RoofRainYield

Chippewa Falls, WI rainwater: 27,604 gallons off a roof

Chippewa Falls, WI: gallons off the roof each year

27,604gallons a year

That is a 1,500 sq ft asphalt roof under Chippewa Falls, WI's normal 34.7 inches of rain, about 795 gallons for every inch that falls.

In Chippewa Falls, 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 Chippewa Falls station (1.0 mi away). Chippewa Falls, WI ranks 59th wettest of the 98 cities covered in Wisconsin.

Month by month in Chippewa Falls

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.12890
Feb1.15914
Mar1.881,494
Apr3.322,639128
May4.083,24334
Jun4.903,895
Jul4.073,23535
Aug4.093,25132
Sep4.163,30624
Oct2.722,162203
Nov1.781,415
Dec1.461,160

Jun is the wettest month (4.90 in, 3,895 gal off the roof); Jan the driest (1.12 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 Chippewa Falls

Best fit: one 55-gallon barrel, which delivers about 357 gallons to the garden in a normal year (78.2% 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 Chippewa Falls's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal35726,152
110 gal35726,152
165 gal35726,152
275 gal35726,152
550 gal35726,152
1,000 gal35726,152
1,500 gal35726,152
2,500 gal35726,152
5,000 gal35726,152

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