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GIS Files and Maps for the Watershed Management Programs

The map below depicts the proposed watershed management program/enhanced watershed management program groups to date. This map is important in that in shows the extent of the Los Angeles Region that will be potentially addressed by a watershed management program/enhanced watershed management program.

The Los Angeles County MS4 Permit requires permittees to monitor their outfalls and/or alternative access points such as manholes or channels in their jurisdictional boundary. In selecting the outfalls for storm water monitoring, the Permit requires permittees to consider using representative data by monitoring at least one major otufall per subwatershed (HUC 12) drainage area within their jursdiction or use altenate approaches as listed in a Regional Board approved integrated monitoring plan or coordinated integrated monitoring plan. The County of Los Angeles has proposed the use of an altenative method to delineate the subwatersheds (proposed HUC-12 equivalents). The new proposed method yields a map of HUC-12 subwatersheds that is based on the most recent elevation data available. The Regional Board is open to comments from the public in the use of this proposed method.

If you have any questions about the map above or the proposed HUC-12 Equivalents please contact Jun Zhu, the Regional Board GIS Coordinator at (213) 576-6692 or TJ Moon of Los Angeles County Public Works at (626) 458-4380.


Program Supervisor
Ivar Ridgeway
(213) 620-2150
Senior Environmental Scientist (Supervisor)