RoofRainYield

Muskego, WI rainwater: 28,557 gallons off a roof

Rainwater from a roof in Muskego, WI

28,557gallons a year

That is a 1,500 sq ft asphalt roof under Muskego, WI's normal 35.9 inches of rain, about 795 gallons for every inch that falls.

In Muskego, WI 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 Muskego 1.0 W station (1.5 mi away). Muskego, WI ranks 39th wettest of the 98 cities covered in Wisconsin.

Month by month in Muskego

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.841,462
Feb1.711,359
Mar2.021,606
Apr3.622,87791
May3.993,17145
Jun4.743,767
Jul3.552,822100
Aug3.873,07660
Sep3.482,766108
Oct2.882,289183
Nov2.301,828
Dec1.931,534

Jun is the wettest month (4.74 in, 3,767 gal off the roof); Feb the driest (1.71 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 Muskego

Best fit: one 55-gallon barrel, which delivers about 455 gallons to the garden in a normal year (77.5% 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 Muskego's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal45526,962
110 gal45526,962
165 gal45526,962
275 gal45526,962
550 gal45526,962
1,000 gal45526,962
1,500 gal45526,962
2,500 gal45526,962
5,000 gal45526,962

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 Wisconsin?

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