Scarsdale, NY rainwater: 40,726 gallons off a roof
Scarsdale, NY: gallons off the roof each year
40,726gallons a year
That is a 1,500 sq ft asphalt roof under Scarsdale, NY's normal 51.2 inches of rain, about 795 gallons for every inch that falls.
In Scarsdale, 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 Dobbs Ferry-Ardsley station (3.1 mi away). Scarsdale, NY ranks 7th wettest of the 90 cities covered in New York.
Month by month in Scarsdale
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.87 | 3,076 | |
| Feb | 3.30 | 2,623 | |
| Mar | 4.37 | 3,473 | |
| Apr | 4.26 | 3,386 | 11 |
| May | 4.27 | 3,394 | 10 |
| Jun | 4.58 | 3,640 | |
| Jul | 4.53 | 3,600 | |
| Aug | 4.44 | 3,529 | |
| Sep | 4.61 | 3,664 | |
| Oct | 4.43 | 3,521 | |
| Nov | 3.88 | 3,084 | |
| Dec | 4.70 | 3,736 |
Dec is the wettest month (4.70 in, 3,736 gal off the roof); Feb the driest (3.30 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 Scarsdale
Best fit: one 55-gallon barrel, which delivers about 16 gallons to the garden in a normal year (75.5% of its need).
If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Scarsdale's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 16 | 39,525 |
| 110 gal | 16 | 39,525 |
| 165 gal | 16 | 39,525 |
| 275 gal | 16 | 39,525 |
| 550 gal | 16 | 39,525 |
| 1,000 gal | 16 | 39,525 |
| 1,500 gal | 16 | 39,525 |
| 2,500 gal | 16 | 39,525 |
| 5,000 gal | 16 | 39,525 |
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