State Water Resources Control Board releases draft San Joaquin River flow and southern Delta salinity objectives for public comment

As part of the update to the 2006 Bay-Delta Water Quality Control Plan, the State Water Resources Control Board (State Water Board) is considering amendments that will establish new flow objectives for three eastside tributaries of the Lower San Joaquin River to better protect fish & wildlife beneficial uses, as well as establish new water quality objectives to protect agricultural beneficial uses in the southern Delta.  The proposal and supporting documents are now posted online and open for written public comment through March 5, 2013.


The Bay-Delta Plan, last updated in 2006, identifies beneficial uses of water in the Delta, sets water quality objectives for those uses, and determines a program of implementation for achieving those objectives.  In updating the Plan, the Board will attempt to balance the competing uses of water by determining what flows are necessary to protect public trust uses, including fish and wildlife, while also considering the public interest in drinking water, hydropower, agriculture and other uses.  The Plan will be implemented by subsequent water rights decisions and water quality certifications for hydropower facilities that are subject to FERC relicensing.  When implemented, the Plan will determine the amount and timing of water entering and moving through the Delta.

This update of the Bay-Delta Plan takes on particular importance as the Delta Reform Act of 2009 requires the State Water Board to develop flow criteria for the Delta ecosystem before any change in the point of diversion is approved for the Bay Delta Conservation Plan. Additionally, the Delta Stewardship Council directs the State Water Board in the final draft Delta Plan Policy ER P1 to adopt and implement updated Delta flow objectives necessary to achieve the coequal goals by June of 2014.

The State Water Board is conducting the update to the Plan in two phases. This first phase, initiated in 2009, updates flow objectives to protect fish and wildlife in the San Joaquin River and its salmon bearing tributaries, as well as updating salinity objectives to protect agriculture in the Southern Delta. The second phase, initiated last year, will address the remainder of the Bay-Delta Plan, including Delta outflow and export objectives, and is expected to be completed in 2014:  “The timing of phase II ensures that the substantial body of information on Delta outflow, exports, and habitat needs developed through the Bay-Delta Conservation Plan process will be fully considered in the State Water Resources Control Board Bay-Delta Plan update.” (SWRCB Fact Sheet, p.1)

A Substitute Environmental Document (SED) for this first phase of the update has been prepared in lieu of an Environmental Impact Report (EIR), which fulfills both CEQA requirements and State Water Board regulations to analyze the environmental and economic effects of the proposed actions.  (Why an SED and not an EIR? See SED, Executive Summary, pg 9)


The State Water Board’s preferred alternative proposes narrative flow objectives to support and maintain salmon populations migrating through the Delta by establishing flow requirements from February through June that are 35 percent of unimpaired flow for three salmon-producing tributaries of the San Joaquin River – the Merced, Stanislaus, and Tuolomne rivers.

Unimpaired flow is defined as “the flow that would occur if all runoff from the watershed remained in the river, without storage in reservoirs or diversions, such as irrigation, power generation, or water supply.”  The draft SED relies on recent scientific studies that have concluded that higher and more variable flow regimes are needed in salmon-bearing tributaries to protect migrating fish through the Delta, and by establishing a flow objective as a percentage of unimpaired flows, a more natural flow pattern can be approximated.  The proposal also encourages adaptive management in order to respond to evolving scientific information, as well as to allow for integration with other regulatory processes.

Unimpaired flow is also a straightforward means to balance the competing uses of water, states the SED:  “The 35% unimpaired flow proposal strikes a balance between providing water for the protection of fish and other competing uses of water, including agriculture and hydropower generation.” (SED, Executive Summary, pages 9-10).

Currently, median flows in some of the tributaries are less than 35% of unimpaired flow more than half the time, so implementing this proposal would require increased flows. The impact analysis has determined that the preferred alternative would generally increase mean annual river flows relative to baseline conditions in the spring months, which would improve conditions for fish and wildlife beneficial uses.  The impact analysis also determined that “this increase in flow would be expected to reduce the average total annual quantity of water available for diversion on all three tributaries by 181 thousand acre-feet (TAF) per year, representing a 9 percent reduction in average annual diversions and a significant impact. There may also be significant impacts on groundwater and other resources associated with any increase in pumping in response to such reduced surface water diversions.” (SED, Executive Summary, pg. 56)

However, just where those increased flows will come from remains to be seen.  The SED states “This update of the Bay-Delta Plan, describe the actions needed to protect the Bay-Delta ecosystem, does not affect the water rights of anyone, either within or outside the Delta.  Any changes to water rights that may be needed to implement the plan will be considered in future proceedings.” (SED, Executive Summary, pg 9).


Also as part of the update, the State Water Board is proposing new numeric objectives for salinity standards to protect agricultural beneficial uses in the south Delta.  The goal of the southern Delta salinity objectives is to place responsibility for meeting objectives on the U.S. Bureau of Reclamation, the Department of Water Resources and others, depending upon their contribution to southern Delta salinity impairments.  Salinity conditions in the South Delta are affected by numerous factors, including low flows, salts imported from San Joaquin River flows, municipal discharges, poor circulation, water diversions, and agricultural drainage.


A Substitute Environmental Document (SED) has been prepared in lieu of an Environmental Impact Report. The SED evaluates a number of different alternatives for consideration by the State Water Board, including analyzing a range of flows from 20 to 60 percent; in making its final decision, the Board could select an alternative of unimpaired flow within this range.  Any changes to the Bay-Delta Plan must be adopted by the State Water Board and approved by the Office of Administrative Law.

To view the documents, click here.  Written public comments on the draft revised objectives, program of implementation, and the draft SED are due by March 5, 2013, with a workshop following on March 20, 2013.  The draft final objectives and SED is expected to be released in May, with the Board considering adoption in August of 2013.





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