ARIZONA WATER COMMISSION

ANNUAL REPORT 1976-1977 ARIZ ONA DEPT r � WATER RES , OURCES. �l�RARY

CONTENTS LETTER TO THE GOVERNOR ...... ARIZON A WATER COMMISSION...... 2 STATEWIDE WATER PLANNING ...... 4 INTERSTATE WATER PLANN ING ...... 12 SUPERVISION OF SAFETY OF DAMS...... 15

Cover photo courtesy of the Institute of Atmospheric Physics, University of Arizona

ARIZONA DEPT. OF WATER RESOURCES LIBRARY KEL FOX, CH. MEMBERS JOHN L. LEIBER, V. CH. PETER F. BIANCO GLEN G. CURT.IS WESLEY E. STEINER W. N. JACK SHAWVER EXECUTIVE DIRECTOR J. C. WETZLER AND WESLEY BOLIN, GOVE:RNOR WILLIAM H. WHEELER STATE WATER ENGINEER EXOFFICIO MEMBERS VICKIE MOONEY ANDREW L. BETTWY SECRETARY MARSHALL HUMPHREY 222 NORTH CENTRAL AVENUE, SUITE 800 J{ro.euix, J\ri�oritt 85004 TELEPHONE (602) 258-7561 ot"t>· .. ,,q,-47 The Honorable Wesley Bolin w2q/q Governor, State of Arizona and Members of the Legislature Phoenix, AZ 85007

Gentlemen:

Fiscal Year 1977 was a year of significant accomplishment for the Arizona Water Commission.

Phase II of the Arizona State Water Plan, Alternative Futures was published in February. This report presents alternative levels of development and related water use which may occur or be caused to occur in the future. Development of Phase III, which will set forth management plans to meet the water demands associated with each alternative future identifiedin Phase II, is currently underway and will be coordinated with the activities of the newly formed Ground Water Management Study Commission.

The allocation of Arizona's remaining entitlement to Colorado River water remained unresolved for several years pending finalizationby the Secretary of the Interior of a proposed allocation of Central Arizona Project water to the five central Arizona Indian reservations. On October 18, 1976, the Secretary finalized his decision and, following public hearings, the Commission in May finalized its recommended allocation of municipal and industrial water to non-Indian users.

Approximately $94 million were appropriated by the U.S. Congress for construction of various Central Arizona Project featuresduring Fiscal Year 1977. Significant CAP activities in FY 1977 included the awarding of contracts to construct an additional 30.2 miles and line 13.5 miles of the Granite Reef Aqueduct and the completion of the Davis-Parker 230kv transmission line. Fallowing federal review of the CAP the decision was also made, and a task force formed, to investigate alternatives to the proposed Orme Dam and Reservoir.

The State Flood Control Assistance Program provided $468,000 in flood control assistance to local entities during Fiscal Year 1977.

During the year 62 developers' reports were reviewed under the Commission's statutory responsibility to evaluate the adequacy of water supply for new subdivisions. From this review 5 proposed subdivisions were found to have an inadequate water supply.

Activities involving the Commission's safety of dams program included supervising the design and construction of 17 new dams, checking the condition of existing dams, and the investigation of specific jurisdictional problems.

The Arizona Water Commission submits this report of its activities for the Fiscal Year July 1, 1976, to June 30, 1977, in compliance with Section 45-509, of the Arizona Revised Statutes. Sincerely,

� Kel M. Fox Chairman ARIZONA WATER COMMISSION

ORGANIZATION

The Arizona Water Commission is comprised of seven members appointed by the Governor for six-year terms and two ex officio members, the State Land Department Commissioner and Chairman of the Arizona Power Authority.

Kel M. Fox, Coconino County, succeeded William H. Wheeler, Pima County, as Chairman of the Commission and John L. Leiber, Pima County, succeeded Peter Bianco, Pinal County, as Vice Chairman on January 26, 1977. In addition to Mr. Wheeler and Mr. Bianco, continuing Commissioners were Glen G. Curtis, Yuma County; W. N. "Jack" Shawver, Maricopa County; and J. C. Wetzler, Maricopa County.

Staff was headed by Wesley E. Steiner, Executive Director and State Water Engineer. He was aided by Deputy Director, Thomas C. Clark; Supervisor of Safety of Dams, Benson G. Scott; Chief Hydrologist, Philip C. Briggs; Flood Control Chief, William D. Mathews; and Planning Chief, C. Laurence Unser.

Ralph Hunsaker served the Commission as Chief Counsel and Robert Lynch served as Environmental Counsel.

2 THE COMMISSIONERS The Commissioners shown were members of the Arizona Water Commission as of the end of the report year. Andrew L. Bettwy, State Land Commissioner, and Marshall Humphrey, Chairman of the Arizona Power Authority, are ex officio members.

KEL M. FOX JOHN L. LEIBER PETER BIANCO Chairman Vice Chairman

GLEN G. CURTIS W. N. �ACK"SHAWVER J. C. WETZLER

WILLIAM H. WHEELER ANDREW L. BETTWY MARSHALL HUMPHREY

3 STATEWIDE WATER PLANNING

STATE WATER PLAN 4. In the next 50 years irrigated agriculture is forecast to continue to use more water than all other uses Phase II of the Arizona State Water Plan was completed combined even if programs are implemented to and released in April, 1977. The report presents reduce agricultural use to achieve a balance between alternative levels of water use which may occur or which supply and demand. The projected irrigated acreage may be caused to occur in Arizona in the 50-year period in Arizona varies from a low of 727,000 acres to a high from 1970 to 2020. The completion of this report is an of 1,416,000 acres in 2020. This compares to a 1970 important step in the formulation of a water resources acreage of 1,225,000 acres. plan for Arizona. 5. Total dependable water supply available to Arizona is Alternatives developed and shown in the Phase II report expected to increase with development in the Little are based on ranges of estimated water use by the five Colorado River Basin and along the Colorado River water using functions: irrigated agriculture, urban, steam until the turn of the century after which dependable electric power generation, mineral production, and fish supplies will slowly decline as the states of the Upper and wildlife. High, low and reasonable intermediate levels Colorado River Basin develop and put to use their of development and water use were projected for each entitlement to waters of the Colorado River. major user. 6. Comparison of total projected water depletions with In projecting the future levels of development of each of projected water supplies shows that substantial these activities, it was assumed that nonagricultural uses overdrafting of groundwater will continue unless uses would generally grow without being constrained by a lack are severely reduced or the supplies available are of water supply. This assumption recognized that these augmented by large importations. With no new uses have an economic advantage over agriculture when agricultural development except on Indian reserva­ it comes to the amount that can be paid for water and if tions and medium projections of nonagricultural use necessary can buy out farm land solely for the purpose of an average annual overdraft of about 885,000 acre­ obtaining a water supply. feet will persist in 1990 growing to 1,575,000 acre-feet in 2020. The projections are based on the assumption that agriculture will be the major user affected by water 7. Maricopa County will continue to use more water resource management in Arizona in the event that State than any other county. A balance of supply and water supplies are not augmented. This appears reason­ demand can be maintained through the importation able in light of current economics and the fact that of Central Arizona Project supplies and a reduction in agriculture is by far the largest of the four activities. In one harvested acreage in the county of approximately of the alternatives investigated the harvested acreage that 300,000 acres by year 2020. Without the retirement of would have to be retired to effect and maintain a balance agricultural lands some sizable overdrafts would between water consumption and supply was determined. continue under all alternatives investigated.

8. In Pima County, the importation of water from the The major conclusions which can be drawn from the Central Arizona Project will make a significant Phase II study are as follows: contribution toward bringing depletion into balance with supply. Nevertheless, groundwater overdrafting 1. Urban water use which represents residential, com­ is projected to continue unless all agriculture is mercial, industrial, and governmental is expected to retired in which case the supplies available can meet increase with population. The 1970 annual statewide the demands until after the year 2000. depletion for urban use of 328,000 acre-feet will increase to between 542,000 and 950,000 acre-feet by 9. Water use by the mineral industry in Pinal County is 2020. Urban uses will face severe competition with forecast to increase substantially although agricul­ other user categories in Pima County. In other ture will continue as the principal water user. counties supplies appear to be sufficient to satisfy most foreseeable urban needs. 10. In Mohave and Yuma Counties most future develop­ ment and associated water use will occur along the Colorado River where no water supply deficiency is 2. Generation of electrical energy and its related water anticipated. Groundwater overdrafting will continue uses in Arizona will increase dramatically. The 1970 to occur in basins away from the River. use rate of approximately 20,000 acre-feet per year will increase to between 248,000 and 787,000 acre­ 11. The widest difference between projected levels of feet per year by 2020. water use occurs in Cochise County because of the potential for new agricultural development. By the 3. The copper producing industry in Arizona will year 2020 total water depletions would range from a continue to grow: Heavy water demands are expected low forecast of 97,000 acre-feet per year to a high of in Pima, Pinal, Gila, Graham and Greenlee Counties 616,000 acre-feet per year. in the future. By 2020 the annual water use may be as high as 841,000 acre-feet compared to a 1970 use of 12. Graham County is similar to Cochise County in that 131,000 acre-feet. agriculture may increase substantially to satisfy the

4 criteria of the alternative projections utilized. The campaign through the media and schools to inform largest expected increase, however, will be for the citizenry about water use and supply and how mineral production which may increase to as much as water can be conserved in and around the home. 50,000 acre-feet per year by 2020 compared to zero in 1970. Zero overdraft is achievable in 2020 under 2. Establishment of a requirement that State agencies medium growth assumptions with retirement of about evaluate and report annually on their water use 20,000 harvested acres of agricultural land. practices, institute such conservation practices as can be achieved within their budget and seek 13. Water supplies in the three northern Arizona counties administrative and legislative approval of measures {Apache, Coconino and Navajo) are believed to be requiring supplemental appropriations. generally adequate to meet future needs. Total water depletions in the three counties may increase to as 3. Appropriate action to clarify Arizona water law much as 130,000 acre-feet by 2020 with the most relative to the definition of beneficial use, reason­ significant increase in water use by steam electric able use and waste. Either one or both of the generating plants. following actions should be encouraged: (1) enact­ ment of legislation which identifies specific con­ 14. Future conditions in Yavapai County are difficult to spicuous and extravagant uses as non-beneficial; assess. Nonagricultural water uses alone are expect­ and/or (2) couft action by the Attorney General to ed to increase from two to three times 1970 levels. deny the granting of permits to appropriate water Because geographic conditions would appear to for certain uses, e.g., subdivision lakes, decorative preclude economical transfers of water between fountains, etc., on the grounds that such uses are basins, some areas will be faced with imbalance of not reasonable in light of the limited water supplies supply and demand even if all agriculture were available. retired. 4. Study by the State of the feasibility of offering a 15. Projected water use and supply conditions in subsidy to farmers who hire professional irrigation Greenlee and Gila Counties are similar. Because of management services and of the State providing anticipated increases in copper mining activities in such a service at reduced cost. these counties water supply deficiencies are forecast under all alternative future conditions. Water use by 5. Study by the State of the feasibility of providing a the mineral industry in the year 2020 is projected to tax credit for farmers who make capital outlays for comprise over 70 percent of total use in Gila County irrigation system improvements and to home­ and over 80 percent in Greenlee County. owners who convert from lawns and gardens to desert landscaping. 16. The overall picture of water supply and use in Santa Cruz County is not expected to change significantly 6. Evaluation and implementation by the State Land unless agriculture is reduced to achieve a balance Department of a system of rental rates for between supply and demand. agricultural leases based on water use and of the feasibility of leases containing provisions requiring The 1977 Legislature created a Groundwater Manage­ highly efficient operations. ment Study Commission with the charge to develop a groundwater management plan for t he State of Arizona by 7. Seek legislation that requires that all toilets sold in December 31, 1979. Because the charge of this new Arizona after January 1, 1980, be of the type that commission is conjunctive with many of the objectives of uses less than 3.5 gallons per flush. Phase Ill studies of the State Water Plan every effort will be made to coordinate the future planning activities of the 8. Encourage cities to adopt ordinances that would Water Commission and the Groundwater Management preclude the practice of flood irrigation of lawns Study Commission. and gardens in all new subdivisions.

In March 1977 Governor Castro requested the Water 9. Recommend to the Groundwater Management Commission to prepare for him a report on potential water Study Commission that serious consideration be conservation programs for Arizona. The report resulting, given to legislation that would permit the formation released in draft form for comment, details how water is of replenishment districts authorized to develop the used by each of the major water users in Arizona, works necessary to increase recharge of ground­ identifies the various water conservation techniques waters from flood waters and from the Central available, discusses possible water conservation pro­ Arizona Project and to impose charges on ground­ grams, and recommends water saving programs for water users in proportion to benefit received. implementation by the State. Following revision to reflect comments received, it will represent a partial report on B. Measures that would primarily save energy and capital Phase 111 of the State Water Plan. 1. Promotion by the State and cities of retrofit The recommendations contained in the report are: programs in existing housing by publicizing and subsidizing installation of the following devices. A. Measures that would conserve energy, capital and water a. Water dams or plastic bottles to be placed in toilet tanks, thus reducing the volume of water 1. Implementation by the State of a public education used for each flush.

5 b. Low-flow shower heads or flow restrictions in CENTRAL ARIZONA PROJECT shower lines. Federal Appropriations c. Low-flow aerators in sink and lavatory faucets. Construction of the Central Arizona Project is dependent d. Hot water pipe insulation. upon annual appropriations by the U. S. Congress. Through Fiscal Year 1977 over $390 million have been 2. Encourage cities to revise building codes to require appropriated for Project features. Approximately $73.4 that new buildings be equipped with the following: million were appropriated in FY 1977 for the construction of Project water development features, bringing the total a. Toilets which use less than 3.5 gallons per flush. appropriated for these features to approximately $163.5 million. b. Low-flow shower heads. In Fiscal Year 1977 three contracts were awarded which c. Low-flow sink and lavatory faucets. provided for the construction of 30.2 miles and lining of I 13.5 miles of the Granite Reef Aqueduct. Specific d. Insulated hot water lines. contracts were for the construction of Reaches 6 and 9 in the amount of $21,933,489 and the lining of Reach 11 at a e. Low water using clothes washers and dish­ cost of $4,660,502. During the year work continued on the washers. Buckskin Mountains Tunnel; Agua Fria, New River, and Salt River Siphons; and Reaches SA and 10 of the Granite 3. Encourage cities and other water purveyors to Reef Aqueduct which total approximately 21.5 miles. implement systems that permit landscape and lawn watering only on alternate days and during specific Congress also appropriated $20.6 million for the con­ hours of the day. struction of CAP power development features in FY 1977,

U.S. Bureau of Reclamation Photo

6 bringing the total appropriated for this purpose to resulted in the decision not to file a final impact statement approximately $226.9 million. Significant power related on this feature. activities in FY 1977 included the completion of the Davis­ Parker 230kv transmission line in February and comple­ Upon assuming office in January of 1977, President tion of 20 power circuit breakers at the Davis and Parker Carter initiated a program to review twenty-one water switchyards. In addition a contract with Arizona Public projects throughout the United States, including the Service Company was signed in May in the amount of Central Arizona Project. The results of this review $485,000 which provides that APS will serve as construc­ confirmed the justification for the CAP, however, major tion agent for a six mile joint use segment of the Liberty­ questions involving endangered species, critical habitat Parker 230kv transmission line. Also in Fiscal Year 1977 and the use of lands now a part of the Fort McDowell the U.S. Bureau of Reclamation estimates that revenues Indian Reservation resulted in a decision to reevaluate the from the sale of power derived from its 24.3 percent concept of Orme Dam and Reservoir as a regulatory interest in the Navajo Generating Station will be storage feature of the Project. In April of 1977 an approximately $40.9 million. This power will eventually be lnteragency Task Force composed of several agencies used to provide pumping energy for the CAP; however, in and groups was formed to study alternatives to the the interim until the CAP comes on line it will be sold to proposed Orme Dam and Reservoir. The Executive meet the region's energy demand and the surplus Director and members of his staff represent the Water revenues realized from the sale of this power, presently Commission on the Task Force and its subcommittees. At estimated at $12.8 million for FY 1977, used to reduce the the close of the fiscal year it was anticipated that the Task cost of CAP water to consumers. Force will complete its recommendations by January 1978. Preparation of the environmental impact statement for Buttes Dam and Reservoir, initiated in FY 1976, has Central Arizona Water Conservation District been deferred pending resolution of several complex legal and institutional restrictions related to water quality The Water Commission continued to provide staff and archaeology. assistance to the Central Arizona Water Conservation District in FY 1976-77. Billings for staff and contract work amounted to approximately $24,400 for the year and Allocation Study covered work on the environmental, repayment, and water supply aspects of CAP. The allocation of Arizona's remaining entitlement to Colorado River water remained unresolved for several A new board of directors took office in 1977 and is years pending finalization by the Secretary of the Interior discharging the District's basic responsibility of acting as of a proposed allocation of Central Arizona Project water the repayment entity for the major portion of CAP to the five central Arizona Indian reservations. On construction costs. Commitments to purchase agricul­ October 18, 1976, the Secretary finalized the Indian tural water were accepted throughout FY 1977, and allocation, awarding 257,000 acre-feet to the five reserva­ proceedings to validate the master repayment contract tions during the first 20 years of Project operation. After were initiated. Ad valorem taxes of 3 cents per hundred the year 2005 the reservations will receive 10 percent of dollars of assessed valuation continued to be collected in total Project water or 20 percent of the agricultural water, Maricopa, Pinal, and Pima Counties, and the District's whichever is greater in any given year. With this reserve fund for project repayment purposes amounted to Secretarial action the Water Commission immediately approximately $3,530,000 at the end of the 1977 Fiscal moved to make public its preliminary recommendations Year. as to how the municipal and industrial portion of Arizona's remaining entitlement in the Colorado River should be allocated among competing applicants. The Commission Environmental Impact Statements held three public hearings in February and March of 1977 and at its monthly meeting in May of 1977 finalized its The Bureau of Reclamation chose to approach environ­ recommendations to the Secretary of the Interior. mental impact statement requirements for the Project on the basis of first preparing a general statement on the In the final month of the fiscal year the Commission entire Project and then developing more detailed focused its attention on the task of developing recom­ statements on individual features. Through Fiscal Year mendations to the Secretary regarding the allocation of 1976, four final Central Arizona Project environmental the agricultural portion of Arizona's remaining Colorado impact statements had been filed with the Council on River entitlement among the various competing non­ Environmental Quality. These were the overall statement Indian users. The problem is sizeable as existing filed on September 26, 1972; the statement on the commitments to purchase Central Arizona Project diversion works located at Lake Havasu, including the agricultural water exceed the anticipated available supply pumping plant and Buckskin Mountains Tunnel, filed on by approximately 300 percent. Completion of the January 15, 1973; the statement for the Granite Reef agricultural recommendations is scheduled for FY 1978. Aqueduct filed on January 22, 1974; and the statement for the Granite Reef Aqueduct Transmission System filed on August 4, 1975. ADEQUACY OF WATER SUPPLIES FOR SUBDIVISIONS

In addition, the draft environmental impact statement for With the enactment of H.B. 2100 {ARS 45-513) in May of Orme Dam and Reservoir was filed with the Council on 1973, the statutory responsibility for review of subdivision Environmental Quality on May 21, 1976, and public water supply adequacy, formerly with the State Health hearings on the statement were conducted on July 9-_10, Department, was placed with the Water Commission. The 1976. Events which transpired subsequent to this action statute requires the developer of a subdivision, prior to

7 recordation of the plat, to submit plans for the Turner Ranches Water and Sanitation Co. development's water supply to the Water Commission White Tanks Water Co. and demonstrate that the supply is adequate to meet the projected needs. Upon submission and review of such Navajo Arizona Water Co. plans, the Water Commission is required to issue a report Pima Hub Water Co. on the adequacy of the development's supply. If the Metropolitan Water Co. supply is inadequate, or if no water is available, a companion statute, ARS 32-2181 D, requires the State Pinal Arizona Water Co. Real Estate Commissioner to require that all promotional Florence Gardens Utility Co. material and contracts for the subdivision contain a summary of the Water Commission's report. Policies, criteria, and guidelines to administer this program have been developed. They define an approach Since enactment of H.B. 2100 the Commission staff has which recognizes the legislative interest in placement of reviewed reports for approximately 400 subdivisions, of the burden of proof of adequacy on the developer. which 45 were judged to have inadequate water supplies. From July 1, 1976 to June 30, 1977, 62 reports were The Water Commission staff works closely with the reviewed with five subdivisions found to have an developers to advise them of the requisite elements in a inadequate supply. satisfactory demonstration of adequacy for each indivi­ dual subdivision. EARLY CONTACT WITH THE COM­ The Water Commission is also empowered, under the MISSION STAFF IS URGED IN ORDER TO EASE THE provisions of ARS 45-513, to designate service areas BURDEN ON ALL CONCERNED. This program is under where an adequate supply of water exists. In such areas the immediate direction of the Water Commission's Chief the developer is not required to submit water supply plans Hydrologist, Philip C. Briggs, who may be contacted to the Commission. directly at 258-8175 regarding questions on these matters. The following tables list service areas designated to date: DESIGNATED MUN ICIPALITIES County City

Apache Springerville, St. Johns FLOOD CONTROL

Cochise Douglas, Willcox Flood Control Planning Coconino Flagstaff, Page In 1973, Senate Bill 1152 established a planning staff Gila Globe within the Water Commission to assist federal agencies in the planning of flood control projects related to or Graham Safford affecting the Central Arizona Project (CAP). The primary Greenlee None purpose of the State legislation was to accelerate specific P.L. 566 projects under consideration by the Soil Maricopa Buckeye, Chandler, El Mirage Conservation Service (SCS) but facing planning or Gilbert, Glendale, Goodyear, Mesa design delays because of manpower limitations. Con­ Peoria, Phoenix, Scottsdale, Surprise struction of these projects on a schedule coordinated with Tempe, Youngtown, Wickenburg appropriate features of the CAP system would result in a substantial reduction of local cost. Mohave Kingman, Lake Havasu City Navajo Holbrook, Winslow Previously, flood control planning has been an exclusive federal function. However, creation of a technical Pima Tucson, South Tucson planning staff has given the State of Arizona this unique Pinal Eloy capability. The planning staff provides specialized expertise in engineering, hydrology, geology and agricul­ Santa Cruz Nogales tural economics. Yavapai Prescott The Harquahala Valley Watershed Project is a P.L. 566 Yuma Parker, Yuma project located in northwestern Maricopa County and eastern Yuma County. The original SCS work plan was DESIGNATED WATER COMPANIES published in January, 1967. The construction of Interstate Highway 10 and the pending CAP construction necessi­ County Company tated the preparation of a supplemental work plan.

Maricopa Consolidated Water Utilities, Inc. The Harquahala supplemental work plan and the Desert Sands Water Co. respective environmental impact statement (EIS) were Ironwood Water Co. prepared as the initial planning effort authorized in Litchfield Park Service Co. Senate Bill 1152. The resultant documents were finalized Pima Utilities Co. this year. The SCS has indicated construction is Rio Vista Water Co. scheduled to begin in September, 1978, with completion Sun City Water Co. scheduled for early 1981.

8 The Lower Queen Creek Watershed Project is a P.L. 566 Floodplaln Management project located in southeastern Maricopa County and northwestern Pinal County. The authorized project plan Section 45-2341 to 45-2346 requires that all local includes both conservation land treatment and structural jurisdictions enter into a floodplain management program measures. The completed project will furnish needed by delineating areas inundated by a 100-yearflood and by flood control protection to rural development, agricul­ adopting regulatory ordinances to control development tural interests, CAP aqueduct, county roads, railroad within the area subject to inundation. facilities and two proposed irrigation distribution systems. The Water Commission was required by statute to develop criteria for establishing the magnitude of the 100- The planning staff has evaluated several Queen Creek year flood. Local agencies are required to notify the proposals and is anticipating completion of project Commission of any public hearings necessary to enact studies the first part of 1978. In compliance with federal floodplain ordinances and to furnish the Commission requirements, the preliminary work plan and respective with a copy of the floodplain regulations adopted. EIS will be prepared and distributed for interagency Members of the Commission staff attend meetings of review. Planning efforts are being accelerated to coordi­ local floodplain boards to assist them in efforts to comply nate with critical CAP construction schedules. with State laws. To further assist agencies, each proposed set of floodplain regulations are reviewed by the Commissior. and comments are developed regarding Flood Control Assistance these regulations.

The purpose of the State Flood Control Assistance Although the deadline for local compliance with the law Program is to assist financially the local sponsors of was February 4, 1974, only thirteen cities and two federal flood control projects. In order to obtain approval counties had furnished the Commission with completed of federal projects, local sponsors are required to provide floodplain regulations as of June 30, 1977. The cost of necessary land rights for the project and to relocate having floodplains delineated was specified as the affected utilities. Historically, many local governments primary reason that the other jurisdictions have not have been unable to meet this requirement, thereby complied. precluding the construction of needed flood control projects. In an effort to encourage and enable those remaining jurisdictions to comply, the 1975 Legislature amended the Appropriations to date for this program have been made requirements of the program and provided authority for during the legislative sessions as follow: State assistance through the provision of engineering and technical services or, optionally, the disbursement of 1973 $2,450,000 funds for such services at the request of the local 1974 895,000 jurisdiction. No funds have yet been appropriated for this 1975 176,000 function. 1976 600,000 1977 5,000,000 Several communities have received delineation mapping Total $9,121,000 from federal agencies and have drafted and adopted regulatory ordinances for the floodplain areas shown. The statutes which created the flood control assistance Unfortunately, in some communities opposition to the program in 1973, required that before State funds could proposed regulations expressed at public hearings has be disbursed, federal construction funds had to be made the local governing bodies reluctant to adopt them budgeted. Due to this constraint no State funds were as ordinances. With the continuing advancement of disbursed in 1973 and 1974. Federal Flood Insurance Administration mapping it is only a matter of time until these communities will be In 1974, legislation provided needed flexibility to the obliged to adopt regulations or face the loss of loans for program by allowing funds appropriated for authorized residential and commercial development. projects to be interchanged between projects if needed. In 1975 further flexibility was provided by allowing the reimbursement of local expenditures prior to the budget­ DROUGHT ASSISTANCE COORDINATION ing of federal construction funds. This flexibility is, however, restricted to monies expended on fee title In early 1977, a concerted effort was made at all levels of ownership of lands required for approved projects. government to address the problems resulting from nearly three years of severe drought conditions in the With this increased flexibility and progress on the eligible Western States. At the federal level, President Carter projects, disbursements totalling $1·,367,652 and sponsored a drought assistance program which com­ $2,123,348 were made in Fiscal Years 1975 and 1976, mitted funds in excess of one billion dollars to reduce respectively. The funds disbursed in FY 1976 exhausted drought-related impacts. State and local governments appropriations except for the $30,000 held in reserve for responded by developing and implementing water the Foote Wash Watershed Project near Safford. The conservation programs. $600,000 appropriated in 1976 was disbursed during the 1976-77 Fiscal Year. It is also anticipated that the In February of 1977 Governor Castro directed the Water $5,000,000 appropriated for the 1977-78 Fiscal Year will Commission to coordinate the drought assistance be disbursed early in the year and that a backlog of several programs for the State. In this role, the Commission million dollars of additional claims will be on hand on participated with 21 other Western States on the Western entry into the next fiscal year. Regional Drought Area Task Force and cooperated with

9 the federal agencies administering assistance program mining operations; and $4,500 for a similar program for funds. The Commission will continue to serve as the data Phelps Dodge Corporation's proposed Copper Basin gathering agency and coordinating link between federal, Mine. All matching funds required from the State for the state, and local agencies until the drought assistance Black Mesa and Copper Basin monitoring programs are programs are found unnecessary. provided by private interests.

The stream gaging program is designed to provide data COOPERATIVE RIVER BASIN STUDIES on the quantity and quality of the surface water resources of the State. The program now includes data from 73 During Fiscal Year 1977 the Water Commission continued stations within the State. Streamflow and quality data to provide coordination and direction to the U.S. gathered at these stations are published annually in the Department of Agriculture in furtherance of that agency's Geological Survey's report series, "Water Resources Data river basin studies in Arizona. Studies are underway or for Arizona." proposed in the Santa Cruz-San Pedro River Basin, Little Colorado River Basin, and Virgin River Basin. The The groundwater program consists of two major parts: objective of the river basin studies are to identify action the statewide collection and analysis of basic ground­ plans and programs available to individuals, and federal, water data, and comprehensive investigation of selected state and local entities in meeting the middle term (15 to groundwater basins. A smaller part of the program 25 years) water and related land resource needs of the involves research studies related to specific hydrologic study area. problems. The three parts of the program are closely related and, to a large extent, are interdependent. The Santa Cruz-San Pedro River Basin study area Groundwater data gathered in the statewide program in encompasses 16,600 square miles and includes the earlier years were published by the State Land Depart­ drainage areas of the Willcox Playa and Whitewater Draw ment and are now being published by the Water in Arizona. A draft report was completed during the year Commission. Reports in the series, Annual Report on and distributed for review. Completion of the final report Groundwater in Arizona and the report, Groundwater, will be in late calendar year 1977. Resources and Water Use in Southern Navajo County, Arizona are examples of reports prepared by the The Little Colorado River Basin study area encompasses Geological Survey and published by the Commission 26,975 square miles of which approximately 80 percent under this program. A bibliography of reports prepared in lies within the State of Arizona. During the fiscal year a this series by the Geological Survey in Arizona was draft plan of work for the study was completed and published four years ago. distributed for review. The study will provide inventories of the existing land use, land ownership, water and related A new hydrologic map series, to facilitate rapid publica­ land resource problems and needs as required to address tion and dissemination of information from basic data the objective of presenting resource data that will offer studies, has been started. Twelve maps have been solutions to problems and assist decision makers in the published, the latest being, "Maps Showing Groundwater orderly development of the water and related land Conditions in the Southern Part of the Black Mesa Area, resources of the area. The report is scheduled for Navajo, Apache and Coconino Counties, Arizona - completion in the 1980 Fiscal Year. 1976." The results of the detailed studies are sometimes published by the Geological Survey in one of their The proposed Virgin River Basin study area encompasses standard report series. over 21,884 square miles in Arizona. Nevada and Utah. Approximately 27 percent of the study area lies in Arizona. Principal effort during the 1977 Fiscal Year was devoted to developing objectives and scope of a study. Final agreement on these matters between the U.S. WATER QUALITY PLA NNING Department of Agriculture and the affected states is pending. The Arizona Water Commission and its predecessor, the Interstate Stream Commission, have actively participated in the consideration given water quality problems of the COOPERATIVE INVESTIGATION State since 1967, when the State Legislature created the OF WATER RESOURCES Water Quality Control Council for the purpose of developing water quality standards pursuant to the The Water Commission is responsible for State participa­ National Water Quality Act of 1965. Philip C. Briggs, Chief tion in the water resources investigations performed by Hydrologist, represents the Water Commission on the the U.S. Geological Survey under cooperative agreement State Water Quality Control Council. and with matching funds from the State of Arizona. Under terms of a contractual agreement, both the Commission In 1973, the Governor designated the Arizona Water and the Survey contributed $346,900 in Fiscal Year 1977 Quality Control Council as the official body responsible for the continuation of programs for the collection of for developing the State's water quality management basic hydrologic data and special hydrologic investiga­ plans in compliance with the Federal Water Pollution tions. Each party's contribution is allocated to make Control Act as amended in 1972. Along with this available $170,900 and $176,000 for the investigation designation, the Governor further directed that staff within the State of surface water and groundwater assistance in developing and implementing the Council's resources, respectively; $28,500 for a special program to water quality plans would be provided by the Department monitor the hydrologic effect of the Black Mesa coal of Health Services and the Arizona Water Commission.

10 Water quality management planning studies were initi­ one of the eleven State officials designated by statute as ated in all study areas throughout the State during 1973 members of the eighteen-member committee. Martin and are now nearing completion. Additional studies, to Wurbs, staff environmentalist, normally sits as Mr. build more specific plans from the above work, begun Steiner's alternate. during the 1976 Fiscal Year, were continued in Fiscal Year 1977. These studies, performed under Section 208 of P.L. During Fiscal Year 1977, the Committee granted two 92-500, are being conducted by all of the six local councils Certificates of Environmental Compatibility to public of government in Arizona. Commission staff is serving, utilities authorizing construction of two new 115 kv along with representatives of many other agencies, on transmission lines. advisory groups to the councils of government. INTERAGENCY ENERGY PLANNING OFFICE

The lnteragency Energy Planning Office was created by WATERSHED MANAGEMENT PRO GRAM Governor Castro on August 13, 1975, to serve as a single interface with federal agencies and to coordinate energy The responsibility for the State's watershed management activities among State agencies concerned with energy program was transferred to the Water Commission from matters. The Water Commission, as one of thirteen the State Land Department in April, 1971. Over the years, energy related State agencies, actively participated in the program has consisted of outlining data needs, I EPO activities during the report year. soliciting necessary federal watershed management research projects within the State, and supporting them A wide range of energy related subjects were considered once underway. Since the beginning of the program in by I EPO members in FY 1977 including the creation of oil 1957, the State has been immeasurably aided in its efforts storage caverns in salt masses in Arizona, the develop­ by a citizens group, the Arizona Water Resources ment of solar energy and the dissemination of energy Committee. related information to the public. Most significant of the year's accomplishments, however, was the development The Arizona Water Resources Committee works closely of a State Energy Policy and Energy Conservation Plan, with the Commission to achieve common objectives. Its both of which were adopted by Governor Castro in the membership is representative of the varied interests in latter part of the fiscal year. In addition, IEPO was watersheds and watershed management. Members are instrumental in obtaining funding from the Federal drawn from industries such as ranching, mining, agricul­ Energy Administration to implement the State's Energy ture, timber, utilities and banking, and from user groups Conservation Plan. such as outdoor recreation and environmentalists. The Committee is now working with the Water Commission and federal agencies to provide advice and support for the program and to facilitate public knowledge of the LICENSING OF WEATHER research findings of the program. As a part of this latter MODIFICATION ACTIVITIES role, the Committee and Commission annually cosponsor a watershed symposium which is open to the general The Water Commission has the responsibility for public. The proceedings are printed annually and can be licensing weather modification activities in accordance obtained free of charge from the Water Commission. with existing statutory provisions. Under State law, federal agencies are exempt from licensing control. There have been seven licenses issued since 1951, the latest POWER PLANT AND being issued in 1974. TRANSMISSION LINE SITING COMMITTEE The only active license holder, North American Weather The Power Plant and Transmission Line Siting Committee Consultants, is conducting an extensive winter snow was established in 1971 to provide a single forum for the seeding program in southern Utah. Five of the Project's expeditious resolution of all matters concerning the ground-based generators are located along the northern location of electric generating plants and transmission Arizona border and were operated during the winter to lines. The Executive Director of the Water Commission is seed target areas in Utah.

11 INTERSTATE WATER PLANNING

COMMITTEE OF FOURTEEN Committee and by Engineer David Gerke on the Work Group. During the fiscal year the Work Group had only The Committee of Fourteen was established in 1962 at the one meeting and the Coordinating Committee did not request of the State Department to advise that Depart­ meet. ment and the U.S. Commissioner of the International Boundary and Water Commission concerning negotia­ No additional progress was made during the year on tions with Mexico over the salinity of water that Mexico development of a suitable river management plan for receives from the Colorado River. Section II of the Parker Division which lies entirely within the Colorado River Indian Reservation from Palo Verde The Committee of Fourteen consists of two members Diversion Dam upstream to Alligator Bend. Numerous appointed by each of the governors of the seven Colorado proposals have been considered in recent years, but none River Basin States. Arizona's two representatives are have received concensus approval because of differences Attorney Tom Choules of Yuma and Wesley E. Steiner, of opinion as to the impacts of proposed plans on fish and Executive Director of the Water Commission. Mr. Steiner wildlife resources. and Mr. Choules serve as Chairman and Secretary, respectively. In the Mohave Valley and Palo Verde Divisions several minor river improvement and stabilization proposals were Previous annual reports of the Commission have included considered by the Work Group and approved for detailed accounts of the Mexican salinity problem and the completion during the year. These included renovation by steps taken to resolve it, culminating in enactment by dredging of a small park lagoon at Needles and deepening Congress of legislation drafted and sponsored by the of an existing boat mooring area at Park Moabi on the Committee of Fourteen to implement the agreement with California side near Topock. In the Palo Verde Division Mexico while protecting interests in the Colorado River below Palo Verde Diversion Dam a short reach of actively Basin States. In this legislation the Committee also gained eroding California bankline was proposed for stabiliza­ authorization of the Colorado River Salinity Control tion. The work was approved after determining there Program authorizing the construction of upstream would be minimum disturbance of existing vegetation. projects to control salt input to the Colorado River.

Now that the salinity problem with Mexico has ostensibly UNMEASURED GROUNDWATER RETURN FLOW been resolved, the Committee meets on a much less TO THE COLORADO RIVER frequent basis to monitor progress on the construction of the physical works necessary to fulfill the agreement with In 1969, during the study to determine operating criteria Mexico and to control the input of salt to the Colorado for Glen Canyon Dam and Reservoir, it became apparent River throughout its basin. that sizeable returns to the Colorado River from the irrigation districts adjoining it were occurring as un­ measured return flows, and were not being credited to the LOWER COLORADO RIVER MANAGEMENT PROGRAM district and state in which they originate. Calculations by the Water Commission indicate that as ml)ch as 200,000 The Bureau of Reclamation administers the Lower acre-feet a year may be returning to the River as Colorado River Management Program, which covers ten underground flow from irrigation districts in Arizona reaches or divisions of the Colorado River from Davis alone. Under the provisions of the U.S. Supreme Court's Dam to the southerly International Boundary with Decree in Arizona vs. California, use is to be charged Mexico. The program has ev9lved from early efforts to against the state allocations in terms of diversion less control serious flooding and sedimentation along the returns. The Bureau of Reclamation, as operator of the River to a multi-purpose program which includes the River, is interpreting this provision as diversions less additional objectives of water salvage, salinity control, measured returns. The three Lower Basin States dispute protection of the environment, preservation and enhance­ this interpretation and contend that credit must also be ment of fish and wildlife resources, and recreational given for returns that show up in the River although not development. measured at their point of discharge to the River. All parties agree that an effort should be made to measure all The Lower Colorado River Management Program Coordi­ -returns. nating Committee was established in 1971 to keep informed on River related activities, and to make The U.S. Geological Survey, at the request of the Bureau recommendations to the Bureau of Reclamation concern­ of Reclamation, formulated a program to measure these ing the program. Membership of the Committee includes presently unmeasured return flows. The past year was the several state and federal agencies having a direct interest seventh in what had been planned to be six-year program, in the Lower Colorado River. Chairmanship of the estimated by the Geological Survey to cost a total of Coordinating Committee rests with the Bureau of approximately $1,500,000. Once installed, calibrated, and Reclamation. Staff work for the Committee is performed verified, the system will be operated under the Survey's by a work group established to expedite coordination of basic data collection program. Hopefully, the data activities. The Water Commission is represented by collection system will be providing credits to Arizona Executive Director Wesley E. Steiner on the Coordinating before the CAP begins operations in 1985.

12 A task force consisting of representatives of the Bureau of whether existing or emerging. This is the second such Reclamation, the Geological Survey, the Bureau of Indian assessment to be conducted under the authority of the Affairs, and the three Lower Basin States was formed to Water Resources Planning Act of 1965 (PL 89-90). advise and direct the technical portions of the study. Arizona's member on the task force is Philip C. Briggs, State, regional, and federal agencies are participating in Chief Hydrologist for the Arizona Water Commission. the 1975 assessment under the Water Resources Coun­ cil's National Programs and Assessment Committee. The task force met once during Fiscal Year 1977 to review Regional assessment activities in the Pacific Southwest and comment on the program. All of the wells required in study area are being coordinated and conducted by the Yuma and Parker areas have been drilled and Regional Study Directors. The Lower Colorado Regional instrumented. The wells are located along lines perpen­ Office of the Bureau of Reclamation serves as di rector for dicular to the River with most lines having wells on each the Lower Colorado Region which includes Arizona. The side of the River. The data obtained from observation of Pacific Southwest Inter-Agency Committee is function­ these wells will allow computation of underflow reaching ing as a coordinator of policy issues between the the River. Eighteen such cross sections comprised of 216 Colorado River Basin States and the Water Resources wells, and sixteen sections comprised of 104 wells were Council. The Water Commission represents Arizona on drilled in the Yuma and Parker areas, respectively. River the Pacific Southwest Inter-Agency Committee. stage recorders have been added at each section in the two areas. Preliminary computations using data collected The initial activity under the assessment's Specific by the system suggest that in the Yuma area the return Problem Analysis phase, consisting of an initial identifica­ flow from both states was about 100,000 acre-feet in 1973. tion of the more severe existing and emerging water and Estimates for the Parker area will be available starting land problems in the Lower Colorado Region, was next year. Thirty-nine sections have been selected in the completed in Fiscal Year 1975-76. During the past year Palo Verde and Cibola areas. Installation of the wells and activities two and three were completed and reports instrumentation in these areas was to be completed by the prepared. In activity two the results of the initial problem end of calendar year 1976. identification were used to develop state-regional futures including desires and objectives, socio economic char­ acteristics, water requirements, water use and supply PRESENT PERFECTED RIGHTS data, and information on nonvolumetric resources. Also, problem areas for further study were delineated and the The U.S. Supreme Court in its decree in Arizona vs. more severe water and related land resource problems for California recognized the supremacy of rights to these areas were briefly described. Colorado River water of uses actually being made at the time the Boulder Canyon Project Act became effective on The activity three report provides a more detailed June 25, 1929. The Court left to the States of Arizona, evaluation of the problems for each area, appraises the California, and Nevada the problem of reaching effects of not solving the problems, identifies recently agreement on magnitude and priority of these perfected completed or ongoing Federal actions toward solving the uses. problems, and considers the need for other major planning studies. A draft for activity four, which will be a After 10 years of effort, in 1974 the states and the summary report of the previous Specific Problem Department of the Interior, representing the Federal Analysis activities, was completed and was being Government, entered into a stipulated agreement cover­ reviewed at the end of the fiscal year. ing all present perfected rights claims. The Department of Justice, however, balked and insisted that the non-Indian claims for perfected rights take the same· form as the WESTERN STATES WATER COUNCIL decreed rights of the Indians. The three states rewrote the stipulation accordingly only to have the five Indian tribes The Council, composed of three representatives appoint­ located along the Lower Colorado River protest and ask ed by each Governor of the eleven Western States, was the Secretary of the lnterior,to withhold his decision on established in 1965 by the Western States Governors' the stipulated agreement while they reviewed the claims. Conference to promote regional understanding and In mid-1975 the Indians challenged all of the major non­ cooperation in water matters. Arizona's members on the Indian claims covered in the stipulation and urged that Council are Yuma water attorney Tom Choules; Froilan federal approval of the stipulated agreement be withheld Cota, Civil Engineer for the Water and Sewers Depart­ until the states agreed to an enlargement of the water ment for the City of Tucson; and Wes Steiner, Executive rights decreed to the reservation by the U.S. Supreme Director of the Water Commission. Mr. Steiner served Court in Arizona vs. California. The States refused to throughout the year as chairman of the Council. accede to the Indian demands and late in the fiscal year submitted to the Court the three states' stipulated During the fiscal year, the Council devoted considerable agreement without the U.S. as a party. To date no action time to the review of problems arising from the Water has been taken by the Court. Pollution Control Act amendments of 1972 (P.L. 92-500) and adopted resolutions calling for enactment of major amendments relative to the definition of navigable waters THE 1975 NATIONAL WATER ASSESSMENT and the treatment of return flows from agriculture. The Council went on record in opposition to the Central The U.S. Water Resources Council, in 1973, initiated a Arizona Indian Tribal Water Rights Settlement Act of study designed to identify and describe the nation's 1976, otherwise known as the Kennedy Bill and provided severe water problems, establish priorities, and empha­ leadership and staff support for activities of the Western size the need to resolve the problems identified - Regional Drought Area Task Force in the development of

13 information on the drought and in coordination of and entities concerned with the Colorado River. Public drought assistance programs. The Council also expend­ hearings on the report were held early in August of 1975 in ed considerable effort in the review of the Federal Water Las Vegas, Nevada, and Grand Junction, Colorado. Policy option papers prepared as a basis for the adoption Following these regional hearings, each of the seven of Presidential policy and in preparing briefing docu­ Basin States held its own hearings and then adopted the ments thereon for the western governors. standards and criteria as a part of their state's plan.

The standards are based on maintaining salinity in the Lower Colorado River at or below 1972 levels while the COLORADO RIVER BASIN Basin States continue to develop their compact­ SALINITY CONTROL FORUM apportioned waters. The salinity standards adopted for three locations on the lower mainstream are as follows: The Forum was established in November of 1973 by water resource and water quality representatives from each of the seven Colorado River Basin States to work with the Salinity in mg/I Environmental Protection Agency in developing the Below Hoover Dam 723 salinity standards for the Colorado River required by the Below Parker Dam 747 Federal Water Pollution Control Act amendments of 1972 At Imperial Dam 879 (P.L. 92-500). Arizona is represented on the Forum by Cliff Tabor, Chairman of the Water Quality Control Council, and Wes Steiner, Executive Director of the Water Early in the fiscal year the Environmental Protection Commission. Agency approved the standards as developed by the Forum and adopted individually by the seven states. Late The Forum, working with the Environmental Protection in the fiscal year the Environmental Defense Fund advised Agency, was successful early in 1975 in developing that it would soon file suit against the EPA on the grounds uniform salinity standards for the Colorado River system. that the standards were not rigorous enough and must be In June of 1975 the Forum published its report entitled supplemented by numerical standards on each of the "Water Quality Standards for Salinity Including Numeric tributaries as they cross state Ii nes. Criteria and Plan of Implementation of Salinity Control, Colorado River Systems" and distributed it for review and The Forum began preparations for the suit while comment to the Governors and other interested groups continuing efforts to implement the salinity control plan.

14 SUPERVISION OF SAFETY OF DAMS

All non-federal dams in Arizona which meet the definition was treated generally exceeded requirements that would of a dam as specified in the Arizona Revised Statutes are ordinarily be expected to assure safe structural perform­ under jurisdiction of the State Water Engineer. A dam is ance. The staff carefully examined all foundation defined in the statutes as an artificial barrier tor the preparation from the standpoint of dam safety and the impounding or diversion of water which is 25 feet or more effectiveness of the seepage barrier. The other dam under in height or which has a storage capacity of more than 50 construction at the end of the year was a tailing dam. acre-feet. Within these broad guidelines, the statutes define a program that covers all aspects of the design, Four of the dams on which construction was pending construction, operation and maintenance of dams and were flood control structures. The remaining two are has as its objective protection of the public against storage dams built in violation of the statutes which were property damage or loss of life from the malfunction or in need of repairs prior to the issuance of a License of failure of a dam. Approval.

The State Water Engineer's staff of professional Only four applications for new dams to be constructed engineers administers the safety program tor the 181 were received during the year. In Fiscal Year 1977 the dams under jurisdiction. This includes 158 earth or earth­ income from fees on these applications and the final fees rock dams (nine of which are tailing dams), 22 concrete or on dams whose construction was completed was $30,010. masonry dams, and one dam constructed of steel. The storage capacity of 59 of these dams is in excess of 1,000 Over the past six years some owners of mine tailing dams acre-feet including seven dams which have a storage have questioned the jurisdiction of the State Water capacity in excess of 10,000 acre-feet. Engineer over tailing dams. In order to clarify the question, legislation was introduced to specifically include dams constructed to store liquid borne material Field and office evaluations of operational dams (tailing) within the broad definition of a dam. Senate Bill accounted for 31 percent of the program effort this year. 1136 was subsequently amended by the Legislature to Dams are evaluated on a schedule based on their size, exclude tailing dams from the jurisdiction of the State condition, and downstream hazard.During the year, 140 Water Engineer. Effective August 27, 1977, the Arizona field evaluations were conducted on 113 dams.Following Revised Statutes, Chapter 45, Section 701 define a dam as these field and office evaluations, the owners of several "any artificial barrier, including appurtenant works for the dams were contacted and requested to make improve­ impounding or diversion of water EXCEPT THOSE ments to their dams. Included in this group were the BARRIERS FOR THE PURPOSE OF CONTROLLING owners of Patagonia, Nelson, Waddell, Odell, Bunch, LIQUID BORNE MATERIAL, twenty-five feet or more in River #3, and Lyman Dams.At the end of the report year height o'r the storage capacity of which will be more than plans were underway to enlarge the spillways at fifty acre-feet, ...." Patagonia and Nelson Dams.The owners of Waddell Dam were actively considering engineering proposals on a Approximately 25 percent of the dams under jurisdiction study of their structure. Plans were nearly complete for are flood control structures.As noted previously, of the 17 the rehabilitation of Odell Dam and some maintenance dams in some stage of application review during the year, work had been performed on Bunch and River #3 Dams. nine were flood control dams.Since 1971, when the State Water Engineer assumed the responsibility tor Super­ Another ma)or segment of the Commission's Safety vision of Safety of Dams, 25 of the 41 new dams Program which accounted for almost 27 percent of the constructed have been earthfill flood control dams. This is staff's time during the year concerns the design review over half of all the flood control structures under and construction supervision of dams. During the year 17 jurisdiction.For the most part, these dams are located in applications were in various stages of review.At the end of Graham, Maricopa, and Pinal Counties. the fiscal year seven dams had been completed while ten dams were either under construction or construction was Flood control dams are constructed in normally dry pending. The seven dams completed included five for washes and are designed to retard flood flows.Protection flood control, one tailing dam and the repair of a dam tor a from severe precipitation occurrences is thus provided tor water supply reservoir. those downstream. The reservoirs behind the dams are normally dry and water, when stored, is only in the Construction was underway on two dams being built in reservoir tor a short period of time. conjunction with the Cholla Power Plant expansion and one in conjunction with the construction of the Coronado Embankment cracking of earth dams is especially Power Plant. The largest of these, Cholla Fly Ash Dam, common in areas of low rainfall and areas of compressible will be nearly one mile long, 70 feet high, and will contain soils foundations such as the Arizona desert. Flood over one million cubic yards of embankment material.The control structures constructed of the fine-grained, silty other two are nearly as large. Foundation preparation for desert soils appear to be especially susceptible to these dams was exceedingly important to the ultimate cracking.This was emphasized by investigations of dams integrity of the dams and reservoirs as well as the effective in Pinal and Maricopa Counties during April, May and elimination of any seepage of poor quality water into the June of 1977.One study of embankment cracking at three ground water aquifer.The care with which the foundation dams owned by the Maricopa County Flood Control

15 District was conducted by a private engineering firm. The District indicated that embankment cracking was so staff observed this work in progress and conferred with extensive that it was deemed prudent to reduce the level the owner and U.S. Soil Conservation Service (the of protection of the dam by breaching it in two locations designer) as they directed the study. Cracking at these rather than subject those downstream to the risk of a dams was not as extensive as it was at McMicken Dam, a failure in the event that water was retained behind the flood control structure which protects Luke Air Force dam. Protection is now provided for storms equal to the Base, Litchfield Park and Sun City. Investigations of flood of record. During the coming years, studies will be McMicken Dam made by the U.S. Army Corps of made and repair work done to restore this dam to its Engineers and the Maricopa County Flood Control previous protection level.

Expansion of Arizona Public Service Company's Cholla Power Plant (background) includes construction of Cholla Fly Ash Dam. When completed the dam will be 70 feet in height, have a crest length of 4,500 feet, and store coal fly ash which is a waste product of the power plant. Foundation preparation of the dam, underway in the foreground, was done carefully to minimize the potential for seepage under the dam. Arizona Water Commission Photo

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