An assessment of the water resources of the Sabana Seca to Vega Baja was made from 1978-80 in cooperation with the Puerto Rico Department of Agriculture. The area is under intense agricultural development with plans for eventual planting of nearly 10,000 acres in rice. The geology of the area consists of a sequence of limestone formation overlain by alluvium and blanket-sand deposits. The surficial deposits and the Aymamon and Aguada Limestones form a water-table aquifer, which supplies most of

more »

... the water in the area. The alluvial valleys of Rio de la Plata and Rio Cibuco, the two principal streams, comprise 50 percent of the area. Karst solution features are abundant to the south, with lagoons, marshes, and swamps adjacent to the coast. ABSTRACT (Continued) The quality of ground water varies from excellent to very poor. Water from shallow wells tapping the limestone and alluvial aquifers is mostly of a calcium-bicarbonate type, with dissolved-solids concentrations ranging from 250 to 350 milligrams per liter. The water is suitable for most uses. Seawater intrusion is a major problem toward the coast due to the cavernous nature of the limestone aquifer. In the vicinity of Highway 2, near the southern boundary of the study area, the depth to the fresh-salt water mixing zone is about 210 feet, Overpumping of wells in the Campanilla area has resulted in sea-water encroachment into the aquifer. Although abundant water supplies are available in the study area, better management practices are essential to optimize their use and prevent further sea-water encroachment. MILES J 3 KILOMETERS