Lancaster, OH rainwater: 31,935 gallons off a roof
Lancaster, OH: gallons off the roof each year
31,935gallons a year
That is a 1,500 sq ft asphalt roof under Lancaster, OH's normal 40.2 inches of rain, about 795 gallons for every inch that falls.
In Lancaster, 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 Lancaster station (0.7 mi away). Lancaster, OH ranks 143rd wettest of the 176 cities covered in Ohio.
Month by month in Lancaster
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.86 | 2,273 | |
| Feb | 2.32 | 1,844 | |
| Mar | 3.40 | 2,702 | |
| Apr | 3.93 | 3,124 | 52 |
| May | 4.17 | 3,314 | 22 |
| Jun | 4.08 | 3,243 | 34 |
| Jul | 4.22 | 3,354 | 16 |
| Aug | 3.37 | 2,678 | 122 |
| Sep | 3.22 | 2,559 | 141 |
| Oct | 3.07 | 2,440 | 160 |
| Nov | 2.69 | 2,138 | |
| Dec | 2.85 | 2,265 |
Jul is the wettest month (4.22 in, 3,354 gal off the roof); Feb the driest (2.32 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
What size rain barrel for Lancaster
Best fit: one 55-gallon barrel, which delivers about 437 gallons to the garden in a normal year (79.8% 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 Lancaster's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 437 | 30,328 |
| 110 gal | 437 | 30,328 |
| 165 gal | 437 | 30,328 |
| 275 gal | 437 | 30,328 |
| 550 gal | 437 | 30,328 |
| 1,000 gal | 437 | 30,328 |
| 1,500 gal | 437 | 30,328 |
| 2,500 gal | 437 | 30,328 |
| 5,000 gal | 437 | 30,328 |
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