The Rio Grande Compact signed in 1938 (between New Mexico, Colorado, and Texas) included the idea that a trans-mountain diversion could bring water from the San Juan River in to the Rio Grande Basin. With consideration of the ‘Winters Doctrine’, the Navajo people have rights to a sizable claim of water in the San Juan River. To support a delivery system to the Navajo Nation, the State of New Mexico insisted upon a non-Indian joint project that would be known as the San Juan-Chama Diversion under the Rio Grande Compact. The project diverts 100,000 acre-feet of water from the San Juan River (portion of the Navajo Nation’s sizable claim) to the Rio Grande Basin. In 1957, the Navajo Tribal Council approved the reduction of their claim to the water for the San Juan-Chama Diversion. In exchange, the Federal government guaranteed a system to deliver 508,000 acre-feet of water on an annual basis to 110,630 acres of farm land.
After 10 years of negotiation, ‘Public Law 87-483, Navajo Indian Irrigation and San Juan-Chama Projects’ was agreed upon and signed by the United States, State of New Mexico, and the Navajo Nation to authorize:
- NIIP: develop and provide a delivery system to 110,630 acres of farmland to the Navajo Nation.
- San Juan-Chama Diversion Project: develop conveyance to transfer approximately 100,000 acre-feet of San Juan River Basin Water annually to Rio Grande Basin.
NIIP began in 1964. The Bureau of Indian Affairs (BIA) is responsible for construction and operations & maintenance of the irrigation delivery system until project completion. The BIA contracts the Bureau of Reclamation (BOR) to plan, design and construct the NIIP infrastructure through the MOU of 1962. The BIA’s responsibility also includes the participation in the San Juan River Endangered Species Recovery Implementation Program that concern federal actions related to NIIP construction and operation.