Shown in the sample calculations below, assuming a 20% reduction in water use and the current 2nd tier price for water in Marina, the estimated payback period to the residential customer with a larger system is 5.3 years. The estimated payback period for the larger commercial system is approximately 2 months.
District does not guarantee payback period or water savings. The payback and water use savings information is provided only as an estimated benefit of the proposed equipment.
| Larger residential irrigation system 4 zones, 1” valves |
15gpm x 4 zones |
| x 10 minutes/run time each | |
| x 3 applications/week | |
| x 42 weeks/year | |
| x 20% est. savings | |
| = 15,120 gals saved | |
| 5.3 year payback period for homeowner | = $56.60/yr savings |
| Commercial irrigation system 12 zones, 1.5” valves |
35 gpm x 12 zones |
| x 20 minutes/run time each | |
| x 3 applications/week | |
| x 42 weeks/year | |
| x 20 % est. savings | |
| = 1,058,400 gals saved | |
| Est. payback occurs after approx. 2 months of irrigation. | = $3,961.92/yr savings |
The water use savings associated with the ET controller rebates are variable based many factors at application sites. Primarily, the larger the area irrigated, the larger the savings.