The Joint Administration Committee of the Santa Margarita and San Luis Rey Watershed Planning Agencies was designated as the agency to conduct studies leading to the development of a comprehensive water-quality management plan for the two watersheds. Hydrologic and salt balances for the Pauma, Pala, Bonsall, and Mission ground-water basins in the San Luis Rey River valley needed to develop the plan were difficult to compute because of the lack of data.
Hydrologic models constructed and verified for 1958-72 for Pauma and Pala basins and for 1946-72 for Bonsall and Mission basins were beneficial in developing the hydrologic balances. Inflow and outflow to the basins used in model verification were consistent with known physical and hydrologic characteristics of the basins.