Mount Vernon, NY rainwater: 39,621 gallons off a roof
Mount Vernon, NY: gallons off the roof each year
39,621gallons a year
That is a 1,500 sq ft asphalt roof under Mount Vernon, NY's normal 49.9 inches of rain, about 795 gallons for every inch that falls.
In Mount Vernon, 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 Bronx station (5.4 mi away). Mount Vernon, NY ranks 18th wettest of the 90 cities covered in New York.
Month by month in Mount Vernon
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.74 | 2,973 | |
| Feb | 3.19 | 2,535 | |
| Mar | 4.37 | 3,473 | |
| Apr | 3.95 | 3,139 | 50 |
| May | 4.06 | 3,227 | 36 |
| Jun | 4.55 | 3,616 | |
| Jul | 4.37 | 3,473 | |
| Aug | 4.82 | 3,831 | |
| Sep | 4.55 | 3,616 | |
| Oct | 4.13 | 3,283 | 27 |
| Nov | 3.45 | 2,742 | |
| Dec | 4.67 | 3,712 |
Aug is the wettest month (4.82 in, 3,831 gal off the roof); Feb the driest (3.19 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 Mount Vernon
Best fit: one 55-gallon barrel, which delivers about 89 gallons to the garden in a normal year (78.4% 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 Mount Vernon's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 89 | 38,317 |
| 110 gal | 89 | 38,317 |
| 165 gal | 89 | 38,317 |
| 275 gal | 89 | 38,317 |
| 550 gal | 89 | 38,317 |
| 1,000 gal | 89 | 38,317 |
| 1,500 gal | 89 | 38,317 |
| 2,500 gal | 89 | 38,317 |
| 5,000 gal | 89 | 38,317 |
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