At 100°F temperature, 3000 acre/feet or 131,000,000 gallons/day evaporate from Amistad Reservoir. Amistad National Recreation Area was established on November 28, 1990. Amistad National Recreation Area consists of 57,292 acres. Amistad National Recreation Area has 17,820 land acres when the reservoir is at conservation pool level of 1117 feet.br>