RoofRainYield

Baraboo, WI rainwater: 30,918 gallons off a roof

How much rain a roof in Baraboo, WI collects

30,918gallons a year

That is a 1,500 sq ft asphalt roof under Baraboo, WI's normal 38.9 inches of rain, about 795 gallons for every inch that falls.

In Baraboo, 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 Baraboo station (0.9 mi away). Baraboo, WI ranks 9th wettest of the 98 cities covered in Wisconsin.

Month by month in Baraboo

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.351,073
Feb1.361,081
Mar2.211,757
Apr4.163,30624
May4.283,4029
Jun5.584,435
Jul4.793,807
Aug4.533,600
Sep3.853,06062
Oct2.912,313180
Nov2.201,749
Dec1.681,335

Jun is the wettest month (5.58 in, 4,435 gal off the roof); Jan the driest (1.35 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 Baraboo?

Best fit: one 55-gallon barrel, which delivers about 217 gallons to the garden in a normal year (79.1% of its need).

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

TankWater used (gal/yr)Spills over (gal/yr)
55 gal21729,651
110 gal21729,651
165 gal21729,651
275 gal21729,651
550 gal21729,651
1,000 gal21729,651
1,500 gal21729,651
2,500 gal21729,651
5,000 gal21729,651

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