The U.S. Bureau of Reclamation (USBR) signed a Finding of No Significant Impact (FONSI) No. 96-01-MP on November 3, 1995 for use of a 28-mile segment of the San Luis Drain (SLD). This segment, known as the Grassland Bypass, will convey agricultural drainage waters from the Grasslands Subarea to the San Joaquin River via a 6 mile segment of Mud Slough (north). An Environmental Assessment (EA) dated April 1991 was prepared in support of the FONSI. A Supplemental EA dated November 1995 updates the 1991 EA, including a discussion of several changes to the previously proposed project as described in the 1991 EA. These changes include a modification of the point of entry to the SLD and an increase in the length of the SLD to be utilized by the project from 19 to 28 miles. An overall map of the area is presented in Figure 1.1.
A Use Agreement (UA) No. 6-07-20-w1319 was signed on November 3, 1995 between USBR and the San Luis & Delta-Mendota Water Authority (SLD-MWA). The UA allows for the use of 28 miles of the SLD for a two year duration. The UA allows for renewal of this interim use for no more than 3 years, if certain conditions are met.
Specifically, renewal is allowed only if the California Regional Water Quality Control Board, Central Valley Region (CVRWQCB) adopts and implements an approvable Basin Plan Amendment/Implementation Plan and has issued a Waste Discharge Requirement, which must be consistent with the recommendations contained in a letter dated November 3, 1995, signed by USBR, U.S. Fish and Wildlife Service (USFWS), U.S. Environmental Protection Agency (USEPA) and the SLD-MWA. Further, renewal is only allowed if the SLD-MWA agrees to specific load limitations contained in the November 3, 1995 consensus letter, and has developed a long term drainage management strategy and plan of implementation consistent with the Basin Plan Amendment. Finally, renewal will be based on an assessment of whether use of the SLD has been consistent with the requirements of the Basin Plan Amendment and the draining parties' approved long-term drainage management plan.
The UA establishes the parameters within which the use of the SLD is allowed. For example, the UA incorporates by reference the load reduction targets included in the November 3, 1995 consensus letter (Table 1.1). The UA establishes a SLD Incentive Fee system by which monetary incentives will be applied to encourage compliance with these load limitations. Exceedence of the annual load targets in excess of 20% will result in closure of the SLD if no acceptable explanation is provided. The UA also incorporates by reference the environmental commitments contained in the FONSI and includes a provision for termination upon a determination that unacceptable adverse environmental effects occur due to the use of the SLD.
These various changes and refinements of the GBP have made necessary certain revisions to an existing monitoring plan, which was finalized after public review in June, 1993. This revised plan incorporates the various changes, including updates of the monitoring stations and sampling and analytical techniques.