The local stakeholders developed a comprehensive series of work plans designed to develop TMDLs to address groups of constituents in the 343 square mile watershed. TMDLs have been completed for three groups of constituents: (1) metals, (2) legacy pesticides, and (3) chlorpyrifos, diazinon and toxicity of unknown causes in water and sediment. The process followed in California appears to be unique in several respects. The purpose of the presentation is to present these unique aspects, with their advantages and disadvantages as experienced with CCW TMDL development, and to relate that experience to urban areas in general.
Stakeholder developed total maximum daily loads
Located in Ventura County California, the Calleguas Creek Watershed (CCW), though relatively small in area, suffers from more water quality impairments than most California watersheds, as defined by the USEPA’s 303(d) list. Local stakeholders, along with the Los Angeles Regional Water Quality Control Board (LARWQCB), began a watershed planning process over eight years ago to develop a better understanding of the watershed and a strategy to address impairments.