Located in Texas, Lake Mexia NR Mexia is a small reservoir built in 1963 by the United States Army Corps of Engineers. The lake's primary purpose is to provide flood control to the surrounding areas, but it also provides recreational opportunities such as fishing, boating, and camping. The hydrology of the lake is fed by two major creeks, Tehuacana Creek and Willow Creek, and several smaller tributaries. The lake's surface flow is mainly used for irrigation of agricultural lands, with cotton being the primary crop. The area also receives snowpack from time to time, which helps to replenish the lake's water levels. The lake has a maximum depth of 40 feet and covers approximately 1,140 acres.