RoofRainYield

Whitewater, WI rainwater: 28,796 gallons off a roof

Whitewater, WI: gallons off the roof each year

28,796gallons a year

That is a 1,500 sq ft asphalt roof under Whitewater, WI's normal 36.2 inches of rain, about 795 gallons for every inch that falls.

In Whitewater, 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 Whitewater station (1.0 mi away). Whitewater, WI ranks 34th wettest of the 98 cities covered in Wisconsin.

Month by month in Whitewater

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.581,256
Feb1.531,216
Mar1.881,494
Apr3.522,798103
May4.193,33020
Jun4.963,942
Jul3.762,98874
Aug4.313,4265
Sep3.522,798103
Oct3.012,392167
Nov2.221,764
Dec1.751,391

Jun is the wettest month (4.96 in, 3,942 gal off the roof); Feb the driest (1.53 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 Whitewater

Best fit: one 55-gallon barrel, which delivers about 375 gallons to the garden in a normal year (79.4% 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 Whitewater's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal37527,371
110 gal37527,371
165 gal37527,371
275 gal37527,371
550 gal37527,371
1,000 gal37527,371
1,500 gal37527,371
2,500 gal37527,371
5,000 gal37527,371

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