RoofRainYield

Spring Valley, NY rainwater: 39,995 gallons off a roof

How much rain a roof in Spring Valley, NY collects

39,995gallons a year

That is a 1,500 sq ft asphalt roof under Spring Valley, NY's normal 50.3 inches of rain, about 795 gallons for every inch that falls.

In Spring Valley, 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 West Nyack 1.3 Wsw station (3.6 mi away). Spring Valley, NY ranks 11th wettest of the 90 cities covered in New York.

Month by month in Spring Valley

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.742,973
Feb3.102,464
Mar4.333,442
Apr4.133,28327
May4.013,18742
Jun4.663,704
Jul4.443,529
Aug4.903,895
Sep4.713,744
Oct4.383,481
Nov3.502,782
Dec4.423,513

Aug is the wettest month (4.90 in, 3,895 gal off the roof); Feb the driest (3.10 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 Spring Valley?

Best fit: one 55-gallon barrel, which delivers about 55 gallons to the garden in a normal year (78.8% 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 Spring Valley's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal5538,814
110 gal5538,814
165 gal5538,814
275 gal5538,814
550 gal5538,814
1,000 gal5538,814
1,500 gal5538,814
2,500 gal5538,814
5,000 gal5538,814

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