RoofRainYield

New Castle, PA rainwater: 33,207 gallons off a roof

Rainwater from a roof in New Castle, PA

33,207gallons a year

That is a 1,500 sq ft asphalt roof under New Castle, PA's normal 41.8 inches of rain, about 795 gallons for every inch that falls.

In New Castle, 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 New Castle 1 N station (1.7 mi away). New Castle, PA ranks 51st wettest of the 68 cities covered in Pennsylvania.

Month by month in New Castle

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.862,273
Feb2.201,749
Mar3.082,448
Apr3.652,90187
May3.893,09257
Jun4.473,553
Jul4.553,616
Aug3.913,10855
Sep3.863,06861
Oct3.222,559141
Nov2.962,353
Dec3.132,488

Jul is the wettest month (4.55 in, 3,616 gal off the roof); Feb the driest (2.20 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 New Castle?

Best fit: one 55-gallon barrel, which delivers about 300 gallons to the garden in a normal year (74.7% 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 New Castle's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal30031,557
110 gal30031,557
165 gal30031,557
275 gal30031,557
550 gal30031,557
1,000 gal30031,557
1,500 gal30031,557
2,500 gal30031,557
5,000 gal30031,557

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