About the San Carlos Irrigation Project

SCIP was authorized by an act of Congress in 1924 to provide irrigation water to lands on the Gila River Reservation and certain lands adjacent to the reservation. In 1928, Congress authorized development of electrical power at Coolidge Dam for irrigation purposes and sale of excess power. However, the Dam was damaged by severe flooding in 1983 and has not been operational since. The Bureau of Indian Affairs conducted informal studies to evaluate the re-construction of hydropower generation at Coolidge Dam, but studies show there is an insufficient cost/benefit ratio to justify the re-construction. This is primarily because the run-off in the upper Gila River Basin is not reliable to recoup the costs to re-build hydrogeneration at the Dam.

Today, SCIP employs approximately 100 employees who work to provide electricity to approximately 13,000 residential, commercial, industrial, and government customers in Pinal County and parts of Pima, Maricopa, Graham, and Gila counties. Its service area spans approximately 2,400 square miles and serves agricultural and rural customers in the Lone Butte industrial park area and large residential populations in the San Carlos, Gila River, and Oracle areas.

To provide service to its customers, SCIP receives power at three points: the Lone Butte Substation, the Coolidge Substation and the Oracle Junction Substation. From there, the power is stepped down through 29 smaller substations, 250 miles of transmission facilities, and about 3,000 miles of distribution lines.

Project facilities include:

The Bi-Partisan Infrastructure Law provides San Carlos Irrigation Project-Power $1 million a year for five years for the use of the San Carlos Irrigation Project Power Division. SCIP has so far been allocated $2 million of the anticipated $5 million to update the Thornton Substation which will improve SCIP’s services.

Thornton Substation and Related Facilities: In 2023, a new substation was constructed to serve customers in the Casa Grande, Arizona area. This project involved designing and constructing a new substation and demolition of the older substation. The new substation enhances the reliability of the power grid, reduces downtime and ensures a dependable energy supply is provided with redundancy built into the system. This work also reduced the risk of electrical hazards. Next, SCIP will be connecting the new substation to a transmission line and adding distribution lines to energize more customers in the Casa Grande area. Preliminary work to design the system is underway.

The project was primarily funded by the Bipartisan Infrastructure Law, a cornerstone of the Investing in America agenda. The Law aims to revitalize and modernize the nation’s infrastructure, creating jobs and fostering economic growth. This milestone achievement signifies a step forward in advancing infrastructure, reliability, and safety.

BIA has not made any final decisions about use of the final three years of BIL funding ($3 million). BIA is preparing a five-year strategic plan that will identify steps to increase reliability to all customers, including those on the San Carlos Apache Reservation.

To best serve the needs of the Tribes and other customers, BIA is developing options for the divestiture of SCIP Power Systems. These options include transferring ownership of the on-reservation facilities to the Tribes. BIA seeks to engage with the Tribes, along with private and public electric utilities in Arizona, to assume ownership and responsibility for BIA's off-reservation electric facilities and customers.

This is potentially a major economic development for Tribes or other stakeholders. Transferring ownership to the Tribes, other stakeholders, or private utilities might also lead to greater efficiency and cost-savings for customers.

The success of this initiative will include extensive engagement among the affected Federal, Tribal, and State parties and will most likely require federal legislation.

BIA is required to rely on customer collections, not congressional appropriations, for operation and maintenance.

The BIA does not immediately plan to increase rates again; however, our cost-of-service studies for rate adjustment purposes will consider the estimated costs to address deferred maintenance and capital improvements.

The Bi-Partisan Infrastructure Law provides San Carlos Irrigation Project-Power $1 million a year for five years for the use of the San Carlos Irrigation Project Power Division. SCIP has so far been allocated $2 million of the anticipated $5 million to update the Thorton Substation which will improve SCIP’s services.