2011 in Review: Bay-Delta Fisheries & Water Supplies

2011 was a great year for all of us who care about California’s native fisheries and water supply.  Thankfully, 2011 was a wet year that ended several years of drought, resulting in record water exports from California’s Bay-Delta estuary (enough to cover more than 6.5 million acres with one foot of water).  These record water exports have replenished water supplies for Southern California, leaving the Metropolitan Water District of Southern California with more water in storage than ever before. 

2011 also saw a big rebound in the population estimates for delta smelt, and a pretty good salmon fishing season.  After several years of the salmon fishery being totally or partially closed, it was a relief for fishermen to be able to get back on the water, and NRDC staff took a successful salmon fishing trip out of San Francisco.  Reports of lots of two year old salmon returning to hatcheries at the end of 2011 have fishermen excited by the prospect of even better fishing (and salmon returns) in 2012. 

Despite even wetter conditions in 2006, delta smelt populations didn’t rebound like they did in 2011.  What was the difference?  The California Department of Fish and Game has said that, “The improvement [in delta smelt numbers] is likely due in large part to higher than usual Delta outflow which resulted in more and better habitat.”  These fall outflows (also known as Fall X2) were controversial, but the fall midwater trawl survey seems to vindicate the state and federal biologists who concluded that this action was needed to protect and recover the delta smelt population.  Likewise, the restrictions on pumping by the CVP and SWP limited the numbers of smelt killed at the pumps the last several years (including this year), ensuring that there were some fish left to take advantage of good flows and habitat conditions this year.

While implementing the biological opinions in the Delta had minimal impact on water supplies this year (hence the record water exports from the Delta), the rebound in smelt numbers shows that these scientifically justified protections are working to restore the estuary and its fisheries.  As one newspaper columnist concluded recently, “the arguments made for the cause of the decline of the Delta fishery being water diversions just received a boost from the Delta smelt abundance survey. The extra water that went down our river systems was in large part responsible for the 11-fold increase of the Delta smelt.”  Or, as the Department of Fish and Game was quoted in a recent story about the rebound in smelt numbers, “flow always helps.”  

Of course, not everything is rosy as 2012 begins.  We’ve yet to see a major storm this winter in the Sierras, with very little snowpack providing a worrying reminder that drought could come back any time.  However, thanks to the wet conditions in 2011, California begins 2012 with above average storage levels in upstream reservoirs, and these nearly full reservoirs should help ensure that water allocations for 2012 will result in a surplus of water for Southern California (more than sufficient water to meet demand, according to Metropolitan) and much higher allocations for Central Valley farmers than a few years ago.  Despite the very low snowpack measurements today, DWR is still predicting an adequate water supply next summer thanks to the reservoir storage.  And the winter is still young, so we're all hopeful for more snow and rain in the months ahead.

In addition, although the fall run Chinook salmon population is on the rebound, populations of endangered winter run Chinook salmon collapsed in 2011 to their lowest level in nearly a decade, with operations at Shasta and Keswick Reservoirs  a likely cause of the collapse.  And even with the rebound in the Delta smelt numbers in the fall midwater trawl survey, it is still a small fraction of its historic population and has a long way to go to recover. 

Still, 2012 has demonstrated that providing adequate flows in the Bay-Delta will help restore our native fish populations and the health of the estuary, and that even with reasonable protections in place for the Delta, the state and federal water projects can export a lot of water that can be saved for drier years ahead.  

It’s great to start 2012 with most of our native fisheries in the Delta starting to rebound, with decent water allocations and with a lot of water stored in reservoirs and groundwater basins.  But we all need to use that water wisely, for we never know what this year (or the next year) will bring.