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Figure 2. Recharge volume in Acre-Feet during first pilot recharge test at the Vidler Recharge Facility |
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This is the second article in a three part series that discusses the development of the Vidler Recharge Facility (VFR) located in the Harquahala Valley, approximately 90 miles west of the Phoenix metropolitan area. The first article in the series focused on the pilot scale recharge facility’s construction and testing. This article will focus on the development of the full scale VRF. After the pilot scale recharge facility testing was completed in 1999, the full-scale recharge facility design was developed and construction of the project was initiated in September 1999. The full-scale application to store 100,000 ac-ft of CAP water annually was also applied for by Vidler Water Company in August of 1999. The permits to store water at the facility were granted by the Arizona Department of Water Resources (ADWR) in September 2000. The full scale VRF design consists of three phases. The first phase of the project’s construction included all required infrastructure needed to convey the CAP water from the Granite Reef Aqueduct to the VRF. As part of this infrastructure, a 220 cfs gravity turnout structure was constructed at the canal. This required the installation of a temporary coffer dam to redirect the flow in the canal away from where the canal lining was removed. An 84-inch diameter Accusonic flow meter is being used to measure the volume of water delivered from the Granite Reef Aqueduct to the VRF. Figure 1 shows the layout of the full-scale recharge facility. Source water is delivered through two concrete slip form ditches to the Phase 1 basins, Figure 1. There are approximately 17,000 feet of these conveyance structures to deliver CAP source water about ¾ of a mile to two ten-acre Sediment/Recharge basins. The Sediment/Recharge basins are used to reduce the suspended solids in the source water. Phase 1 consists of approximately 84 acres of recharge basins in addition to two existing four-acre pilot scale basins that are incorporated as part of the full-scale project. Currently the VRF has a total of approximately 112 acres of recharge basins. Phases 2 and 3 when constructed will add approximately 100 acres of recharge basins nearly doubling the VRF’s capacity. Each row of recharge basins includes two pods of five typically 4-acre basins. There are currently four pods (A through D) and two Sediment/Recharge basins. Basin B of the pilot scale recharge facility was incorporated as Basin 4 of Pod A of the full-scale recharge facility. Source water delivered to each of the Sediment/Recharge basins is measured using a weir prior to recharging. Hourly flow rates are being recorded by a data logger. Currently, the facility includes 20 vadose zone recharge wells. Ten each have been installed in recharge basins 11 and 20 of Pods C and D. The vadose zone recharge wells are used to facilitate the flow of water to the aquifer and overcome fine grain surface soils. |
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Figure 1. Slip form ditches |
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Development of a Large Scale Groundwater Storage Facility in Western Arizona by Dorothy Timian-Palmer , P.E., Greg L. Bushner , R.G., and Gary G. Small , P.G.
Part 2 of 3 / Volume 1, Issue 2 |
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Date: July/August 2002 |
