Making the Most of Underground Water Storage Facilities: Three Case Studies in Arizona

Transcription

1 ABSTRACT & POWERPOINT PRESENTATION Making the Most of Underground Water Storage Facilities: Three Case Studies in Arizona Robert F. Buss, P.E. Associate Vice President Carollo Engineers Phoenix, Arizona Managed Aquifer Recharge Symposium January 25-26, 2011 Irvine, California Symposium Organizers: National Water Research Institute Orange County Water District Water Research Foundation

2 Making the most of Underground Water Storage Facilities: 3 Case Studies in Arizona Topic: Operational Experience Robert F. Buss - Carollo Engineers ABSTRACT Three case studies of how water providers in Arizona addressed their particular water resources challenges using spreading basins to recharge water underground for future recovery as well as make the most of these public water projects for other beneficial purposes. These providers are: the Central Arizona Water Conservancy District (CAWCD), the Town of Gilbert, and the City of Chandler. Lessons learned include: 1. Location is key to success, so take the time to find the right property and geology. 2. Make the recharge facility a place to visit for public education and recreation. 3. Team up with other city departments to maximize the use of the property. Case 1: the CAWCD The CAWCD s primary mission is to deliver the State s full allocation of 1.5 million acre-feet of Colorado River Project (CAP) water per year to Pima, Pinal, and Maricopa counties. The CAWCD has developed a series of artificial groundwater recharge projects in the Phoenix and Tucson Active Management Areas (AMA) to store excess CAP water underground for future recovery. The newest and largest of these facilitie is the Tonopah Desert Recharge Project (TDRP). 1 Buss Making the most of Underground Water Storage Facilities: 3 Case Studies in Arizona

3 TDRP s current permitted volume over 20 years is 2 million acre-feet. This 541-acre site was designed with 207 acres of recharge area in 19 individual basins having sloping bottoms, a gravity delivery pipeline system, control building, remotely operated control valves for each basin and telemetry back to CAP Operations in Phoenix for monitoring and control. TDRP consistently exceeds the CAP s design crteria of 2.5 feet infiltration per acre per day since operations began in January 2006 with an overall average infiltration rate of more than 5.3 feet per day. TDRP s success is due to finding the right geology. Case 2: the Town of Gilbert The Riparian Preserve at Water Ranch was developed out of the Town s need to manage it s water resources to match the demands of its growing population. Designed with a modest infiltration capacity of 4 inches per day per acre, the Town leaders excited its citizenry by locating it adjacent to a County Library, and designing it with a 5-acre urban fishing lake, over 3 miles of hiking trails, picnic ramadas, play areas and numerous habitat educational opportunities. Since its opening in 1998, the Riparian Preserve has enjoyed constant use by people in Gilbert and throughout the Valley of the Sun, and is an immensely popular urban destination. Case 3: the City of Chandler 2 Buss Making the most of Underground Water Storage Facilities: 3 Case Studies in Arizona

4 Taking over 8 years to plan, design and construct, the Chandler Heights Recharge Project (CHRP) is similar in its function and strategic need as the Riparian Preserve above. This 113 acre showcase facility houses a police Sub-Station, Parks & Recreation educational facility, a 5-acre urban fishing lake, miles of hiking trails, habitat viewing opportunities, and 80- acres of recharge basins. It has been operating since 2008 and is a point of pride for Southeast Chandler. 3 Buss Making the most of Underground Water Storage Facilities: 3 Case Studies in Arizona

5 Session 7: Operational Experience in Arizona Systems

6 Making the most of Underground Water Storage Facilities: 3 Case Studies in Arizona Presented by: Robert F. Buss, P.E.

7 Case Study 1: Tonopah Desert Recharge Project (TDRP) Owner: Central Arizona Water Conservation District (CAWCD) Operational: 2006

8 Project Location Was Deliberately Chosen Western Maricopa County, 60 miles west of Phoenix Adjacent to the CAP Canal

9 Project Location Was Deliberately Chosen Site must meet the CAP storage goal of 150,000 AF / YR Not to Exceed 2 million AF CAP Water over 20 years

10 Looking NE Towards the TDRP Site Pre Construction

11 Looking North Towards the TDRP Site Post Construction

12 Project Elements Were Carefully Selected Monitoring Wells

13 Project Elements Were Carefully Selected Piezometer Wells

14 Project Elements Were Carefully Selected 3 year Performance Data 4/25 6/5 7/24 9/5 10/28 12/4 1/28 3/1 4/28 3/1 4/28 6/1 7/28 9/1 10/28 12/

15 Project Elements Were Carefully Selected 3 year Performance Data Design infiltration rate = 2.5 ft /ac /day Actual infiltration rate = 6 ft / ac / day Total 500,240 AF stored as of Dec 2009 Aquifer is receiving water = GW level is about 125 feet

16 TDRP Recharge Basins Fact Sheet Permitted Capacity 150,000 AF / YR Recharge Area 19 Recharge basins over 207 acres Estimated Recharge Rate 6 FT/ AC / Day

17 Recovery Plan Has Been Prepared and Reviewed Direct Recovery Groundwater wells and pipelines Located adjacent to CAP Canal, to pump back into canal Recover GW from upper portion of aquifer

18 Recovery Plan Has Been Prepared and Reviewed In-Direct Recovery Customer can store CAP allocation at recharge facility. Withdraw same amount from their service area, using their GW wells.

19 Case Study 2: Riparian Preserve at Water Ranch Owner: Town of Gilbert, Arizona Operational: 1999

20 Riparian Preserve at Water Ranch Demonstrates the Town s commitment to: Plan for its future water resource needs Provide diverse recreation and learning opportunities Preserve open space and wildlife habitat

21 Riparian Preserve - located in the heart of the Town

22 Ramadas, Restrooms, and Education

23 Simplified Operations

24 Coordination with County Regional Library view from inside

25 Riparian Preserve Recharge Basins Fact Sheet Permitted Capacity 4,369 AF / YR Recharge Area 7 Recharge basins over 36 acres Estimated Recharge Rate inches/day

26 Recharge Performance Data 40,330 AF water stored as of Dec 2010 Aquifer is receiving water = GW level is about 149 feet below surface.

27 Case Study 3: Chandler Heights Recharge Project (CHRP) Owner: City of Chandler, Arizona Operational: 2008

28 Master Plan Established Major Elements for Design Phase Site analysis Initial programming Departmental coordination Workshops Public participation Site plan development Permitting

29 Facility Planning Addressed Public Concerns and Solicited Input Trails Fishing Habitat Programming Equestrian

30 Police Substation Integrated into Nontraditional Setting

31 Environmental Education Building w/classrooms Environmental Education Building

32 Veterans Oasis Park Amenities: Moving Water & Shade Recirculation Stream Basin 5 Stream

33 Chandler Heights Recharge Basins Fact Sheet Permitted Capacity 2,240 AF / YR Recharge Area 5 Recharge basins over 32 acres Estimated Recharge Rate inches/day

34 The Lake and Campus are separate from Recharge Basins

35 The Recharge Basins are east of Lake and Campus

36 Recharge Data 3 Years MG MG MG TOTAL = 966 MG Depth to Groundwater Varied from 35 to Varied from 38 to Varied from 38 to 44

37 Chandler Heights Recharge Project looking NE

38 Summary & Findings Geology is key to efficient recharge performance. Deliberate public involvement on the design elements will win public support. Water, shade, education, fishing and trails are greatly desired by the public. Recharge facility can be a public point of pride.

39 Contributors: Acknowledgements Tim Gorey, Central Arizona Water Conservation District (CAWCD) Patty Jordan, Town of Gilbert, Arizona John Pinkston, City of Chandler, Arizona