This document summarizes irrigation water usage and costs under different weather conditions. It shows the irrigation demand, water collected, and monthly water bills for drought, excess rain, and normal conditions. Capturing rainfall reduces monthly bills by $443-828 depending on conditions. Over 30 years, using captured rainwater would save $682-6,856 compared to the cost of installation, with normal conditions providing the highest profit.

1. Irrigation Demand
Irrigation Water Used Water Used Water Used Water Used Water Used
Area (ft^2)
(ft/week) (ft^3/week) (gal/week) (gpd) (gal/month) (gal/year)
9,200.00 0.0417 383.64 2,870.01 410.00 11,480.04 120,540.46
6,290.00 0.0417 262.293 1,962.21 280.32 7,848.86 70,639.70
32,174.00 0.0417 1,341.66 10,036.93 1,433.85 40,147.71 361,329.37
14,869.15 2,124.16 59,476.61
552,509.53
Irrigation
Total Available Total Water Irrigation
Collection Yearly % Water
Water To Collect Collected for Yearly
Condition Demand Saved
(gal) Year (gal) Demand (gal)
(gal)
Drought 133,427.97 51,219.00 552,509.53 501,290.53 9%
Excess 458,173.80 88,619.00 552,509.53 463,890.53 16%
Normal 313,184.60
120,000.00 552,509.53 432,509.53 22%
Drought Condition
Bill Using
Month Monthly Bill Captured Savings Drought Rain Condition
Water $900.00
Jan $ 472.51 $ 454.28 $ 18.23 $850.00
Feb $ 472.51 $ 463.83 $ 8.68 $800.00
Monthly
March $ 830.35 $ 751.76 $ 78.59 $750.00 Water Bill
Apr $ 830.35 $ 767.10 $ 63.25 $700.00
May $ 830.35 $ 780.07 $ 50.28 Bill With
$650.00
June $ 830.35 $ 829.57 $ 0.78 Water
$600.00 Savings
July $ 830.35 $ 751.76 $ 78.59
$550.00
Aug $ 830.35 $ 751.76 $ 78.59
$500.00
Sept $ 830.35 $ 795.29 $ 35.06
$450.00
Oct $ 830.35 $ 810.54 $ 19.81
Nov $ 830.35 $ 829.59 $ 0.76 $400.00
1 2 3 4 5 6 7 8 9 10 11 12
Dec $ 472.51 $ 461.66 $ 10.85 Months
$ 8,890.68 $
8,447.21 $ 443.47

2. Excess Rain Condition
Bill Using
Month Monthly Bill Captured Savings Excess Rain Condition
Water $900.00
Jan $ 472.51 $ 432.23 $ 40.28 $850.00
Feb $ 472.51 $ 469.04 $ 3.47 $800.00
Monthly Water
March $ 830.35 $ 751.76 $ 78.59 $750.00
Bill
Apr $ 830.35 $ 751.76 $ 78.59 $700.00 Bill with Water
May $ 830.35 $ 751.76 $ 78.59 $650.00 Savings
June $ 830.35 $ 751.76 $ 78.59 $600.00
July $ 830.35 $ 751.76 $ 78.59 $550.00
Aug $ 830.35 $ 751.76 $ 78.59 $500.00
Sept $ 830.35 $ 751.76 $ 78.59 $450.00
Oct $ 830.35 $ 773.19 $ 57.16 $400.00
Nov $ 830.35 $ 799.87 $ 30.48 1 2 3 4 5 6 7 8 9 10 11 12
Dec $ 472.51 $ 455.15 $ 17.36 Months
$ 8,890.68 $
8,191.80 $ 698.88

3. Normal Rain Condition
Bill Using
Month Monthly Bill Captured Savings
Water
Normal Rain Condition
$900.00
Jan $ 472.51 $ 432.23 $ 40.28 $850.00
Feb $ 472.51 $ 432.23 $ 40.28
$800.00
March $ 830.35 $ 751.76 $ 78.59
$750.00
Apr $ 830.35 $ 751.76 $ 78.59
$700.00 Monthly Water
May $ 830.35 $ 751.76 $ 78.59
$650.00 Bill
June $ 830.35 $ 751.76 $ 78.59
July $ 830.35 $ 751.76 $ 78.59 $600.00 Bill with Water
$550.00 Savings
Aug $ 830.35 $ 751.76 $ 78.59
Sept $ 830.35 $ 751.76 $ 78.59 $500.00
Oct $ 830.35 $ 751.76 $ 78.59 $450.00
Nov $ 830.35 $ 751.76 $ 78.59 $400.00
Dec $ 472.51 $ 432.23 $ 40.28 1 2 3 4 5 6 7 8 9 10 11 12
Months
$ 8,890.68 $
8,062.53 $ 828.15
i=3% n=30 yrs 2012 SAWS Rates
Savings for One
Condition Cost Benefit Total Profit
Year
Drought $ 443.47 $ 9,375.00 $ 8,692.01 $ (682.99)
Excess $ 698.88 $ 9,375.00 $ 13,698.05 $ 4,323.05
Normal $ 828.15 $ 9,375.00 $ 16,231.74 $ 6,856.74