Martinsville, IN rainwater: 36,156 gallons off a roof
Rainwater from a roof in Martinsville, IN
36,156gallons a year
That is a 1,500 sq ft asphalt roof under Martinsville, IN's normal 45.5 inches of rain, about 795 gallons for every inch that falls.
In Martinsville, 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 Martinsville 2 Sw station (1.4 mi away). Martinsville, IN ranks 22nd wettest of the 88 cities covered in Indiana.
Month by month in Martinsville
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.16 | 2,512 | |
| Feb | 2.43 | 1,931 | |
| Mar | 3.55 | 2,822 | |
| Apr | 4.83 | 3,839 | |
| May | 4.97 | 3,950 | |
| Jun | 5.31 | 4,220 | |
| Jul | 4.08 | 3,243 | 34 |
| Aug | 3.44 | 2,734 | 113 |
| Sep | 3.52 | 2,798 | 103 |
| Oct | 3.47 | 2,758 | 110 |
| Nov | 3.61 | 2,869 | |
| Dec | 3.12 | 2,480 |
Jun is the wettest month (5.31 in, 4,220 gal off the roof); Feb the driest (2.43 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
Barrel or cistern in Martinsville?
Best fit: one 55-gallon barrel, which delivers about 296 gallons to the garden in a normal year (82.2% of its need).
Before you buy, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Martinsville's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 296 | 34,675 |
| 110 gal | 296 | 34,675 |
| 165 gal | 296 | 34,675 |
| 275 gal | 296 | 34,675 |
| 550 gal | 296 | 34,675 |
| 1,000 gal | 296 | 34,675 |
| 1,500 gal | 296 | 34,675 |
| 2,500 gal | 296 | 34,675 |
| 5,000 gal | 296 | 34,675 |
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