Cohoes, NY rainwater: 33,453 gallons off a roof
Rainwater from a roof in Cohoes, NY
33,453gallons a year
That is a 1,500 sq ft asphalt roof under Cohoes, NY's normal 42.1 inches of rain, about 795 gallons for every inch that falls.
In Cohoes, 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 Troy L&D station (1.9 mi away). Cohoes, NY ranks 69th wettest of the 90 cities covered in New York.
Month by month in Cohoes
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 2.65 | 2,106 | |
| Feb | 2.43 | 1,931 | |
| Mar | 2.91 | 2,313 | |
| Apr | 3.09 | 2,456 | 157 |
| May | 3.79 | 3,012 | 70 |
| Jun | 4.61 | 3,664 | |
| Jul | 4.64 | 3,688 | |
| Aug | 3.92 | 3,116 | 54 |
| Sep | 3.83 | 3,044 | 65 |
| Oct | 4.23 | 3,362 | 15 |
| Nov | 2.84 | 2,257 | |
| Dec | 3.15 | 2,504 |
Jul is the wettest month (4.64 in, 3,688 gal off the roof); Feb the driest (2.43 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 Cohoes?
Best fit: one 55-gallon barrel, which delivers about 275 gallons to the garden in a normal year (76.3% 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 Cohoes's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 275 | 31,948 |
| 110 gal | 275 | 31,948 |
| 165 gal | 275 | 31,948 |
| 275 gal | 275 | 31,948 |
| 550 gal | 275 | 31,948 |
| 1,000 gal | 275 | 31,948 |
| 1,500 gal | 275 | 31,948 |
| 2,500 gal | 275 | 31,948 |
| 5,000 gal | 275 | 31,948 |
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