Predicted effects of a proposed water-resources management plan in the lower San Luis Rey River Valley, California, using digital ground-water flow models

A proposed plan for water-resource management in the lower San Luis Rey River valley, Calif. has been evaluated using digital models of ground-water flow. Two projections of water-level changes and salt balance in 1977 were made. The first projection used 1972 climatic and pumping conditions. The second projection used these same conditions plus a plan of recharging and pumping various areas of the aquifer. The predicted salt balance in 1977 under the proposed plan improved for the Pala, Bonsall, and Mission basins when compared to the predicted 1977 salt balance using 1972 pumpage alone. The plan did not affect the predicted salt balance for the Pauma basin. Under the plan, water levels decreased in the Pala basin and water levels increased in the Bonsall and Mission basins. In addition, an area of potential water logging exists in the Mission basin. The plan did not affect water levels for the Pauma basin. (Woodard-USGS)