 The dam abutments and the spillway leaked considerably until the 1970s, when the Bureau of Reclamation finally took corrective action by installing drainage systems and placing stabilizing fill.The canal head works and diversion tunnel for the Navajo Indian Irrigation Project were started in 1966 and were completed on July 3, 1967; this allowed the commencement of irrigation water deliveries from Navajo Lake, although the main canal was not completed to its full length until 1977.Operations of the irrigation system were transferred to the Bureau of Indian Affairs shortly thereafter.