Stanford officials look to solve Searsville dilemma
Original post made on Jan 18, 2013
Read the full story here Web Link posted Thursday, January 17, 2013, 7:00 PM
on Jan 18, 2013 at 12:28 pm
Is there an opportunity here that, while not solving all the problems identified, goes a long way toward mitigating many of them?
Perhaps the silt should be seen as a resource to be recovered and utilized over the long term rather than as a problem to be gotten rid of all at once. Silt is the type of soil that ever gardener wants, especially in the towns along the bay where impervious clay is the more common soil type. If the silt were dredged and made available to private gardeners and both commercial & civic landscaping services, I expect that we would come to see it as a resource to be valued & utilized rather than the "millions of tons of silt" that need disposing.
Removing it at a rate of 5% to 10% per year would allow Searsville Lake to eventually return to health, providing increasing flood control for the communities below, water for Stanford's irrigation and, perhaps, recreational & educational opportunities for future generations.
Adding a fish ladder to the dam would be the crowning touch as steelhead could once again access the spawning beds upstream from the lake.
on Jan 18, 2013 at 4:03 pm
Any discussion of THE Lake brings back fond memories of our younger days swimming in the lake, diving off of the pontoons in the middle and taking in the rays on the beautiful beach. And of course our days extended into in the evening when we would have early super among the trees. Also, we became very resourceful in our ways of avoiding the toll booth at the gate.
What a shame we no longer have this recreation resource. I see nothing in the report that mentions recreation nor did I hear anything in the fascinating oral report about the dam.
Our conservation arm is lucky that I have no say over the future of the lake, because if it was up to me I would restore it to the recreation use it once was...
on Jan 20, 2013 at 1:38 pm
Hi Brent- I totally understand the desire to restore recreational activity at the reservoir. My dad went to Stanford and took my mom on dates there back in the day. My brothers and I fished it growing up. For better or worse, it will not be reopened for recreation as Stanford has more research studies going on there now than when they closed it to protect the studies.
Hi Steve- I agree with you that there are many uses for the sediment, including many more times the amount in Searsville that is desperately needed for SF Bay wetland restoration efforts and to help combat rising sea levels as this sediment is what builds up those wetlands during high tides.
While fish ladders and fishways are attractive options to consider, more and more studies are showing that these high tech options are not very effective and often cost millions of dollars to build and maintain. Here is a great recent article and study on this problem related to large dam on the east coast with sea-run fish:
In addition to the issues described in the article and other west coast studies, fish ladders are challenging in flashy watersheds like San Francisquito and particularly Corte Madera Creek , where Searsville Dam sits, as relatively high surface flows are needed to properly operate such facilities. Additionally, adult steelhead that do make it above dams and reservoirs to spawn (as well as their numerous downstream migrating offspring) must be trapped as they migrate back downstream to avoid being eaten by the high density of non-native fish in the reservoir and in order for them to safety make it downstream of the dam. Then they need water to swim to the Bay and this is further depleted by the huge evaporation rates from the reservoir and Stanford's diversions at the dam itself. Fortunately, we expect a thorough investigation of these issues and options as Stanford's technical studies progress this year.
Previous Stanford studies have also determined that even if Searsville was dredged to it's original capacity, it's significance on flood protection downstream would be very minimal and potentially on parr with benefits gained by restoring natural wetlands and overflow floodplain areas currently submerged by the reservoir.