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. . 6. Outlet works repairs should be made to reduce leakage through the gate seals. Deteriorated concrete adjacent to the gates ~ should be replaced. An inspection should be made of the upstream half of the outlet works tunnel to determine its condition. 7. Conclusions and recommendations concerning geotechnical aspects of the dam rehabilitation are presented in the geotechnical report, Appendix D. 8. A dam monitoring program should be instituted immediately to record fluctuations in phreatic water levels and changes in seepage rate at the dam toe. Test wells and inclinometers should be installed so that stability of the north abutment can be monitored. Appropriate storage limits should be established if dam stability problems are found to exist. 9. The SLVID should consider limiting storage in Rio Grande Reser- voir between July 1 and October 31 to 40,000 acre-feet so that the dam can pass the one-half probable maximum flood. This action would remove Rio Grande Dam from the Corps of Engineers' "unsafe" classification. Depending on the results of the water level monitoring program and consultation with the State Engineer, it may be possible to store up to 52,000 acre-feet (reservoir capacity) during times other than the potential flood season. Storage for short durations during the period of July through October may also be possible. 10. A flood warning program should be implemented as soon as possible to minimize or eliminate loss of life due to a large flood or dam fai lure. 11. From an engineering viewpoint, it is recommended that Rio Grande Dam be rehabilitated to pass the probable maximum flood because of the high hazard rating based on potential property damage and probable loss of life. However, the cost of providing this type . -8-