ALVARADO PARK LAKE. Alvarado Park Lake is formed by a dam on Turkey Creek, a tributary of Chambers Creek and the Trinity River, two miles southwest of Alvarado in central Johnson County (at 32°22' N, 97°13' W). The county-owned reservoir was built in 1966 by Jack P. McKinney for floodwater retention, municipal water storage, and recreation. The lake's drainage area is thirty-one square miles, and its capacity is 4,700 acre-feet. The dam is 3,500 feet long and forty-nine feet high and has a crest width of fourteen feet. The top of the dam has an elevation of 704.1 feet, and the normal water level is 691.8 feet.