ADMINISTRATIVE
COMMITTEE |
||||
2. |
CONSIDER EXPENDITURE OF FUNDS
FOR EMERGENCY WINTERIZATION OF THE SLEEPY HOLLOW STEELHEAD REARING FACILITY
TO WITHSTAND WINTER STORM SEDIMENT LOAD FROM THE BASIN COMPLEX FIRE |
|||
|
||||
Meeting
Date: |
November 10, 2008 |
Budgeted: |
No |
|
|
||||
From: |
|
Program/ |
Aquatic Resources/ |
|
|
General
Manager |
Line Item
Nos.: |
Fisheries |
|
|
||||
Prepared
By: |
|
Cost
Estimate: |
$36,000 |
|
|
||||
General Counsel Approval: N/A |
||||
Committee Recommendation: The Administrative Committee considered this item on November 10, 2008 and recommended ____________. |
||||
CEQA Compliance: A Notice of Exemption will be filed. |
||||
SUMMARY: The
recent Basin Complex Fire burned most of the Carmel River Watershed above Los
Padres Reservoir, and some of the upper Cachagua Creek Watershed. Reports by experts from the U.S. Forest
Service predict that winter storm flows may be up to three times higher than
normal for a given amount of rainfall, and may carry up to ten times as much
suspended sediment downstream as would normally occur. Without immediate modifications to the Sleepy
Hollow Steelhead Rearing Facility (SHSRF), the Monterey Peninsula Water
Management District (MPWMD) will be unable to hold fish through the first
significant storm in December and will need to release them into the river
early. The suspended sediment levels
anticipated in the Carmel River this winter are likely to cause the intake
pumps to the SHSRF to fail. This failure
would likely result in the loss of the majority of fish being reared in the
facility within about eight hours. Even
if the pumps do not fail, the severe sediment load itself would be harmful to
the fish being reared at the SHSRF, and could cause a significant increase in
mortality.
RECOMMENDATION: Staff recommends that the District Board authorize expenditure of funds up to $36,000 for an emergency project to winterize and protect the SHSRF from potential harmful sediment loads during storm flows. These funds are available in the District’s flood/drought emergency reserves. At this time, the recommended project is to retrofit the SHSRF’s two large circular tanks to be a temporarily recirculating system for up to eight weeks after the first major winter storms.
BACKGROUND: While
the District has existing plans to upgrade the water intakes to the SHSRF,
those plans are designed to solve coarse sediment or suspended bed load
problems that threaten the intake pumps in the coming years. This probable increase in coarse sediment is
due to the anticipated loss of sediment trapping capacity at San Clemente
Reservoir. Those plans do not address
the suspended sediments that are expected to be generated in the near term,
beginning this winter runoff season, until the watershed revegetates and the
fire damaged soils stabilize. Fisheries
staff believe that a potential order of magnitude increase in the amount of
suspended sediment normally observed in SHSRF intake waters in recent winters,
will make operation of the SHSRF untenable during any large storm, and for
weeks after most of this year’s winter storms.
The water will likely be so murky, with 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 fishes’ ability to breath and irritates their gills to the extent that some
will try to jump out of the rearing channel.
The suspended sediment load may also be so great as to interfere with
the District’s backpack electrofisher, which is the method used on the last
pass to capture remaining fish. It takes
two to three weeks for a five-person crew to remove fish from the 800-feet long
rearing channel, and the pumps could fail at any time under an extreme sediment
load, which could result in a near complete loss of any fish remaining in the
rearing channel. As a result, Fisheries
staff have been consulting with representatives of the Natural Resource
Conservation Service, Resource Conservation District of Monterey County, State
Office of Emergency Services, National Marine Fisheries Service (NMFS), and the
California State Department of Fish and Game (CDFG) as to what options should
and could feasibly be pursued. These
discussions have led to three options:
1) Isolate the SHSRF from its river intake, and
turn it into a recirculating system, whereby fish would continue to be reared
in the rearing channel using its static water volume, filtered and
re-circulated back to the headworks using equipment leased from Rain-for-Rent
[initial estimated cost of $23,322.08 for 8 week lease], with electrical work
done by J.M. Electric [estimate pending].
2) Remove the fish from the rearing channel in
early December, release the smallest ones into the river and hold the larger
ones in the two 22-foot and 30-foot circular Tanks #1 and #3, that were part of
the original Facility, but have not been in use in recent years. These tanks would need to be plumbed with
modular aquaculture filtration units, that include U.V. sterilization of the
filtered effluent, before it is returned to the tanks [cost for modular units
of approximately $31,200, not including additional electrical upgrades].
3) Begin releasing all of the 30,000 plus
steelhead being held in the SHSRF, a) as soon as we have any significant
forecast for large winter storms, or b) as soon as Los Padres Reservoir
approaches the level at which it will spill freely and no longer impede
sediment coming downstream, or c) December 1, whichever occurs first.
Option #1: Staff
are still refining this option based on the Rain-for-Rent
bid, and hope to finalize the design by the week of November 10, 2008. If this approach is successful, it could
provide a long term back-up for some of the SHSRF intake upgrades, and the
District could eventually purchase the pipe, pumps, and filter systems
necessary to make the installation permanent.
If the movement of coarse bedload were to threaten or break the normal
intake pumps under a new intake design, then the SHSRF could be taken off line
and run in a recirculating mode, while the intake pumps were pulled for repair
or replaced with stand-by pumps. This
approach allows the rescued fish to continue living in the rearing channel,
while conditions for survival in the river may be very poor. The drawback of this approach is that it
requires balancing the flow of two sets of pumps, wiring them into the existing
facility alarm system, and filtering the large volume of recirculating rearing
channel wastewater, which may slowly accumulate organic toxins and wastes from
the steelhead being reared in it.
Option #2: The
second option of rearing fish in the two large diameter tanks is potentially
more expensive, but is technologically simpler.
Staff does not yet know if the modular filtration units can be shipped
and installed in time before the winter storms.
The District would also own the equipment being purchased versus leasing
it annually. However, there are two
significant drawbacks. The fish face an
extra stage of handling from the rearing channel into the tanks, then back into
the river, versus going directly from the rearing channel to release, and this
will increase SHSRF holding mortality. This approach will also increase unaccounted
for fish losses due to intra-specific predation in the open water of a circular
tank that does not have any escape cover.
So we could only keep two of the largest size classes of fish, and the
rest would still have to be released to the river, so they would not be preyed
upon in the tanks.
Option #3: The
last option is the least costly, but is not congruent with the SHSRF’s
mitigation objectives of holding fish until the lower river habitat they were
rescued from has been re-wetted and allowed to recover for up to 30 days. Fish released early from the SHSRF will
compete for food and space with, and prey on, the smaller fish living in the
river. Despite the recent rain, flow in
the river is still very low at this time, flowing approximately six cubic feet
per second at the USGS Robles Del Rio gaging station. The river front has also not yet advanced
very far downstream from the point it dried back to in the summer. Thus, there are not likely to be enough holding
areas to readily accommodate an additional 30,000 plus steelhead from the
SHSRF, in approximately eight to nine miles of river. This approach might be mitigated by
increasing flows from Los Padres Reservoir to increase habitat volume. Any flow increases will need the concurrence
of California American Water, CDFG, and NMFS and require a thorough evaluation
of their potential impacts to water supply.
The impending winter storm flows are also likely to bring so much
sediment downstream that it could harm significant numbers of the fish holding
in the river, which may be unable to find shelter from the storm flows in
zero-visibility water, and may be harmfully affected if not killed by the
suspended sediment load. Releasing the
SHSRF fish into this environment before they are able to access the ocean could
cause significant mortality to the rescued fish that have been carefully reared
this year, and reduce their contribution to the returning adult run over the
next three to four years.
Risk Analysis: It
is important to consider the qualitative risks of the potential loss of
steelhead productivity in evaluating these three options. The first option of recirculating and
filtering the rearing channel’s flows is the most experimental, and staff are
still in the process of designing it with enough redundant systems and fail
safes to make it as reliable as possible.
It depends on maintaining all of the recirculating volume of the rearing
channel, as we will not be able to replace any losses with river water, as it
will be too sediment-laden to utilize.
We will fill Tank # 3 with approximately 8,950 gallons of water as a
reserve supply. If this system fails, we
would have only about eight hours to get as many fish as possible out of the
rearing channel and into the river, before the dewatering of the channel would
begin stranding fish. The benefit of
this option, is that if it does not fail, the fish are not handled an extra
time versus the second option, and continue to be reared in the environment
they have become used to.
The second option of moving most fish into the 22-foot and 30-foot
circular rearing tanks requires more fish handling than normal, and the fish
being held in the open rearing tanks might be subject to a great deal of
cannibalism. If we can get them to feed
heavily enough, cannibalism may be minimal, but it may take the fish a few days
to as much as few weeks to adjust to a new environment and return to regular
feeding patterns. This option relies on
pre-fabricated filter systems designed for aquaculture and aquarium systems
that are very reliable. If they fail,
the tanks would hold their volume, and staff could release all the fish to the
river in only a couple of days, if needed.
The third option follows normal SHSRF procedures, but occurs weeks
prior to the time we would prefer to release fish. The risk to the steelhead we have reared is
that they may find themselves in crowded, low-flow conditions, prior to the
return of winter storm flows, competing with the natal fish in the river. Then, once the first large storms hit, the
fish may be unable to find refuge from storm flows in the crowded habitat, and
be tumbled down-river in very turbid water.
The severe turbidity and sediment load of this winter’s storms may cause
very high mortalities of any fish in the river, and we would be losing the
mitigation benefit of having reared many of these fish, if they die before
reaching the ocean.
IMPACT TO STAFF/RESOURCES: If the Board wishes to pursue either of these options as a potentially effective approach to keeping the SHSRF running during future winter storms, then funds would need to be authorized for this effort this Fiscal Year. Pursuing these alternatives will take a significant amount of the Associate and Senior Fisheries Biologists’ time as project managers, and will delay the production of the 2007-2008 Annual Mitigation and Monitoring Report by two to three months. If the approach is proven tenable this winter, then funds would be needed in the following Fiscal Years, if the Rain-for-Rent contract is renewed or another equivalent bidder is found. Informal contacts with State and Federal resource agencies responsible for steelhead management indicate that they cannot provide any grant funding to underwrite this effort, but applications have been made to the Federal Emergency Management Agency and the State Office of Emergency Services for funding to offset part or all of these expenses. District staff will continue to pursue such applications for funding as directed by the Board, as a means to offset potential costs to the District for this purpose.
EXHIBITS
2-A Draft Conceptual Diagram of the Plumbing and
Pumps for a Design of a Recirculating Rearing Channel.
2-B Example of a Modular Filtration System for
the Rearing Tanks at the Sleepy Hollow Rearing Facility
U:\staff\word\committees\Admin\2008\20081110\02\item2.doc