The Central Coast Regional Water Quality Control Board (Central Coast Water Board) adopted Resolution No. R3-2016-0003 on July 14, 2017, amending the Water Quality Control Plan for the Central Coast Region (Basin Plan). The State Water Resources Control Board approved the amendment under Resolution No. 2018-0013 on March 6, 2018. TMDLs are a requirement of the federal Clean Water Act. Waterbodies assigned TMDLs by this action include the Alisal Creek, Alisal Slough, Blanco Drain, Chualar Creek, Espinosa Slough, Gabilan Creek, Merritt Ditch, Natividad Creek, Old Salinas River, Quail Creek, Reclamation Canal, Salinas River (Lower), Tembladero Slough, and other tributary surface waterbodies as identified in the Basin Plan amendment.

The Central Coast Water Board's goal for establishing TMDLs in the Lower Salinas River watershed is to rectify water quality impairments related to toxicity and pesticides. The impairments are based on surface waters not meeting the Basin Plan narrative water quality objectives for toxicity and pesticides. Resolution No. R3-2016-0003 establishes total maximum daily loads (TMDLs), numeric targets, and an implementation plan for sediment toxicity and pyrethroid pesticides in sediment in the lower Salinas River watershed.

Responsibility for achieving pollutant load reductions falls upon several entities as described in Attachment A to Resolution No. R3-2016-0003 (Basin Plan amendment). The Central Coast Water Board is relying on existing regulatory measures (i.e., the Agricultural Order and stormwater permits) to ensure implementation actions are carried out by implementing parties, as well as utilizing a Management Agency Agreement and pesticide management plan between the California Department of Pesticide Regulation, the State Water Resources Control Board, and the Central Coast Water Board to address impairments.

Milestones are established for achieving the TMDLs and the Central Coast Water Board will track progress towards achieving the TMDLs through review of implementation actions and monitoring conducted by the implementing parties If existing efforts are not expected to achieve the TMDLs as scheduled, the Executive Officer or the Water Board may require changes to existing monitoring, reporting, or implementation efforts pursuant to California Water Code Sections 13263, 13267 or 13383.