In November, Fish Agencies made a presentation to a group of non-governmental organizations (NGOs) outlining how the Bay Delta Conservation Plan (BDCP) could be operated to benefit fish. However, the study they presented hasn’t gotten much publicity. That’s probably because it would be very difficult to operate BDCP to actually benefit fish.
The Fish Agencies – U.S. Fish and Wildlife Service (USFWS); National Marine Fisheries Service (NMFS), which is part of the National Oceanic and Atmospheric Administration (NOAA); and the California Department of Fish and Game (DFG) – developed water flow and storage operational criteria that would contribute to recovery of seven species: winter run Chinook, fall run Chinook, spring run Chinook, delta smelt, longfin smelt, white and green sturgeon, and San Joaquin salmonids. They tried different balances of operating criteria and ended up with one referred to as Combined Species 5, or CS5, that provided the best results for fish.
Then they looked at three ways of operating the system to achieve those results:
- Curtailing state and federal water exports from the Delta without changing operation of Folsom, Shasta, Trinity, or Oroville dams.
- Limiting Delta exports and operating the Central Valley Project (CVP) facilities (Folsom, Shasta, and Trinity) differently.
- Operating the CVP facilities plus the State Water Project’s (SWP) Oroville Dam differently, integrating operations between the state and federal projects.
What the Fish Agencies found is that the proposal for Peripheral Tunnels with 3 intakes and 9000 cfs capacity meets MOST CS5 flow targets for avoiding entrainment of fish in the south Delta and for adequate fall and summer outflow for delta smelt habitat.
ALL CS5 targets EXCEPT spring outflow can be achieved by modifying exports in the Delta; it wouldn’t be necessary to make many changes in operating dam storage upstream.
However, spring outflow targets CANNOT be fully achieved unless upstream dams are operated differently.
Two scenarios would allow BDCP to partially meet spring outflow targets. A “capped” scenario would protect upstream storage conditions and synchronize tributary inflow and releases. An “uncapped” scenario would involve a very different operation of Oroville Dam and some changes in operation of Folsom and Trinity reservoirs for large releases of spring flows.
Operating Oroville differently would put at risk recreational resources, water delivery, and hydropower, as well as summer and fall flows for sturgeon.
At the BDCP public meeting in November, Resources Secretary Jerry Meral said that neither Shasta nor Oroville dam is part of the BDCP planning area. But the Fish Agencies’ report suggests that upstream storage facilities would have to be operated differently to meet the goals for species recovery under BDCP.
All the CS5 alternatives involve average annual exports below 4.7 million acre feet per year – a step in the right direction but still too high.
This document assumes that only Peripheral Tunnels are used to meet the criteria that will allow fish take permits. The Department of Water Resources (DWR) didn’t ask the Fish Agencies that did this study to consider whether conditions for fish could be improved with some modification of exports but no tunnels.
Based on this modeling, the Fish Agencies say the proposed operations are ready for a draft Environmental Impact Statement (EIS) under the National Environmental Policy Act (NEPA). Project operations include a Decision Tree to evaluate the effectiveness of spring and fall Delta outflow criteria. According to the Fish Agencies’ summary, “Based on the result of these evaluation, the proposed delta outflow criteria may be refined over the next 10-15 years (between permit issuance and operation of a new north delta facility).”
Translation: Federal and state permitting agencies have given DWR a scenario that comes as close as they can get to what BDCP wants in order to break ground for tunnels.
But even then, NMFS disagrees with DWR “on the underlying science and necessity of including certain additional operational criteria” for the proposed tunnels. “Specifically, NMFS recommended inclusion of spring bypass flow criteria, green sturgeon outflow criteria, and addition South delta criteria . . . in December through June” (all included in a version of CS5 from earlier this year); NMFS suggested these additional criteria may be necessary permit terms for the initial operations.