ITEM: |
CONSENT CALENDAR |
||||
|
|||||
2. |
Consider Expenditure of
Budgeted Funds for Preparation of Water Intake Study for the Sleepy Hollow
Steelhead Rearing Facility |
||||
|
|||||
Meeting
Date: |
May 21, 2009 |
Budgeted: |
Yes |
||
|
|||||
From: |
General
Manager |
Program/ Line Item No: |
Aquatic Resources/ Fisheries – 2-3-1 F |
||
|
|||||
Prepared
By: |
|
Cost
Estimate: |
$22,000 |
||
|
|||||
General Counsel Approval: N/A |
|||||
Committee Recommendation: The Administrative Committee considered this item on May 13, 2009 and recommended approval. |
|||||
CEQA Compliance: N/A |
|||||
SUMMARY: At
their December 16, 2002 meeting, the Board authorized funds for a sole source, design
and build contract with List Engineering Company to retrofit the SHSRF raw
water intakes to withstand expected increases in sedimentation resulting from
the impending annual draw down of water levels in the reservoir formed by San
Clemente Dam (SCD). These annual actions
were mandated to enhance the earthquake safety of the dam, by the California
Department of Water Resources, Division of Safety of Dams. Due to the cost of the preferred option
identified in the List Engineering report of February 14, 2003, the Board
decided at its February 27, 2003 meeting to proceed with only an Interim
Retrofit Project, at a lesser cost than the full preferred option. Since that time, three major events have
occurred that could affect the selection of a preferred option to permanently
retrofit the SHSRF raw water intakes to make them more reliable, and resistant
to sediment entrained into the facility.
First, California American Water (CAW) has completed an EIR/EIS (January
2008) for the buttressing or removal of SCD, which included significant
additional analyses of the probable coarse sediment loads that would occur
downstream of SCD under either a dam removal/Carmel River channel rerouting
option or an option to buttress and retain the dam. Second, the Basin Complex Fire occurred in
the summer of 2008, significantly altering the vegetative cover of
approximately 20% of the Carmel River Watershed. The California Department of Forestry and
Fire Protection, assisted by the U.S. Forest Service, produced two reports
analyzing the probable increases in fine sediment loads that could occur
annually in the
RECOMMENDATION: Staff recommends that the District Board authorize expenditure of budgeted funds not to exceed $22,000 in Fiscal Year 2008-2009 for a contract with List Engineering Company to review and revise their February 14, 2003 report. Their revision should be based on the attached list of thirteen factors (Exhibit 2-A) which should be considered in either re-confirming the original preferred option to retrofit the SHSRF raw water intakes, or in selecting a new one. Staff will proceed with securing a proposal from List Engineering to complete this work if approved.
BACKGROUND: While
the District has existing conceptual plans to upgrade the water intakes to the
SHSRF, in the form of the February 14, 2003, List Engineering report, those plans
were only to solve coarse sediment or suspended bed load problems that
threatened the intake pumps in the coming years, due to the annual draw down of
the reservoir formed by San Clemente Dam.
The probable increase in coarse sediment originally anticipated in 2003
was due to the anticipated loss of sediment trapping capacity at San Clemente
Reservoir, as the reservoir filled in.
Additionally, coarse sediment loads reaching the SHSRF will worsen under
either primary option identified in CAW’s 2008 EIR/EIS for the San Clemente Dam
Seismic Safety Project. Either dam
removal or sluicing of accumulated sediments from a buttressed dam will
negatively affect the reliability of the SHSRF intakes. If coarse sediment loads increase as
expected, they could lead to the rapid failure of both primary intake pumps in
any normal operating season. The
original List Engineering plans also do not address the fine suspended
sediments that are expected to be generated in the near term as an aftermath of
the Basin Complex Fire, until the watershed re-vegetates and the fire damaged
soils stabilize. Fisheries staff believe
that there is a potential for up to an order of magnitude increase in the
amount of fine suspended sediment normally observed in SHSRF intake waters in
recent winters, which could make operation of the SHSRF untenable during any
large storm, and for weeks after most winter storms. The water could become so murky, with
literally zero visibility, that the fish will not be able to feed, and staff
will not be able to see them while attempting to net them out of the rearing
channel. This level of suspended
sediment also reduces the ability of the fish to breath and so irritates their
gills that some will likely try to jump out of the rearing channel. The suspended sediment load may also be so
great as to interfere with staff’s backpack electrofisher, which is the method
used on the last pass to capture the remaining fish. It takes two to three weeks for five-person
crews to remove fish from the 800-feet long rearing channel, and yet the pumps
could fail at any time under such an extreme sediment load, which could result
in a near complete loss of any fish remaining in the rearing channel.
IMPACT TO STAFF/RESOURCES: Managing this contract and report revision will take a moderate amount of the Senior Fisheries Biologists’ time as project manager. Funds have also been requested for Fiscal Year 2009-2010 to complete this proposed contract, if all the billable work cannot be completed by June 2009.
EXHIBITS
2-A Scope of Work for a Revision of the 2003
List Engineering Report on the “Sleepy Hollow Steelhead Rearing Facility
(SHSRF) Sediment Control and Intake Retrofit”.
U:\staff\word\boardpacket\2009\20090521\ConsentCal\02\item2.doc