RoofRainYield

Bethel Park, PA rainwater: 33,684 gallons off a roof

Bethel Park, PA: gallons off the roof each year

33,684gallons a year

That is a 1,500 sq ft asphalt roof under Bethel Park, PA's normal 42.4 inches of rain, about 795 gallons for every inch that falls.

In Bethel Park, 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 Bridgeville 1.4 Sw station (4.7 mi away). Bethel Park, PA ranks 47th wettest of the 68 cities covered in Pennsylvania.

Month by month in Bethel Park

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.152,504
Feb2.702,146
Mar3.382,686
Apr3.482,766108
May4.243,37014
Jun4.493,569
Jul4.343,4491
Aug3.602,86194
Sep3.572,83797
Oct3.132,488152
Nov3.072,440
Dec3.232,567

Jun is the wettest month (4.49 in, 3,569 gal off the roof); Feb the driest (2.70 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

What size rain barrel for Bethel Park

Best fit: one 55-gallon barrel, which delivers about 350 gallons to the garden in a normal year (75.1% of its need).

Before you buy, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Bethel Park's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal35032,014
110 gal35032,014
165 gal35032,014
275 gal35032,014
550 gal35032,014
1,000 gal35032,014
1,500 gal35032,014
2,500 gal35032,014
5,000 gal35032,014

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