ADMINISTRATIVE COMMITTEE |
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1. |
CONSIDER EXPENDITURE OF
BUDGETED FUNDS TO REVISE THE FEBRUARY 2003 LIST ENGINEERING REPORT ON THE “SLEEPY HOLLOW STEELHEAD
REARING FACILITY (SHSRF) SEDIMENT CONTROL AND INTAKE RETROFIT” |
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Meeting
Date: |
May 13, 2009 |
Budgeted: |
Yes |
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From: |
General
Manager |
Program/ Line Item No: |
Aquatic Resources/ Fisheries – 2-3-1 F |
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Prepared
By: |
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Cost
Estimate: |
$22,000 |
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General Counsel Approval: N/A |
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Committee Recommendation: The Administrative Committee considered this item on May 13, 2009 and recommended ____________. |
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CEQA Compliance: N/A |
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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 1-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
1-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\committees\Admin\2009\20090513\01\item1.doc