Dams Along the San Antonio River

Dams Along the San Antonio River. . Dams Have Been Built along the San Antonio River since the early 1700s when missionaries and Native Americans diverted water from the river into hand-dug ditches (acequias) to irrigate their crops. A system of dams and ditches assured the survival of San Antonio's missions and surrounding communities throughout the 1700s. After the missions were closed and lands distributed to local residents beginning in the 1790s, the dams and acequias continued to provide water for household and agricultural use. New dams were also built during the 1800s to channel water that powered flour mills and factories., Many dams were swept away by floods, while others were damaged or demolished during the 1900s as part of flood control projects. When the river channel was reconstructed at this location in the late 1950s, the new Espada dam was built to raise the river level, assuring that water still flowed over the original dam and into the acequia. A new structure also replaced the historic San Juan dam nearby to restore water to that mission's acequia on the opposite bank. Today the historic Espada dam is part of the only complete and continually operational Spanish acequia system in the state., Captions , Lower Left: The Spanish colonial Espada dam, built about 1735, channels water into an acequia that flows approximately three-and-a-half miles to Mission Espada. The new Espada dam, completed in the late 1950s, spans the river channel ahead to the left. The historic Espada dam and acequia can be seen nearby. , Courtesy: University of Texas at San Antonio Libraries Special Collections, Lower Middle: The Espada aqueduct, built about 1740, carries the Espada acequia over Piedras Creek. The aqueduct is the only remaining Spanish structure of its type in the United States. The Espada acequia and aqueduct are designated National Historic Landmarks. , Courtesy: Lewis F. Fisher, San Antonio, Lower Right: San Antonio's Spanish colonial acequia system, illustrated on this map, is recognized as a National Civil Engineering Landmark. The system included seven ditches, five dams and an aqueduct, and it irrigated several thousand acres of farm land (labores). , Courtesy: City of San Antonio.