Granite Reef (Hayden-Rhodes) Aqueduct

The Granite Reef Aqueduct is a feature of the Central Arizona Project designed to bring Colorado River water into the interior of the state. It consists of 173.9 miles of open, concrete-lined canal, seven major siphons, three tunnels, and three pumping plants. A transmission system links the pumping plants (Bouse Hills, Little Harquahala Mountains, and Hassayampa) to power provided through lines running to Boulder City, Nevada. Construction of the transmission system included the Harcuvar substation in La Paz County and a tap station, the Hassayampa Tap, in Maricopa County.The Granite Reef system is divided into units, or reaches, which facilitated the organization and administration of the various construction phases of the project.

The Granite Reef (Hayden-Rhodes) Aqueduct project provided the unprecedented opportunity for an extended, large-scale archaeological study of the little known desert region of western Arizona. Over a period of five years, data were collected and analyzed from an area exceeding 13,500 hectares (34,000 acres) in size. The project was organized around a series of data recovery tasks and problem oriented analyses which were guided by a consistent, explicit research orientation.

Archaeological investigations of the Granite Reef Aqueduct and Transmission System (GRATS) were initiated in 1968, the year in which construction of the Central Arizona Project was authorized by the Colorado River Basin Act (P.L. 90-537). Two feasibility alignment surveys (Euler 1968; Dittert, Fish and Simonis 1969) provided data for the general programmatic environmental statements for the Central Arizona Project (U.S. Bureau of Reclamation 1972). Subsequently more feature specific environmental statements were prepared for various parts of GRATS (U.S. Bureau of Reclamation 1973, 1974, 1975) incorporating more detailed archaeological studies (Bair 1974; Bondley and Brooks 1973; Grady 1973; Kemrer, Schultz and Dodge 1972; Renk 1972). As a direct result of the feasibility alignment surveys, further archaeological investigations were carried out as part of mitigation proceedings for three Granite Reef construction features at the time construction was initiated (Larson and others 1976; Reynolds 1974;Rodgers 1977).

As final construction specifications for the Granite Reef project were developed, substantial portions of the aqueduct and transmission line routes were realigned and numerous features were added. Because the actual area affected by the construction differed significantly from the original feasibility alignment, a "resurvey" of virtually the entire project area was required. The "resurveys" were begun in February 1976. Six construction units were investigated individually in two phases, survey and mitigation. A final report was produced for each phase: Reach 5A (Brown 1976d, 1976~1, Reach 5 borrow area (Brown 1976a, 1976b), Reach 6 (Antieau 19771, Reach 9 (Brown 1977a, 1977b), Reach 10 (Brown 1976e, 1976f) and the Salt River Siphon (Brown 1978; Brown and Rogge 1980; Rogge 1977).

By the spring of 1977 it was apparent that this segmented approach did not facilitate either the archaeological research or the construction schedule. Therefore a contracting concept was developed which would at once unify and make more efficient the Granite Reef cultural resources study. The "on call" concept was developed by the Bureau of Reclamation to reconcile the requirements of project scheduling, compliance with federal and state regulations governing cultural resources, and current standards of archaeological research. On October 7, 1977 the Granite Reef "on-call" Cultural Resource Contract Number 8-07-32-V0039 was awarded to the Office of Cultural Resource Management, Arizona State University (ASU).

Because it was not possible to specify the extent of the work to be done under the contract, general guidelines were set up for the scheduling of individual cultural resource study tasks which corresponded to specific construction units. Each task was a self contained subunit of the overall project, initiated by the approval of a budget and scheduling proposal and summarized in an interim report.The subdivided structure of the "on-call" cultural resource study facilitated a multistage approach to the investigation.

The first task specified under the contract was the preparation of a general research design which outlined relevant research problems and detailed data recovery and analysis techniques (Brown and Rice 1978). These basic tenets determined the overall direction of the study although the specific emphasis of the research was continually refined.

As data were accumulated, individual problems were redefined and combined into a more integrated approach. The field and laboratory work proceeded in stages with frequent intervals for the evaluation of results and methods. Each segment of the project area was subjected to the same set of uniform, systematic survey procedures. There followed a period of assessment during which the field data were examined to identify general spatial relationships which could define areas for further study. An interim report describing the survey results and outlining recommendations for mitigation was prepared along with the documentation necessary for evaluation by the SHPO and for seeking eligibility determinations for the National Register of Historic Places. Mitigation procedures varied from task to task depending on the specific resources to be studied and were described in brief interim reports.

Following construction of the Granite Reef (Hayden-Rhodes) Aqueduct, Reclamation established a database of archaeological resources within the CAP right-of-way based on the original Class III survey data. An unknown number of these sites were either destroyed by construction or excavation, while others are no longer located within the CAP right-of-way. In 2014, Reclamation began hiring cultural resource management firms to revisit and reevaluate archaeological resources located within its right-of-way and obtain up to date data on site eligibility and condition.