Santa Ana Dam on Algodones Ditch near Santa Ana Pueblo, NM

Santa-Ana-Pueblo-SealSanta Ana Dam had been classified as a high hazard dam, under the USBR’s Safety of Dams (SOD) criteria. The dam breach analysis indicated that there would be significant property damage and a reasonable likelihood that loss of life might occur. This earth fill dam did not meet current criteria for seismic stability, and seepage was evident at the base of the dam whenever water collected in the upstream pool. The Pueblo of Santa Ana elected to take the least costly option: functionally breaching the dam by creating an armored notch in the embankment. Riverbend’s engineers analyzed the hydraulic capacity of the dam, the hydrologic response of the watershed, and the size of the breach notch that would be required to reduce the dame hazard classification. Riverbend’s engineers also performed the dam breach analysis, and developed the flood inundation mapping for the affected areas downstream.