# Presentation: 083296

## Pima County’s Role in Water Sustainability for the Green Valley and Sahuarita Area

## Outline

- Review of Pima County’s Functions as Water Manager
- Evaluate Existing Green Valley Water Conditions
- Review Supply Studies
- Suggest Solutions

## Pima County’s 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

## 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

## Green Valley Effluent Recharge

- Quail Creek Ponds

- GVWWTF and Recharge Ponds

## 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

## 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

## Slide 8

***May 17, 2002***

***July 1, 2003***

***May 17, 2002***

***October 4, 2005***

***Stream “A” ***

## 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

## 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

## Recharge Sites

- LSCRP

- Marana High Plains

- Riparian Oxbow

- LSCMRF

## Randolph South Detention Basins

## 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

## 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

## 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.

## Projected Water Level Trends

## Typical Water-Level Trend - ASLD Well SE of I-19  & Duval Mine Road at D(17,13) 36BCC

## Green Valley Water Use

## Equity Model of CAP Extension

## 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**