Streamflow and endangered species habitat in the lower Isleta reach of the middle Rio Grande

Product Type: Open-file Report

Year: 2008

Author(s): Bovee, K.D., T.J. Waddle, and J.M. Spears

Pages: 177

Suggested Citation: Bovee, K.D., T.J. Waddle, and J.M. Spears. 2008. Streamflow and endangered species habitat in the lower Isleta reach of the middle Rio Grande: U.S. Geological Survey Open-File Report 2008-1323. 177 p.

Abstract

San Acacia Dam is located in a reach of the Rio Grande that has been designated as critical habitat for two endangered species, the Rio Grande silvery minnow (Hybognathus amarus) and the southwestern willow flycatcher (Empidonax traillii extimus). Under present operations, the Rio Grande upstream from the dam is used to convey irrigation water to the Socorro main canal at San Acacia Dam. In order to increase operational flexibility and improve irrigation delivery efficiency, the “Bernardo Siphon” has been proposed to intercept up to 150 cubic feet per second from the Lower San Juan Riverside Drain on the east side of the Rio Grande and transport it under the river into a drainage canal on the west side. Irrigation deliveries to the Socorro main canal would be conveyed by way of the drainage canal rather than the Rio Grande. The objective of this study was to provide the Bureau of Reclamation (BOR) and other stakeholders with a tool to evaluate the effects of different operational modes of the Bernardo siphon on habitat for H. amarus and E. t. extimus in this section of river...