i19 Stormwater Capture Master Plan LosAngelesDWP Geophysical Polys

The feature dataset contains geophysical properties to analyze where obstacles to infiltration exist and where infiltration would be most desirable. Such properties include areas of mapped landslides or liquefaction potential, depth to groundwater, slope, hydrologic soil group, and geology (pervious or impervious). An aquifer classification system was also developed to guide prioritization. Each aquifer underlying Los Angeles was classified according to the ability of LADWP to pump the aquifer for use in LADWP’s distribution network. Each sub-basin in the LADWP model was assigned a Category A (High), B (Medium), or C (Low) depending on its combination of geophysical obstacles and opportunities and aquifer class. Areas categorized as “A” or “High” were those having the fewest hydrogeologic constraints (i.e. few obstacles to infiltration, highly infiltrative soils, permeable aquifers) and were overlying the highest priority aquifers. These would be most conducive to infiltration BMPs. Category “B” or “Medium” areas were somewhat geologically constrained and overlying mid-level priority aquifers. These areas were also considered suitable for infiltration BMPs. Category “C” or “Low” areas contain obstacles to infiltration and/or were overlying low-priority aquifers, making them more conducive to direct use BMPs.