1. Summary Findings of the RVHA Water Team
May 21, 2015

2. Summary
Hydrologists’ consensus it that the primary ground water source is a “perched aquifer with fingers” on the north & east slope of the McDowell Mountains
The eastern portion of the Rio Verde Foothills Planning Area is affected by an aquifer heavily influenced by the Verde River
General trend is toward increasing depth to potable water
Water in the eastern portion of the Planning Area is generally not potable due to silt
There are significantly fewer successful wells in the area than issued permits suggest
Three private water companies provide water to the roughly 24% of area residents dependent on hauled water
Local conditions are sufficiently variable that no definitive statements can be made regarding water availability in a given location

3. Summary of RVHA Survey Highlights; of 112 Respondents:
69 people reported having a working well on their property (62%).
58 respondents (52%) reported being on shared wells. There were just under 4 households per well on average. 
5 wells were reported as having gone dry (5%)
12 people reported having a change in flow from their well. 9 reported on their own well, 3 on shared wells. (11%)
26 reported only hauling water (24%)
Illustrations follow:

4. Legend Dynamite Rd. Jomax Road Dixileta Drive Lone Mountain Rd.
Dove Valley Rd.
Carefree Hwy.
Cloud Rd.
136 St.
144 St.
152 St.
160 St.
168 St.
176 St.
Yes on Question 1: There is a working well on my property
Yes on Question 3: There has been a change in the flow from our well .
Yes on Question 8: We haul water only.
Yes on Question 4: Our well has dried up.
Legend

5. Dynamite Rd.
Jomax Road
Dixileta Drive
Lone Mountain Rd.
Dove Valley Rd.
Carefree Hwy.
Cloud Rd.
136 St.
144 St.
152 St.
160 St.
168 St.
176 St.

6. ADWR Well Permit Data Summary*
81% of permits executed
Not all wells were successful, and not all completion reports were completely filed
* As of mid-July 2014

7. Test Well A CBD1*
* Apparently abandoned

8. Test Well A CDB2

9. Test Well A ADD*
* Closest Test Well to the Verde River

10. Test Well A CCC

11. Going forward
Water is available in the area via ground water in some locations and from the 3 water companies serving the ‘Foothills.
Caution is that supply from neither are fully assured as ground water levels are receding and the water companies operate at the discretion of the City of Scottsdale
Water availability and environmental sensitivity as a wildlife corridor between McDowell preserve areas and Tonto National Forest favor maintaining low density
Rooftop rain catchment and grey water reuse could significantly augment ground water and hauled water for non potable uses, and should be encouraged
Adoption of “Low Impact Development” principles utilized in Tucson and other arid regions could support both Flood Control objectives and sustain aquifer health

12. Appendix Key numbers relating to rain water capture
Roughly 85% of water processed via septic system is returned to the aquifer. However, only between 45-55% of household water use makes it to the septic system. The remainder is used for landscape watering, washing driveways, patios, and cars, etc.
A cubic foot of water is 7.48 gallons. Capturing only 4 in. of rainfall on a 3000 sq. ft. roof yields 1000 cubic feet of water. This is nearly 7500 gallons.
Use of captured rain water for landscape watering and other non-potable uses could reduce the net impact of groundwater pumping to under 20% of the pumped volume in areas served by septic systems.