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:

Darby Fuerst,

Program/

Aquatic Resources/

 

General Manager

Line Item Nos.:

Fisheries

 

Prepared By:

Kevan Urquhart

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

 

 

 

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