This document analyzes the irrigation water demand and potential savings from water capture for three different weather conditions: drought, excess rain, and normal. It calculates the yearly irrigation water demand as 552,509 gallons and models the monthly water bills and savings that could result from using captured rainwater instead of municipal water under each condition. The greatest potential savings are seen under excess rain conditions, where monthly bills could be reduced by up to $698.88 annually using captured water.

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
Total Irrigation Irrigation
Total Water
Collection Available Yearly Yearly % Water
Collected for
Condition Water To Demand Demand Saved
Year (gal)
Collect (gal) (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
$400.00
Nov $ 830.35 $ 829.59 $ 0.76
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
Excess Rain Condition

2. 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
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