A Review of Delta Fish Population Losses from Pumping Operations in the Sacramento-San Joaquin River Delta Prepared by Larry Walker Associates January 2010 0 REPORT OVERVIEW determined that despite the creation of fish “protection” facilities, the vast majority of juvenile Chinook Salmon (63% to 99%) and An Examination of delta smelt (up to 99%) that are “entrained” Causes and Mitigation of near major water project facilities in the South Delta do not survive. Delta Fish Loss From The Clifton Court Forebay (CCF) is a Pumping Operations regulating reservoir located between the The issues facing the Sacramento-San Delta and the SWP intake. CCF helps water Joaquin Delta are serious and complex. project operators control water level and Although the challenge of how to restore the water velocity at the screens. CCF also has Delta ecosystem and its fish populations become a convenient feeding ground for a while improving water supply reliability has large number of predators that include fish taken center stage recently, it is not a new and birds. A recent 2009 study of delta issue. For more than 30 years researchers smelt found that as many as 94% to 99% of have documented the significant direct the smelt introduced into the CCF were impacts the south Delta water project eaten by predators. These are referred to as operations have on Delta fish and their “pre-screen” losses. habitat. At the same time, the amount of water pumped from the Delta through the The SWP and the CVP have fish protection Central Valley Project (CVP) and the State facilities that try to collect the fish before Water Project (SWP) doubled from 1991 to they reach the Delta pumps. Fish louvers 2005 as illustrated in the December 2009 are placed in front of the pumps to prevent report by the Public Policy Institute of fish from entering the pumps, but are not California called “California Water Myths.” completely effective. A 1996 report by the California Department of Water Resources The recent collapse of Delta fish populations (DWR) and the California Department of creates the need for immediate and renewed Fish and Game (DFG) cited studies action to reduce fish losses in and around the performed by the departments in 1970-71 water project facilities. Many questions that determined the screens may allow as remain and more research is necessary to many as 30% of fish which enter the fish fully examine the numerous issues facing protection facilities to reach the pumps. the Delta. However, there is a significant amount of data – which this paper Fish are collected in the fish protection summarizes – that should not be overlooked. facilities so they can be “salvaged.” From the collection area they are placed in holding tanks, then loaded into tank trucks, driven to Significant Fish Losses specific locations in the Delta, and Documented at Delta discharged from the trucks through pipes that extend out into Delta waters. Water Pump Operations For More Than 30 years In a 2009 Biological Opinion, National From 1976 to 2009, numerous research Marine Fisheries Service (NMFS) reports studies by credible Delta experts have there is typically debris in the holding tanks 1 along with the fish, which can disorient, facility at the SWP. These salvage statistics injure and kill fish due to turbulent forces in greatly understate the total number of fish the pipeline when the fish are released. entrained, since they do not include the number of fish lost to predators or lost NMFS anticipates that 10% to 30% of through the fish screens. In fact, recent salvaged fish are lost to predators at the estimates indicate that 5-10 times more fish Delta release sites and that an additional are lost than are salvaged, largely due to the number die after release due to stress or high predation losses in and around water injury associated with the handling process. project facilities. A 1996 report by DWR and DFG concluded In 2008, Wim Kimmerer, a prominent that for every salmon salvaged at the fish ecologist and Delta researcher, estimated protection facilities, more than three are lost that approximately 30 times more delta to predators or are lost through the fish smelt are entrained than are salvaged. screens. The report stated that these loss rates “demonstrate a serious problem.” In 2008, United State Fish and Wildlife Service (USFWS) also reported that high The same 1996 report stated that over a 15- entrainment rates during winter months are year period (1979 to 1993), 110 million fish suspected as a contributing cause of the were reported to have been salvaged at early 1980s delta smelt decline and the Skinner Fish Facility, the fish protection pelagic organism decline or “POD.” The POD refers to the record low numbers of four species of fish that occupy the open waters of the upper San Francisco Bay estuary. Fish entering Clifton Court Despite Substantial Forebay Losses and History of Recommendations to Mitigate, Little Has Been Done to Affect Change 25% The 1996 DWR/DFG study made a number 75% are lost reach of recommendations to mitigate documented to predation salvage in Forebay facility Of those 25%... Graphical • An additional 1-12% are lost during Depiction handling and trucking operations • Estimated 10-30% due to post-release of Loss/Survival Rate 20-30% predation of loss at • Overall loss of 12-32% of salvaged fish salvage Only approximately 11-18% Entrained Fish facility 70-80% louvers salvaged of all entrained fish survive 2 fish losses such as replacing existing fish Prior to that work, most efforts have sought screens, reducing the number of salmon to assess the effects of project operations or entering the CCF and encountering the export volumes through correlation screens, and moving the intake for the analyses. Such analyses have limitations California aqueduct. Little or no action was and are greatly affected by the study period taken to implement these suggestions. selected and other assumptions. In 2000 the CALFED Record of Decision There is a lack of data to fully quantify the highlighted the need to improve the fish impact that the ongoing fish mortality in and screens at the South Delta pumps. Although around the south Delta pumps is having on these improvements were to be in operation total fish populations. by2006, they remain on hold. Also absent is a strong analysis of “indirect” Now underway is the Bay Delta fish losses associated with hydrodynamic Conservation Plan (BDCP), an effort and habitat changes brought by south Delta intended to allow the water exporters to pumping operations. obtain another incidental take permit for fish losses associated with their operations. A Call to Action While the BDCP is proposed to serve co- For 30 years scientists and regulatory equal goals of water supply and ecosystem agencies have documented the significant restoration, operational improvement impacts the water export operations have on recommendations to date include a less than Delta fish – and yet little action has been comprehensive predator control program taken to correct the situation. When the and plans to study non-structural barriers to POD signaled the Delta ecosystem is in real prevent fish from entering the CCF and trouble a few years ago, the response was to other areas of the Delta. No measures to shift the blame from the known impacts of improve the south Delta fish screens or the water exports to potential other salvage facilities have emerged. “stressors.” The fish protection facilities at the South Certainly, more research must be done to Delta pumps, including the fish screens and fully understand all of the issues that may be salvage facilities, remain largely unchanged affecting the health of the Delta and what since they were first engineered over 40 action should be taken to address them, but years ago. the comprehensive and integrative research needed to yield sound data on these issues Full Impact of Pumping will take years. In the meantime, immediate Operations Still Must Be action should be taken to mitigate the known and well documented impacts of the water Determined exports on the Delta ecosystem and In 2008, Wim Kimmerer published a paper endangered fish species. Too much is at that demonstrated that fish mortality stake to allow further delay in addressing the associated with project operations can be ongoing fish mortality associated with the causing adverse impacts on the populations water project operations, especially when of these species. the evidence paints such a clear picture. 3 INTRODUCTION Overview of the Delta The Sacramento-San Joaquin River Delta is an inland river delta and estuary in northern California at the western edge of the Central Valley near the confluence of the Sacramento and San Joaquin rivers. It lies east of where the rivers enter Suisun Bay (an upper arm of San Francisco Bay). Water flows from the Sacramento and San Joaquin Valleys to the Delta where it enters a maze of sloughs and waterways leading to the San Francisco Bay. The flow of water in the Delta is directed by an extensive system of levees. The flow Map Source: PPIC Report - Envisioning the Sacramento-San Joaquin patterns through the Delta Delta. are largely determined by: municipal water diverters surrounding and Tidal influences that move salt water in within the Delta itself. The two largest water and out of the Delta daily; export systems are the Central Valley Flows from major rivers that vary Project (CVP) and the State Water Project considerably throughout the year; (SWP). Both systems take water from the Operation of flow control structures on southern part of the Delta and send it to certain waterways in the Delta; and other parts of the state, primarily the south.