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News & Resources |
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Tuscon Chapter News AHS Tucson Chapter Meeting InformationTucson Chapter Officer ElectionsPast meetings:… |
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Location:
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Montgomery and Associates
1550 East Prince Road Tucson, AZ |
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Social half hour:
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6:00 PM
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Program:
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6:30 PM
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Topic to be announced
TUCSON CHAPTER OFFICER ELECTIONS
A big THANK YOU to our dedicated Tucson Chapter officers for 2012 – we appreciate your service!
Past meeting summaries:
November 2011 Meeting Summary
- Write up provided by Shane T. Clark, University of Arizona
ADWR Tucson AMA Model Updates
On Tuesday, November 8th, 2011, the Tucson Chapter hosted a special guest lecture by Dale Mason, a hydrologist with Arizona Department of Water Resources (ADWR) modeling team. This talk was attended by 14 people and was held at the offices of Montgomery and Associates, 1550 East Prince Road, in Tucson.
Here is a brief summary of his lecture for those AHS members unable to attend.
ADWR continuously updates their published groundwater flow models in order to provide the best tools possible in the long-term management of water resources in the state Active Management Areas (AMAs). The Prescott, Salt River Valley, Pinal, Santa Cruz, and Tucson AMA groundwater models have been updated in order to help plan for the agency's goal of achieving safe yield by 2025. The updates to the Tucson AMA model were the main focus of Dale Mason's presentation. The original published Tucson AMA model simulates groundwater conditions with annual stress periods starting in 1940 and ending 1999. This published model is now updated to simulate reported pumping, recharge, streamflow and boundary conditions through 2009. The model domain remains the same with 0.5 by 0.5 mile wide cell grids. The Tucson AMA model incorporates historical reported pumping from the ADWR 55-well registry database. The model also incorporates reported annual recharge for underground storage facilities and other permitted projects, as well as including improved historical agricultural recharge volume calculations. Model calibration is evaluated with residual analysis and comparison of observed and simulated groundwater level hydrographs, using the latest well specific head data.
A significant improvement to the Tucson AMA model is that that it now includes a defined layer bottom for model layer 3. The previous model simulated a 1-foot thick model layer which effectively specified transmissivity rather than hydraulic conductivity. The newly assigned model bottom is based on regional depth to bedrock maps, and a cap is placed on the maximum layer bottom altitude to better represent known regional transmissivities. Additionally, measured episodic stormflow events are now added to the model as total annual streamflow and are distributed along the major drainages according to the Burkham equation (USGS Water Supply Paper 1939-B). The model updates for all AMA models will aid in long-term planning and will help address future stream flow recharge uncertainties. These changes will help to provide realistic future planning scenarios in the respective AMAs. See the November AHS newsletter for a brief description of updates to the other ADWR AMA models. The AHS Tucson Chapter extends a very warm thanks to Dale Mason for his informative presentation. Additionally, the Tucson Chapter would like to thank Montgomery and Associates for providing the space for our monthly talk.
October 2011 Meeting Summary
- Write up provided by Shane T. Clark, University of Arizona
Central Arizona Project's Artificial Recharge Program with Emphasis on the Tonopah Desert, Superstition Mountains, and Pima Mine Road Recharge Projects
On Tuesday, October 11th, 2011 the Tucson Chapter hosted a special guest lecture by Timothy L Gorey, who is the Senior Hydrogeologist for the Central Arizona Project (CAP). The talk was attended by 15 people and was held at the offices of Montgomery and Associates, 1550 East Prince Road, in Tucson.
Here is a brief summary of his lecture for those AHS members unable to attend.
Timothy Gorey gave a presentation on the development and management of CAP recharge projects. One of CAP's incumbent roles is to build and operate groundwater recharge projects for Maricopa and Pima Counties. In accordance with the 1986 Arizona Underground Storage and Recovery Act, CAP has constructed and currently operates six recharge facilities for a combined annual capacity total of nearly 300,000 acre-feet per year (AF/yr) of underground storage for future recovery. Each CAP recharge project has unique features and operational requirements. Initially, all projects were designed to be operated manually. As each program grew, it became imperative due to staffing requirements and distance of recharge locations, that the system become remotely operated from CAP headquarters.
A seventh recharge facility, Superstition Mountains Recharge Project (SMRP), has just begun operating in September 2011. CAP is currently expected to provide 25,000 acre-feet (AF) of recharge to its 40-acre basins. The official siting for the SMRP began in 2001 and was completed in 2003. The field investigation and study was conducted by GeoTrans, Inc. A study area, 410 square miles in the East Salt River Valley, was selected based on proximity to the CAP canal, and land availability. An initial fatal flaw analysis and reconnaissance level field investigation was conducted. The field investigation included: 31 backhoe trenches dug to 10-15 foot depths, 8 sonic borings drilled to 99 feet, 3 borings drilled to 300 feet, 1 boring drilled to 500 feet , 4 basin infiltration tests conducted, and 10 cylinder infiltration tests conducted. The results of the field investigation were that the site was deemed suitable for a large-scale recharge facility.
The SMRP is on 40 surface acres with the land owner being the US Bureau of Reclamation. The SMRP is permitted to recharge in two phases: 1) 40 acre basins at 25,000 AF/yr, 2) 155 acre basins at 56, 500 AF/yr. The initial site design stipulated 155 acres for the basin area but was decreased due to disagreements with the Arizona State Land Department. The SMRP is operated by six 250 hp electric pumps with variable frequency drive controls. The pumps are contained in a 42 inch protective steel casing which is mounted on bridging across the canal. Each of these pumps produces a 25cubic feet per second (cfs) capacity totaling 150 cfs, and feed into a 20 inch discharge pipe manifold. A 5-inch HDPE pipe carries the water over the Sonoqui dike and is delivered to each basin via a 30 inch pipe. The delivery system for each basin is remotely operated by a SCADA system (Alan Bradley Programmable Logic control) through a control center at CAP headquarters. The approximated cost of the facility is $6.9 million.
CAP operates other recharge facilities such as the Pima Mine Road Recharge Facility (PMRRF) and the Tonopah Desert Recharge Project (TDRP) which administers groundwater aquifer recharge. PMRF is 37 acres of surface basins and is permitted to recharge 30,000 AF/yr. TDRP is 220 acres of surface basins and is permitted to recharge 150,000 AF/yr. CAP maintenance of these facilities includes removal of sediment infill, weed control, control of algae growth, air entrainment issues, and opening clogged valves. CAP's solution to the clogged valves by clam shells was to redesign inlet structures. The Ross values were replaced with Hilton jet flow gate valves that now allow the clam shells to pass through.
CAP is not the only entity that utilizes Colorado River water via the CAP canal. There are 20-30 publically and privately owned recharge facilities drawing off the CAP canal system in addition to CAP.
The AHS Tucson Chapter extends a very warm thanks to Timothy Gorey for his informative presentation. Additionally, the Tucson Chapter would like to thank Montgomery and Associates for providing the space for our monthly talk.
© 2010 Arizona Hydrological Society - All rights reserved
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| Date:
December 13, 2011 For general information about chapter meetings, click here. |
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