Rochester, NY rainwater: 27,890 gallons off a roof
How much rain a roof in Rochester, NY collects
27,890gallons a year
That is a 1,500 sq ft asphalt roof under Rochester, NY's normal 35.1 inches of rain, about 795 gallons for every inch that falls.
In Rochester, NY 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 Rochester Gtr Intl Ap station (4.8 mi away). Rochester, NY ranks 88th wettest of the 90 cities covered in New York.
Month by month in Rochester
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.55 | 2,027 | |
| Feb | 2.13 | 1,693 | |
| Mar | 2.49 | 1,979 | |
| Apr | 2.99 | 2,376 | 170 |
| May | 2.86 | 2,273 | 186 |
| Jun | 3.37 | 2,678 | 122 |
| Jul | 3.56 | 2,830 | 98 |
| Aug | 3.31 | 2,631 | 130 |
| Sep | 3.18 | 2,527 | 146 |
| Oct | 3.22 | 2,559 | 141 |
| Nov | 2.76 | 2,194 | |
| Dec | 2.67 | 2,122 |
Jul is the wettest month (3.56 in, 2,830 gal off the roof); Feb the driest (2.13 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 Rochester?
Best fit: one 55-gallon barrel, which delivers about 768 gallons to the garden in a normal year (77.4% 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 Rochester's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 768 | 25,907 |
| 110 gal | 768 | 25,907 |
| 165 gal | 768 | 25,907 |
| 275 gal | 768 | 25,907 |
| 550 gal | 768 | 25,907 |
| 1,000 gal | 768 | 25,907 |
| 1,500 gal | 768 | 25,907 |
| 2,500 gal | 768 | 25,907 |
| 5,000 gal | 768 | 25,907 |
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 New York?
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