RoofRainYield

Butler, PA rainwater: 34,344 gallons off a roof

Butler, PA: gallons off the roof each year

34,344gallons a year

That is a 1,500 sq ft asphalt roof under Butler, PA's normal 43.2 inches of rain, about 795 gallons for every inch that falls.

In Butler, 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 Butler 2 Sw station (1.7 mi away). Butler, PA ranks 45th wettest of the 68 cities covered in Pennsylvania.

Month by month in Butler

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.362,671
Feb2.662,114
Mar3.282,607
Apr3.502,782106
May3.803,02069
Jun4.333,4422
Jul4.163,30624
Aug4.023,19541
Sep4.093,25132
Oct3.302,623131
Nov3.342,655
Dec3.372,678

Jun is the wettest month (4.33 in, 3,442 gal off the roof); Feb the driest (2.66 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 Butler

Best fit: one 55-gallon barrel, which delivers about 302 gallons to the garden in a normal year (74.5% 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 Butler's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal30232,662
110 gal30232,662
165 gal30232,662
275 gal30232,662
550 gal30232,662
1,000 gal30232,662
1,500 gal30232,662
2,500 gal30232,662
5,000 gal30232,662

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