HomeMy WebLinkAboutMINUTES - 02271996 - C26 TO: BOARD OF SUPERVISORS
FROM: J. MICHAEL WALFORD, CHIEF ENGINEER
DATE: February 27, 1996
SUBJECT: APPROVE THE ADDENDUM TO THE NEGATIVE DECLARATION FOR THE FORMA-
TION OF DRAINAGE AREA 76 and the MIRANDA CREEK IMPROVEMENT PROJECT,
IN THE ALAMO AREA.
Project No.: 7542-6D8563 CP#96-7
SPECIFIC REQUEST(S)OR RECOMMENDATION(S)&BACKGROUND AND JUSTIFICATION
I. RECOMMENDED ACTION:
APPROVE the Addendum to the Negative Declaration, CP#96-7, (the custodian of which is the
Chief Engineer and is located at 255 Glacier Drive, Martinez),
DIRECT the Director of Community Development to file a Notice of Determination with the County
Clerk, and
DIRECT the Chief Engineer to arrange for payment of the $25.00 handling fee to the County
Clerk.
II. FINANCIAL IMPACT:
Funds for the project will come from the Drainage Area 76 funds.
III. REASONS FOR RECOMMENDATIONS AND BACKGROUND:
The Addendum to the Negative Declaration for the Formation of Drainage Area 76 and the
Miranda Creek Improvement Project identifies some changes to the design of the improvements
to the creek. The changes are as follows:
1. The project involves the installation of approximately 510 ft. of 84-inch pipe and another
30 ft. of 108-inch pipe, instead of 800 ft. of 72- to 96-inch pipe.
Continued on Attachment: X SIGNATUR
_RECOMMENDATION OF COUNTY ADMINISTRATOR
_RECOMMENDATION OF BOARD COMMITTEE
APPROVE OTHER
SIGNATURE(S):
ACTION OF BOARD ON 02/27/1996 APPROVED AS RECOMMENDED x OTHER_
VOTE OF SUPERVISORS
X UNANIMOUS (ABSENT )
AYES: NOES:
ABSENT: ABSTAIN:
Contact: Vickie Germany(313-2296)
Orig. Div: Public Works(Design Division)
cc: P. Harrington, Flood Control
P. Gavey, Real Property I hereby certify that this Is a true and
aiofkrvids=07f Thos'oyhoet
J. Olsen, Design BodSupesorentered the athy
Flood Control Engineering ATTEMD: FED211&U 27 1 qc)6
Accounting PHIL BATCHELOR,Clerk of the Board
Engineering Services of Supervisors and County Administrator
County Administrator
County Auditor-Controller Sy Deputy
County Counsel
Community Development
ADDENDUM TO THE NEGATIVE DECLARATION FOR THE FORMATION OF DRAINAGE AREA 76
r and the MIRANDA CREEK IMPROVEMENT PROJECT
Page 2
February 27, 1996
III. REASONS FOR RECOMMENDATIONS AND BACKGROUND (continued):
2. Water from the Stratmore outfall pipe will be diverted to a point approximately 650
downstream, instead of 800 ft. downstream. Approximately 3 cubic yards of material will
be removed from an approximately 80 ft. reach of the creek, downstream of the earthen
outfall ditch, to provide positive drainage for the new storm drain.
3. The bypass storm drain will be connected to the creek with an approximately 30-ft. long
earthen outfall ditch. The outfall structure is no longer required.
4. Like the previously planned area for the outfall (Station 2+50), the new area (Station 4+25)
lacks the thick riparian area. In addition, the area was previously disturbed with an outfall
from a drainage ditch.
5. The extent to which residential improvements (i.e., mature landscaping and fences) will be
disturbed is reduced. The tennis court will no longer be impacted.
On the basis of the previously adopted Negative Declaration and Addendum, the proposed
project could not have a significant effect on the environment. Since the revised project involves
only minor technical changed or additions [CEQA Guidelines Section 15164(b)] to a previously
adopted Negative Declaration an addendum to the Negative Declaration, not a new Negative
Declaration, is appropriate.
IV. CONSEQUENCES OF NEGATIVE ACTION:
Delay in approving the project and the Addendum to the Negative Declaration will result in delay
of construction of the project.
VG:mat
H AMATOA76REMMENDUM.BO
ADDENDUM
to the
NEGATIVE DECLARATION
for the FORMATION OF DRAINAGE AREA 76 and
the MIRANDA CREEK IMPROVEMENT PROJECT
County File # CP#93-87
CP# 96-7
Prepared by:
Maureen Toms, Planner
Contra Costa County Public Works Department
255 Glacier Drive
Martinez, CA 94553-4897
January 1996
Clea
ADDENDUM
to the
NEGATIVE DECLARATION
for the FORMATION OF DRAINAGE AREA 76 and
the MIRANDA CREEK IMPROVEMENT PROJECT
County File # CP#93-87
CP# 96-7
Prepared by:
Maureen Toms, Planner
Contra Costa County Public Works Department
255 Glacier Drive
Martinez, CA 94553-4897
January 1996
66,l � •
vi ental Planner (Chief Planning Official)
,AlUbiic Works Department
Title:
Lead Agency: County of Contra Costa
Date:
c`ozj�
ADDENDUM
to the
NEGATIVE DECLARATION
for the FORMATION OF DRAINAGE AREA 76 and
the MIRANDA CREEK IMPROVEMENT PROJECT
County File #CP#93-87
CP# 96-7
PREFACE
The Negative Declaration (which consists of the Initial Study, Checklist and Supplement
to Environmental Checklist) evaluated the proposed project which involves the
construction of a large (72- to 96-inch) diameter storm drain bypass system on Miranda
Creek from the Stratmore drain outfall (opposite the westerly end of Bunce Meadows
Drive) to a point approximately 800 feet downstream, where the creek has adequate
capacity against flooding.
This document serves as an Addendum to the Negative Declaration for the Formation of
Drainage Area 76 and the Miranda Creek Improvement Project (County File#CP# 93-87).
Consequently, the revised Negative Declaration for the project consists of the Negative
Declaration and the Addendum.
The Contra Costa Community Development Department (CDD) is the lead agency for the
project, and on March 1, 1994, the Board of Supervisors (Board) as the Governing Board
for the Contra Costa County Flood Control District (FCD) approved the project and filed
a Notice of Determination with the County Clerk. The Board acknowledged that the project
could not have a significant effect on the environment.
CEQA PROCESS
The California Environmental Quality Act (CEQA) prescribes that an Addendum [CEQA
Guidelines Section 15164(b)] to a previously adopted Negative Declaration shall be
prepared by either the lead agency or the responsible agency if minor technical changes
or additions are necessary. In accordance with CEQA Guidelines Section 15164(d), the
Board shall consider the Addendum along with the Negative Declaration prior to making
a decision on the project. According to CEQA Guidelines Section 15164 (c) an
Addendum does not require circulation for public review but can be included in or
1
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attached to the Negative Declaration. As noted in the Preface, the Addendum is attached
to the Negative Declaration for the Formation of Drainage Area 76 and the Miranda Creek
Improvement Project (County File #CP# 93-87).
EXPLANATION OF THE ADDENDUM
The Addendum to the Negative Declaration for the Formation of Drainage Area 76 and
the Miranda Creek Improvement Proiect identifies minor technical changes to the design
of the improvements to the creek. The changes are as follows:
1. The project involves the installation of approximately 510 ft. of 84-inch pipe
and another 30 ft. of 108-inch pipe, instead of 800 ft. of 72-to 96-inch pipe.
2. Water from the Stratmore outfall pipe will be diverted to a point
approximately 650 downstream, instead of 800 ft. downstream.
Approximately 3 cubic yards of material will be removed from an
approximately 80 ft. reach of the creek, downstream of the earthen outfall
ditch, to provide positive drainage for the new storm drain.
3. The bypass storm drain will be connected to the creek with an approximately
30-ft. long earthen outfall ditch. The outfall structure is no longer required.
4. Like the previously planned area for the outfall (Sta. 2+50), the new area
(Sta. 4+25) lacks the thick riparian area. In addition, the area was previously
disturbed with an outfall from a drainage ditch.
5. The extent to which residential improvements (i.e., mature landscaping and
fences) will be disturbed is reduced. The tennis court will no longer be
impacted.
ADDITION TO THE NEGATIVE DECLARATION
This section identifies the language which is added/or changed (bold face type) or
deleted (strikeout) to the text and figures of the Negative Declaration:
Initial Study, p. 2, Parcel #: 192-031-017, 192 118-024-
Initial Study, p. 2, Project Description, 1st sentence: The project consists of the
construction of approximately 510 ft. of 84-inch pipe and
approximately 30 ft. of 108-inch diameter storm drain bypass system on Miranda Creek
from the Stratmore drain outfall (opposite the westerly end of Bunce Meadows Drive) to
a point approximately 8@8 650 feet downstream.
Initial Study, p. 2, Project Description, 3rd sentence: The construction work involves the
2
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installation of approximately 880 540 feet of storm drain pipe, manholes, an 30-ft. long
earthen outfall structure ditch at the downstream end of the bypass, and the placement
of rock slope protection to prevent erosion (see Figures 3 & 4).
Supplement to Environmental Checklist, p. 1, 2nd paragraph, item 4: Field visits on March
4, 1992, March 24, 1993, July 1, 1993, October 5, 1993, and October 7, 1993, April 11,
1995, August 14, 1995, September 30, 1995, and October 24, 1995.
Supplement to Environmental Checklist, p. 1, 3rd paragraph, 2nd sentence: The removal
of approximately three cubic yards of material from the bottom of an approximately
80 ft. reach of the creek, downstream of the earthen outfall ditch will result in a
minor, insignificant change in the Ttopography to of the project area will change during
construetion, but will be restored upon eornpletion of the project.
Supplement to Environmental Checklist, p. 1, 4th paragraph, 1 st sentence: Flows entering
Miranda Creek from the Stratmore outfall structure will be diverted approximately 880 650
feet downstream in order to avoid the area of the creek identified to have insufficient
capacity (see Figures 3 & 4).
Supplement to Environmental Checklist, p. 2, 2nd paragraph, 1st sentence: Miranda
Creek, downstream from the existing Stratmore outfall structure, will continue to receive
flows, but at a reduced amount because stormwater which currently enters Miranda Creek
via the existing Stratmore outfall structure will be intercepted and conveyed approximately
880 650 feet downstream.
DETERMINATION
On the basis of the previously adopted Negative Declaration and Addendum, the
proposed project could not have a significant effect on the environment. Since the revised
project involves only minor technical changed or additions [CEQA Guidelines Section
15164(b)] to a previously adopted Negative Declaration an addendum to the Negative
Declaration, not a new Negative Declaration, is appropriate.
CAWPWIN61\DA76REV\ADDENDUM-RV
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FIGURE 3
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SITE PLAN
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LEGEND DRAINAGE AREA 75
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SITE PLAN
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DESIGNED:H.FINCH CHECKED:R AGNEW E-E:
CONTRA PUBLIC WORKS DEP/ TMENT
COSTA INITIAL STUD %'
COUNTY OF ENVIRONMENTAL SIGNIFICANCE
FILE#7505-6F8176
CP# q- _g�
PROJECT NAME: Formation of Drainage Area 76 and the Miranda Creek Improvement Project
PREPARED BY. Maureen Tom6f, _ DATE: December 28, 1993
REVIEWED BY.b.. �,,;o�, DATE: Q4 m i 9L5
RECOMMENDATIONS:
( ) Categorical Exemption Negative Declaration
( ) Environment Impact Report Required () Conditional Negative Declaration
The project will not have a significant effect on the environmertL The recommendation is based on the
followiing summary of the Environmental Evaluation:
1. The project will not create unstable earth conditions,changes in geologic substructures or increase
the exposure of people or property to geologic or water related hazards.
2. There are no rare or endangered species of plants or animals in the project area. The project will not
increase the rate of use of natural resources.
3. The project will not convert prime agricultural land to non-agricultural use or impair the agricultural
productivity of prime agricultural land. The project will not disrupt or divide the physical arrangement
of the community.
4. The project will not degrade the quality of the environment.
5. The project will not have the potential to achieve short-term goals to the disadvantage of the long-term
environmental goals.
Construction activities will create minor short term,temporary impacts. But no significant impacts will occur
since the following best management practices are incorporated into the project and in project specifications:
6. There will be no significant change in air quality in the project area. Construction machinery and
vehicles will emit exhaust fumes and possibly objectionable odors during construction which may
temporarily deteriorate local air quality. To minimize the impact,contract specifications shall stipulate
the use of properly tuned and muffled equipment. Air quality impacts will also be reduced by
eliminating unnecessary idling of machines when not in use. Adherence to standard dust control
practices shall be required in order to reduce air quality impacts and potential for erosion during
construction.
7. In order to avoid water quality impacts, construction of either end of the storm drain bypass shall
occur during periods of low or no flow(eg.April to October). If water is present,the construction area
shall be de-watered by installing cofferdams and diverting water through a pipe,around the work site,
and discharged downstream in a non-erosive manner. Furthermore,sediment traps and/or filters shall
be installed on an as needed basis.
8. There are no rare or endangered species of plants in the project area. If native trees are removed,
they will be replaced at a 3:1 ratio with native species. Areas of the creek,disturbed by construction
activities, will be seeded.
9. Best management practices mentioned in #6, and limiting work hours to 7:30 a.m. - 5:00 p.m.,
Monday through Friday, unless modified upon written approval,will reduce construction noise levels
and shall be incorporated as part of the construction contract.
10. Standard construction safety practices will be followed during construction to ensure no accidental
release of hazardous substances or increase the potential for exposure to these substances. In order
to ivniri an arr iriantal rut. i tnriarnrni inri i itilitinz �erill ho In a*ori anri mPrt.o.-! -,;-. +- a—' +ron-hinn
Initial Study of Er )nmental Significance C ' P
Drainage Area 76
Page 2
emergency response or evacuation plan.
11. During construction, equipment and construction activities may temporarily inhibit smooth circulation,
but standard traffic control measures, such as flagging, warning signs, temporary detours, shall be
incorporated into the contract specifications and will minimize this impact.
12. If cultural resources are encountered during construction,all work will be halted within a 30 yard radius
of the finding and a qualified archaeologist retained to ascertain the nature of the discovery. Measures
recommended by the archaeologist and approved by the Public Works Department will be
implemented.
What changes to the project would mitigate the identified impacts?
N/A
USGS Quad Sheets: Las Trampas, CA Base Map Sheet# G15 Parcel# 192-031-018
192-031-019
192-110-020
192-110-021
GENERAL CONSIDERATIONS:
1. Location: The project is located in the Alamo area of central Contra Costa County (see Figure 1).
The approximate boundaries of the proposed drainage area are Livorna Road on the north, Stone
Valley Road on the south,Shell Ridge (within Mt. Diablo State Park)to the east,and Interstate 680 to
the west. The majority of the Drainage Area is located within the County and a minor amount is within
the City of Walnut Creek(see Figure 2). The drainage area encompasses approximately 1,470 acres
of low to very low density single family residences,open space,agricultural land,and state park land.
The Miranda Creek bypass pipe will be constructed in the vicinity of the westerly end of Bunce
Meadows Drive (see Figures 3 &4).
2 Project Description:
The project consists of the construction of a large(72-to 96-inch)diameter storm drain bypass system
on Miranda Creek from the Statmore drain outfall(opposite the westerly end of Bunce Meadows Drive)
to a point approximately 800 feet downstream; the formation of a drainage area; and adoption of a
plan of improvement and impervious surface fee ordinance for financing project costs. The fee,based
on the square footage of impervious surface would be assessed on future development, excluding
developments with vesting tentative maps. The construction work involves the installation of
approximately 800 feet of storm drain pipe, manholes,an outfall structure at the downstream end of
the bypass, and the placement of rock slope protection to prevent erosion (see Figures 3&4). The
purpose of the project is to bypass storm water and divert it downstream where the creek has
adequate capacity against flooding.
In the vicinity of the existing Stratmore drain outfall, were the bypass pipe crosses under the creek,
approximately 2,500 square feet of creek area will be disturbed. Presently,this area is covered with
grouted and ungrouted rock slope protection. The bypass storm drain outfall structure will be
constructed adjacent to the creek and connected to the creek with a short channel. The location of
the proposed outfall structure was selected to avoid as much riparian vegetation as possible. At the
point of reentry into the creek, approximately 1,500 square feet of creek will be disturbed. Areas of
the creek, disturbed by construction activities,will be seeded.
3. Does it appear that any feature of the project will generate significant public concern? (]yes []no
[Jj maybe (Nature of concern): Several property owners where the bypass will be installed are in
favor of the project, however, construction traffic and noise may be of concern,
4. Will the project require approval or permits by other than a County agency? [J]yes [j no Agency
Name(s) Department of Fish and Game and Army Corps of Engineers
5. Is the project within the sphere of influence of any W Yes, Walnut Creek
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SUPPLEMENT TO ENVIRONMENTAL CHECKLIST
ENVIRONMENTAL EVALUATION
Formation of Drainage Area 76 and the Miranda Creek Improvement Project
- The project consists of the formation of Drainage Area 76, the construction of a storm drain bypass
system on Miranda Creek, and the adoption of a drainage fee ordinance. The drainage area
encompasses approximately 1,470 acres in the Alamo area of central Contra Costa County.
In the process of preparing the Environmental Checklist and conducting the evaluation, the following
resources were reviewed:
1. Contra Costa Resource Mapping System
2. The County General Plan and EIR on the General Plan, January 1991
3. RAREFIND - California Natural Diversity Data Base, October 28, 1993
4. Field visits on March 4, 1992, March 24, 1993, July 1, 1993, October 5, 1993, and October 7,
1993
5. Sonoma State Cultural Resources Records Search, October 21, 1993
6. Species list from U.S. Fish and Wildlife Service (USFWS), December 3, 1993
1. EARTH:
(A, C, D, F & G) Since review of the Resource Mapping System did not identify any unique geologic
or physical features, and the Botella clay and Conejo clay soils in this area have only a slight hazard
of erosion, trenching activities are not expected to result in unstable earth conditions or change
geologic substructures. Topography in the project area will change during construction, but will be
restored upon completion of the project. An earthquake fault, which is inferred active on the basis of
a tectonic model, is located approximately 600 feet west of the project area. However, it is not
expected that the project will increase the exposure of people or property to geologic hazards.
Flows entering Miranda Creek from the Stratmore outfall structure will be diverted approximately 800
feet downstream in order to avoid the area of the creek identified to have insufficient capacity (see
Figures 3 & 4). Since flows will be reduced, the project will result in a minor reduction in the amount
of erosion currently occurring in the reach of the creek to be bypassed. Changes in erosion, siltation
and deposition are minor and will not significantly modify the channel.
(B & E) Some vegetative cover will be removed during the installation of the bypass pipe, which will
expose soils to wind and water erosion. This impact is minor and temporary. Adherence to standard
dust control practices include, but are not limited to, general watering of graded areas, use of chemical
stabilizers and seeding, will reduce this impact. Dust control practices shall be incorporated into
construction contracts.
2. AIR:
(A & B) Short-term emissions and objectionable odors are generated during construction activities,
but they are minor and temporary. Contract specifications shall stipulate the use of properly tuned and
muffled equipment. Air quality impacts will also be reduced by eliminating unnecessary idling of
machines when not in use. Implementation of dust control practices noted in #1 - EARTH (B & E) will
also avoid air quality impacts.
Supplement to Environmental Checklist
Drainage Area 76 - Miranda Creek Improvements
Page 2
(C) Since the installation of a bypass pipe does not create barriers to air movement, or create
impervious surfaces, no alteration of climate,air movement, moisture, or temperature will occur because
of the proposed project.-
3.
roject:3. WATER:
(A - 1) The watershed is drained by Miranda Creek and its tributaries and empties into San Ramon
Creek (see Figures 2 & 3). Flows originating from Miranda Creek, upstream of the existing Stratmore
outfall structure, will not be changed. Miranda Creek, downstream from the existing Stratmore outfall
structure, will continue to receive flows, but at a reduced amount because storm water which currently
enters Miranda Creek via the existing Statmore outfall structure will be intercepted and conveyed
approximately 800 feet downstream. The Statmore drain flows account for approximately one-third of
the total flow in Miranda Creek, downstream of its existing junction with the creek. The flows in Miranda
Creek, downstream of the proposed outfall, will not change as a result of the project.
Upon completion of the project, changes to the amount of surface water along Miranda Creek, within
the project area, will vary. The maximum reduction is approximately 1.1 feet. Changes in the amount
of surface water in the creek are not significant since this reach of the creek has insufficient capacity
for flows from a higher-than-average storm event and often results in the flooding of adjacent properties
(see #4 - PLANT LIFE A-D).
The project will not result in a change in absorption rates or the rate and amount of surface runoff.
Groundwater will not be affected by the proposed project. The project will not reduce the water
available to the public since a public water source is not affected. The project will help reduce the
exposure of property to flooding downstream from the existing Stratmore outfall structure. Construction
at either end of the bypass pipe shall occur during periods of low or no flow (eg. April to October) to
avoid water quality impacts. If water is present, the construction area shall be de-watered by installing
cofferdams and diverting water through a pipe, around the work site, to be discharged downstream
in a non-erosive manner. Furthermore, sediment traps and/or filters shall be installed-on an as needed
basis.
4. PLANT LIFE:
(A - D) The Resource Mapping System, RAREFIND, U.S. Fish and Wildlife Service species list, and
field visits indicate no rare or endangered species of plants exist in the area. The project will not create
a barrier to the normal replenishment of existing species. The project will not reduce the acreage of
any agricultural crop and will not introduce new species of plants to the area.
The bypass pipe will be constructed in the roadway (Bunce Meadows Drive) and across private
property, requiring the removal of some landscaping. The property owners will be compensated for
the loss of landscaping. During construction of the proposed bypass outfall, some native trees along
the creek may be removed. If native trees are removed, they will be replaced at a 3:1 ratio with native
species- Areas of the creek, disturbed by construction activities, will be seeded. The minor reduction
of creek flows in the reach of the creek where storm water will be diverted may enable vegetation to
6 *S *I
environment is significant.) ✓
d. Does the project have environmental effects which will cause
substantial adverse effects on human beings, either directly or -
indirectly? - _ ✓
III. Discussion of Environmental Evaluation. (see attachment)
IV. Determination
On the basis of this Checklist and Environmental Evaluation: .
✓❑ 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 NEGATIVE DECLARATION WILL BE
PREPARED.
I find the proposed project MAY have a significant effect on the
environment, and an ENVIRONMENTAL IMPACT REPORT is required.
Dategre =
Reviewed By:
MT:mat
c:da76\ceqachk.mir
(form rev. 12193)
*Please Notea 'IS" is for significant; "I°° is for insagnificant.,
5 *S *I
17. Human Health. Will the proposal result in:
a. Creation of any health hazard or potential health hazard (excluding
mental health)? _ ✓
b. Exposure of people to potential health hazards? _ ✓
18. Aesthetics. Will the proposal result in the obstruction of any scenic vista
or view open to the public, or will the proposal result in the creation of an
aesthetically offensive site open to public view? _ ✓
19. Recreation. Will the proposal result in an impact upon the quality or quantity
of existing recreational opportunities? _ ✓
20. Cultural Resources.
a. Will the proposal result in the alteration of the destruction of a
prehistoric or historic archaeological site? _ ✓
b. Will the proposal result in adverse physical or aesthetic effects to a
prehistoric or historic building, structure, or object? _ ✓
C. Does the proposal have the potential to cause a physical change which
would affect unique ethnic cultural values? _ ✓
d. Will the proposal restrict existing religious or sacred uses within the
potential impact area? _ ✓
21. 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? _ ✓
b. Does the project have the potential to achieve short-term, to the
disadvantage of long-term, environmental goals? (A short-term impact
on the environment is one which occurs in a relatively brief, definitive
period of time while long-term impacts will endure well into the future.) _ ✓
C. Does the project have impacts which are individually limited, but
cumulatively considerable? (A project may impact on two or more
separate resources where the impact on each resource is relatively
small, but where the effect of the total of those impacts on the
*Please Note: "S" is 'for significant; "I"' is for insignificant.
4 *S *I
d. Alterations to present patterns of circulation or movement
of people and/or goods? _ ✓
e. - Alterations to waterborne, rail or air-traffic? _ ✓
f. Increase in traffic hazards to motor vehicles, bicyclists or pedestrians? _ ✓
14. Public Services. Will the proposal have an effect upon, or result in a need for new or altered
governmental services in any of the following areas:
a. Fire protection? _ ✓
b. Police protection? _ ✓
C. Schools? ✓
d. Parks or other recreational facilities? ✓
e. Maintenance of public facilities, including
roads? ✓
f. Other governmental services? _ ✓
15. Energy. Will the proposal result in:
a. Use of substantial amounts of fuel or energy? _ ✓
b. Substantial increase in demand upon existing sources of energy,
or require the development of new sources of energy? _ ✓
16. Utilities/Service Systems. Will the proposal result in a need for new systems, or substantial
alterations to the following utilities?
a. Power or natural gas? _ ✓
b. Communications systems? _ ✓
C. Water? ✓
d. . Sewer or septic tanks? _ ✓
e. Storm water drainage? _ ✓
f. Solid waste and disposal? _ ✓
*Please Note: "S" is for significant; "I" is for insignificant.
3 *S *I
organisms or insects)? _ ✓
b. Reduction of the numbers of any unique, rare or endangered
species of animals? _ ✓
C. Introduction of new species of animals into an area, or result in
a barrier to the migration or movement of animals? _ ✓
d. Deterioration to existing fish or wildlife habitat? _ ✓
6. Noise. Will the proposal result in:
a. Increases in existing noise levels? _ ✓
b. Exposure of people to severe noise levels? _ ✓
7. Light and Glare. Will the proposal produce new light or glare? _ ✓
8. Land Use. Will the proposal result in a substantial alteration of the present
or planned land use of an area? _ ✓
9. Natural Resources. Will the proposal result in:
a. Increase in the rate of use of any natural resources? ✓
10. Risk of Upset. Will the proposal involve:
a. A risk of an explosion or the release of hazardous substances
(including, but not limited to, oil, pesticides, chemicals or
radiation) in the event of an accident or upset conditions? ✓
b. Possible interference with an emergency response plan or an
emergency evacuation plan? _ ✓
11. Population. Will the proposal alter the location, distribution, density, or
growth rate of the human population of an area? _ ✓
12. Housing. Will the proposal affect existing housing, or create a demand
for additional housing? _ ✓
13- Transportation/Circulation. Will the proposal result in:
a. Generation of substantial additional vehicular movement? ✓
b. Effects on existing parking facilities, or demand for new parking? _ ✓
C. Substantial impact upon existing transportation systems? _ ✓
*Please Note: °'S" is for significant; "I" is for insignificant.
CONTRA COSTA COUNTY
CEQA ENVIRONMENTAL CHECKLIST FORM
I. Background
1. Name of Proponent: Contra Costa County Flood Control and Water Conservation
District -
2. Address and Phone Number of Proponent: 255 Glacier Drive
Martinez, CA 94553-4897
(510) 313-2000
3. Date of Checklist Submitted: December 28, 1993
4. Name of Proposal: Drainage Area 76 - Miranda Creek Improvements
II. Environmental Impacts
(Explanations of all significant, (S), answers are required on attached sheets.)
*S *1
1. Earth. Will the proposal result in:
a. Unstable earth conditions or changes in geologic substructures? _ ✓
b. Disruptions, displacements, compaction or overcovering of the
soil? ✓
C. Change in topography or ground surface relief features? _ ✓
d. The destruction, covering or modification of any unique geologic
or physical features? _ ✓
e. Any increase in wind or water erosion of soils, either on
or off the site? ✓
f. Changes in deposition or erosion of beach sands, or changes in
siltation, deposition or erosion which may modify the channel of
a river or stream or the bed of the ocean or any bay, inlet
or lake? ✓
g. Exposure of people or property to geologic hazards such
as earthquakes, landslides, mudslides, ground failure, or
similar hazards? ✓
2. Air. Will the proposal result in:
a. Substantial air emissions or deterioration of ambient air quality? _ ✓
b. The creation of objectionable odors? _ ✓
C. Alternation of air movement, moisture, or temperature, or any change
2 *S *I
in climate, either locally or regionally? ✓
3. Water. Will the proposal result in:
a. Changes in currents, or the course of direction of water movements,
in either marine or fresh waters? ✓
b. Changes in absorption rates, drainage patterns, or the rate and amount
of surface runoff? ✓
C. Alterations to the course or flow of flood waters? ✓
d. Change in the amount of surface water in any water body? ✓
e. Discharge into surface waters, or in any alteration of surface water
quality, including but not limited to temperature, dissolved oxygen
or turbidity? _ ✓
f. Alteration of the direction or rate of flow of ground waters? _ ✓
g. Change in the quantity of ground waters, either through direct additions
or withdrawals, or through interception of an aquifer by cuts
or excavations? ✓
h. Substantial reduction in the amount of water otherwise available
for public water supplies? _ ✓
i. Exposure of people or property to water related hazards such as
flooding or tidal waves? _ ✓
4. Plant Life. Will the proposal result in:
a. Change in the diversity of species, or number of any species of plants
(including trees, shrubs, grass, crops, and aquatic plants)? _ ✓
b. Reduction of the numbers of any unique, rare or
endangered species of plants? _ ✓
C. Introduction of new species of plants into an area, or in a barrier
to the normal replenishment of existing species? _ ✓
d. Reduction in acreage of any agricultural crop? ✓
5. Animal Life. Will the proposal result in:
a. Change in the diversity of species, or numbers of any species of animals
(birds, land animals including reptiles, fish and shellfish, benthic
*Please Note: "S" is for significant; "I" is for insignificant.
FIGURE 4
STA 10.75
Byposs Storm Droln END OF PROPOSED PROJECT
Creek under crossing Strotmore Droln Autfoll
an of
o or 119 o0
III JENNIFER LN.
_ $
80 JENNIFER LN. a r? c�t �: F 4 r
16 d
31 VERNAL CT.
130 BUNCE MEADOWS DR.
i h' C7' � t,,.?• :..W WIMI{6.Gf4 tiND
P' t 125 BUNCE MEADOWS DR.
41 VERNAL CT. 11 , .r\A
t,
O,pO.°° tal•�'1
126 BUNCE MEADOWS DR.
•t... c
6.0 0 119 BUNCE MEADOWS D F'400Ws
181 STONE VALLEY WAY DR I V E
Alp rox.Location
offordam If, WOOD
e o0•p0 113 BUNCE MEADOWS DR.
PROPOSED ALIGNMENT FOR THE
72-to 96-INCH DIAMETER BYPASS PIPE
•'.�t'� trr• :•rirvt
da
1030 INA OR.
187 STONE VALLEY AY ` "' ��' �•1^°'�"Mh STA 2.50 -BEGINNING OF
...... ,wam rhw PROPOSED
ti0••••.4 C
1
v Z.0 p0 1040 INA DR.
195 STONE VALLEY W
Bypass 4torm Droln Outfo
' Conform with ex/stl reek
t
? ` 0 100• 200'
0'0 p0 SCAM P a 100'
'PROPOSED MIRANDA CREEK IMPROVEMENT PROJECT
'FOR SCEMATIC PURPOSES
LEGEND: CONTRA COSTA FLOOD CONTROL AND
T.O.B. — TOP OF BANK
WATER CONSERVATION DISTRICT
T.O.S. — TOE OF SLOPE I CONTRA COSTA COUNTY, CALIFORNIA
DECEMBER 14,1993
Supplement to Environmental Checklist
Drainage Area 76 - Miranda Creek Improvements '
Page 4
10. RISK OF UPSET:
(A) The proposed project has the potential to release hazardous substances, such as accidental
petroleum spills, during construction. Per standard specifications, standard construction safety
practices will be followed during construction to ensure no accidental release of hazardous substances
or increase the potential for exposure to these substances. The County Resource Mapping System
did not identify any petroleum pipelines or electric transmission lines in the Miranda Creek improvement
project area. In order to avoid an accidental cut, underground utilities will be located and marked prior
to any trenching activities.
(B) As discussed in #13 - TRANSPORTATION/CIRCULATION (A - D & F), traffic control measures will
minimize the interference with an emergency response or evacuation plan.
11 & 12. POPULATION AND HOUSING:
The proposal will not alter the location, distribution, density, or growth rate of the human population of
the area, nor will it affect existing housing or create a demand for additional housing (see #8 - LAND
USE).
13. TRANSPORTATION/CIRCULATION:
(A - D & F) The project does not generate additional traffic, increase the demand for additional
parking, alter circulation patterns,or impact existing transportation systems,except during construction.
During construction, equipment and construction activities may temporarily inhibit smooth circulation,
but traffic control measures, such as flagging, warning signs, temporary detours, shall be incorporated
into the contract specifications and will minimize this impact. Transportation and circulation impacts
will end upon completion of the project.
(E) The project will not alter waterborne, rail, or air traffic.
14. PUBLIC SERVICES:
(A- D) The project does not increase the need for fire or police protection, schools, or parks (see #8 -
LAND USE).
(E & F) The proposed bypass pipe will require occasional maintenance. These activities are usually
of very short duration and will be incorporated into the routine maintenance program for the area. The
formation of the drainage area and adoption of a drainage fee is needed to pay for improvements to
Miranda Creek.
�. A(a.
Supplement to Environmental Checklist
' Drainage Area 76 - Miranda Creek Improvements
Page 3
grow further down the banks of the creek, which may impede further erosion of the banks.
Implementation of practices noted in #3 WATER (A-i)-will also minimize impacts on plant life.
5. ANIMAL LIFE:
(A- D) The project will not cause a change in the diversity of or number of species in the project area.
The Resource Mapping System, RAREFIND, U.S. Fish and Wildlife Service species list, and field visits
showed no rare or endangered animal life in the area. The project will not result in the introduction.of
new species of animals into an area or result in a barrier to the migration or movement of animals, nor
will it result in the deterioration of existing fish or wildlife habitat. The minor reduction of creek flows
in the project area will not have a significant impact on animal life. Implementation of practices noted
in #3 WATER (A - 1) will also minimize impacts on animal life.
6. NOISE:
(A & B) In general, construction activities produce noise levels of 86 dBA at 50 feet, which is well
below the threshold of pain of 120-140 dBA. Best management practices noted in #2 - AIR (A & B),
and limiting work hours to 7:30 a.m. - 5:00 p.m., Monday through Friday, unless modified upon written
approval, reduce construction noise levels and shall be incorporated as part of the construction
contract.
Once the bypass pipe is installed it will not generate noise.
7. LIGHT AND GLARE:
Installation of the underground bypass pipe, of and by itself, will not produce any new light or glare.
8. LAND USE:
Drainage Area 76 encompasses approximately 1,470 acres of low to very low density single family
residences, open space, agricultural land, and state park land. The installation of the bypass pipe will
minimize existing localized flooding. The project, including the installation of the bypass pipe under the
roadway and across several properties, will not result in the alteration of the present or planned land
use of the area as noted in the County's General Plan.
9. NATURAL RESOURCES:
(A) During construction equipment will use fuel, but given the short span of construction, this impact
is not significant. Once completed the bypass pipe will consume no natural resources aside from those
resources (i.e. gasoline) used during periodic maintenance activities.
Supplement to Environmental Checklist
' Drainage Area 76 - Miranda Creek Improvements
Page 5
1'5 - 19. ENERGY UTILITIES HUMAN HEALTH AESTHETICS AND RECREATION:
Installation of a bypass pipe will not result in wasted energy. The pipe requires no energy to operate,
so new utilities are not required. Since the bypass pipe is underground, health hazards are not
created. The project will not result in the obstruction of any scenic vista or view, nor will it result in the
creation of an aesthetically offensive site open to public view. As mentioned in #4 PLANTS, some
landscaping will be removed as a result of the project, however, since the property owners will be
compensated for the loss of landscaping, replacement will be at their discretion. No recreational
opportunities currently exist where the bypass pipe will be installed.
20. CULTURAL RESOURCES:
(A- D) According to the Resource Mapping System and the Sonoma State University Records Search
the project area contains no recorded historical or archeological sites. The County General Plan has
designated portions of the drainage area (east of the Miranda Creek project area) as a highly sensitive
area, however the project area has been previously disturbed through construction of residences, the
roadway, and the Stratmore outfall system, and the installation of underground utilities. Per standard
specifications, all personnel connected with the project will be informed of the possibility of finding
archaeological resources (e.g., human remains, artifacts, bedrock, bone or shell). If during construction
such resources are encountered, all work will be halted within a 30 yard radius of the finding and a
qualified archaeologist retained to ascertain the nature of the discovery. -Measures recommended by
the archaeologist and approved by the Public Works Department will be implemented.
21. MANDATORY FINDINGS OF SIGNIFICANCE:
(A-D) Due to construction equipment, air quality will be temporarily degraded at the project site.
However, no permanent long-term impacts will result (see #2 - AIR). There are no cumulative impacts
associated with the project. The project will not substantially reduce the habitat of-a fish or wildlife
species, threaten to eliminate a plant or animal community , or cause a fish or wildlife population to
drop below self sustaining levels. No endangered species of plants or animals are within the project
area. There will be no encroachment upon any habitat or elimination of any animal, fish, or wildlife
community (see #'s 4 & 5 - PLANT and ANIMAL LIFE). Should examples of the major periods of
California history or prehistory be found, measures described in #20 - CULTURAL RESOURCES shall
be implemented. The project does not have the potential to achieve short-term, to the disadvantage
of long-term, environmental goals. In addition, there will be no adverse environmental effects on
humans as long as the suggestions for items 1 (B & E), 2 (A & B), 6 (A & B), 10 (A & B), and 13 (A -
D & F) are implemented.
VG:MT:mat
c:da76\da76rev.sup
CALIFORNIA ENVIRONMENTAL QUALITY ACT
NOTICE OF DETERMINATION
CONTRA COSTA COUNTY COMMUNITY DEVELOPMENT DEPARTMENT
651 PINE STREET 4TH FLOOR NORTH WING MARTINEZ, CALIFORNIA 94553-0095
Telephone: (510) 313-2296 Contact: Vickie Germany, Public Works Dept.
Project Description,Common Name (if any)and Location: ADDENDUM TO NEGATIVE DECLARATION
FOR THE FORMATION OF DRAINAGE AREA 76 AND THE MIRANDA CREEK IMPROVEMENT
PROJECT, County File #96-7: The project involves the installation of storm drain bypass system
(approximate 510 feet of 86-inch pipe and another 30 feet of 108-inch pipe) on Miranda Creek from
the Stratmore drain outfall (opposite the westerly end of Bunce Meadows Drive) to a point
approximately 650 feet downstream. The construction work involves the installation of approximately
540 feet of storm drain pipe, manholes, 30-foot long earthen outfall ditch at the downstream end of
the bypass, and the placement of rock slope protection to prevent erosion.
The project was approved on
Pursuant to the provisions of the California Environmental Quality Act:
An Environmental Impact Report was prepared and certified.
The Project was encompassed by an Environmental Impact Report previously prepared for
A Negative Declaration approved by the Board of Supervisors on March 1, 1994 was issued
indicating that preparation of an Environmental Impact Report was not required.
Copies of the record of project approval and the Negative Declaration or the final EIR may be examined at the office
of the Contra Costa County Community Development Department.
QThe Project will not have a significant environmental effect.
The Project will have a significant environmental effect.
Mitigation measures were made a condition of approval of the project.
A statement of overriding considerations was adopted.
Findings were adopted pursuant to Section 15091 of the State CEQA Guidelines.
Date: By:
Community Development Department Representative
AFFIDAVIT OF FILING AND POSTING
1 declare that on I received and posted this notice as required by California Public
Resources Code Section 21152(c). Said notice will remain posted for 30 days from the filing date.
Signature Title
Applicant:
CCC Public Works Dept.
Attn: Janet Frattini
255 Glacier Drive
Martinez, CA 94553 County Clerk Fee Due - $25