Pima Countys Role in Water Sustainability for the Green Valley and Sahuarita Area

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Pima Countys Role in Water Sustainability for
the Green Valley and Sahuarita Area
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Outline

• Review of Pima Countys Functions as Water
  Manager
• Evaluate Existing Green Valley Water Conditions
• Review Supply Studies
• Suggest Solutions

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Pima Countys Water Management Role

• We are not a water provider
• We treat and reuse/recharge/recycle wastewater
• We perform flood control and recharge and reuse
  floodwaters
• We manage County land and water
• We regulate land use plans and consider water
  impacts from these plans

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Wastewater in Green Valley

• Green Valley Wastewater Treatment Facility
• Treated 2.0 mgd in 2007
• Recharged 1880 AF Quail Creek ponds -2007
• Quail Creek recovers for Golf Course
• Recharged 120 AF at County ponds -2007

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Green Valley Effluent Recharge
GVWWTF and Recharge Ponds
Quail Creek Ponds
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Flood Control Functions and Water Supply

• Detention/retention Locally and Regionally
• Multi-purpose Recharge/reuse of Surplus
  Effluent/Floodwaters (Recharge Authority)
• Water Harvesting Guidance on Local Level

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Kino Environmental Restoration Project

• 125-acre Ajo Detention Basin Transformed to
  Multi-purpose Facility
• Detains and reuses up to 1880 AF storm water for
  irrigating ball fields and hydro-riparian use
• Riparian Restoration of hydro-riparian stream
  courses and xero-riparian upland vegetation
• Wildlife viewing, trails and educational programs
  
• Irrigation of adjacent ball fields with captured
  storm water and treated effluent, if needed

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Stream A
May 17, 2002

May 17, 2002
July 1, 2003
October 4, 2005
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Marana High Plains Recharge Facility

• Diversion of Effluent to 1.25 mi. Riparian Oxbow
• Recharge of 350-600 AF/yr to four multi-purpose
  recharge basins
• Allows for recharge, riparian habitat
  enhancement, recreation and education

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Other Recharge/Detention Projects

• Lower Santa Cruz Managed Recharge Facility
• Lower Santa Cruz Replenishment Facility-CAP
• Avra/Black Wash Recharge-Effluent
• Arroyo Chico Multi-Use Project-Stormwater

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Recharge Sites
Marana High Plains
LSCMRF
Riparian Oxbow
LSCRP
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Randolph South Detention Basins
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Pima County Land Use and Water

• Water Resources Comprehensive Plan Amendment
  (Res. No. 2008-72)
• Water Supply Impact Reviews on Comprehensive Plan
  Amendments and Rezonings. Five Issues
• - Water Service and Renewable and Potable
  Supply
• - Water Depth and water level trends
• - Subsidence
• - Proximity to known groundwater-dependent
  ecosystems
• - location within a hydrogeologic basin
• Water Resource Impact Assessment for Rezoning
  with Site Analysis

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Pima County Owns/Manages Land in Green Valley

• Canoa Ranch 4800 Acres. Possible Effluent
  recharge/recovery in conjunction with restoration
• Green Valley Wastewater Treatment Facility
• Manages Floodplains and Floodways

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Green Valley Water Conditions

• Overdraft by as much as 30,000-40,000 AF/yr
• Water level declines by as much as 2-3 ft/yr in
  some areas
• Projected declines variable but 2-3 ft/yr from
  Sahuarita to Continental Roads.

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Projected Water Level Trends
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Typical Water-Level Trend - ASLD Well SE of I-19
Duval Mine Road at D(17,13) 36BCC
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Green Valley Water Use
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Equity Model of CAP Extension
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Recommendations For Green Valley

• Evaluate Sustainable Volume of CAP Needed
• - 30,000-40,000 AF/yr.
• - Smaller Pipeline feasible -36 ? Significant
  cost reduction from previous studies.
• - Seek financing options and technical
  assistance from public agencies and special
  districts to fund
• Implement Stronger Water Conservation Measures
• Evaluate Water Harvesting Opportunities