RoofRainYield

Hanover, PA rainwater: 37,340 gallons off a roof

How much rain a roof in Hanover, PA collects

37,340gallons a year

That is a 1,500 sq ft asphalt roof under Hanover, PA's normal 47.0 inches of rain, about 795 gallons for every inch that falls.

In Hanover, PA 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 Hanover 1.2 Sw station (1.2 mi away). Hanover, PA ranks 21st wettest of the 68 cities covered in Pennsylvania.

Month by month in Hanover

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.382,686
Feb2.842,257
Mar4.113,267
Apr3.702,94181
May4.253,37812
Jun4.123,27529
Jul4.343,4491
Aug3.903,10056
Sep5.244,165
Oct3.953,13950
Nov3.482,766
Dec3.672,917

Sep is the wettest month (5.24 in, 4,165 gal off the roof); Feb the driest (2.84 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 Hanover?

Best fit: one 55-gallon barrel, which delivers about 180 gallons to the garden in a normal year (78.5% 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 Hanover's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal18036,020
110 gal18036,020
165 gal18036,020
275 gal18036,020
550 gal18036,020
1,000 gal18036,020
1,500 gal18036,020
2,500 gal18036,020
5,000 gal18036,020

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 Pennsylvania?

No rainwater harvesting regulations

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