a small revision to the spillway channel design at the dam.
Other Site Facility Improvements, hi addition, an existing dirt access road will be upgraded and
extended to permit egress over the restored spillway apron between a control building to be
constructed adjacent to the dam, on the north side of the dam, and across the crest of the dam.
New gates and security fencing is proposed around the control building. Removable bollards are
to be placed at the access road to allow for pedestrian access and limited (authorized maintenance
vehicles) vehicular access. Permanent bollards are to be placed at the end of the dam crest
vehicular turn-around to allow for pedestrian trail access only.
A new two-room I/O control building will be constructed on an approximate 60-foot by 50-foot
graded (fill) pad along the east side of the spillway channel, between this channel and the dam
face. This building will house the Hydraulic Power Unit that operates and supplies pressurized
hydraulic fluid, and pressurized air, to the three butterfly valves on the laid-back I/O pipeline. An
air compressor, storage tank and dam control system will also be located in the control building
for clearing the fish screens. The building will be approximately 480 square feet in area (32-feet
long by 15-feet wide), with a roof ridge height of approximately 14 feet above pad. The building
will have concrete footings and floor slab, with walls constructed of 8-inch cement block.
Architectural treatments will include a gable roof of wood rafters with composite shingle roofing.
At the top of the dam, replacement and improvement of an all-weather (asphalt-concrete
pavement on crushed aggregate base) access service road to the control building, across the
spillway apron and across the dam crest is also proposed. A turn-around is proposed at the
eastern portion of the dam crest to facilitate access and safety. These improvements will permit
access for both construction equipment, and future operation and maintenance activities. Security
fencing around the control building is also proposed. The security fencing will be constructed of
6-foot high chain link with barbed wire crown (total 7-feet high). This fencing will be installed
around the perimeter of the I/O control building and associated parking spaces. Permanent
bollards are proposed at the proposed turn-around, and removable bollards will be installed at the
dam access road near its intersection with the existing sewer trunk line access road located just
westerly of the dam area. The security fencing and bollards are intended to deter vehicular
traffic to the area, but not preclude pedestrian access to the reservoir, dam crest and authorized
trails. Low-pressure sodium illumination security lighting will be provided around the control
building. This lighting will be shielded, and directed downward away from residences and
adjacent open spaces.
Dam Operations. The general CMWD operations program for the reservoir upon completion of
the remedial improvements is to maintain an annual median water surface elevation of
approximately 208 ft amsl, which is the level of the open inoperable (rusted) outflow control
valve on the outlet tower. This has been the long-term maximum elevation of the reservoir over
the past several years. The reservoir water levels drop significantly during the summer months
since the natural creek flows are predominantly influenced by rainfall events and rates of
Rev. 07/03/04
evaporation. Over the past thirty years the surface water levels have ranged from 196-ft amsl to
217-ft amsl. Since the reservoir is a drainage control facility, the operations management will
keep the level at around 208 ft. elevation. Operations management will either allow accumulation
or draw down of water volume (and thus surface levels) in response to short-term rainfall events,
contingent on the natural flow regime and evaporation factors.
In anticipation of a minor rain event, it is anticipated that no water draw down would occur since
any accumulation of storm water will be retained and then released downstream. Prediction of a
significant rain event however, would necessitate a commensurate draw down to minimize the
potential for flows over the dam spillway and potential flooding downstream. Under this draw
down scenario, the water level would drop in anticipation of the rainfall event and then
accumulate during the event. Following the rainfall event, the surplus would be released to
maintain the approximate annual median elevation around 208-ft elevation. Thus, the water
surface elevation would continually be returned to approximately the median level via any
necessary volume reduction, accumulation, operation, evaporation and natural hydrology.
ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED:
The summary of environmental factors checked below would be potentially affected by this project,
involving at least one impact that is a "Potentially Significant Impact," or "Potentially Significant Impact
Unless Mitigation Incorporated" as indicated by the checklist on the following pages.
I I Aesthetics | | Geology/Soils [~| Noise
Agricultural Resources Q Hazards/Hazardous Materials D Population and Housing
Air Quality [X] Hydrology/Water Quality Q Public Services
Biological Resources Q Land Use ancj Planning Q Recreation
Cultural Resources [~I Mineral Resources Transportation/Circulation
| I Mandatory Findings of„. .~ Utilities & Service SystemsSignificance —' J
Rev. 07/03/04
DETERMINATION.
(To be completed by the Lead Agency)
D I find that the proposed project COULD NOT have a significant effect on the environment, and a
NEGATIVE DECLARATION will be prepared.
I find that although the proposed project could have a significant effect on the environment, there will not
be a significant effect in this case because the mitigation measures described on an attached sheet have
been added to the project. A MITIGATED NEGATIVE DECLARATION will be prepared.
I find that the proposed project MAY have a significant effect on the environment, and an
ENVIRONMENTAL IMPACT REPORT is required.
I find that the proposed project MAY have "potentially significant impact(s)" on the environment, but at
least one potentially significant impact 1) has been adequately analyzed in an earlier document pursuant to
applicable legal standards, and 2) has been addressed by mitigation measures based on the earlier analysis
as described on attached sheets. A Negative Declaration is required, but it must analyze only the effects
that remain to be addressed.
I find that although the proposed project could have a significant effect on the environment, there WILL
NOT be a significant effect in this case because all potentially significant effects (a) have been analyzed
adequately in an earlier ENVIRONMENTAL IMPACT REPORT or NEGATIVE DECLARATION
pursuant to applicable standards and (b) have been avoided or mitigated pursuant to that earlier
ENVIRONMENTAL IMPACT REPORT or NEGATIVE DECLARATION, including revisions or
mitigation measures that are imposed upon the proposed project. Therefore, nothing further is required.
Planner's Signature^/ / Date
Assistant Planning Director's Signature Date
Rev. 07/03/02
ENVIRONMENTAL IMPACTS
STATE CEQA GUIDELINES, Chapter 3, Article 5, Section 15063 requires that the City conduct an Environmental
Impact Assessment to determine if a project may have a significant effect on the environment. The Environmental
Impact Assessment appears in the following pages in the form of a checklist. This checklist identifies any physical,
biological and human factors that might be impacted by the proposed project and provides the City with information
to use as the basis for deciding whether to prepare an Environmental Impact Report (EIR), Negative Declaration, or
to rely on a previously approved EIR or Negative Declaration.
• A brief explanation is required for all answers except "No Impact" answers that are adequately supported
by an information source cited in the parentheses following each question. A "No Impact" answer is
adequately supported if the referenced information sources show that the impact simply does not apply to
projects like the one involved. A "No Impact" answer should be explained when there is no source
document to refer to, or it is based on project-specific factors as well as general standards.
• "Less Than Significant Impact" applies where there is supporting evidence that the potential impact is not
significantly adverse, and the impact does not exceed adopted general standards and policies.
• "Potentially Significant Unless Mitigation Incorporated" applies where the incorporation of mitigation
measures has reduced an effect from "Potentially Significant Impact" to a "Less Than Significant Impact."
The developer must agree to the mitigation, and the City must describe the mitigation measures, and briefly
explain how they reduce the effect to a less than significant level.
• "Potentially Significant Impact" is appropriate if there is substantial evidence that an effect is significantly
adverse.
• Based on an "EIA-Part II", if a proposed project could have a potentially significant adverse effect on the
environment, but all potentially significant adverse effects (a) have been analyzed adequately in an earlier
EIR or Mitigated Negative Declaration pursuant to applicable standards and (b) have been avoided or
mitigated pursuant to that earlier EIR or Mitigated Negative Declaration, including revisions or mitigation
measures that are imposed upon the proposed project, and none of the circumstances requiring a
supplement to or supplemental EIR are present and all the mitigation measures required by the prior
environmental document have been incorporated into this project, then no additional environmental
document is required.
• When "Potentially Significant Impact" is checked the project is not necessarily required to prepare an EIR
if the significant adverse effect has been analyzed adequately in an earlier EIR pursuant to applicable
standards and the effect will be mitigated, or a "Statement of Overriding Considerations" has been made
pursuant to that earlier EIR.
• A Negative Declaration may be prepared if the City perceives no substantial evidence that the project or
any of its aspects may cause a significant adverse effect on the environment.
• If there are one or more potentially significant adverse effects, the City may avoid preparing an EIR if there
are mitigation measures to clearly reduce adverse impacts to less than significant, and those mitigation
measures are agreed to by the developer prior to public review. In this case, the appropriate "Potentially
Significant Impact Unless Mitigation Incorporated" may be checked and a Mitigated Negative Declaration
may be prepared.
Rev. 07/03/02
• An EIR must be prepared if "Potentially Significant Impact" is checked, and including but not limited to
the following circumstances: (1) the potentially significant adverse effect has not been discussed or
mitigated in an earlier EIR pursuant to applicable standards, and the developer does not agree to mitigation
measures that reduce the adverse impact to less than significant; (2) a "Statement of Overriding
Considerations" for the significant adverse impact has not been made pursuant to an earlier EIR; (3)
proposed mitigation measures do not reduce the adverse impact to less than significant; or (4) through the
EIA-Part II analysis it is not possible to determine the level of significance for a potentially adverse effect,
or determine the effectiveness of a mitigation measure in reducing a potentially significant effect to below a
level of significance.
A discussion of potential impacts and the proposed mitigation measures appears at the end of the form under
DISCUSSION OF ENVIRONMENTAL EVALUATION. Particular attention should be given to discussing
mitigation for impacts, which would otherwise be determined significant.
Rev. 07/03/02
CALAVERA DAM LOCATION MAP
Carlsbad, California
#021025 OCT 2003
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Issues (and Supporting Information Sources).
I. AESTHETICS - Would the project:
a) Have a substantial adverse effect on a scenic vista?
b) Substantially damage scenic resources, including but
not limited to, trees, rock outcroppings, and historic
buildings within a State scenic highway?
c) Substantially degrade the existing visual character or
quality of the site and its surroundings?
d) Create a new source of substantial light and glare,
which would adversely affect day or nighttime views
in the area?
II. AGRICULTURAL RESOURCES - (In determining
whether impacts to agricultural resources are significant
environmental effects, lead agencies may refer to the
California Agricultural Land Evaluation and Site
Assessment Model-1997 prepared by the California
Department of Conservation as an optional model to use
in assessing impacts on agriculture and farmland.) Would
the project:
a) Convert Prime Farmland, Unique Farmland, or
Farmland of Statewide Importance (Farmland), as
shown on the maps prepared pursuant to the
Farmland Mapping and Monitoring Program of the
California Resources Agency, to non-agricultural
use?
b) Conflict with existing zoning for agricultural use, or
a Williamson Act contract?
c) Involve other changes in the existing environment,
which, due to their location or nature, could result in
conversion of Farmland to non-agricultural use?
III. AIR QUALITY - (Where available, the significance
criteria established by the applicable air quality
management or air pollution control district may be relied
upon to make the following determinations.) Would the
project:
a) Conflict with or obstruct implementation of the
applicable air quality plan?
b) Violate any air quality standard or contribute
substantially to an existing or projected air quality
violation?
Potentially
Significant
Impact
Potentially
Significant
Unless Less Than
Mitigation Significant No
Incorporated Impact Impact
D D
D D IEI
D D
D
D D D
n n
D
[x]
n Rev. 07/03/02
Issues (and Supporting Information Sources).
c) Result in a cumulatively considerable net increase of
any criteria pollutant for which the project region is
in non-attainment under an applicable federal or state
ambient air quality standard (including releasing
emissions which exceed quantitative thresholds for
ozone precursors)?
d) Expose sensitive receptors to substantial pollutant
concentrations?
e) Create objectionable odors affecting a substantial
number of people?
IV. BIOLOGICAL RESOURCES - Would the project:
a) Have a substantial adverse effect, either directly or
through habitat modifications, on any species
identified as a candidate, sensitive, or special status
species in local or regional plans, policies, or
regulations, or by California Department of Fish and
Game or U.S. Fish and Wildlife Service?
b) Have a substantial adverse effect on any riparian,
aquatic or wetland habitat or other sensitive natural
community identified in local or regional plans,
policies, or regulations or by California Department
of Fish and Game or U.S. Fish and Wildlife Service?
c) Have a substantial adverse effect on federally
protected wetlands as defined by Section 404 of the
Clean Water Act (including but not limited to marsh,
vernal pool, coastal, etc.) through direct removal,
filing, hydrological interruption, or other means?
d) Interfere substantially with the movement of any
native resident or migratory fish or wildlife species
or with established native resident or migratory
wildlife corridors, or impede the use of native
wildlife nursery sites?
e) Conflict with any local policies or ordinances
protecting biological resources, such as a tree
preservation policy or ordinance?
f) Conflict with the provisions of an adopted Habitat
Conservation Plan, Natural Community Conservation
Plan, or other approved local, regional, or state
habitat conservation plan?
g) Impact tributary areas that are environmentally
sensitive?
Potentially
Significant
Impact
Potentially
Significant
Unless
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
D
D
D n
n
n
12 Rev. 07/03/02
Issues (and Supporting Information Sources).
V. CULTURAL RESOURCES - Would the project:
a) Cause a substantial adverse change in the
significance of a historical resource as defined in
§15064.5?
b) Cause a substantial adverse change in the signifi-
cance of an archeological resource pursuant to
§15064.5?
c) Directly or indirectly destroy a unique paleontologi-
cal resource or site or unique geologic feature?
d) Disturb any human remains, including those interred
outside of formal cemeteries?
VI. GEOLOGY AND SOILS - Would the project:
a) Expose people or structures to potential substantial
adverse effects, including the risk of loss, injury or
death involving:
i. Rupture of a known earthquake fault, as
delineated on the most recent Alquist-Priolo
Earthquake Fault Zoning Map issued by the
State Geologist for the area or based on other
substantial evidence of a known fault? Refer to
Division of Mines and Geology Special
Publication 42.
ii. Strong seismic ground shaking?
iii. Seismic-related ground failure, including
liquefaction?
iv. Landslides?
b) Result in substantial soil erosion or the loss of
topsoil?
c) Be located on a geologic unit or soil that is unstable,
or that would become unstable as a result of the
project, and potentially result in on- or off-site
landslide, lateral spreading, subsidence, liquefaction,
or collapse?
d) Be located on expansive soils, as defined in Table 18
- 1-B of the Uniform Building Code (1997), creating
substantial risks to life or property?
Potentially
Significant
Impact
Potentially
Significant
Unless
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
D
D D
D
13 Rev. 07/03/02
Issues (and Supporting Information Sources).
VII.
e) Have soils incapable of adequately supporting the
use of septic tanks or alternative wastewater disposal
systems where sewers are not available for the
disposal of wastewater?
HAZARDS AND HAZARDOUS MATERIALS -
Would the project:
a) Create a significant hazard to the public or the
environment through the routine transport, use, or
disposal of hazardous materials?
b) Create a significant hazard to the public or
environment through reasonably foreseeable upset
and accident conditions involving the release of
hazardous materials into the environment?
c) Emit hazardous emissions or handle hazardous or
acutely hazardous materials, substances, or waste
within one-quarter mile of an existing or proposed
school?
d) Be located on a site which is included on a list of
hazardous materials sites compiled pursuant to
Government Code Section 65962.5 and, as a result,
would it create a significant hazard to the public or
environment?
e) For a project within an airport land use plan, or
where such a plan has not been adopted, within two
miles of a public airport or public use airport, would
the project result in a safety hazard for people
residing or working in the project area?
f) For a project within the vicinity of a private airstrip,
would the project result in a safety hazard for people
residing or working in the project area?
g) Impair implementation of or physically interfere with
an adopted emergency response plan or emergency
evacuation plan?
h) Expose people or structures to a significant risk of
loss, injury or death involving wildland fires,
including where wildlands are adjacent to urbanized
areas or where residences are intermixed with
wildlands?
VIII. HYDROLOGY AND WATER QUALITY - Would the
project:
a) Violate any water quality standards or waste
discharge requirements?
Potentially
Significant
Impact
Potentially
Significant
Unless
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
n
n n
n n
n n
n
n
n
n
IEI
14 Rev. 07/03/02
Issues (and Supporting Information Sources).
b) Substantially deplete groundwater supplies or
interfere substantially with ground water recharge
such that there would be a net deficit in aquifer
volume or a lowering of the local ground water table
level (i.e., the production rate of pre-existing nearby
wells would drop to a level which would not support
existing land uses or planned uses for which permits
have been granted)?
c) Impacts to groundwater quality?
d) Substantially alter the existing drainage pattern of the
site or area, including through the alteration of the
course of a stream or river, in a manner, which would
result in substantial erosion or siltation on- or off-
site?
e) Substantially alter the existing drainage pattern of the
site or area, including through the alteration of the
course of a stream or river, or substantially increase
the flow rate or amount (volume) of surface runoff in
a manner, which would result in flooding on- or off-
site?
f) Create or contribute runoff water, which would
exceed the capacity of existing or planned
stormwater drainage systems or provide substantial
additional sources of polluted runoff?
g) Otherwise substantially degrade water quality?
h) Place housing within a 100-year flood hazard area as
mapped on a Federal Flood Hazard Boundary or
Flood Insurance Rate Map or other flood delineation
map?
i) Place within 100-year flood hazard area structures,
which would impede or redirect flood flows?
j) Expose people or structures to a significant risk of
loss injury or death involving flooding, including
flooding as a result of the failure of a levee or dam?
k) Inundation by seiche, tsunami, or mudflow?
1) Increased erosion (sediment) into receiving surface
waters.
m) Increased pollutant discharges (e.g., heavy metals,
pathogens, petroleum derivatives, synthetic organics,
nutrients, oxygen-demanding substances and trash)
into receiving surface waters or other alteration of
receiving surface water quality (e.g., temperature,
dissolved oxygen or turbidity)?
Potentially
Significant
Impact
Potentially
Significant
Unless
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
n
D D
D
D
15 Rev. 07/03/02
Issues (and Supporting Information Sources).
n) Changes to receiving water quality (marine, fresh or
wetland waters) during or following construction?
o) Increase in any pollutant to an already impaired
water body as listed on the Clean Water Act Section
303(d) list?
p) The exceedance of applicable surface or groundwater
receiving water quality objectives or degradation of
beneficial uses?
IX. LANDUSE AND PLANNING - Would the project:
a) Physically divide an established community?
b) Conflict with any applicable land use plan, policy, or
regulation of an agency with jurisdiction over the
project (including but not limited to the general plan,
specific plan, local coastal program, or zoning
ordinance) adopted for the purpose of avoiding or
mitigating an environmental effect?
c) Conflict with any applicable habitat conservation
plan or natural community conservation plan?
X. MINERAL RESOURCES - Would the project:
a) Result in the loss of availability of a known mineral
resource that would be of future value to the region
and the residents of the State?
b) Result in the loss of availability of a locally
important mineral resource recovery site delineated
on a local general plan, specific plan, or other land
use plan?
XL NOISE - Would the project result in:
a) Exposure of persons to or generation of noise levels
in excess of standards established in the local general
plan or noise ordinance or applicable standards of
other agencies?
b) Exposure of persons to or generation of excessive
groundbourne vibration or groundbourne noise
levels?
c) A substantial permanent increase in ambient noise
levels in the project vicinity above levels existing
without the project?
d) A substantial temporary or periodic increase in
ambient noise levels in the project vicinity above
levels existing without the project?
Potentially
Significant
Impact
Potentially
Significant
Unless
Mitigation
Incorporated
Less Than
Significant No
Impact Impact
n
DDK1
n
D D D
n
n
n
n
n
n n [X]
n
16 Rev. 07/03/02
Issues (and Supporting Information Sources).
e) For a project located within an airport land use plan
or, where such a plan has not been adopted, within 2
miles of a public airport or public use airport, would
the project expose people residing or working in the
project area to excessive noise levels?
f) For a project within the vicinity of a private airstrip,
would the project expose people residing or working
in the project area to excessive noise levels?
XII. POPULATION AND HOUSING - Would the project:
a) Induce substantial growth in an area either directly
(for example, by proposing new homes and
businesses) or indirectly (for example, through
extension of roads or other infrastructure)?
b) Displace substantial numbers of existing housing,
necessitating the construction of replacement housing
elsewhere?
c) Displace substantial numbers of people, necessitating
the construction of replacement housing elsewhere?
XIII. PUBLIC SERVICES
a) Would the project result in substantial adverse
physical impacts associated with the provision of
new or physically altered government facilities, a
need for new or physically altered government
facilities, the construction of which could cause
significant environmental impacts, in order to
maintain acceptable service ratios, response times, or
other performance objectives for any of the public
services:
i) Fire protection?
ii) Police protection?
iii) Schools?
iv) Parks?
v) Other public facilities?
XIV. RECREATION
a) Would the project increase the use of existing
neighborhood and regional parks or other
recreational facilities such that substantial physical
deterioration of the facility would occur or be
accelerated?
Potentially
Significant
Impact
Potentially
Significant
Unless
Mitigation
Incorporated
Less Than
Significant No
Impact Impact
D El
D
El
D
D
D
El
El
17 Rev. 07/03/02
Issues (and Supporting Information Sources).
b) Does the project include recreational facilities or
require the construction or expansion of recreational
facilities, which might have an adverse physical
effect on the environment?
XV. TRANSPORTATION/TRAFFIC - Would the project:
a) Cause an increase in traffic, which is substantial in
relation to the existing traffic load and capacity of the
street system (i.e., result in a substantial increase in
either the number of vehicle trips, the volume to
capacity ratio on roads, or congestion at
intersections)?
b) Exceed, either individually or cumulatively, a level
of service standard established by the county
congestion management agency for designated roads
or highways?
c) Result in a change in air traffic patterns, including
either an increase in traffic levels or a change in
location that results in substantial safety risks?
d) Substantially increase hazards due to a design feature
(e.g., sharp curves or dangerous intersections) or
incompatible uses (e.g., farm equipment)?
e) Result in inadequate emergency access?
f) Result in insufficient parking capacity?
g) Conflict with adopted policies, plans, or programs
supporting alternative transportation (e.g., bus turn-
outs, bicycle racks)?
XVI. UTILITIES AND SERVICES SYSTEMS - Would the
project:
a) Exceed wastewater treatment requirements of the
applicable Regional Water Quality Control Board?
b) Require or result in the construction of new water or
wastewater treatment facilities or expansion of
existing facilities, the construction of which would
cause significant environmental effects?
c) Require or result in the construction of new storm
water drainage facilities or expansion of existing
facilities, the construction of which could cause
significant environmental effects?
d) Have sufficient water supplies available to serve the
project from existing entitlements and resources, or
are new or expanded entitlements needed?
Potentially
Significant
Impact
Potentially
Significant
Unless
Mitigation
Incorporated
Less Than
Significant No
Impact Impact
EI
n
n
n
EI
n
EI
El
18 Rev. 07/03/02
Issues (and Supporting Information Sources).
Potentially
Significant
Impact
Potentially
Significant
Unless
Mitigation
Incorporated
Less Than
Significant
Impact
No
Impact
e) Result in a determination by the wastewater
treatment provider, which serves or may serve the
project that it has adequate capacity to serve the
project's projected demand in addition to the
provider's existing commitments?
f) Be served by a landfill with sufficient permitted
capacity to accommodate the project's solid waste
disposal needs?
g) Comply with federal, state, and local statutes and
regulations related to solid waste?
XVII. MANDATORY FINDINGS OF SIGNIFICANCE
a) Does the project have the potential to degrade the
quality of the environment, substantially reduce the
habitat of a fish or wildlife species, cause a fish or
wildlife population to drop below self-sustaining
levels, threaten to eliminate a plant or animal
community, reduce the number or restrict the range
of a rare or endangered plant or animal or eliminate
important examples of the major periods of
California history or prehistory?
D D D
Db) Does the project have impacts that are individually
limited, but cumulatively considerable? ("Cumula-
tively considerable" means that the incremental
effects of a project are considerable when viewed in
connection with the effects of past projects, the
effects of other current projects, and the effects of
probable future projects?)
c) Does the project have environmental effects, which
will cause the substantial adverse effects on human
beings, either directly or indirectly?
DISCUSSION OF ENVIRONMENTAL EVALUATION
The following is a technical explanation for each answer provided in the checklist provided on the
previous pages. After each question is posed, a summary of the existing conditions is presented, followed
by an analysis of potential project impacts, the finding and appropriate factual justification. In cases
where the finding is "Less than Significant Impact with Mitigation Incorporated", the finding is followed
by a description of the mitigation measures that would reduce the impact to below a level of significance.
Information sources are cited for each discussion.
I. AESTHETICS - Would the project:
a) Have a substantial adverse effect on a scenic vista?
Existing Condition: The subject Lake Calavera reservoir and associated dam facilities are located
within the viewshed of a number of residential homes to the north and west of the site. It is also visible
briefly from motorists on lightly traveled Tamarack Avenue, a collector street west of Lake Calavera. In
addition, the City of Carlsbad Open Space and Conservation Map designates a planned public trail, with
19 Rev. 07/03/02
picnic area and view point traveling within the open spaces along the northern edge of the reservoir area.
All lands within and adjacent to the area of proposed impacts are designated by the General Plan Land
Use Element for open space uses, and are correspondingly zoned Open Space. The area of the proposed
repairs could generally be characterized as a natural area, although the reservoir was artificially created
through construction of the dam in the early 1940's.
An existing Intake/Outflow tower presently rises between 11 and 36 feet above the surface of Lake
Calavera, depending upon surface water elevation at the time of measurement. An under water 30-inch
outlet pipe exists under the foot of the dam, and exits at the downstream base. This piping is largely
invisible to the public. A spillway, presently in a state of disrepair, and access service road off Tamarack
Avenue also exists at the facility.
Environmental Evaluation: The visible portion of the outlet tower will be eliminated through
implementation of the proposed project. In replacement of this tower, a water intake/outlet apparatus,
consisting primarily of a 24-inch pipe with three 18-inch ports with valves, and a single air/vacuum vent
assembly will be constructed. This apparatus will be constructed in a laid-back fashion, on the lakeside
dam face. These facilities will be installed utilizing a portable crane and a barge.
An approximately 14-foot tall (to peak of roof), 480-square foot control building is proposed adjacent to
the existing dam crest. This building will house a compressor and dam controls, and will be
architecturally treated with a pitched roof, and composite shingle roofing materials. This structure will be
constructed in a location where no structure presently exists, and will be visible to the public.
Gunite repairs to the existing spillway and repairs and improvements to the existing service road will also
occur to the north of the dam, and across the dam crest. Chain link security fencing is proposed around
specific areas of the site.
Temporary impacts associated with the use of a temporary structure placed around the existing outlet
tower will occur during the 2-month tower removal period. Minor temporary visual impacts resulting
from grading for the access road and control building will also result from the construction operation.
Finding: Less than significant impact - The proposed dam apparatus repairs and construction
would be visible from a location that has been designated and protected as a scenic vista point per the
Carlsbad General Plan. The most visible aspect will be the proposed control building. Aesthetic
treatment is proposed for this building, including materials, colors, roof design and tile materials, and
other features that will be aesthetically pleasing. The maximum height of the proposed structure will be
no more than 14 feet. The security fencing will be visible; however its aesthetic impact is expected to be
minimal. The project will eliminate the existing highly visible outlet tower presently located within the
reservoir surface area, and replace it with a laid-back piping apparatus that will be much less visible.
Construction utilizing a temporary crane and barge will not result in significant visual impacts.
Therefore, the project will not have a substantially adverse impact on any scenic vista.
b) Substantially damage scenic resources, including but not limited to, trees, rock
outcroppings, and historic buildings within a State scenic highway?
Existing condition: No trees or rock outcroppings will be impacted by the proposed project. No
buildings, including historic buildings, are located in or adjacent to the subject dam site. The area of
proposed impact is not located within the viewshed of a State scenic highway or any State highway that is
designated by CalTrans as eligible for listing as a scenic highway.
Environmental Evaluation: Since no trees, rock outcroppings or historic buildings, and no State
scenic highways are in the vicinity of the proposed project, no significant impact to such resources is
anticipated.
20 Rev. 07/03/02
Finding: No impact - The site is not within the viewshed of a state scenic highway or any state
highway that is designated by CalTrans as eligible for listing. Please also refer to the preceding response.
c) Substantially degrade the existing visual character or quality of the site and its
surroundings?
Existing condition: The existing visual character of the site is that of an artificially created reservoir,
surrounded by natural rolling hillsides. Coastal sage scrub native vegetation covers the surrounding
upland areas, and riparian vegetation, including primarily southern willow scrub vegetation occurs to the
east of the Lake Calavera reservoir. The proposed project involves repair of the dam apparatus, including
the elimination of the upper portion of the existing outlet tower and its replacement with laid-back piping
equipment, and construction of a control building, re-gunite shooting of an existing spillway, construction
of security fencing, and construction of an all-weather access road that includes a turn-around.
Environmental Evaluation: Permanent visual impacts of the proposed project will primarily involve
the control building. This building will be architecturally treated with a pitched roof, and composition
shingle roofing materials. Elimination of the visible portions of the existing vertical tower would be
considered a beneficial impact of the project. Improvements to the spillway apron and channel will not
constitute significant impacts. In the segment of the channel that will be improved with Armorloc, the
visual character will be improved. Therefore, the project will not have a substantially adverse impact on
any scenic vista.
Finding: Less than significant impact - Please also refer to response I (a), above.
d) Create a new source of substantial light and glare, which would adversely affect day or
nighttime views in the area?
Existing condition: The subject area contains no lights and produces no glare at the present time.
Environmental Evaluation: The proposed control building facility will be equipped with low-level
security lighting on the exterior of the structure that will be directed downward and away from the
residences to the north and west. The lights will be mounted on the building wall, directed downward to
prevent the light from penetrating significantly beyond the immediate site. Routine maintenance of the
facilities will be performed during daylight hours only, during which time internal lighting will be
utilized. A switch will be located at the entry gate to manually turn on the light if required for
un-scheduled operations or non-routine maintenance activities. A similar switch will be located at the exit
gate to manually turn off the lights after personnel have completed their work.
Finding: Less than significant impact - The low-level security lighting will not result in a
significant new source of substantial light and/or glare, and would not significantly affect nighttime views
in the area.
II. AGRICULTURAL RESOURCES - Would the project:
a) Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance
(Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and
Monitoring Program of the California Resources Agency, to non-agricultural use?
Existing condition: The subject site is designated as "Other Land" and not designated as any category
of important farmland on the "California Department of Conservation - San Diego County Important
Farmland" exhibit dated September, 2002. No agriculture is presently practiced on the subject site.
Environmental Evaluation: The area that would be impacted by the proposed project is not
designated as any category of important farmland on the "California Department of Conservation - San
Diego County Important Farmland" exhibit dated September 2002. In addition, the proposed project
21 Rev. 07/03/02
involves maintenance improvements to existing uses, and will not result in a change to these existing uses
of the site.
Finding: No impact - The subject site is designated as "Other Land" on the "San Diego Important
Farmland, September 2002" map of the Farmland. This category is defined as "Land which does not
meet the criteria of any other category." Other categories include Prime Farmland, Farmland of Statewide
Importance, Unique Farmland, Farmland of Local Importance, and Grazing Land. No agriculture is
presently practiced on the site. The proposed project involves maintenance improvements to existing
uses, and will not result in a change to these existing uses of the site. As a result, it is concluded that the
project would not convert farmland to non-agricultural use.
b) Conflict with existing zoning for agricultural use, or a Williamson Act contract?
Existing condition: The subject project is located on property that is zoned for open space uses.
Although agricultural operations are allowed in the Open Space zone, no such operations are presently
conducted in the area of the proposed remedial improvements. The City of Carlsbad policy on
agricultural uses is articulated in the General Plan Land Use Element. This policy indicates that the City's
agricultural policies are intended to support agricultural activities while planning for the possible future
transition of the land to more urban uses consistent with the General Plan. The subject property is not
encumbered by a Williamson Act contract.
Environmental Evaluation: Inasmuch as the proposed project is a repair operation of existing
facilities, the subject site presently contains effectively the same land uses and facilities as those
proposed. The property is not zoned specifically for agricultural uses, although agricultural uses would
be allowed, and is not encumbered by a Williamson Act contract.
Finding: No impact - Please refer to the preceding response. The site is on property established for
the proposed purpose, and is considered the continuation of such existing uses. No effect on agricultural
uses will result from implementation of the project. The property is not zoned for agricultural uses, and
no Williamson Act contract encumbers the property.
c) Involve other changes in the existing environment, which, due to their location or nature,
could result in conversion of Farmland to non-agricultural use?
Existing condition: The proposed project involves remedial improvements to existing dam facilities.
No farmland exists in the area for which the improvements are proposed.
Environmental Evaluation: Since the project primarily involves remedial improvements to existing
facilities, the original (1940's) development of the area has removed or buried the original soil profile.
Therefore, no changes of significance to the existing environment will occur as a result of the proposed
improvements. The project will increase the opportunity for irrigation water storage, and thus could
potentially improve future opportunities for farming.
Finding: No impact - The proposed project will not affect any existing or identified farmland, nor
will it cause changes to any factors, such as water supply, access, or drainage that would affect any active
agricultural use.
III. AIR QUALITY - Would the project:
a) Conflict with or obstruct implementation of the applicable air quality plan?
Existing condition: The existing use of the site is dam facilities and operations, which use is
imperative to the existence of the Lake Calavera reservoir. Remedial and maintenance improvements of
these existing uses are proposed in order to allow for full and efficient functioning of dam facilities.
22 Rev. 07/03/02
These improvements will allow for restored management of flood control and water storage. The site
produces no measurable air pollution at this time.
The project area has a warm-summer Mediterranean climate characterized by warm, dry summers and
mild, wet winters. The dominant meteorological feature affecting the region is the Pacific High Pressure
Zone, which produces prevailing winds from the west to northwest. These winds tend to blow pollutants
away from the coast toward the inland areas. Consequently, air quality near the coast is generally better
than that which occurs at the base of the coastal mountain range.
Fluctuations in the strength and pattern of winds from the Pacific High Pressure Zone interacting with the
daily local cycle produce periodic temperature inversions that influence the dispersal or containment of
air pollutants in the San Diego Air Basin (SDAB).
The federal Clean Air Act (CAA) was enacted in 1970 and amended in 1977 and 1990 for the purposes of
protecting and enhancing the quality of the nation's air resources to benefit the public's health, welfare and
productivity. In 1971, in order to achieve the purposes of the CAA, the EPA developed primary and
secondary national ambient air quality standards. Six pollutants of primary concern were designated;
ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, lead and suspended particulates. A proposed
project's air quality impacts must be addressed relative to compliance with the standards adopted pursuant
to these pollutants.
The proposed project will be required to comply with all San Diego Air Pollution Control District
(APCD) Rules and Regulations. Air emissions will be produced during construction, however this
construction period will be temporary in nature. The dam facilities will be powered by electricity, for
powering the hydraulic and pneumatic pumps, air compressors and instrumentation controls. The air
backwash system will utilize a 10-horsepower compressor, also powered by electricity.
The proposed project is located within the SDAB. The SDAB is a federal and state non-attainment area
for ozone (03), and a state non-attainment area for respirable particulate matter less than or equal to 10
microns in diameter (PMio). The applicable attainment plan for these criteria pollutants is the Regional
Air Quality Strategy, which is prepared and administered by the San Diego APCD.
Environmental Evaluation: Short-term air quality impacts during construction would occur from
heavy equipment exhaust emissions, construction-related trips by workers, delivery trucks, and material
hauling trucks, and from associated fugitive dust generation. Heavy construction equipment is usually
diesel-powered. In general, emissions from diesel-powered equipment contain more nitrogen oxide
compounds (NOx), sulfur oxide compounds (SOx), and PMio, and less carbon monoxide (CO) and
reactive organic compounds (ROCs), than emissions from gasoline-powered engines. NOx compounds
and ROCs are precursors to ozone formation.
Construction of the proposed project is anticipated to involve equipment such as tractors, scrapers,
backhoes, cranes, grader, dump and concrete trucks, and miscellaneous tractor-trailer delivery trucks.
The type of equipment that may be found at any one time at the site during the construction period will
vary. The construction operation is anticipated to extend 6 to 10 months in duration, although heavy
machinery will not be in operation during this entire period. Short term sources of construction-related
air emissions include (a) fugitive dust from grading activities, (b) construction exhaust, and (c)
construction related by worker commute, delivery trucks, and material-hauling trucks.
The APCD does not have specific significance thresholds for air pollutants generated during construction.
However, the APCD does specify Air Quality Impact Analysis (AQIA) Trigger Levels for review of new
stationary sources. Although these trigger levels are specified for stationary sources, they are used here to
assess the potential impacts due to air emissions during project construction. The AQIA construction
Trigger Levels are defined as:
NOx 250 pounds per day
23 Rev. 07/03/02
SOx 250 pounds per day
CO 550 pounds per day
100 pounds per day
No AQIA Trigger Levels specified for ROCs have been adopted. If anticipated project emissions exceed
any of these Trigger Levels, a more detailed Air Quality Impact Analysis may be required by the APCD.
For this evaluation, project construction air emissions were estimated using the California Air Resources
Board UrbemisTG version 3.2 air emission estimation program.
The Urbemis7G program does not include emission factors for SOx compounds. The equipment emission
factors used in UrbemisVG are the same as those found in the South Coast Air Quality Management
District CEQA Air Quality Handbook, and the Handbook does include emission factors for SOx
compounds. A comparison of the CEQA Air Quality Handbook NOx and SOx compound emission
factors reveals that the SOx emission factors are consistently less than the corresponding NOx emission
factors for the same types of equipment. Therefore, it can be concluded that the total SOx emissions from
a project will be less than the total NOx emissions from that project.
The San Diego APCD Trigger Levels for NOx and SOx compounds are the same (250 pounds per day).
Consequently, for this assessment it can be concluded that if the total NOx emissions projected by
UrbemisVG are less than the AQIA Trigger Levels, then the total SOx emissions will also be below the
Trigger Levels.
As indicated, the amount and types of equipment on-site at any one time during the construction period
will vary. This assessment conservatively assumes that all of the projected equipment could be working
on-site simultaneously. Under this assumption, the maximum projected daily air emissions during
construction would be:
NOx 158 pounds per day
SOx <1 58 pounds per day
CO 92 pounds per day
PMjo 26 pounds per day
Finding: Less than significant impact - The project construction operation is considered relatively
small in scale. Nonetheless, air quality impacts can result from the construction of the project. The Air
Pollution Control District (ACPD) regulates controls for construction equipment and procedures such as
dust control during construction. The project is required to comply with all APCD Rules and
Regulations. All project construction is required to incorporate best management practices to reduce dust
and air pollution impacts. Any air emissions produced during construction would be not significant and
would be temporary. Permanent operation of the dam would not be a source of air pollutant emissions,
since the facilities will be powered by electricity.
Given the small amount of grading and construction overall and the fact that the permanent facility will
be powered by electricity, air emissions associated with this project are not anticipated to result in any
significant air quality impacts.
b) Violate any air quality standard or contribute substantially to an existing or projected air
quality violation?
Existing condition: Remedial and maintenance improvements of the existing dam facilities are
proposed. The site does not contribute to any air quality violation at this time.
Environmental Evaluation: Please refer to the preceding technical evaluation in Section III (a).
Finding: No impact - Emission controls for construction equipment and procedures such as dust
control during construction are regulated by the Air Pollution Control District (ACPD). The project is
24 Rev. 07/03/02
required to comply with all APCD Rules and Regulations. Any air emissions produced during
construction would be temporary. Operation of the dam facilities would not be a source of air pollutant
emissions, since the facilities will be powered by routine electricity.
It is concluded that the proposed project will not contribute substantially to any existing or projected air
quality violation.
c) Result in a cumulatively considerable net increase of any criteria pollutant for which the
project region is non-attainment under an applicable federal or state ambient air quality
standard?
Existing condition: Inoperable dam facilities that are in need of remedial maintenance exist on the
site at the current time. The subject site produces no air pollution at this time. The project proposes
replacement and upgrade of these existing facilities.
Environmental Evaluation: Please refer to evaluation at III (a).
Finding: No impact - Please refer to response to III (a).
d) Expose sensitive receptors to substantial pollutant concentrations?
Existing condition: Dam facilities operations that are in need of remedial maintenance and upgrade
exist on the site at the current time. No sensitive air quality receptors are located near the subject site.
Environmental Evaluation: Please refer to evaluation at III (a). The project would not alter wind
patterns, moisture levels or temperatures in the area.
Finding: No impact - Please refer to response to III (a).
e) Create objectionable odors affecting a substantial number of people?
Existing condition: Dam operations that are in need of remedial maintenance exist at the current
time. The site does not contain objectionable odors under the existing condition.
Environmental Evaluation: Construction of the remedial improvements will not create substantial
odors. No drawdown or impact to reservoir waters is proposed. No additional mud flats will be created
or exposed. The proposed project operations will be powered hydraulically and pneumatically, and thus
will not create odors of any significance.
Finding: No Impact - Proposed project operations or construction will result in any significant
odor impacts.
IV. BIOLOGICAL RESOURCES - Would the project:
a) Have a substantial adverse effect, either directly or through habitat modifications, on any
species identified as a candidate, sensitive, or special status species in local or regional plans,
policies, or regulations, or by California Department of Fish and Game or U.S. Fish and
Wildlife Service?
Existing condition: The subject site is located along the upper length of Calavera Creek. It
encompasses a man-made earth-fill dam and reservoir that impounds runoff from the upper Calavera
Creek watershed. Construction of the dam (and thus creation of the reservoir) has affected the natural
physiography and biology of the site. Approximately 100 to 500 acre-feet of drainage water are retained
annually as storm water runoff and to minimize downstream flooding. The reservoir level controls are
presently inoperable.
25 Rev. 07/03/02
Biological investigations for the proposed project have been conducted by Merkel & Associates. Onsite
vegetation and wildlife, and vegetation and wildlife in the surrounding area, including around the
reservoir, was mapped. A list of floral and faunal species observed was recorded. A search for sensitive
plants and animals was conducted. Focused biological surveys for the Least Bell's Vireo, the Southern
Willow Flycatcher, the Southwestern Pond Turtle, the California Gnatcatcher and the Thread-leaved
Brodiaea were conducted. A U.S. Army Corps of Engineers and a California Dept. of Fish & Game
jurisdictional delineation were conducted and confirmed by representatives of these agencies.
Bathymetry for Lake Calavera was created by collecting depth (fathometer) readings from a survey vessel
as it circumnavigated the reservoir. The results of this analysis are on file in the Carlsbad Planning
Department and incorporated herein by reference to this environmental assessment in the form of the
Biological Resources Report, Merkel & Associates, dated May 1, 2003. Focused surveys for animals and
plants are on file in the Carlsbad Planning Department and incorporated herein by reference.
Environmental Evaluation: The majority of the native upland vegetation that occurs within and
surrounding the area of the project is classified as Diegan Coastal Sage Scrub (DCSS). Mule Fat Scrub
(MFS) is mapped along much of the southern side of the reservoir and is typically situated between the
DCSS and the Southern Willow Scrub (SWS) and Freshwater Marsh (FWM) that rings the boundaries of
the reservoir. Upstream of the reservoir, areas of Coastal Live Oak (CLO) riparian forest are intermingled
with the SWS and FWM habitats.
Much of the area south and southeast of the reservoir has been previously brushed by historical farming
or other maintenance activities, or has burned in wildfire, and as a result the area is limited in native
vegetation. These areas are predominated by Valley Needlegrass and Non-native Grasslands. Forbs and
ruderal vegetation occurs within these areas, including Mustards, Tarplant, Japanese Honeysuckle and
Doveweed. The subject area could be suitable habitat for Thread-leaved Brodiaea, a plant listed by the
state as Endangered and federally listed as Threatened. Two separate focused surveys (Fall, 2002 and
Summer, 2004) for Brodiaea did not result in detection of this plant.
The only fish species specifically identified in Lake Calavera and the upstream creek is the Mosquitofish.
This species is not native to the area, but due to widespread introductions, is not ubiquitous in California.
Largemouth Bass, White Crappie, Bluegill and at least one species of catfish, probably Bullhead, are also
known to exist in the reservoir. None of these fish species are native or sensitive. No direct biological
significance is attributed to the loss of the various non-native fish occurring in the reservoir.
Relatively few amphibians are known to inhabit the subject area. The Pacific Treefrog, Garden Slender
Salamander, and Western Toad are active during periods of wet winter weather. The American Bullfrog
would also be expected in the area. None of these species are sensitive. The federally listed Arroyo Toad
habitat was not found on the site.
Historical direct and indirect effects of human encroachment into the area have likely had a negative
impact on most reptile species occurring within the area. Lizards common to the site include the Western
Fence Lizard, the Side-blotched Lizard and the Southern Alligator Lizard. Sensitive reptile species that
were not observed but may occur within the area include the Coast Horned Lizard, Coronado Skink,
Belding's Orange-throated Whiptail, Coastal Western Whiptail and Legless Lizard.
A focused survey for the Southwestern Pond Turtle was conducted for the subject site. The Southern
Pacific Pond Turtle is listed as a federal and state species of special concern that has been largely
extirpated from freshwater habitat in southern California. Species of special concern is a regulatory status
that may warrant future listing as threatened or endangered. Onsite pond turtle habitat includes Open
Water and Coastal and Valley Freshwater Marsh. A pond turtle trapping survey was undertaken during
July and August of 2002. This trapping survey revealed the existence of at least one Southwestern Pond
Turtle within the subject reservoir area. The methodology and results of this survey by Merkel &
Associates, dated September 4, 2002, are on file in the Carlsbad Planning Department and incorporated
herein by reference.
26 Rev. 07/03/02
Snake species expected to occur onsite include the Common Kingsnake, Southern Pacific Rattlesnake,
Striped Racer, Coast Patchnose Snake and Gopher Snake. Each of these species has been reported within
five miles of the subject site, in habitats similar to those onsite. None of these species are considered rare
or endangered.
Merkel recorded fifty-one bird species over the survey period. The reservoir provides open water habitat
for species such as Pied-billed Grebe, Mallard, Northern Shoveler, Gadwall, Bufflehead and Ruddy Duck.
Also the Common Merganser, Virginia Rail, Common Moorhen and the American Coot. The SWS on
the upstream portion of the reservoir provides habitat for many common species, such as the Bushtit,
House Wren, Ruby-crowned Kinglet, Blue-gray Gnatcatcher, Hermit Thrush, Orange-crowned Warbler,
Spotted Towhee, and Tree Swallows.
The Least Bell's Vireo, a federal and state listed endangered species, and the Little Willow Flycatcher, a
state listed endangered species (no federal listing) are sensitive migratory species that can occur in SWS
habitat. Merkel and Associates between April and July of 2002 conducted a field survey for these species
in the subject area. The survey results revealed no sightings of the Least Bell's Vireo, but did detect a
single sighting of a Little Willow Flycatcher, which was determined by the biologist to be migratory, a
transient in the area. Follow-up surveys for both of these bird species were conducted in July 2004. No
vireos or flycatchers were detected during these surveys. A number of potential predators (White-tailed
Kites, Cooper's Hawk, Red-tailed Hawk) of these species were noted within the biological study area.
During the 2002 biological survey, a pair of federally threatened Coastal California Gnatcatcher was
found near the north shore of the reservoir, approximately 250 feet north of the dam construction area. In
addition, a single male was observed at the base of the downstream face of the dam. A follow-up focused
Gnatcatcher survey during April and May, 2003, revealed that the northerly pair had migrated farther
north (to approximately 600 feet away from the construction area), and the single Gnatcatcher on the dam
face was not observed at all. No other Gnatcatchers have been sighted within the subject study area in
either survey.
Although relatively few mammals were observed in the area of the proposed project, this is in part due to
the fact that most native mammal species are nocturnal and not easily observed during daytime surveys.
The California Ground Squirrel, Cottontail and Dusky-footed Woodrat were observed. Also observed
within the non-native and disturbed areas were the characteristic mounds of Botta's Pocket Gopher.
Tracks of the Spotted Skunk were identified. Other expected rodents include the San Diego Pocket
Mouse, Pacific Kangaroo Rat, Deer Mouse and Cactus Mouse. These species form an important prey
base for mammalian carnivores, raptorial birds, and snakes. Coyote is also expected to occur onsite.
These species are not federally or state listed.
Biological impacts associated with the proposed project involve impacts to Diegan Coastal Sage Scrub
(DCSS), which is the preferred habitat of the Gnatcatcher. These impacts, totaling 0.78 acres, result from
construction of the control building, the spillway apron and channel improvements and peripheral
construction. They will result in indirect impacts to the California Gnatcatcher. Such impacts will
require issuance DCSS "Take" permit from the City of Carlsbad through their HMP program. This
permit will require mitigation at a minimum 2:1 (replacement:impact) ratio for permanent impacts due to
the fact that the DCSS in the area is considered "occupied" by the Gnatcatcher. Temporary impacts are
mitigated at 1:1 ratio. Thus, mitigation is proposed through allocation of a total of 1.39 acres of quality
DCSS credit including 1.22 acres preservation of existing habitat (considered "occupied" by the
California Gnatcatcher) within the Carlsbad area, plus 0.17 acres of habitat restoration at the temporary
outlet box construction service road.
27 Rev. 07/03/02
Diegan Coastal Sage Scrub Impacts (in acres)
Habitat Type
Diegan Coastal
Sage Scrub
I/O Control
Building
(Permanent)
0.09
Spillway Apron
and Channel
Improvements
(Permanent)
0.52
Service Road and
Outlet Box
(Temporary)
0.17
Total
0.78
Diegan Coastal Sage Scrub Mitigation (in acres)
Habitat
Type
Diegan
Coastal
Sage Scrub
TOTAL
Permanent
Impacts
0.61
0.61
Permanent
Impacts
Ratio
2:1
2:1
Permanent
Impacts
Mitigation
1.22
1.22
Temporary
Impacts
0.17
0.17
Temporary
Impacts
Ratio
1:1
1:1
Temporary
Impacts
Mitigation
0.17
0.17
Total
Required
Mitigation
0.17
1.39
In order to minimize any potential for impacts beyond those identified above, a mitigation measure has
been included which requires that the project proponent ensure that the limits of construction are clearly
defined with temporary fencing prior to brush clearing activities and clearly visible to personnel on foot
and equipment operators. Construction personnel shall strictly limit their activities and vehicles to the
proposed project construction areas, approved staging areas, and routes of travel. The project proponent
and/or biological monitor shall contact the USFWS to verify that the limits of construction have been
properly staked and are readily identifiable, prior to construction.
Inasmuch as no significant effect on the reservoir level is proposed during the construction operation, and
the general operations management plan will continually return the reservoir level to approximately the
median level (208 elevation) as the natural flow regime permits, no significant impacts to upstream,
reservoir perimeter, or downstream riparian or wetlands biology, including oak trees and other wetland
dependent resources, is anticipated.
Finding: Potentially significant unless mitigation incorporated - Any potential impact resulting
from habitat modifications to wetland vegetation communities in the vicinity of the project are considered
potentially significant to those habitats and the special status species which inhabit such habitats.
DCSS impacts totaling 0.78 acres (0.61 acres permanent and 0.17 acres temporary) will result from
implementation of the project. This is considered a significant impact that can be mitigated to a level of
insignificance through issuance of a "take" permit in accordance with the City of Carlsbad HMP and
appropriate mitigation. These DCSS impacts shall specifically be mitigated through restoration of the
area impacted by the temporary construction access trail from the spillway to the outlet box (0.17 acres)
and credit for preservation of the balance (2:1 ratio) by permanent legal preservation of 1.22 acres of
quality DCSS habitat (considered "occupied" by the California Gnatcatcher) within Carlsbad or the
surrounding vicinity.
Diegan Coastal Sage Scrub Mitigation Proposed (in acres)
Habitat Type
Diegan Coastal Sage
Scrub
Permanent
Conservation
Protection
1.22
Restoration of Spillway
Construction Access
Trail
0.17
Total (Ac.)
1.39
b) Have a substantial adverse effect on any riparian, aquatic or wetland habitat or other
sensitive natural community identified in local or regional plans, policies, or regulations or
by California Department of Fish and.Game or U.S. Fish and Wildlife Service?
28 Rev. 07/03/02
Existing condition: Please refer to explanation of existing condition Section FV(a).
Environmental Evaluation: Wetland habitat related biological impacts will result from the project,
primarily involve the potential for impacts to wetland vegetation associated with the construction of the
spillway apron and channel improvements, and the laid-back structure. Riparian and wetland impacts
anticipated to result from implementation of the project are estimated as follows:
Riparian and Wetland Impacts (CDFG Jurisdiction) (in acres)
Habitat Type
Southern Willow Scrub
Mule Fat Scrub
Freshwater Marsh
TOTAL
Spillway
(Permanent)
0.002
0.005
0.007
Spillway Channel
(Permanent)
0.055
0.055
Outlet Box
(Temporary)
0.002
0.010
0.012
Total (Ac.)
0.004
0.060
0.010
0.074
A total of 0.074 acres of impacts to riparian and wetland biology (permanent and temporary) will result
from construction of the project. Inasmuch as management of the dam facilities upon completion of the
remedial improvements does not anticipate any long-term changes in the historical overall reservoir level
regime, no significant impacts to wetland and riparian biology is projected to result from future dam
operations.
Mitigation for the above temporary and permanent impacts is as follows:
Riparian and Wetland Mitigation (in acres)
Habitat
Type
Southern
Willow
Scrub
Mule Fat
Scrub
Freshwater
Marsh
TOTAL
Permanent
Impacts
0.002
0.060
0.062
Permanent
Impacts
Ratio
3:1
3:1
3:1
Permanent
Impacts
Mitigation
0.006
0.180
0.186
Temporary
Impacts
0.002
0.010
0.012
Temporary
Impacts
Ratio
1:1
1:1
1:1
Temporary
Impacts
Mitigation
0.002
0.010
0.012
Total
Required
Mitigation
0.008
0.180
0.010
0.198
A total of 0.198 acres of wetlands mitigation is required to mitigate for the potential permanent and
temporary biological impacts that will result from construction of the project. This mitigation program
will involve wetland creation of 0.198 acres of southern willow scrub (SWS) vegetation in a location
along the edge of the north shore of the reservoir that is presently highly disturbed and vegetated with
non-native grasslands (NNG).
Maintenance, inspection, monitoring and reporting of the status of the above mitigation program to the
appropriate agencies will also take place.
Marsh, riparian and other wetlands near the perimeter of the reservoir will not be impacted by the project
inasmuch as no significant modification of the water level regime during or after the construction
operation is anticipated.
Finding: Potentially significant unless mitigation incorporated - The proposed project will result
in permanent and temporary impacts to wetland habitat, which will require a minimum of 0.198 acres of
mitigation. A Streambed Alteration Agreement will be required from the CDFG pursuant to Section 1600
of the State Resources Code.
29 Rev. 07/03/02
c) Have a substantial adverse effect on federally protected wetlands as defined by Section 404
of the Clean Water Act (including but not limited to marsh, vernal pool, coastal, etc.)
through direct removal, filing, hydrological interruption, or other means?
Existing condition: Section 404 of the Clean Water Act regulates discharges of dredged or fill
material into Waters of the United States, including wetlands. As such, Section 404 regulates the
following activities associated with the proposed project; (a) gunite improvements to the dam spillway
apron (b) gunite and Armorloc improvements to the spillway channel, and (c) construction impacts
resulting from the slip-lining program at the dam outlet box.
Environmental Evaluation: The proposed project will result in a total of 0.134 acres of impacts to
"water of the U.S." as a result of; (a) permanent impacts resulting from the clearing and gunite
improvements to the dam spillway apron and channel and (b) construction impacts associated with the
installation of sleeving equipment at the outlet box located at the bottom of the downstream face of the
dam.
US Army Corps of Engineers Section 404 Impacts (in acres)
Habitat Type
Southern Willow Scrub
Mulefat Scrub
Freshwater Marsh
Non-wetland Waters
TOTAL
Spillway Apron
(Permanent)
0.002
0.005
0.020
0.027
Spillway Channel
(Permanent)
0.055
0.040
0.095
Outlet Box
(Temporary)
0.002
0.010
0.012
Total
0.004
0.060
0.010
0.060
0.134
US Army Corps of Engineers Section 404 Mitigation (in acres)
Habitat
Type
Southern
Willow
Scrub
Mulefat
Scrub
Freshwater
Marsh
Non-
wetland
Waters
TOTAL
Permanent
Impacts
0.002
0.060
0.060
0.122
Permanent
Impacts
Ratio
3:1
2:1
2:1
Permanent
Impacts
Mitigation
0.006
0.120
0.120
Temporary
Impacts
0.002
0.010
0.012
Temporary
Impacts
Ratio
1:1
1:1
Temporary
Impacts
Mitigation
0.002
0.010
0.012
Total
Required
Mitigation
0.008
0.120
0.010
0.120
0.258
The USAGE regulates discharges or dredging or fill materials into Waters of the United States. A total of
0.258 acres of wetlands mitigation is required to mitigate for the potential permanent and temporary
biological impacts to these Waters of the U.S. that will result from construction of the project. This
amount includes the biological impacts associated with the CDFG Jurisdiction impacts articulated in the
previous response. Thus, the 0.074 acres of CDFG impacts and 0.198 acres of mitigation are included
within the USAGE Jurisdiction impacts and mitigation (which are larger due to the addition of 0.120
acres of "non-wetland waters") as jurisdiction to the USAGE.
Therefore pursuant to CDFG and USAGE policies, the total wetland/riparian mitigation required is 0.258
acres. This mitigation program will involve wetland creation of 0.198 acres of southern willow scrub
(SWS) vegetation in a location along the edge of the north shore of the reservoir that is presently highly
disturbed and vegetated with non-native grasslands (NNG). This mitigation will ensure compliance with
appropriate mitigation ratios, and also with the federal "No net loss" policy for wetlands.
30 Rev. 07/03/02
Maintenance, inspection, monitoring and reporting of the status of the above mitigation program to the
appropriate agencies will also take place.
Finding: Potentially significant unless mitigation incorporated - The project is required to process
and receive approval from the US ACE for a Section 404 permit. The project will be required to mitigate
for impacts associated with filling of delineated areas at a minimum 3:1 ratio (SWS) and 2:1 ratio (MFS
and Non-wetland Waters). This mitigation is included in the mitigation measures identified in this
environmental assessment.
If approved in conjunction with the mitigation measures articulated in this environmental assessment, the
proposed project will result in less than significant impact on federally protected wetlands, as defined in
Section 404 of the Clean Water Act.
d) Interfere substantially with the movement of any native resident or migratory fish or
wildlife species or with established native resident or migratory wildlife corridors, or
impede the use of native wildlife nursery sites?
Existing condition: Please refer to existing condition response FV(a).
Environmental Evaluation: The subject project will result in elimination of an existing above-water
intake tower, and construction of other improvements including a replacement (laid-back on the internal
dam face) intake pipe, construction of a small control building, parking lot and fencing. No overall
change in water quality or quantity of the reservoir is anticipated as a result of implementation of the
proposed project. Upon completion of the project and removal of the construction materials and
equipment, the site will return to the pre-project ecological status, with the exception of the constructed
control building and its associated driveway/parking spaces, for which mitigation is required pursuant to
biological resource impact mitigation. The proposed fencing around the operations will provide an
obstacle to larger wildlife over the specific dam area, but this is not considered a significant barrier due to
the relatively small area covered by this fencing.
Finding: Less than significant impact - The proposed fencing is not considered a significant
barrier to wildlife migration due to the relatively small area encompassed by the fence. No significant
impact to fish or bird species is anticipated.
e) Conflict with any local policies or ordinances protecting biological resources, such as a tree
preservation policy or ordinance?
Existing condition: The City of Carlsbad has no adopted tree preservation policy or ordinance that
would affect the subject project.
Environmental Evaluation: The subject project will not impact trees or other biological resources
protected by policy or ordinance except as otherwise described in response FV(a) and FV(c) above.
Finding: No impact - No tree preservation impacts will result from implementation of the project.
f) Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community
Conservation Plan, or other approved local, regional, or state habitat conservation plan?
Existing condition: The approved City of Carlsbad Habitat Management Plan for Natural
Communities in the City of Carlsbad, Nov. 2004, identifies the subject site as a "Proposed Hardline
Conservation Area". This document indicates that the subject Lake Calavera site, owned by the City of
Carlsbad, is planned as a mitigation bank for City public facility infrastructure biological impacts. This
land use is consistent with the open space uses identified in the General Plan and the Zoning Ordinance.
The HMP designates a natural preserve system and provides a regulatory framework for determining
31 Rev. 07/03/02
impacts and assigning mitigation. No other local, regional or state habitat conservation plans specific to
this site encumber the property.
Environmental Evaluation: The proposed dam use is consistent with the existing use on the property,
hi addition, the improvements proposed, which will provide for full functioning of the dam operations,
are consistent with open space and hardline habitat preserve uses. The project will cause no change to the
allowed open space uses on the site.
The City of Carlsbad has not yet finalized a mitigation bank agreement with the Wildlife Agencies which
is necessary in order to achieve authorized mitigation bank status for the Lake Calavera property. In
addition, pursuant to the requirements of the Habitat Management Plan, the Lake Calavera property does
not constitute appropriate mitigation for "occupied" habitat, and thus, DCSS mitigation for permanent
impacts resulting from the subject project will not occur within the Lake Calavera property. They will
instead involve conservation and permanent protection of occupied habitat elsewhere in or within the
vicinity of Carlsbad.
Finding: No impact - The proposed project is consistent with the City of Carlsbad Habitat
Management Plan. It also does not conflict with the zoning or General Plan land uses allowed on the
site. The proposed mitigation is consistent with the Habitat Management Plan.
g) Impact tributary areas that are environmentally sensitive?
Existing condition: biologically sensitive areas, as described in the City of Carlsbad Habitat Management
Plan, surround the subject site. Much of these areas are hydraulically tributary to the subject site.
Environmental Evaluation: The proposed project will result in construction of a control building and
parking lot, improvements and replacement of the I/O tower facility and improvements to the surface of
the spillway apron and channel. These project impacts will not significantly impact tributary areas
inasmuch as temporary biology impacts are minimal and permanent impacts associated with these
improvements will not significantly impact tributary areas. No drawdown or other significant impacts to
the reservoir volume or surface level will result from implementation of the project.
Finding: No impact - No significant impact to the environmentally sensitive tributary areas is
anticipated to result from the project.
V. CULTURAL RESOURCES - Would the project:
a) Cause a substantial adverse change in the significance of a historical resource as defined in
§1 5064.5?
Existing condition: The subject project proposes a continuation of the existing use on the property,
including installation of replacement reservoir outflow apparatus with a laid-back pipeline secured to the
upstream-side face of the existing dam, and other repair/replacement improvements. Other improvements
include replacement of hydraulic and pneumatic I/O controls to replace the existing manually operated
devices, and minor repairs and maintenance to the dam, spillway apron, spillway channel and installation
of an all-weather access road will also occur. Debris within the spillway channel as well as some floor
erosion has reduced the present carrying capacity of the channel, and thus, spillway repairs will be
conducted to restore the channel to its original design capacity.
Replacement and improvement of an all-weather access service road to the control building, across the
spillway and across the dam crest is also proposed. These improvements will permit access for both
construction equipment, and future operation and maintenance activities. Security fencing around any
and all of these facilities is also proposed.
32 Rev. 07/03/02
A small amount of grading will be involved in excavation for construction of the control building.
Scraping of the existing dirt driveway, to be overlain with all-weather materials, will also occur. With
these exceptions, all of the proposed improvements will not involve significant grading nor will it cause
significant disruption of soil.
Environmental Evaluation: A Historic Resources Inventory and Evaluation Report for the Lake
Calavera Remedial Improvements Project has been conducted by ASM Affiliates, Inc., dated March
2005. This report concludes that the project Area of Potential Effect (APE) contains only one historic
resource, the 1942 Lake Calavera Dam. It concludes that the dam does not meet the criteria for listing in
the National Register of Historic Places (NRHP) nor does it appear to meet the criteria to be considered a
historical resource for the purposes of CEQA. It is thus not eligible to either the National Register or the
California Register.
Finding: No impact - Investigation concludes that the subject site does not contain any aspect
which would be considered historical or meet the criteria for listing in the National Register of Historic
Places (NRHP) nor meet the criteria to be considered a historical resource for the purposes of CEQA.
b) Cause a substantial adverse change in the significance of an archeological resource
pursuant to §15064.5?
Existing condition: A records search of archaeological resources in the area has been conducted.
Although the general area represents a favorable location for prehistorical human habitation, no recorded
cultural resource sites or historic landmarks have been logged within the immediate area.
Environmental Evaluation: A review of existing cultural resources in the area of the subject project
indicates that no impact to cultural resources will result from implementation of the subject project. Eight
prehistoric sites are recorded within one-half mile of the study area however none of these sites will be
impacted through implementation of the dam remedial improvements. In addition, the proposed project
will not result in significant excavation, or significantly impact the soil in the subject project area.
Since the project primarily involves remedial improvements to existing facilities, the original
development of the dam has removed or buried much of the original soil profile, and thus significantly
reduced the opportunity for discovery of prehistoric artifacts. Additionally, with the exception of the
relatively minor grading associated with the construction pad for the proposed control building, the
proposed project will not grade, or significantly impact the soil in the subject project area. Nonetheless,
several locations at which cultural resources have been identified to exist or have existed in the general
area, and thus the potential does exist for the discovery of cultural resources during excavation.
Finding: Potentially significant unless mitigation incorporated - Due to the potential for
significant impacts to cultural resources, an archaeological/cultural resource specialist monitor should be
available on-site to monitor the grading for the control building for archaeological resources. The
archaeologist shall be empowered to stop the grading operation in the specific area of resource discovery,
until all significant artifacts are recovered. A written report on the results of cultural resource discovery
shall be prepared and submitted to the City of Carlsbad Planning Department. Artifacts determined to be
significant shall be donated to a museum or local Indian collection pursuant to City policy.
c) Directly or indirectly destroy a unique paleontological resource or site or unique geologic
feature?
Existing condition: The subject site is located in an area geologically characterized by largely
decomposed granite, granitic rock and Santiago formation sedimentary rock. The scraping of topsoil, and
minimal grading associated with development of the control building will impact a relatively small
amount of this soil, which has been known to frequently contain fossil finds. Proposed improvements
which are to be located within the reservoir, and also those improvements to be located on the dam face
33 Rev. 07/03/02
(which is the artificial embankment of soil) will not impact native soils. Paleontological resources are
typically found in native soils.
Environmental Evaluation: Santiago formation sedimentary soils have been known to contain fossil
finds. The proposed project will have minimal impact on these sedimentary soils, primarily due to the
limited excavation required for construction of the control building. A significant impact would result if
important fossils were destroyed during construction of this control building. As a result, this impact can
be mitigated to a level less than significant by requiring a paleontological monitor of the grading for the
control building.
Finding: Potentially significant unless mitigation incorporated - Due to the potential for
significant impacts to paleontological fossil finds, a paleontological monitor should be available on-site
during the grading for the control buildings, to monitor and assess whether fossils are unearthed. The
paleontologist shall be empowered to salvage and curate any significant fossils identified, which shall be
donated to a museum or Indian collection pursuant to City policy.
d) Disturb any human remains, including those interred outside of formal cemeteries?
Existing condition: No record exists which would indicate the likelihood that human remains are
interred or would be expected to be encountered during construction of the proposed project. The site has
previously been disturbed by dam construction activities.
Environmental Evaluation: The proposed project is not anticipated to impact any known human
remains.
Finding: No impact - No human burials or remains are known to exist in the location of the subject
project.
VI. GEOLOGY AND SOILS - Would the project:
a) Expose people or structures to potential substantial adverse effects, including the risk of
loss, injury or death involving:
i. Rupture of a known earthquake fault, as delineated on the most recent Alquist-
Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or
based on other substantial evidence of a known fault? Refer to Division of Mines
and Geology Special Publication 42.
Existing condition: The project area is situated in the western portion of the Peninsular Ranges
geomorphic province of southern California. This geomorphic province encompasses an area that extends
125 miles from the Transverse Ranges and the Los Angeles Basin, south to the Mexican border, and
beyond another 775 miles to the southern tip of Baja California. The westernmost portion of the province
in San Diego County, in which the site is located, generally consists of Upper Cretaceous, Tertiary and
Quaternary age sedimentary rocks.
The most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the north
San Diego County area, indicates that the project is considered to be in a seismically active area, as is
most of southern California. This map however, indicates that the subject site is not underlain by known
active faults, nor is there evidence of ground displacement in the area during the last 11,000 years.
The Rose Canyon fault zone is the closest known fault, which is the onshore portion of an extensive fault
zone that includes the Offshore Zone of Deformation and the Newport-Inglewood fault to the north of the
subject site. This fault zone, located approximately six miles westerly of the subject site, is made of
predominately right-lateral strike-slip faults that extend south-southeast through the San Diego
metropolitan area. The zone extends offshore at La Jolla, and continues north-northwest generally
34 Rev. 07/03/02
parallel to the coastline. Portions of the Rose Canyon fault zone in the San Diego area have been
recognized by the State Geologist to be considered active.
Additionally, the Julian and Temecula segments of the Elsinore fault zone, about 23 miles to the northeast
of the subject site are also referenced in the Division of Mines and Geology Special Publication 42.
Environmental Evaluation: Based on resource investigation and field observations by Ninyo &
Moore (Geotechnical Design Evaluation, dated November 19, 2002), no active faults have been mapped
across the project site. The closest fault is located approximately six miles westerly of the site. The
Elsinore fault zone is located approximately 22 miles east of the site, and the Coronado Bank fault is
located approximately 25 miles west of the site. The potential for rupture resulting from earthquake is
considered to be low. The subject site is not within a fault-rupture hazard zone as indexed in the Division
of Mines and Geology Special Publication 42.
Finding: No impact - The project site is not within a fault-rupture hazard zone as determined in the
geotechnical report, and as indexed in the Division of Mines and Geology Special Publication 42;
therefore the project would not expose people or structures to potential substantial adverse effects.
ii. Strong seismic ground shaking?
Existing condition: Southern California is recognized as a seismically active area. As indicated in
the response to Item VI(a)(i), the Rose Canyon fault zone is the closest known fault, located
approximately six miles westerly of the subject site. This fault is made of predominately right-lateral
strike-slip faults that extend south-southeast through the San Diego metropolitan area. The second-closest
active area of potential ground motion is the Julian and Temecula segments of the Elsinore fault zone. No
other known active faults are located within the vicinity of the project.
The most significant seismic event likely to affect the proposed facilities would be a maximum moment
magnitude 6.9 earthquake along the Rose Canyon fault zone, in which the horizontal peak ground
acceleration has a 10% probability of exceedance in 50 years is 0.27g (27% of the acceleration of
gravity) and a 5% probability of exceedance in 50 years is 0.4 Ig. The existing dam operations have not
failed or been otherwise impacted due to seismic ground shaking during its over-60 year existence.
Environmental Evaluation: The project site will likely be subject to ground shaking in response to
either a local moderate or more distant large-magnitude earthquake. Seismic risk at the site is comparable
to the risk for the San Diego area in general. The closest source to the site for ground motion, and the
source that would produce the greatest ground acceleration at the site, is the Del Mar segment of the Rose
Canyon/Newport-Inglewood fault zone, about 6 miles west, and potentially the Julian and Temecula
segments of the Elsinore fault zone, about 22 miles to the northeast of the project site. Project design will
meet or exceed existing earthquake design standards, including provision of emergency power failure
back up, manual operation of emergency draining, and UBC compliance for the control building.
Finding: Less than significant impact - The existing dam operations have not failed due to seismic
ground shaking during the dam's over 60 year existence. Earthquake faults exist within southern
California, including three fault zones within 26 miles of the site. Historical records have indicated
however, that the risk of strong seismic ground shaking of the project site is minimal, and thus is
considered a less than significant impact.
iii. Seismic-related ground failure, including liquefaction?
Existing condition: Liquefaction of soils with minimal cohesion can be caused by strong vibratory
motion due to earthquakes. Research indicates that loose granular soils and silts that are saturated by a
relatively shallow groundwater table are most susceptible to liquefaction. Preliminary geotechnical
evaluation of the subject site indicates that the site is underlain by relatively dense formational sandstone
and granitic rock, and thus not considered susceptible to ground failure or liquefaction.
35 Rev. 07/03/02
Environmental Evaluation: Relatively dense formational sandstone and granitic rock underlies the
site. The potential for liquefaction or seismically induced settlement in the vicinity of the proposed
improvements is considered to be nil. The existing dam facilities have not however, failed or experienced
damage due to seismic-related ground failure, including liquefaction during its 60 years of existence.
Finding: No impact - The potential for liquefaction or seismically induced settlement in the
vicinity of the proposed improvements is considered to be nil. In addition, the base of the existing Inlet
tower will remain. The proposed laid-back piping and intake port system will be moderately flexible, and
thus not be significantly susceptible to damage from seismic shaking or liquefaction. Maintenance and
operations personnel will inspect the facilities daily, including the foundation of the control building. If
cracks or voids are identified, replacement material could be pumped under the foundation for structural
support.
iv. Landslides?
Existing condition: No landslides have been identified as having the potential to damage or affect the
proposed project facilities. None have impacted the subject site during the over 60 years of existing dam
facility existence.
Environmental Evaluation: No landslides are anticipated to affect the proposed dam facilities.
Finding: No impact - The project will not increase the likelihood of landslides.
b) Result in substantial soil erosion or the loss of topsoil?
Existing condition: Notwithstanding that the subject project proposes a continuation of the existing
use on the property, some grading and movement of surface soils will be involved in the construction of
the proposed project. Additionally, minor repairs and maintenance to the dam, spillway apron, and
spillway channel will also occur. Debris presently existing within the spillway channel as well as some
floor erosion has reduced the present carrying capacity of the channel, and thus, spillway repairs will be
conducted to restore the channel to its original design capacity.
Environmental Evaluation: The proposed improvements and maintenance to the existing spillway
channel, including gunite replacement of the channel surface, will reduce the potential for soil erosion
within this channel. A small amount of grading is proposed for the control-building pad, and the access
drive improvements, during the construction period. During this grading, the exposure of soils would
lead to an increased chance for the erosion of soils from the site. Such grading will follow best
management practices for the control of erosion, such as straw bale or sandbag barriers, silt fences, slope
roughening, and outlet protection in exposed areas. Finished grades will be promptly hydroseeded or
otherwise protected as required per the adopted City Grading Ordinance. If necessary, temporary slope
cover such as jute matting or mulch will be applied to newly graded slopes to reduce the impact to soil
erosion or the loss of topsoil to a level of less than significant.
Upon completion of the project, the water storage regime in the reservoir will not be significantly
different than that which operates pre-remediation of facilities, except that control over the reservoir
water volume will again be managed by CMWD, rather than by the elevation of the single valve outlet
and climatic conditions and runoff. CMWD will manage the reservoir volume in an effort to avoid high-
volume discharges of impounded water. Under existing circumstances, no ability to control high-volume
floodwater discharges exists, and thus downstream erosion occurrences take place during flood
conditions.
The project will have no effect on reservoir erosion or upstream erosion potential.
36 Rev. 07/03/02
Finding: Less than significant impact - It is concluded that impacts to soil erosion or the loss of
topsoil will be less than significant because management of reservoir water levels will allow the operator
to reduce the potential for downstream erosion occurrences that take place during flood conditions. With
regard to construction operations, the project is required to comply with the City of Carlsbad grading
ordinance, including erosion control protection, over the limited areas in which bare soil will be
temporarily exposed. Further, the proposed improvements to the spillway and spillway channel will
result in a general long-term reduction of potential for downstream sediment transport.
c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a
result of the project, and potentially result in on- or off-site landslide, lateral spreading,
subsidence, liquefaction, or collapse?
Existing condition: Please refer to existing condition VI(a)(i, ii, and iii).
Environmental Evaluation: Please refer to evaluation VI(a)(i, ii, and iii). Routine soil settlement is
expected to undergo total settlements of less than approximately 0.5 inches. Differential settlements are
typically less than about one-half of the total settlement.
Finding: Less than significant impact - Please refer to response VI(a)(i, ii, and iii).
d) Be located on expansive soils, as defined in Table 18-1-B of the Uniform Building Code
(1997), creating substantial risks to life or property?
Existing condition: The site of the proposed remedial improvements is composed of largely
decomposed granite, granitic rock and Santiago formation sediments. Santiago formation geology is best
described as light-colored, poorly-bedded, poorly-indurated, fine to medium grained sandstone
sedimentary rock. Rock outcrop covers 2% to 10% of the surface in the vicinity. Some alluvium was
encountered to the west of the dam structure at a depth of approximately 12 feet, but this is not considered
to render the site significantly expansive pursuant to Table 18-1-B of the Uniform Building Code.
Environmental Evaluation: Table 18-1-B of the Uniform Building Code does not identify the
Santiago formation geology as highly expansive.
Finding: No impact - It is concluded that expansive soils are not a geological hazard for the
subject project. Therefore no substantial risks to life or property associated with expansive soils exist.
e) Have soils incapable of adequately supporting the use of septic tanks or alternative
wastewater disposal systems where sewers are not available for the disposal of wastewater?
Existing condition: The subject project does not propose and will not necessitate the use of sewer,
septic tank, or alternative wastewater disposal systems. No rest rooms or other wastewater facilities are
proposed.
Environmental Evaluation: The proposed project is a public infrastructure repair improvement. No
sewer or wastewater facilities are necessary for full construction and operation of the project. As a result,
such facilities are not proposed.
Finding: No impact - No septic tanks or alternative sewage disposal systems are included in the
project description.
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VII. HAZARDS AND HAZARDOUS MATERIALS - Would the project:
a) Create a significant hazard to the public or the environment through the routine transport,
use, or disposal of hazardous materials?
Existing condition: During construction of the proposed project, a small amount of construction
materials such as petroleum projects, paint, oils and solvents will be transported and used on the site.
Upon completion of construction of the project, no use of such products on the site is anticipated. Other
than during this construction phase, the project will not routinely utilize any hazardous substances or
materials. The project area could presently be considered an attractive nuisance for adventurers and
loiterers. The proposed project would eliminate access to this nuisance hazard.
Environmental Evaluation: Construction of the proposed project will involve operation of heavy
machinery, which utilizes petroleum products, and paint, oils and solvents. No permanent use of such
hazardous materials is anticipated. All transport, handling, use, and disposal of substances will comply
with all federal, state, and local laws regulating the management and use of hazardous materials. The
proposed project would eliminate the existing attractive nuisance through implementation of the proposed
security fencing program.
Finding: Less than significant impact - It is concluded that the routine amount of hazardous
materials utilized during the construction period is not significant, and therefore the impact to the public
or the environment through the routine transport, use, or disposal of hazardous materials is less that
significant.
b) Create a significant hazard to the public or environment through reasonably foreseeable
upset and accident conditions involving the release of hazardous materials into the
environment?
Existing condition: Please refer to the preceding response.
Environmental Evaluation: No significant hazard involving the release of hazardous material into the
environment would be anticipated since only a small amount of hazardous materials will be utilized, and
only during the construction period.
Finding: Less than significant impact - Please refer the response to Section VII(b). No
extraordinary risk of accidental explosion or the release of hazardous substances is anticipated with
construction, development, implementation or operation of the proposed project.
c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances,
or waste within one-quarter mile of an existing or proposed school?
Existing condition: The subject project is approximately 450 linear feet (0.09 mi.) from the nearest
elementary school, which is future Calavera Hills Elementary School, located on Tamarack Avenue,
northwest of the dam site. Therefore the site is within one-quarter mile of a proposed school.
The project is not anticipated to emit any hazardous emissions or handle hazardous or acutely hazardous
materials, substances or wastes once operational. During the construction period, a small amount of
hazardous materials, including petroleum products, and paint, oils and solvents will be utilized.
Environmental Evaluation: Hazardous products will be utilized on the proposed project only during
the construction period. These substances are not anticipated to include any materials that would not
likely be stored on the school site. No permanent storage or transport of hazardous materials will occur
on the subject project.
38 Rev. 07/03/02
Finding: Less than significant impact - No permanent storage or use of hazardous material will
occur on the subject dam project. Limited hazardous materials utilized during the construction period will
not constitute a significant impact on health or operations of the adjacent school.
d) Be located on a site which is included on a list of hazardous materials sites compiled
pursuant to Government Code Section 65962.5 and, as a result, would it create a significant
hazard to the public or environment?
Existing condition: The subject site is not included on a list of hazardous materials sites (Federal
database) compiled pursuant to Government Code Section 56962.5.
Environmental Evaluation: The subject site is not included on a list of hazardous materials sites
(Federal database) compiled pursuant to Government Code Section 56962.5. In addition, it is not on the
EPA database of current and potential Superfund sites currently or previously under investigation. Also,
to the best of EPA's knowledge, it has been determined that no steps will be taken to list this site on the
National Priorities List (NPL). It is not on any list of registered hazardous waste generators, or on a
database of sites that treat, store, dispose of, or incinerate hazardous waste.
Finding: No impact - The subject property is not included on any list of hazardous materials, and
has no known previous use history that would involve the use or storage of hazardous materials.
e) For a project within an airport land use plan, or where such a plan has not been adopted,
within two miles of a public airport or public use airport, would the project result in a
safety hazard for people residing or working in the project area?
Existing condition: The subject dam remedial improvements are located approximately 15,000 linear
feet (2.85 miles) due north of McClellan-Palomar Airport. The City of Carlsbad does have an adopted
airport land use plan.
Environmental Evaluation: Since the proposed project is located in excess of two miles (2.85 miles)
from the closest airport (McClellan-Palomar Airport), the site does not meet the minimum qualifications
as having the potential for safety hazard for people residing or working in the project area.
Finding: No impact - As a result of its 2.85-mile distance from McClellan-Palomar Airport, the
project does not meet the minimum qualifications as a potential safety hazard.
f) For a project within the vicinity of a private airstrip, would the project result in a safety
hazard for people residing or working in the project area?
Existing condition: No private airstrip exists in the vicinity of the subject project.
Environmental Evaluation: The project is not within the vicinity of a private airstrip and no people
will reside on the site. Construction work on the site will be temporary. Routine inspection and
maintenance workers) will typically be occupying the site only of a short duration, daily.
Finding: No impact - The project is not within the vicinity of a private airstrip.
g) Impair implementation of or physically interfere with an adopted emergency response plan
or emergency evacuation plan?
Existing condition: The proposed project involves repair and rehabilitation of an existing use on the
property. The project is not located on or adjacent to a public street.
Environmental Evaluation: Neither construction nor operation of the dam operations facilities will
significantly affect, block, or interfere with traffic on public streets, including any streets that would be
39 Rev. 07/03/02
used for an emergency response plan or emergency evacuation plan. Routine maintenance activities will
be accomplished by means of an existing private drive access to the site. The private drive approximately
250 feet in length, and is designed to avoid any impacts to the public street system.
Finding: No impact - No improvements are proposed in any area which would physically interfere
with an adopted emergency response plan or emergency evacuation plan.
h) Expose people or structures to a significant risk of loss, injury or death involving wildland
fires, including where wildlands are adjacent to urbanized areas or where residences are
intermixed with wildlands?
Existing condition: The closest houses to the subject activity area are 400 feet to the west. The
project will not result in any drawdown or drying of the reservoir water level. The proposed project is
located within an area that is not residential. The subject proposed improvements will comply with UBC
requirements for safety and electrical codes.
Environmental Evaluation: The proposed project is not residential and thus will not expose new
residences to wildland fire risk. It will not result in any drawdown or drying of the reservoir water level
and thus will not contribute to virus or insect breeding. The project will introduce however, electrical
apparatus into a wildlands area. The project improvements however, are required to comply with UBC
regulations and electrical safety codes, and thus will not result in any significant additional exposure of
neighboring residences to wildfire risk.
Finding: No impact - It is concluded that the proposed project will not expose residences in the
vicinity to significant wildland fire risk.
VIII. HYDROLOGY AND WATER QUALITY - Would the project:
a) Violate any water quality standards or waste discharge requirements?
Existing condition: The proposed project is primarily a repair and maintenance plan for existing dam
operational facilities at Lake Calavera dam. Construction of the improvements is required by law to
comply with all federal, state and local water quality regulations, including the Clean Water Act,
California Administrative Code Title 23, and specific basin plan objectives identified in the "Water
Quality Control Plan for the San Diego Basin.
The subject project is located on Calavera Creek, which is a main tributary to Agua Hedionda Lagoon.
The Water Quality Control Plan for the San Diego Basin identifies specific objectives for the Carlsbad
Hydrologic Unit and Agua Hedionda Hydrologic Subarea. These objectives include the requirement to
comply with National Pollutant Discharge Elimination System (NPDES) Best Management Practices
(BMP's). The project must also obtain a NPDES permit prior to construction. The permit will require
that the project develop and implement specific erosion control and storm water pollution prevention
plans to protect downstream water quality of Calavera Creek.
As a result of the inoperable nature of the outflow valves, the existing dam facilities are not in compliance
with the requirements of the DSOD. DSOD emergency regulations dictate that dam managers shall have
the ability to drawdown at least 50% of the volume of the reservoir water within a maximum of seven (7)
days. While the Calavera Dam does not presently have this ability, implementation of the proposed
remedial improvements would result in operational facilities that would allow the dam to comply with the
requirement.
Environmental Evaluation: Application, certification and compliance with an NPDES permit for
implementation of the subject project will ensure that water quality will be maintained to a level of
acceptability. No drawdown of the reservoir level is proposed for the project. Crane facilities located on
the disturbed area of the shore will position the temporary structure, remove the tower and place the laid-
40 Rev. 07/03/02
back structure. Cut-off and removal of the top portion of the existing I/O tower will result in a small
amount of concrete dust entering the reservoir water. A temporary pump hose will be inserted into the
enclosure. No addition of materials to the reservoir water is proposed, with the exception of the piping
and electronic controls.
Downstream of the dam, an existing low-flow channel for downstream Calavera Creek of approximately
3 feet across and 6 inches deep has formed, although some wider areas exist. Approximate average base
flows are estimated at 3 cfs with velocities of approximately 2 feet per second. This creek travels through
primarily clay soils, although portions of the channel consist of sandy-clayey soils. The low flow channel
has nearly vertical side slopes, however they are fairly stable. Although erosion of the channel banks has
occurred in the past, significant active erosion is not occurring on a regular basis.
Although minimal vegetation occurs within the main channel of downstream Calavera Creek, dense
vegetation, including brush and dense grasses, line the area on either side of the creek channel. Rocks
occur within the channel in certain areas. The lack of vegetation within the main channel indicates the
channel maintains a relatively constant flow velocity, reducing the potential for vegetation establishment.
Implementation of the proposed project will also result in the ability of the dam facilities to comply with
the DSOD requirement for 50% water volume drawdown within the required maximum of seven (7) days.
This ability could allow for (under emergency circumstances) high volume water release that cannot
occur now without uncontrolled breach of the dam. Such emergency circumstances are not considered a
violation of water quality standards or waste discharge requirements.
Finding: Significant unless mitigation incorporated - The proposed project could result in
temporary degradation of water quality if it does not demonstrate compliance with all federal, state, and
local regulations for water quality. The project proponent shall adhere to applicable RWQCB regulations
for control of sedimentation and erosion, including the installation of temporary detention basins or other
means of stabilization or impoundment required by the State Water Resources Control Board. All
exposed graded areas shall be treated with erosion control pursuant to City of Carlsbad erosion control
standards, including hydroseed, berms, desiltation basins, jute matting, sandbags, bladed ditches, or other
appropriate methods. Compliance with DSOD requirements for emergency drawdown timeframes is
considered a beneficial effect of the proposed project.
b) Substantially deplete groundwater supplies or interfere substantially with ground water
recharge such that there would be a net deficit in aquifer volume or a lowering of the local
ground water table level (i.e., the production rate of pre-existing nearby wells would drop to
a level which would not support existing land uses or planned uses for which permits have
been granted)?
Existing condition: The proposed project is located within and around existing Lake Calavera, which
is a surface-water reservoir. Geotechnical test borings by Ninyo & Moore, excavated for the subject
project, did not encounter groundwater. However, as evidenced by the reservoir, groundwater is located
relatively near the surface in the close vicinity of the reservoir. Groundwater levels may be expected to
fluctuate due to seasonable variations, water usage and other factors.
The project proposes access for construction of the laid-back pipe improvements however no
modification of the reservoir level is proposed.
A permit for construction of the project will necessitate a Section 401 certification from the Regional
Water Quality Control Board, with conditions designed by the RWQCB to prevent adverse water quality
effects on surface water and groundwater.
Environmental Evaluation: No significant modification of creek tributary, reservoir water or
downstream volume or surface elevation is proposed during the construction period or after construction
is completed. Pumping of the water volume within the temporary structure in order to allow for
41 Rev. 07/03/02
construction of the I/O operations will not affect ground waters. No pumping of sub-surface waters is
proposed. Thus no significant impact to water quality will result from the project.
Finding: No impact - The proposed project could not result in depletion of groundwater in the
immediate vicinity of Lake Calavera due to the fact that no significant modification of reservoir water
volume or surface elevation is proposed.
c) Impacts to groundwater quality?
Existing condition: Please see the preceding description of existing condition.
Environmental Evaluation: Pumping of the water volume within the temporary structure in order to
allow for construction of the I/O operations will not affect ground water quality. Thus no significant
impact to groundwater quality will result from the project.
Finding: No impact - The proposed project will comply with federal, state and local water quality
requirements and thus no significant impact to groundwater will result from implementation of the
project.
d) Substantially alter the existing drainage pattern of the site or area, including through the
alteration of the course of a stream or river, in a manner, which would result in substantial
erosion or siltation on- or off-site?
Existing condition: The tributary drainage area to Lake Calavera is approximately 3.6 square miles.
The average yearly rainfall within this drainage area is 13 inches. Drainage runoff enters Lake Calavera
via a number of small branch tributaries to Upper Calavera Creek. This drainage extends several miles
eastward into southwest Vista, in the vicinity of Hwy. 78. About 85% of the upstream watershed is
outside the City of Carlsbad city limits. Nearly all of the surface runoff within the drainage area that
reaches Lake Calavera occurs between December and late March. The natural drainage pattern of this
sub-watershed has been influenced through installation of the dam, which has created the reservoir.
Water exits the reservoir via an existing outflow tower, and during flood conditions, the spillway. None of
these basic hydrologic factors will change with implementation of the proposed project.
The subject project will include improvements the Calavera Dam operations facility. These
improvements will not alter the existing constructed drainage of the site except to make the dam facilities
mechanically operational. Improvements to the spillway channel are proposed which are intended to
restore its water-transport efficiency.
Environmental Evaluation: Construction of the improvements to the dam facilities will not
significantly alter the existing drainage pattern of the site. Upon completion of the proposed remedial
construction, the dam outlet controls will be operational. All indications are that this ability to operate
and manage the dam facilities will allow the control of floodwaters so that they have less downstream
impact than they do under the existing, uncontrolled situation. In anticipation of a major rain event, the
dam manager will have the ability to perform an appropriate drawdown to minimize the potential for
flows over and into the dam spillway. Under this scenario, the water level could be dropped in
anticipation of the rainfall event and then rise again during the event. Following the rainfall event, the
surplus would be released to maintain the approximate 208 annual median elevation. This increased
efficiency in control of downstream flows will decrease the potential for downstream flooding. As a
result, also the improvements proposed will result in a net long-term reduction of downstream
sedimentation in Calavera Creek, primarily due to the gunite and Armorloc improvements (impervious
and semi-impervious surface) of the spillway and spillway channel. A very minor incremental increase in
the amount of impervious ground surface will result from construction of the control building and the
spillway improvements.
42 Rev. 07/03/02
Finding: No impact - The proposed project will not substantially alter the existing pattern of
runoff from and through the reservoir. As a result, it is concluded that no significant impact to drainage
flow will result from implementation of the project.
e) Substantially alter the existing drainage pattern of the site or area, including through the
alteration of the course of a stream or river, or substantially increase the flow rate or
amount (volume) of surface runoff in a manner, which would result in flooding on- or off-
site?
Existing condition: Please refer to the preceding existing condition. No modification to the drainage
pattern of the site is proposed.
Environmental Evaluation: The proposed improvements to the dam facilities will not significantly
alter the existing drainage pattern of the site. Improvements proposed will result in a net reduction of
downstream sedimentation in Calavera Creek, primarily due to the gunite improvements (impervious
surface) of the spillway apron and a portion of the spillway channel. The remainder of the spillway
channel will be surfaced with Armorloc material, which is a porous material. A very minor incremental
increase in the amount of impervious surface will result from construction of the control building.
The flow rate or volume of runoff through the dam and down Calavera Creek will be managed more
efficiently, and thus may increase or decrease in flow volume and/or velocity as decided by CMWD
operators. The project will also result in a slight, but not significant increase in runoff due to the increase
in the area of impervious surface of the project.
Finding: Less than significant impact - The flow rate or volume of runoff through the dam and
down Calavera Creek will be managed more efficiently through implementation of the proposed project,
and thus could increase if determined desirable by the dam manager. The project will also result in a
slight, but not significant increase in runoff due to the increase in the area of impervious surface of the
project.
f) Create or contribute runoff water, which would exceed the capacity of existing or planned
storm water drainage systems or provide substantial additional sources of polluted runoff?
Existing condition: Impervious surfaces associated with development of the project will
incrementally increase runoff to a limited degree. Gunite and concrete improvements to the spillway and
spillway channel will improve efficiency and reduce the erosive potential of runoff transport downstream
into Lower Calavera Creek.
Environmental Evaluation: Impervious surfaces will increase in area and efficiency of runoff
transport down Calavera Creek; however, since the project will be required to comply with federal, state
and local water quality regulations, no significant creation of additional runoff will result. No impact to
existing storm drain systems and no additional sources of polluted runoff will result from implementation
of the project.
Finding: Less than significant impact - Limited impervious surfaces at the dam will incrementally
increase runoff from the site but will be directed to Calavera Creek, resulting in no net effect. No
additional pollution of surface waters is anticipated to result from the project.
g) Otherwise substantially degrade water quality?
Existing condition: The proposed project involves remedial improvements to existing dam and
spillway facility operations, in order that they return to an operable condition. None of these
improvements are anticipated to degrade water quality from its existing quality level.
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Environmental Evaluation: Minor impacts to water quality resulting from sediment due to the
construction of the project are anticipated. Construction of these improvements however, is required by
law to comply with all federal, state and local water quality regulations, including the Clean Water Act
and associated NPDES regulations. Therefore temporary impacts associated with the construction
operation will be mitigated. The project will not result in permanent or long term degradation of water
quality, and is anticipated to improve downstream water quality through elimination of features (spillway
disrepair) that presently cause downstream sedimentation.
No modification of the water volume, surface level or pH is proposed or anticipated during the
construction period.
Finding: Less than significant impact - Please refer to the preceding responses.
h) Place housing within a 100-year flood hazard area as mapped on a Federal Flood Hazard
Boundary or Flood Insurance Rate Map or other flood delineation map?
Existing condition: The proposed project involves improvements to existing flood control and water
storage facilities, and does not involve the placement of housing or any residential or associated land use.
Environmental Evaluation: No placement of housing is proposed through implementation of the
project, and therefore no impact will result.
Finding: No impact - No housing is proposed.
i) Place within 100-year flood hazard area structures, which would impede or redirect flood
flows?
Existing condition: The replacement of a reservoir outlet pipe structure, with a laid-back water intake
and air/vacuum vent assembly will all occur within the 100-year flood area. Only the laid back piping
structure located on the upstream face of the dam is considered construction of a new structure. No other
structural facilities will be located within the 100-year flood hazard area.
Environmental Evaluation: Installation of the laid-back water intake/outlet assembly and air/vacuum
vent assembly structure is very small in size (approximately 24" in diameter; 50' in length), and as a result
will effect only an insignificant volume of flood hazard area. This facility, however will significantly
improve the flood control capabilities and controls of the reservoir, and thus is not considered to result in
impeded or increased flows of the creek. The project will demolish the upper 28 feet of the existing
concrete tower, located within the 100-year flood area.
Finding: No impact - It is concluded that the proposed project will restore the dam operations, and
thus improve the operator's ability to avoid impeded or increased downstream flows.
j) Expose people or structures to a significant risk of loss injury or death involving flooding,
including flooding as a result of the failure of a levee or dam?
Existing condition: The existing dam outlet pipeline, partially clogged with debris at the tower base,
is in need of repair. In addition, improvements are necessary at the outlet box structure, spillway apron,
dam drainage channel, access road and security fencing. All of these aspects of the existing facility are
proposed for improvement and upgrade. These improvements will allow for increased control of
floodwaters, and the improved operations of the dam.
Environmental Evaluation: No significant impact will result from the proposed project because it
will improve an existing deficient system of flood control and water containment operations. The dam
structure has demonstrated in over 60 years in operation that it is not subject to failure from floodwaters.
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Finding: No impact - It is concluded that the proposed project will result in improved flood
control operations.
k) Inundation by seiche, tsunami, or mudflow?
Existing condition: The proposed project site is located at an elevation of 200 ft. above sea level,
approximately three miles from the Pacific Ocean. No mudflow conditions are located within or near the
subject area.
Environmental Evaluation: Conditions for seiche, tsunami or mudflow do not exist at or near the
project site.
Finding: No impact - The potential for damage to the project from seiche, tsunami or mudflow are
very low due to the project's location and elevation.
1) Increased erosion (sediment) into receiving surface waters.
Existing condition: Construction of the proposed project will temporarily create exposed
(unvegetated) soil in portions of the proposed project area. The project applicant must however, obtain a
National Pollutant Discharge Elimination System permit prior to construction. The permit will require
that the project develop and implement specific erosion control and storm water pollution prevention
plans to protect downstream water quality of Calavera Creek.
Environmental Evaluation: The construction phase of the project could result in increased erosion
into Calavera Creek. As a result of the NPDES permit requirements associated with the proposed project,
no significant increase in erosion (sediment) into receiving surface waters will result from the project.
Finding: Significant unless mitigation incorporated - The project will be required to demonstrate
compliance with NPDES sediment control requirements during the construction phase.
m) Increased pollutant discharges (e.g., heavy metals, pathogens, petroleum derivatives,
synthetic organics, nutrients, oxygen-demanding substances and trash) into receiving
surface waters or other alteration of receiving surface water quality (e.g., temperature,
dissolved oxygen or turbidity)?
Existing condition: The subject site is on an upstream leg of Calavera Creek. The project does not
propose to create or allow any pollutant discharges into receiving surface waters or other waters upstream
or downstream of the subject project.
Environmental Evaluation: The project proposes no increase in pollutant discharges. The project
will be required to process and receive an NPDES permit, and water quality certification from the
RWQCB. No heavy, metals, pathogens, petroleum derivatives, synthetic organics, nutrients, oxygen-
demanding substances, or trash will be produced by the project.
No impact - No increase in pollutants will result from the project.
Changes to receiving water quality (marine, fresh or wetland waters) during or following
construction?
Existing condition: The project does not propose any modification of water quality exiting the site
into receiving surface waters or other waters. The quality of water exiting the dam during or following
construction is not anticipated to vary from the existing situation.
Environmental Evaluation: No impact to receiving water quality will result from the proposed
project. Construction operations will be required to comply with NPDES regulations.
45 Rev. 07/03/02
Finding: No impact - No receiving water quality will be adversely affected through
implementation of the proposed project.
o) Increase in any pollutant to an already impaired water body as listed on the Clean Water
Act Section 303(d) list?
Existing condition: Agua Hedionda Lagoon is listed on the Clean Water Act Section 303(d) list as an
"Impaired" water body. This water body is impaired due to excess buildup of sedimentation and fecal
bacteria. The proposed project ultimately drains (2 miles southwesterly) to Agua Hedionda Lagoon.
Environmental Evaluation: As designed, the proposed project will not be increasing the pollutants
into downstream waters, including Agua Hedionda Lagoon.
No impact- No pollutants are proposed to be released from the site.
The exceedance of applicable surface or groundwater receiving water quality objectives or
degradation of beneficial uses?
Existing condition: The project will allow the Carlsbad Municipal Water District the option of
restored management of flood control and water containment. This option will increase the ability to
provide for downstream (or upstream) beneficial uses.
Environmental Evaluation: No significant impact to beneficial uses, or water quality objectives will
result from the proposed project. The ability to improve on these uses and objectives, due to greater
ability to manage reservoir levels, will be increased through implementation of the proposed project.
Finding: No impact - Please refer to the preceding responses.
IX. LAND USE PLANNING - Would the project:
a) Physically divide an established community?
Existing condition: The subject site is located on a 288-acre parcel encompassing Lake Calavera
reservoir and dam. The property is undeveloped and identified on the City of Carlsbad Land Use Element
of the General Plan as Open Space. Zoning is also for open space uses. Surrounding land uses in the
immediate vicinity of the proposed project are open space. Further to the west are newer single-family
residential neighborhoods of Sheffield, Nantucket and Capistrano. An older, existing single-family
neighborhood, located within the city limits of Oceanside, exists over 1A mile to the north. Calavera
Mountain (Cerro de La Calavera) is also open space, and exists south of the Calavera Dam.
Environmental Evaluation: The proposed improvements involve primarily the replacement of
existing uses, all within a large open space preserve. No division of an existing community would result
from development of the project.
Finding: No impact - The project would not physically separate any contiguous residential areas
since none exist within the open spaces in and around the site.
b) Conflict with any applicable land use plan, policy, or regulation of an agency with
jurisdiction over the project (including but not limited to the general plan, specific plan,
local coastal program, or zoning ordinance) adopted for the purpose of avoiding or
mitigating an environmental effect?
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Existing condition: The City of Carlsbad General Plan identifies the subject site as open space.
Zoning is also designated open space. No specific plan covers the property. The site is not located with
the Coastal Zone. The project proposes no change to any land use on the site.
Environmental Evaluation: The project involves the repair of public utility infrastructure within the
open space land use designation in the Carlsbad General Plan. This utility use already exists on the site.
The proposed use is compatible with the open space designation. No incompatibility exists between the
proposed project and the land use regulations on the property.
Finding: No impact - The project is not in conflict with any applicable land use plan, policy, or
regulation of any agency with jurisdiction over the project.
c) Conflict with any applicable habitat conservation plan or natural community conservation
plan?
Existing condition: The City of Carlsbad Habitat Management Plan for Natural Communities in the
City of Carlsbad, Dec. 1999, identifies the subject site as a "Proposed Hardline Conservation Area". This
land use is consistent with the open space uses identified in the General Plan and the Zoning Ordinance.
No other habitat conservation plans specific to this site encumber the property.
Environmental Evaluation: The proposed dam use is consistent with the existing, legal use on the
property at this time. In addition, the improvements proposed, which will provide for full functioning of
the dam operations, are consistent with open space and hardline habitat preserve uses.
Finding: No impact - The subject project site is consistent with the City of Carlsbad Habitat
Management Plan for Natural Communities in the City of Carlsbad.
X. MINERAL RESOURCES - Would the project:
a) Result in the loss of availability of a known mineral resource that would be of future value
to the region and the residents of the State?
Existing condition: The proposed project involves the replacement and improvement of existing dam
operational facilities. No significant excavation or inundation will result from implementation of the
project. No known or expected mineral deposits of future value to the region and the residents of the state
are located in the immediate vicinity of the subject project.
Environmental Evaluation: The subject site has been already largely disturbed. As a result of the
minimal excavation and disruption of the surface of the land that will result from the proposed project, no
significant impact to the potential for valuable mineral deposits is anticipated from the project.
Finding: No impact - No known mineral resource of regional or statewide value are known that
would be affected through implementation of the project. Additionally, the project would affect a
relatively small area of earth disruption, and any substantial mineral resource recovery under these
minimal circumstances would not be expected.
b) Result in the loss of availability of a locally important mineral resource recovery site
delineated on a local general plan, specific plan, or other land use plan?
Existing condition: The subject site is not designated on the City of Carlsbad General Plan or the
Zoning Ordinance as a locally important mineral resource recovery site. The property is not regulated by
any specific plan or other regulatory land use plan.
Environmental Evaluation: As a result of the fact that the City has not designated the subject
property as an important mineral resource recovery site in any regulatory land use document, it is
47 Rev. 07/03/02
determined that implementation of the dam remedial operations will not result in the loss of availability of
a locally important mineral resource recovery site.
Finding: No impact - No adopted regulatory land use documents designate the subject site as any
mineral resource recovery location.
XI. NOISE - Would the project result in:
a) Exposure of persons to or generation of noise levels in excess of standards established in the
local general plan or noise ordinance or applicable standards of other agencies?
Existing condition: The subject site presently contains dam operations apparatus, including an
existing inlet tower located within the reservoir area. None of these apparatus create any noise due to
their presently inoperable condition. Much of these inoperable facilities are located below the water
surface.
Existing urban development in the area are located to the west and north of the site. To the west are
newer single-family residential neighborhoods of Sheffield, Nantucket and Capistrano. An older, existing
single-family neighborhood, located within the city limits of Oceanside, exists over % mile north of the
site.
Both the City of Carlsbad and the City of Oceanside have adopted noise regulations for their respective
communities. The Noise Element of the Carlsbad General Plan states that the City's policy is that 60
dB(A) Community Noise Equivalent Level (CNEL) is the maximum exterior noise level to which
residential units should be subjected, except that 65 dB(A) is the maximum for residential units subject to
noise from McClellan-Palomar Airport. The City of Oceanside allows somewhat greater flexibility for
public uses, not to exceed 65dB(A) exterior noise level at residential property lines.
The construction of the proposed project is anticipated to create the greatest amount of noise. The City of
Carlsbad Municipal Code (Chapter 8.48) prohibits construction activity that would create disturbing,
excessive, or offensive noise after sunset of any day, and before 7 A.M. Monday through Friday, and
before 8 A.M. on Saturday, and all day Sunday and specified holidays. The Noise Ordinance does not set
a defined noise level standard for construction activities, but simply limits the hours of construction.
The significance of construction noise produced during project construction is typically assessed in
accordance with the County of San Diego Noise Ordinance. San Diego County Noise Ordinance Section
36.410 stipulates that construction noise shall not exceed 75 dB for more than 8 hours during any 24-hour
period.
Environmental Evaluation: Construction of the proposed dam facilities will involve the operation of
grading and other construction equipment that create higher than usual construction noise, although these
activities may not take more than a few days. Pumping of concrete is generally less loud than
earthmoving equipment, but will take a longer period to complete. Residences in the area are of sufficient
distance away, and the duration of construction noise on the project so short, that the contour lines
identifying maximum noise level compliance does not overlap any of the surrounding homes.
Once the construction is complete and the dam facilities are operational, the dam operations will rely on
electricity for powering hydraulic pumps, air compressors and instrumentation controls located in the
control building. The butterfly valves on the laid-back pipeline are hydraulically and pneumatically
actuated by the hydraulic and pneumatic pack in the control building. These also will be powered by
electricity, and be operated underwater. The air backwash system will utilize a 10-horsepower
compressor, also powered by electricity.
Operation of the Inlet/Outlet system hydraulic and pneumatic actuators will make no audible noise since
they function on electricity, and will be operated underwater. Any noise associated with the hydraulic
48 Rev. 07/03/02
and pneumatic pack will be confined to inside the control building. The air backwash system for the
intake screens (a maintenance feature to keep the screens clean of accumulated debris or algae) also will
run underwater, although the air burst associated with the backwash could be startling to a person
standing close to the Inlet/Outlet system. This is anticipated to be a relatively infrequent event.
The loudest noise will occur from the 10-horsepower compressor that powers the air backwash system.
This compressor has been designed fully internal of the control building, and will be only nominally
audible outside the control building. None of these apparatus are projected to exceed 60dBA at 100 feet
from the control building. This level is less than that required by the City of Carlsbad General Plan.
Finding: Less than significant impact - Both construction noise levels and permanent noise levels
are anticipated to comply with City of Carlsbad General Plan standards.
b) Exposure of persons to or generation of excessive groundbourne vibration or groundbourne
noise levels?
Existing condition: The Intake/Outlet system hydraulic and pneumatic actuators operate underwater
on the laid-back piping system located on the lakeside dam face. The balance of the noise and/or
vibration creating apparatus is located within the control building. None of these features will create
excessive vibration of groundbourne noise levels.
Environmental Evaluation: Noise and vibration creating hardware will not create vibrations beyond a
few feet away from the control building. This low level of vibration will not result in any significant
impacts to residences, because the closest residences are located a minimum of 400 feet from the subject
site.
Finding: No impact - The project will not produce any groundbourne vibration or noise beyond a
few feet from the dam operations facilities.
c) A substantial permanent increase in ambient noise levels in the project vicinity above levels
existing without the project?
Existing condition: Please refer to response XI(a).
Environmental Evaluation: Please refer to response XI(a).
Finding: Less than significant impact - The project will result in a small incremental permanent
increase in noise in the vicinity of the site. Since this increase will not be expected to exceed levels limits
identified in the Carlsbad General Plan, the increase is not considered substantial or significant.
d) A substantial temporary or periodic increase in ambient noise levels in the project vicinity
above levels existing without the project?
Existing condition: Please refer to response XI(a).
Environmental Evaluation: Please refer to response XI(a).
Finding: Less than significant impact - During construction, a temporary increase in ambient noise
levels in the project vicinity is anticipated. Construction will be scheduled to conform to the noise level
limitations specified in the Carlsbad Municipal Code, so the increase is not considered substantial or
significant.
e) For a project located within an airport land use plan or, where such a plan has not been
adopted, within 2 miles of a public airport or public use airport, would the project expose
people residing or working in the project area to excessive noise levels?
49 Rev. 07/03/02
Existing condition: The subject dam remedial improvements are located approximately 15,000 linear
feet (2.85 miles) due north of McClellan-Palomar Airport. The City of Carlsbad has adopted a public
airport land use plan.
Environmental Evaluation: Since the proposed project is located in excess of two miles (2.85 miles)
from the closest airport (McClellan-Palomar Airport), the site does not meet the minimum qualifications
as having the potential for safety hazard for people residing or working in the project area. No significant
impact is anticipated to result from noise generated from this airport.
Finding: No impact - As a result of its 2.85 miles distance from McClellan-Palomar Airport, the
project does not meet the minimum qualifications as a potential safety hazard. The project will not
expose people residing or working in the project area to excessive noise levels.
f) For a project within the vicinity of a private airstrip, would the project expose people
residing or working in the project area to excessive noise levels?
Existing condition: No private airstrip exists in the vicinity of the subject project.
Environmental Evaluation: The project is not within the vicinity of a private airstrip and no people
will reside on the site. Construction work on the site will be temporary. Routine inspection and
maintenance workers will be of a short duration, daily.
Finding: No impact - The project is not within the vicinity of a private airstrip.
XII. POPULATION AND HOUSING - Would the project:
a) Induce substantial growth in an area either directly (for example, by proposing new homes
and businesses) or indirectly (for example, through extension of roads or other
infrastructure)?
Existing condition: The subject project involves remedial improvements to an existing dam facility.
No new development or new land uses are proposed.
Environmental Evaluation: The proposed project involves the replacing and upgrading of inoperable
dam facilities and equipment. It does not involve the development of new homes or businesses, nor does
it involve the extension of new infrastructure. The project will not create new areas for development. It
will allow for greater efficiency of flood control, and increased water storage volume and control. The
project should have no discernible impact on growth, either directly or indirectly.
Finding: No impact - The project will not induce substantial grown, nor will it induce population
growth by providing infrastructure to support unplanned growth.
b) Displace substantial numbers of existing housing, necessitating the construction of
replacement housing elsewhere?
Existing condition: No housing exists in the area of the proposed improvements. The subject area is
totally surrounded by existing and planned open space.
Environmental Evaluation: The proposed project will not displace any existing housing because no
housing exists in the subject area of dam improvements.
No impact - No housing will be displaced by the project.
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c) Displace substantial numbers of people, necessitating the construction of replacement
housing elsewhere?
Existing condition: The project site is zoned for open space uses, and is undeveloped. It is not
planned for future urban development. The proposed use is consistent with the existing use of the
property.
Environmental Evaluation: The proposed project will not displace any people because no people,
residences or other development exists in the area.
Finding: No impact - The project site is presently undeveloped, and is planned for future and
buildout open space use. As a result, no people or houses will be displaced by implementation of the
project.
Xffl. PUBLIC SERVICES
a) Would the project result in substantial adverse physical impacts associated with the
provision of new or physically altered government facilities, a need for new or physically
altered government facilities, the construction of which could cause significant
environmental impacts, in order to maintain acceptable service ratios, response times, or
other performance objectives for any of the public services:
i. Fire protection?
Existing condition: The subject dam facilities will introduce electrical pumps and equipment into a
natural area that presently does not contain these apparatus.
The project proponent has no plans to utilize the reservoir for storage of emergency fire protection water.
Environmental Evaluation: Notwithstanding that additional electrical pumps and devices will be
housed in an open space area which does not presently contain these apparatus, fire access to the site will
be adequate, and no measurable increase in the need for fire services will be required. The subject project
will not measurably affect current fire response times.
Finding: Less than significant impact - The proposed facility will not have any measurable affect
on the fire service demands or needs of the area.
ii. Police protection?
Existing condition: The subject dam improvements will introduce costly equipment into an open
space area that presently has none. The project design includes significant protective and security
devices. A security fence is proposed to be installed around the proposed dam equipment.
Environmental Evaluation: The introduction of costly equipment into a rural area increases the risk
of burglary and/or vandalism of the facilities; however the inclusion of protective and security devices
will minimize this risk. The project will eliminate an existing nuisance that has in the past attracted
adventurers and loiterers.
Finding: No impact - The dam facilities will not generate any measurable increase in the need for
police services and will not measurably affect current police response times. Therefore, the proposed
facility will not have an affect on the police service needs of the area.
iii. Schools?
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Existing condition: The dam improvements are a public infrastructure project, which do not generate
school students.
Environmental Evaluation: The project will have no impact on school student generation.
Finding: No impact - The project will not generate any need for school services and, therefore,
will have no impact on schools serving the area.
iv. Parks?
Existing condition: The dam improvements will not generate any demand for park facilities.
Environmental Evaluation: The project will create no increase in park demand.
Finding: No impact - The project will create no increased demand on parks serving the area, and
therefore, will have no impact on parks/recreation areas.
v. Other public facilities?
Existing condition: The dam improvements will not generate any significant demand for any other
public facilities.
Environmental Evaluation: The project will create no increased demand for public facilities. It will
however, allow for increased storage of water, and thus would be expected to result in a beneficial effect
on water and flood control facilities.
Finding: No impact - The proposed project will be constructed and operated by Carlsbad
Municipal Water District and will make no demands on other public facilities or services. The project
will increase the adequacy and efficiency of the municipal flood control system.
XTV. RECREATION
a) Would the project increase the use of existing neighborhood and regional parks or other
recreational facilities such that substantial physical deterioration of the facility would occur
or be accelerated?
Existing condition: The proposed project is an infrastructure improvement that creates no demand for
neighborhood or regional parks, or other recreational facilities.
Several unauthorized off-road vehicle trails exist in the vicinity of the proposed project. Recreational
hikers and outdoor enthusiasts presently utilize these trails. In addition, the City of Carlsbad Citywide
Community Trail program designates the Calavera Creek sewer trunk line maintenance road as a future
north/south pedestrian recreational trail.
Environmental Evaluation: The subject project will result in no impact on demand for parks or other
recreational facilities.
In addition, the proposed project will not impact the authorized pedestrian recreational trails in the area.
The security fencing is planned so that pedestrian trail access is maintained to all areas except for the
specific dam operations facilities such as the control building, the dam crest, and the laid back and
Intake/Outflow structure. With the exception of these particular areas, pedestrian access to the existing
trails will largely remain available, although off-road vehicular access to the open spaces in the area will
be curtailed by the fencing and gates.
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Finding: Less than significant impact - The dam facility improvements will exert no added
demand on recreational facilities of any kind. Security fence impacts to recreational hikers and outdoor
enthusiasts will be minimal.
b) Does the project include recreational facilities or require the construction or expansion of
recreational facilities, which might have an adverse physical effect on the environment?
Existing condition: The proposed project is an infrastructure improvement that creates no demand for
neighborhood or regional parks, or other recreational facilities. Several unofficial trails are located within
the vicinity of the proposed project, primarily along the north and south sides of Lake Calavera, running
parallel with the length of the reservoir.
Environmental Evaluation: The subject project will have no impact on demand for parks or other
recreational facilities. The proposed improvements may increase the opportunity for Lake Calavera to
function as a recreational area, if the City of Carlsbad desires it to function in that manner in the future.
Finding: No impact - No recreational facilities are included in the proposed project and none are
required by the proposed use.
XV. TRANSPORTATION/TRAFFIC - Would the project:
a) Cause an increase in traffic that is substantial in relation to the existing traffic load and
capacity of the street system?
Existing condition: The existing site is located in the northeast quadrant of the city of Carlsbad,
generally east of College Boulevard and south of Lake Boulevard in Oceanside. The site does not
generate any measurable traffic at this time. Operation, inspection and maintenance of the dam will
generate on the average of approximately one trip per day to and from the site (two total trips).
Environmental Evaluation: Traffic generation of approximately 2 ADT is considered a very low
volume, and will create no substantial difference in traffic congestion in the area.
No impact - A very low traffic volume will be generated by the proposed project.
b) Exceed, either individually or cumulatively, a level of service standard established by the
county congestion management agency for designated roads or highways?
Existing condition: All street segments and intersections in the area of the subject project presently
operate at acceptable levels of service (LOS "D" or better during the AM and PM peak hour periods).
The proposed project will generate approximately 2 ADT. This amount of ADT increase is so minimal as
to not rise to the level that it could possibly cumulatively exceed the adopted LOS established by the City
of Carlsbad Growth Management Program.
Environmental Evaluation: The increase of 2 ADT onto the adjacent street system does not result in
any impacted road segments or intersections exceeding the level of service standard established by
SANDAG or by the City of Carlsbad. The proposed project will not significantly impact traffic flow in
the area of the project.
Finding: No impact - The proposed project will not significantly impact traffic levels of service on
any street segment or intersection in the vicinity of the project.
c) Result in a change in air traffic patterns, including either an increase in traffic levels or a
change in location that result in substantial safety risks?
53 Rev. 07/03/02
Existing condition: The proposed dam facility improvements will have no impact on air traffic
demand or air traffic patterns.
Environmental Evaluation: No impact on air traffic will result from implementation of the dam
improvements.
Finding: No impact - The project would not generate or require air traffic and would not
physically interfere with air traffic patterns.
d) Substantially increase hazards due to a design feature or incompatible uses?
Existing condition: The project design proposes a driveway access off of existing Tamarack Avenue,
in the same location as the existing driveway to the dam. This is a private driveway, and is gated. The
improvements proposed also include a private road across the spillway and an access road across the dam
crest. All of these roads will be protected by security gating so that only authorized City personnel will
be able to access the area. No improvements or modifications to any public roads are proposed.
Environmental Evaluation: None of the improvements proposed will be accessible to the public. No
improvements or modifications to any public roads are proposed. The access location on Tamarack
Avenue does not constitute a hazardous situation.
Finding: No impact - The project will not change the geometry of public roads. The very low level
of traffic using the dam facilities access road would have virtually no effect on normal traffic on Cannon
Road.
e) Result in inadequate emergency access?
Existing condition: One vehicular access to the project site is proposed. This access is located on a
private drive off of Tamarack Avenue. This access will function as main access (private), and also as an
emergency access route.
Environmental Evaluation: The singular access to the site is considered adequate to serve the project.
The surrounding area is zoned for existing and future open space, and thus no through access, or
secondary access, is determined to be necessary.
Finding: No impact - Due to the low ADT generated by the project, no emergency access separate
from the ordinary access is necessary. The proposed project access will not affect any public or private
access to other property.
f) Result in inadequate parking capacity?
Existing condition: The proposed project is projected to generate two ADT (one trip in, one trip out,
daily). As a result, the project has been designed with a minimum of one parking space (although a
tandem space can also be accommodated).
Environmental Evaluation: The proposed two (one tandem) parking spaces are considered adequate
parking for the proposed use. Since the project is not open to the public, no public parking is proposed.
Finding: No impact - Sufficient space to park operations, inspection and maintenance vehicles is
provided on-site.
g) Conflict with adopted policies, plans or programs supporting alternative transportation
(e.g., bus turnouts, bicycle racks, etc.)?
54 Rev. 07/03/02
Existing condition: The subject site is not identified on any regional or community plans relative to
alternative transportation. The site is not central to any transportation corridor or route.
Environmental Evaluation: The project is located on a site that is not considered integral to any
alternative transportation policies. Thus the project will not conflict with any such policies.
Finding: No impact - As a result of the fact that regional and local policies include no reference to
the site in terms of alternative transportation programs, facilities, it is concluded that the project would not
conflict with adopted policies, plans, or programs supporting alternative transportation.
XVI. UTILITIES AND SERVICES SYSTEMS - Would the project:
a) Exceed wastewater treatment requirements of the applicable Regional Water Quality
Control Board?
Existing condition: The subject project involves remedial operations on the Calavera Dam facilities,
and upgrade and installation of modern dam equipment. The project involves management and storage to
natural drainage runoff. No wastewater or sewage creation, transport or treatment is involved in the
project.
Environmental Evaluation: The proposed dam project would have no impact or effect on any sewage
system. No rest rooms are proposed in the facility.
Finding: No impact - The project would have no effect on wastewater treatment.
b) Require or result in the construction of new water or wastewater treatment facilities or
expansion of existing facilities, the construction of which would cause significant
environmental effects?
Existing condition: Please refer to the previous response. The project involves remedial operations
on existing dam facilities, and upgrade and installation to modern dam equipment. The project involves
management and storage of natural drainage runoff. No wastewater or sewage creation, and no potable
water distribution would result from implementation of the project. No wastewater or water facility
expansion would be required.
Environmental Evaluation: The subject project would create no demand on wastewater treatment
facilities, and would not require the construction of new water or wastewater treatment facilities. It would
not require expansion of any existing water or wastewater facilities.
Finding: No impact - No additional demand on water distribution or wastewater collection or
treatment facilities would result from implementation of the proposed project.
c) Require or result in the construction of new storm water drainage facilities or expansion of
existing facilities, the construction of which could cause significant environmental effects?
Existing condition: The subject project involves the repair, upgrade and installation of modern dam
operation facilities on Calavera Dam. As such, the project is considered a storm water collection
infrastructure project. The project involves storm water collection improvements as identified in the
project description. No other new storm water drainage facilities are proposed.
Environmental Evaluation: The subject project is adequate in size and scope to adequately provide
for the project purpose. No additional new or expanded drainage facilities will be necessitated by
implementation of the proposed project. Both upstream and downstream facilities contain adequate
capacity and functionality to accept the storm water demands resulting when the project is complete.
55 Rev. 07/03/02
Implementation of the proposed project will be expected to increase functionality, reliability and
improved management operations of the subject water storage and dam structure.
Finding: No impact - No new storm water drainage facilities are proposed or would be required
from development of the proposed project.
d) Have sufficient water supplies available to serve the project from existing entitlements and
resources, or are new or expanded entitlements needed?
Existing condition: The project is a drainage infrastructure improvement, and does not propose or
necessitate connection to potable water supplies.
Environmental Evaluation: No water supply impacts are proposed through implementation of the
project. The project will have no impact on water supplies, other than the beneficial potential for
additional managed water storage area.
Finding: No impact. The project will not connect to potable water supplies, and therefore will
have no impact on water supplies.
e) Result in a determination by the wastewater treatment provider, which serves or may serve
the project that it has adequate capacity to serve the project's projected demand in addition
to the provider's existing commitments?
Existing condition: The subject project does not include a rest room or other potential sewer-demand
generating uses. The project will not be occupied permanently in any way. No wastewater treatment will
be necessitated by the project.
Environmental Evaluation: No impact to wastewater treatment will result from implementation of
the subject project.
Finding: No impact - No increase in wastewater treatment will result from the project.
f) Be served by a landfill with sufficient permitted capacity to accommodate the project's solid
waste disposal needs?
Existing condition: Construction of the project will result in the potential for a minimal amount of
solid waste disposal of scrap construction materials. No permanent solid waste creation is anticipated
through operation of the proposed project.
Environmental Evaluation: The project will not ordinarily generate any appreciable volume of solid
waste, and solid waste collection from the site will not be required. Any minor amount of solid waste
generated during routine maintenance will be taken off-site for appropriate disposal.
Finding: No impact - No measurable significant impact on solid waste creation is expected to
result from the subject project.
g) Comply with federal, state, and local statutes and regulations related to solid waste?
Existing condition: See previous response. The subject project is not anticipated to create any
measurable significant amount of solid waste. The project is required to comply with federal, state and
local statutes and regulations related to solid waste.
Environmental Evaluation: Any solid waste generated on the site during construction or operation
would be removed and disposed of in an appropriate facility in accordance with applicable local, state,
and federal regulations.
56 Rev. 07/03/02
Finding: No impact - The project will create no significant impact on solid waste collection and
disposal, and will comply with federal, state and local statutes.
XVII. MANDATORY FINDINGS OF SIGNIFICANCE
a) Does the project have the potential to degrade the quality of the environment, substantially
reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop
below self-sustaining levels, threaten to eliminate a plant or animal community, reduce the
number or restrict the range of a rare or endangered plant or animal or eliminate
important examples of the major periods of California history or prehistory?
Existing condition: The subject site presently houses a dam and reservoir. The dam facilities are
presently inoperable, and the proposed project is necessary for management and control over the dam
operations,
Environmental Evaluation: A less than significant potential exists that the proposed project will
substantially reduce the habitat of a fish or wildlife species. Biological impacts associated with the
proposed project involve impacts to 0.67 acres of DCSS occupied by the California gnatcatcher and 0.134
acres of impacts to wetlands and non-wetland waters of the U.S. These impacts will be mitigated through
implementation of the project to a level less than significant.
Also, erosion control, noise control and other precautions will be taken during construction to ensure that
wildlife is not significantly impacted by the construction operations. No significant impacts to fish
habitat will result from the project.
Finding: Less than significant impact - Please refer to the responses to Sections IV and V.
b) Does the project have impacts that are individually limited, but cumulatively considerable?
("Cumulatively considerable" means that the incremental effects of a project are
considerable when viewed in connection with the effects of past projects, the effects of other
current projects, and the effects of probable future projects?)
Existing condition: The subject project involves the repair and construction of existing public
infrastructure at Calavera Dam. This improvement is a necessary infrastructure element in order that
management and operation of the dam facilities can be restored. The dam is currently being used for
flood control and water storage.
Environmental Evaluation: The impacts resulting from implementation of the project are not
considered cumulatively considerable. The project is considered cumulatively environmentally
beneficial.
Finding: No impact - It is concluded that no cumulatively considerable impacts will result from
implementation of the proposed project.
c) Does the project have environmental effects, which will cause substantial adverse effects on
human beings, either directly or indirectly?
Existing condition: The subject project will replace and repair existing facilities on Calavera Dam.
Environmental Evaluation: The project does not have environmental effects that will cause
substantial adverse effects on human beings, either directly or indirectly.
57 Rev. 07/03/02
Finding: No impact - Potential adverse effects on the human population have been evaluated in
preceding sections of this checklist. No unmitigable adverse environmental effects attributable to the
project have been identified.
58 Rev. 07/03/02
EARLIER ANALYSIS USED AND SUPPORTING INFORMATION SOURCES
The following documents were used in the analysis of this project and are on file in the City of Carlsbad
Planning Department located at 1635 Faraday Avenue, Carlsbad, California, 92008.
1. Final Master Environmental Impact Report for the City of Carlsbad General Plan Update
(MEIR 93-01), City of Carlsbad Planning Department (March 1994).
2. Remedial Improvements at Lake Calavera prepared for Carlsbad Municipal Water
District by Cathcart, Garcia & VonLangen Engineers, in associated with Powell/PBS&J
(December 2002)
3. Biological Resources Report for Lake Calavera prepared for Carlsbad Municipal Water
District by Merkel & Associates (May 1, 2003)
4. Calavera Hills Phase II, Bridge & Thoroughfare District, Detention Basins Final EIR
prepared for the City of Carlsbad Planning Department by RECON, Inc. (November
2001).
5. Current Rules and Regulations, County of San Diego Air Pollution Control District
(November, 2002).
6. San Diego County Important Farmland, California Department of Conservation
(September, 2002).
7. Lake Calavera Environmental FirstSearch Report. Environmental FirstSearch (January
30, 2003).
8. Uniform Building Code - Volume 1 (1997); Table 18-1-B.
9. Special Publication 42, California Geological Survey; State Geologist Division of Mines
and Geology (May 1996).
10. Geotechnical Design Evaluation Lake Calavera Improvements. Nino & Moore
(November 19, 2002).
11. Focused Least Bell's Vireo Survey at Lake Calavera. Merkel & Associates (July 30,
2002).
12. Focused Southwestern Pond Turtle Surveys at Lake Calavera. Merkel & Associates
(September 4, 2002).
13. Focused Survey for Thread-leaved Brodiaea at Lake Calavera. Merkel & Associates
(September 4, 2002).
14. 45-day Letter Report of Focused Coastal California Gnatcatcher Survey for the Lake
Calavera Improvements. Merkel & Associates (June 5, 2003).
15. Hydraulic Impact Study for Lake Calavera. Rick Engineering, (February 3, 2004).
16. 2004 Least Bells Vireo and Southwestern Willow Flycatcher Surveys for Lake Calavera.
Merkel & Associates (August 12, 2004).
59 Rev. 07/03/02
17. Lake Calavera Thread-leaved Brodiaea (Brodiaea filifolia) Survey Results. Merkel &
Associates (August 24, 2004).
18. Historic Resources Inventory and Evaluation Report for the Lake Calavera Remedial
Improvements Project. ASM Affiliates, Inc. (March 2005).
LIST OF MITIGATING MEASURES
To mitigate potentially significant project impacts, the following mitigation measures shall be applied to
the development of the proposed project.
WITH THE INCLUSION OF THESE MITIGATION MEASURES, THE PROPOSED PROJECT WILL
AVOID ANY POTENTIALY SIGNIFICANT ADVERSE IMPACTS, AND AS A RESULT NO
SUBSTANTIAL EVIDENCE EXISTS THAT THE PROJECT, INCLUDING THESE MITIGATION
MEASURES, WILL HAVE A SIGNIFICANT EFFECT ON THE ENVIRONMENT.
BIOLOGICAL RESOURCES:
1. Prior to commencement of the project, and pursuant to Section 404 of the Clean Water Act, the
project proponent shall consult with the U.S. Army Corps of Engineers (USAGE) regarding the impacts
of the project, and obtain any permits and perform necessary mitigation required by the USAGE. A
wetland/riparian restoration plan shall be prepared and approved by the USAGE prior to wetland impacts.
2. Prior to commencement of the project, and pursuant to Section 1600 of the State of California
Resources Code, the project proponent shall consult with the California Department of Fish & Game
(CDFG) regarding the impacts of the project, and obtain any permits and perform necessary mitigation
required by the CDFG. A wetland/riparian restoration plan shall be prepared and approved by the CDFG
prior to wetland impacts.
3. Prior to any impacts to DCSS, the project proponent shall process and receive authorization for a
"take" permit pursuant to the adopted HMP. Direct impacts to 0.78 acres of occupied DCSS resulting
from implementation of the project shall be mitigated at a 2:1 ratio (permanent impacts) through
permanent conservation of 1.22 acres of occupied DCSS in a location deemed acceptable to the Wildlife
Agencies. This permanent conservation shall be through purchase, easement or other acceptable means of
preservation of DCSS habitat within Carlsbad or the surrounding vicinity. The project proponent shall
additionally mitigate for temporary DCSS impacts at a 1:1 ratio through restoration of the area impacted
by the cutting of the temporary construction access trail from the spillway to the outlet box (0.17 acres).
A restoration plan shall be prepared and implemented for this 0.17-acre restoration. The restoration plan
shall include site preparation guidelines, implementation monitoring, performance standards, long-term
maintenance and monitoring methodology, with a commitment to funding.
4. No clearing of occupied gnatcatcher habitat or construction that would result in direct impacts to
DCSS or which occurs within 300 feet of occupied DCSS shall take place between February 15 and
August 31 unless authorized by the Wildlife Agencies after consultation. An updated protocol-level
gnatcatcher survey shall be performed no longer than one year before the initiation of project construction
to provide an accurate mapping of current occupied habitat. If clearing and construction cannot be
restricted to outside of the breeding season appropriate conservation measures shall be implemented,
subject to the approval of the Wildlife Agencies, to ensure that no impact to this species occurs.
Avoidance of noise-related impacts to occupied habitat can be assured through implementation of noise
reduction methods (e.g., a temporary noise barrier or wall) to reduce noise within occupied habitat to a
level below 60 dBA and/or as allowed by the Wildlife Agencies. If construction cannot be restricted to
outside of the breeding season, kept to a minimum of 300 feet away from suitable habitat, or if
construction noise is less than 60 dBA within suitable habitat, an updated focused survey is not expected
to be necessary.
60 Rev. 07/03/02
5. The project proponent shall ensure that the limits of construction are clearly defined with
temporary construction fencing prior to brush clearing activities and clearly visible to personnel on foot
and equipment operators. Construction personnel shall strictly limit their activities and vehicles to the
proposed project construction areas, approved staging areas, and routes of travel. The project proponent
and/or biological monitor shall contact the USFWS to verify that the limits of construction have been
properly staked and are readily identifiable, prior to construction.
6. A Wildlife Agency-approved biological monitor shall be present to monitor clearing, grading and
construction activities for the project. The biological monitor shall have the authority to stop construction
and require additional precautions or conservation measures to protect the open space areas as necessary.
CULTURAL RESOURCES:
1. The project proponent shall retain a qualified archaeological/cultural resource specialist to
monitor the grading for the control building. The archaeologist shall be empowered to stop the grading
operation in the specific area of resource discovery, until all significant artifacts are recovered. A written
report on the results of cultural resource discovery shall be prepared and submitted to the City of Carlsbad
Planning Department. Artifacts determined to be significant shall be donated to a museum or Indian
collection pursuant to City policy. If Native American resources are discovered, the Luiseno Band shall
be advised, and allowed the opportunity to consult and assist in the recovery.
2. The project proponent shall retain a qualified paleontologist to monitor and perform inspection of
any soil excavation that takes place in natural geology. If fossils are exposed, the paleontologist shall be
empowered to divert or direct grading away from an exposed fossil to facilitate evaluation and, if
necessary, salvage. Should fossils be found, the paleontologist shall make provisions for preparation and
curation before the fossils are donated to their final repository. All fossils collected shall be donated to a
museum with a systematic paleontological collection, such as the San Diego Natural History Museum or
a similar Indian collection.
HYDROLOGY/WATER QUALITY:
1. Prior to commencement of the project, and pursuant to Section 401 of the Clean Water Act, the
project proponent shall notify the Regional Water Quality Control Board (RWQCB) of the activities
proposed, and shall receive water quality certification for the construction operation, if required by the
RWQCB.
2. The project proponent shall comply with the National Pollutant Discharge Elimination System
(NPDES) permit regulations as promulgated by the California RWQCB for the San Diego region. This
shall include control of all non-storm discharges during construction, and development and
implementation of a monitoring and reporting program to assess the storm water pollution prevention
plan.
3. The project proponent shall control erosion, siltation, and emission of construction related
pollutants through compliance with the City of Carlsbad Standard Urban Storm Water Mitigation Plan,
Stormwater Management Plan (SWMP) required under the County of San Diego Watershed Protection,
Stormwater Management, and Discharge Control Ordinance (WPO) (Section 67.871), General
Construction Stormwater Permit (Order No. 99-08, NPDES CAS 000002) and the General Municipal
Stormwater Permit (Order No. 2001-01, NPDES CAS0108758). In compliance with the General
Construction Stormwater Permit, a SWPPP shall be prepared and approved prior to clearing of the site.
The project proponent shall be responsible for monitoring and maintaining the BMP's identified below on
a weekly basis. In addition, prior to commencement of clearing, the City Engineer must determine that
project plans have incorporated adequate temporary desilting control.
Some of the BMP's that shall be used during construction include, but are not limited to:
61 Rev. 07/03/02
• Silt fence, fiber rolls, or gravel bag berms
• Check dams
• Street sweeping and vacuuming
• Storm drain inlet protection
• Stabilized construction entrance/exit
• Vehicle and equipment maintenance, cleaning and fueling
• Hydroseed, soil binders, or straw mulch
• Material delivery and storage
• Stockpile management
• Spill prevention and control
• Waste management for solid, liquid, hazardous and sanitary waste
• Concrete waste management
4. All equipment staging, maintenance and dispensing of fuel, oil or any other such activity shall
occur in designated upland areas. The designated upland areas will be located in such a manner as to
prevent any runoff of these materials from entering waters of the United States, including wetlands.
62 Rev. 07/03/02
APPLICANT CONCURRENCE WITH MITIGATION MEASURES
THIS IS TO CERTIFY THAT I HAVE REVIEWED THE ABOVE MITIGATING MEASURES AND CONCUR
WITH THE ADDITION OF THESE MEASURES TO THE PROJECT.
Date Signature
63 Rev. 07/03/02
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