Powell, OH rainwater: 33,461 gallons off a roof
How much rain a roof in Powell, OH collects
33,461gallons a year
That is a 1,500 sq ft asphalt roof under Powell, OH's normal 42.1 inches of rain, about 795 gallons for every inch that falls.
In Powell, OH 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 Dublin 3.2 Ene station (2.6 mi away). Powell, OH ranks 86th wettest of the 176 cities covered in Ohio.
Month by month in Powell
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.02 | 2,400 | |
| Feb | 2.35 | 1,868 | |
| Mar | 3.46 | 2,750 | |
| Apr | 3.86 | 3,068 | 61 |
| May | 4.43 | 3,521 | |
| Jun | 4.61 | 3,664 | |
| Jul | 4.29 | 3,410 | 7 |
| Aug | 3.63 | 2,885 | 90 |
| Sep | 3.29 | 2,615 | 132 |
| Oct | 2.95 | 2,345 | 175 |
| Nov | 3.00 | 2,384 | |
| Dec | 3.21 | 2,551 |
Jun is the wettest month (4.61 in, 3,664 gal off the roof); Feb the driest (2.35 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 Powell
Best fit: one 55-gallon barrel, which delivers about 369 gallons to the garden in a normal year (79.3% 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 Powell's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 369 | 31,952 |
| 110 gal | 369 | 31,952 |
| 165 gal | 369 | 31,952 |
| 275 gal | 369 | 31,952 |
| 550 gal | 369 | 31,952 |
| 1,000 gal | 369 | 31,952 |
| 1,500 gal | 369 | 31,952 |
| 2,500 gal | 369 | 31,952 |
| 5,000 gal | 369 | 31,952 |
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 Ohio?
Legal. Ohio regulates rainwater cisterns used as a drinking-water source as private water systems (OAC chapter 3701-28): local health department permit, continuous disinfection and filtration. No state rule restricting non-potable collection or storage size.
Checked against the current source on 2026-11-06. Source