1. RAINWATER HARVESTING WITH
CLOUD-BASED INFRASTRUCTURE
Holly Piza, PE
Urban Drainage and Flood Control District

2. The Problem with Rainwater Harvesting

3. Setup

4. Setup

5. Setup

6. Sizing for Stormwater Capture
• WQCV Event = 0.6 inches
• Annual Rainfall = 15 inches
• April through September --1 to 2 inches per month)
• 7,300 SF roof
• 3000 gallon cistern
• Appox. 0.7” event
• 678 SM roof
• 11.3 CM cistern
• Appox. 18mm event
or…

7. Purge Event (Screenshot)

8. Purge followed by rain

9. Conclusions

10. 2012 Irrigation Supply

11. 2013 Irrigation Supply

12. 2014 Irrigation Supply

13. Conclusions
• Sizing for WQCV + 15% was about right.

14. Costs
Pump and Cistern $3800
Downspout $902
Smart Technology $15,000 (UDFCD share)
Water Augmentation and Filing $2000 For 5 years
Total: $21,702
Cost saved in irrigation water = $33
Cost difference between a 0.75” tap and a 1” tap
> $11,000

15. Thank You
• WERF
• Geosyntec
• OptiRTC
• Urban Watersheds Research Institute
• Trevor Toms
• Denver Botanic Gardens
• Welby Farms
Contact:
hpiza@udfcd.org