A Water Quality Improvement Approach for the San Joaquin River Basin

The Lower San Joaquin River in the San Joaquin Valley of California is listed on the Federal Clean Water Act (CWA) 303 (d) list as impaired for elevated levels of salinity and boron. Additionally, the Lower San Joaquin River (LSJR) and southern portion of the Sacramento-San Joaquin Delta is listed for low levels of dissolved oxygen. These listings are but two of many recognized water management problems on the San Joaquin River, two of which where regulatory action was being actively pursued. It was recognized by many interested parties along the River that traditional TMDL type, load-based solution being pursued by regulatory authorities would be practically limited and potentially counterproductive. Therefore water interests having a stake the method of solution, set about to develop an alternative implementation plan that would integrate multiple solutions to achieve the water quality objectives. Over an 18-month period the San Joaquin River Water Quality Management Group (Group) identified and evaluated potential actions and scenarios to address constituents and mechanisms contributing to the salinity, boron and dissolved oxygen levels. The outcome of the Group deliberations is a suite of tools/actions to modify flow, address the physical changes and reduce or manage loads, which once implemented, in an integrated manner will improve water quality of the river. The actions will assure the achievement of water quality standards for salinity and significantly improve performance toward achievement of standards for dissolved oxygen. The process of developing the recommendations and the analysis of their expected results will be described in this paper.