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Hieroglyphic Mountains Recharge Project

Introduction
Facility Components
Operations
Maintenance
Water Deliveries

INTRODUCTION
On January 2, 2003, the Central Arizona Project (CAP) began delivering water to the Hieroglyphic Mountains Recharge Project (HMRP). The direct recharge facility is located in the West Salt River Sub-basin of the Phoenix AMA, west of the intersection of 163rd Avenue and the CAP canal. The project has an annual permitted recharge capacity of 35,000 acre-feet (AF) per year. The project was developed and constructed using State Demonstration Project funds.
HMRP consists of three basins that cover approximately 38 acres along a one-mile stretch of the CAP right-of-way. The basins are divided into a total of seven cells with each cell capable of being operated individually. Water is diverted from the CAP canal to the project through a pump station. The pump station consists of four electric turbine pumps that can deliver up to 25 cubic feet per second (cfs) each. The flow is measured by an acoustic flow meter with an accuracy of +/- 0.5%.

Initial deliveries to the project, January 2, 2003 (Basin 2B)
Project Facts
Permit Capacity: 35,000 AF per year for 20 years Cost: $5.47 million Basins: Three basins, divided into 7 cells, totaling 38 acres Location: T5N, R2W, Section 23 and 24 South ½ Project Operational: January 2003 Operational Delivery Capacity: 90 cfs

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FACILITY COMPONENTS
HMRP is composed of three basins, divided into seven individual cells. The cells range in size from 1.8 to 8.4 acres, for a total of approximately 38 acres of recharge basins. The water is pumped from the CAP canal using four electric turbine pumps rated at 25 cfs each. The pumps are housed in individual sound reducing cabinets to protect the nearby neighbors.

Pump station at HMRP
The pumps are manifolded into a 42-inch pipeline with an acoustic flowmeter recording the flows. Water is delivered to each basin through an upturned pipe with an apron of riprap to act as an energy dissipater. Flows to the individual cells are not measured. Pressure transducers installed in stilling wells record the water level in each cell. The normal operating level is less than 2 feet.

Inlet pipe with riprap and the basin stilling well with the pressure transducer installed inside
Data is collected for the amount of water pumped, water levels in each basin, and pump status for each pump. The data is relayed to the CAP Control Center where it is displayed in real time.

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OPERATIONS
Water levels are measured in each basin with depths typically held at 2 feet or less. As water levels rise, basin rotations are utilized to dry each basin and rejuvenate the infiltration rates. Initial infiltration rates in the individual cells ranged from 3.1 to 6.8 feet per day and have remained over 3 feet per day for the project has a whole.

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MAINTENANCE

Maintenance is required to maintain good infiltration rates, ensure that the electrical and mechanical equipment operates properly, and to manage weed growth. Maintaining good infiltration rates is imperative with recharge projects and is accomplished through a combination of basin rotation and mechanical scraping and ripping. The physical attributes of the project, pumps, valves, remote data acquisition system, all require regular preventative maintenance (PM) to ensure reliable operations.

The basins are operated with approximately 80% of the basin area wet and 20% dry. By rotating the wet/dry cycle through the seven cells, algae growth is kept to a minimum.

HMRP basins with the northern basin in the wet
cycle and the southern basin in the dry cycle

The pumping station has four electric turbine pumps that require regular PM's. Also, the trash rack between the forebay and the canal requires regular cleaning. During periods of monsoons, tumbleweeds clog the intake to the pumps and require back flushing.

Electric pump at the HMRP turnout

Trashrack between the forebay and the canal at
the HMRP turnout with the tumbleweeds beginning to build up

WATER DELIVERIES

Water deliveries to HMRP are measured at the turnout by an acoustic flowmeter at the pump station on the CAP canal. Deliveries to the individual basins are not measured.

Water deliveries are tabulated daily for each basin and added up for the month. Evaporation losses are calculated using the 1970 Cooley Method that calculates a maximum daily evaporation dependent on the time of year and the number of wetted acres for that day. Average evaporation losses are less than 1% of the stored volume.

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Central Arizona Project

H2O Quality

Hieroglyphic Mountains Recharge Project