Harrison, OH rainwater: 35,695 gallons off a roof
Harrison, OH: gallons off the roof each year
35,695gallons a year
That is a 1,500 sq ft asphalt roof under Harrison, OH's normal 44.9 inches of rain, about 795 gallons for every inch that falls.
In Harrison, 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 Miamitown station (5.6 mi away). Harrison, OH ranks 13th wettest of the 176 cities covered in Ohio.
Month by month in Harrison
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.28 | 2,607 | |
| Feb | 2.86 | 2,273 | |
| Mar | 3.90 | 3,100 | |
| Apr | 4.76 | 3,783 | |
| May | 4.71 | 3,744 | |
| Jun | 4.75 | 3,775 | |
| Jul | 4.04 | 3,211 | 39 |
| Aug | 3.57 | 2,837 | 97 |
| Sep | 3.18 | 2,527 | 146 |
| Oct | 3.16 | 2,512 | 148 |
| Nov | 3.28 | 2,607 | |
| Dec | 3.42 | 2,718 |
Apr is the wettest month (4.76 in, 3,783 gal off the roof); Feb the driest (2.86 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 Harrison
Best fit: one 55-gallon barrel, which delivers about 348 gallons to the garden in a normal year (80.9% of its need).
If you buy one, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Harrison's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 348 | 34,057 |
| 110 gal | 348 | 34,057 |
| 165 gal | 348 | 34,057 |
| 275 gal | 348 | 34,057 |
| 550 gal | 348 | 34,057 |
| 1,000 gal | 348 | 34,057 |
| 1,500 gal | 348 | 34,057 |
| 2,500 gal | 348 | 34,057 |
| 5,000 gal | 348 | 34,057 |
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