HomeMy WebLinkAboutMINUTES - 08061996 - C32 TO: BOARD OF SUPERVISORS, AS GOVERNING BOARD OF CONTRA COSTA COUNTY
AND CONTRA COSTA COUNTY FLOOD CONTROL AND WATER CONSERVATION
DISTRICT
FROM: J. MICHAEL WALFORD, CHIEF ENGINEER
DATE: AUGUST 6, 1996
SUBJECT: WILDCAT CREEK SEDIMENT BASIN MAINTENANCE, SIERRA CLUB ET AL LETTERS,
BOARD REFERRAL JULY 23, 1996, ITEM C.79
SPECIFIC REQUEST(S)OR RECOMMENDATION(S)&BACKGROUND AND JUSTIFICATION
I. Recommended Action:
A ACCEPT report from the Chief Engineer and a separate report from the Coalition to
Restore Urban Waters, acknowledging disagreement and direct all interested parties to
continue to work toward a mutually agreeable solution regarding the controversy over
District's proposal to remove sediment from the Wildcat Creek Sediment Basin as required
by the approved Operation and Maintenance Plan for the Wildcat and San Pablo Creeks
Project; and
B APPROVE Chief Engineer's offering to allow the volunteer vegetation on the sediment
basin floor within 50-feet of the south bank to remain until September 1, 1997, to provide
time for the Corps of Engineers or the Coalition to develop a replacement sedimentation
basin configuration that is equivalent in all respects to the basin originally designed by the
Corps of Engineers and provides a shaded, maintainable, low flow channel for fish
passage; and
C CONCUR with staffs plans to desilt this fall the other areas of the sediment basin outside
,the limits of the 50-foot wide corridor of volunteer vegetation.
D ADOPT the attached resolution to the Corps of Engineers indicating the District's desire
that the sediment basin be redesigned to provide for a shaded fish passage facility that is
functional without excessive low flow reestablishment work each year and the District's
reluctance to accept Contract 3A (Wildcat Creek) until said ctive action is approved
for construction.
Continued on Attachment: X SIGNATURE:
_RECOMMENDATION OF COUNTY ADMINISTRATOR
_RECOMMENDATION OF BOARD COMMITTEE
APPROVE OTHER
SIGNATURE(S):
ACTION OF BOARD ON NG p 6 1996 APPROVED AS RECOMMENDED OTHER_
VOT OF SUPERVISORS
UNANIMOUS (ABSENT )
AYES: NOES:
ABSENT: ABSTAIN:
MFK:drg t Nereby eef*that thla b a true and coned am of
\admin\milt\bo6.t8 an action taken and entered on the minuMa of-tM
9 floard of SuPiN
The date shown.
ATTESTED:
Orig. Div: Public Works(ADMIN) PHIL BATCHELOR,CIe board
Contact: Milton Kubicek(313-2203) ofSupervlsorsand County AO*MW&lot
cc: CAO ,
County Counsel o A. ��ospuv
V.Alexeeff,GMEDA
J.Cutler,CDD
M.Walford,Admin
G. Connaughton,Mtce.
continued last page
Wildcat Creek Sediment.Basin Maintenance, Sierra Club et al letters, Board Referral July 23, 1996, Item
C.79
August 6, 1996
Page Two
E CONCUR with staff's position to not accept any modification to the sedimentation basin
originally designed by the Corps of Engineers or the original maintenance plan that will
result in higher maintenance costs without first obtaining approval from the Board.
II. Financial lmpact:
Decreasing the size of the sedimentation basin will increase the long term maintenance costs for
Wildcat Creek through more frequent sediment removal, more sediment bypassing the basin, and
increased difficulty in handling the sediment to be removed. The costs could be in the tens of
thousands of dollars.
With the loss of Special District Augmentation Funding, maintenance costs for Wildcat and San
Pablo Creeks must be funded from the County's Stormwater Utility Area No. 17 (unincorporated
area) revenues.
III. Reasons for Recommendations and Background:
Staff has been in consultation with Ms. Ann Riley, Coalition to Restore Urban Waters, for over a
year regarding the volunteer vegetation on the sediment basin flow. According to the Wildcat
Creek Master Plan, Mitigation Plan, and Operation and Maintenance Plan, no vegetation was
envisioned in the basin floor area due to the known need for periodic removal of sediment from
the sediment basin. The basin cross section was to be maintained as shown in Section 96+25
Plate 3, sheet 12 of 40 attached. This Section has an "n" value of .04 to .042 which, according
to the sediment removal guidelines for Section 96+25 Exhibit G, sheet 36 of 40 of the
Maintenance Manual, allows sedimentation accummlation of up to two feet of depth in the basin
before it must be desilted. Unfortunately, the cross section Station 96+25 of the sediment basin
looks like Plate 3, sheet 28 of 40. The large, dense vegetation yields a value of n=0.070 which
is unacceptable according to the freeboard reduction curves in Exhibit G, sheet 36 of 40. Also
attached are plan sheets 3 through 6 of 10 from the Maintenance Manual which shows the
approved mitigation plan for Wildcat Creek.
The sediment basin was constructed, at considerable local cost, as a mitigation measure to trap
sediment upstream of the mitigation planting area to reduce the need for sedimentation removal
activities within the mitigation area. Failure to control the sediments in Wildcat Creek will increase
the need for sediment removal along the entire improved portion of Wildcat Creek at a significant
increase in local cost and considerable environmental damage. Any sediment removal work
within the mitigation area, even if it is warranted by the approved maintenance plan, is going to
meet significant public objection. It is imperative that the sedimentation basin function as
originally envisioned. Failure to do so could ultimately result in degradation of the new flood
protection.
Sheet 6 of 10 shows the sediment basin area. Note that the plan shows no vegetation on the
basin floor. On the next sheet, 6A, the extent of volunteer vegetation has been indicated. The
cross hatched area is the area where vegetation is to remain until September 1, 1997 by the
proposed letter agreement with the Coalition to Restore Urban Waters.
The sediment basin design by the Corps of Engineers did not adequately address creation of a
perpetual low flow channel for fish passage. The low flow channel constructed by the Corps of
Engineers fills in with sediment each time a significant rain event occurs. Reestablishing the low
flow channel each year is not practical. The task is complicated by the absence of adequate
access and the saturated condition of the soil. The Corps of Engineers' plan provides for fish
passage along the entire length of the improved creek, except through the sedimentation basin.
We recommend that the Corps of Engineers be requested to correct this deficiency.
Engineers for the Coalition to Restore Urban Waters have suggested that the basin may be
adequate even with the volunteer vegetation remaining. Staff does not recommend any decrease
in the sediment storage area to further enhance vegetation on the project. At best, decreasing
the storage volume increases our long term maintenance costs by requiring more frequent
removal work. At worst, it reduces the efficiency of the basin to trap sediments thereby
accelerating the deposit of sediments downstream in the environmentally sensitive areas.
C, 3;L.,
..Wildcat Creek Sediment Basin Maintenance, Sierra Club et al letters, Board Referral July 23, 1996, Item
C.79
-August 6, 1996
Page Three
cc: Congressman George Miller
367 Civic Dr#14
Pleasant Hill, CA 94523
Assemblyman Tom Bates
State Capitol
P. O. Box 942849
Sacramento, CA 94249-0001
Ann Riley, Executive Director
Carole Schemmerling
Coalition to Restore Urban Waters
1250 Addison, Suite 107
Berkeley, CA 94702
Larry B. Fishbain
913 Cerrito Street
Albany, CA 94706
Lillie Mae Jones
Community Youth Council for Leadership and
Education Cycle
258 6th Street
Richmond, CA 94807
Norman La Force, Chair
Sierra Club, SF Bay Chapter
5237 College Avenue
Oakland, CA 94618
Paul Bowers
Mark Boedtker
John N. Reese, Colonel
USA COE
1325 J Street
Sacramento, CA 95814-2922
Margaret A. Roper
Brian Hunter
Department of Fish & Game
P. O. Box 47
Yountville, CA 94599
Tim Vendlinski
Environmental Protection Agency
75 Hawthorne Street
San Francisco, CA 94105
Ken Burger
East Bay Regional Parks
2950 Peralta Oaks Ct.
Oakland, CA 94605-0381
Mr. Pat O'Brien
East Bay Regional Parks District
P. O. Box 5381
Oakland, CA 94605-0381
Barbara Vincent
2500 Lowell Ave.
Richmond, CA 94804
THE BOARD OF SUPERVISORS, CALIFORNIA
AS THE BOARD OF SUPERVISORS OF CONTRA COSTA COUNTY
AND AS THE GOVERNING BODY OF THE CONTRA COSTA COUNTY
FLOOD CONTROL AND WATER CONSERVATION DISTRICT
Adopted this Order on August 6, 1996 by the following vote:
AYES: Supervisors Rogers, Bishop, DeSaulnier, Torlakson, Smith
NOES: None
ABSENT: None
ABSTAIN: None RESOLUTION NO 96/351
SUBJECT: WILDCAT CREEK SEDIMENT BASIN MAINTENANCE, NORTH
RICHMOND AREA
Project # 7527-6D8601
WHEREAS the Corps of Engineers has constructed flood control improvements on Wildcat
Creek that are multipurpose: flood control, environmental enhancement, and recreational,;
and
WHEREAS one of the environmental features is the creation of a vegetation shaded low
flow channel to promote fish passage; and
WHEREAS the Corps of Engineers has expended considerable monies to install a fish
ladder in the concrete channel under the Southern Pacific Railroad tracks; and
WHEREAS the Corps of Engineers low flow fish passage channel constructed across the
sedimentation basin is obliterated by sedimentation deposits each time it rains; and
WHEREAS said low flow channel cannot reasonably be maintained functional; and
WHEREAS without a functional low flow channel across the sedimentation basin, the
millions of dollars spent on the project to include environmental enhancements and a
channel for fish passage will be for naught.
NOW THEREFORE BE IT RESOLVED by this Board that the Corps of Engineers is
requested to redesign the sedimentation basin to provide a separate fish passage channel
through the sediment basin; and
BE IT FURTHER RESOLVED that this Board is reluctant to accept Contract 3A\/ViIdcat
Creek for maintenance until the fish passage through the sediment basin issue is
successfully resolved.
I lierelry oaeiN Md tAb b s hss and oonrl�t a0py 01
f�perdtaandnOmd no SUpeivtgam a►th date shownmbubs ai tlM
ATTESTEq:
i PHIL BATC LOR,Clerk Offt board
of Supervisors and County AdminlatraW
ti ��.oeaair
MFK:drg
l
g1adminlmilt1res6.t8
Orig.Dept.: Public Works(AD)
Contact Person: Milton Kubicek €
cc: See next page
RESOLUTION NO. 96/351
WILDCAT CREEK SEDIMENT BASIN MAINTENANCE, NORTH RICHMOND AREA
Project # 7527-6D8601
August 6, 1996
Page Two
cc: CAO
County Counsel
V. Alexeeff, GMEDA
J. Cutler, CDD
M. Walford, Admin.
G. Connaughton, Mtce.
Congressman George Miller
Assemblyman Tom Bates
State Capitol
P. O. Box 942849
Sacramento, CA 94249-0001
Ann Riley, Executive Director
Carole Schemmerling
Coalition to Restore Urban Waters
1250 Addison, Suite 107
Berkeley, CA 94702
Larry B. Fishbain
913 Cerrito Street
Albany, CA 94706
Lillie Mae Jones
Community Youth Council for Leadership and
Education Cycle
258 6th Street
Richmond, CA 94807
Norman La Force, Chair
Sierra Club, SF Bay Chapter
5237 College Avenue
Oakland, CA 94618
Paul Bowers
Mark Boedtker
John N. Reese, Colonel
USA COE
1325 J Street
Sacramento, CA 95814-2922
Margaret A. Roper
Brian Hunter
Department of Fish &Game
P. O. Box 47
Yountville, CA 94599
Tim Vendlinski
Environmental Protection Agency
75 Hawthorne Street
San Francisco, CA 94105
Ken Burger
East Bay Regional Parks
2950 Peralta Oaks Ct.
Oakland, CA 94605-0381
Mr. Pat O'Brien
East Bay Regional Parks District
P. O. Box 5381
Oakland, CA 94605-0381
Barbara Vincent
2500 Lowell Ave.
Richmond, CA 94804
RESOLUTION NO.96/351