Power plants require lots of water for cooling. Where will the water for STP 3 and 4 come from?
Cooling water for all STP units (existing and proposed) comes from the plant’s 7,000-acre reservoir (encompassing 11 square miles of surface area). The embankment around the reservoir is 14 miles long, and the average water depth is 45 feet. The approximate volume is 200,000-acre feet. The reservoir and associated environs provide a protected habitat for many species of fish and birds, as well as alligators. Make-up water for the reservoir comes from the nearby Colorado River, about 10 miles from the Gulf of Mexico. This is a coastal area that receives more rainfall each year than we get in San Antonio. Pumping from the river into the plant reservoir is only necessary to make up for water losses such as evaporation. It is done only during periods of high water flow, so no downstream needs such as freshwater flow into bays and estuaries are affected. The 12,200-acre STP site originally was designed for four generating units, and the existing cooling reservoir can easily accommodate the
