Plymouth, IN rainwater: 31,999 gallons off a roof
Plymouth, IN: gallons off the roof each year
31,999gallons a year
That is a 1,500 sq ft asphalt roof under Plymouth, IN's normal 40.3 inches of rain, about 795 gallons for every inch that falls.
In Plymouth, IN a single barrel does most of the work. Storms come often enough that a small tank refills before it runs dry, and a bigger one would mostly sit full.
Rainfall: NOAA 1991-2020 climate normals, the Plymouth station (1.1 mi away). Plymouth, IN ranks 76th wettest of the 88 cities covered in Indiana.
Month by month in Plymouth
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.63 | 2,090 | |
| Feb | 2.33 | 1,852 | |
| Mar | 2.45 | 1,947 | |
| Apr | 3.63 | 2,885 | 90 |
| May | 4.33 | 3,442 | 2 |
| Jun | 4.24 | 3,370 | 14 |
| Jul | 4.39 | 3,489 | |
| Aug | 4.05 | 3,219 | 37 |
| Sep | 3.20 | 2,543 | 143 |
| Oct | 3.38 | 2,686 | 121 |
| Nov | 3.03 | 2,408 | |
| Dec | 2.60 | 2,066 |
Jul is the wettest month (4.39 in, 3,489 gal off the roof); Feb the driest (2.33 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
Which tank size is worth it in Plymouth
Best fit: one 55-gallon barrel, which delivers about 322 gallons to the garden in a normal year (79.0% of its need).
If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Plymouth's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 322 | 30,492 |
| 110 gal | 322 | 30,492 |
| 165 gal | 322 | 30,492 |
| 275 gal | 322 | 30,492 |
| 550 gal | 322 | 30,492 |
| 1,000 gal | 322 | 30,492 |
| 1,500 gal | 322 | 30,492 |
| 2,500 gal | 322 | 30,492 |
| 5,000 gal | 322 | 30,492 |
Simulated storm by storm through a normal year using the station's count of days with 0.1 in or more of rain each month.
Is rainwater collection legal in Indiana?
No statewide rainwater harvesting regulations; check county for local incentives
From the 2015 (Pacific Northwest National Laboratory report 24347); not yet re-checked against current law, so check with your state water agency before building anything large. Source