RoofRainYield

La Crosse, WI rainwater: 29,781 gallons off a roof

La Crosse, WI: gallons off the roof each year

29,781gallons a year

That is a 1,500 sq ft asphalt roof under La Crosse, WI's normal 37.5 inches of rain, about 795 gallons for every inch that falls.

In La Crosse, 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 La Crosse Wfo station (1.7 mi away). La Crosse, WI ranks 17th wettest of the 98 cities covered in Wisconsin.

Month by month in La Crosse

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.12890
Feb1.13898
Mar1.931,534
Apr4.023,19541
May4.913,902
Jun5.294,205
Jul4.263,38611
Aug4.473,553
Sep4.003,17944
Oct2.912,313180
Nov1.941,542
Dec1.491,184

Jun is the wettest month (5.29 in, 4,205 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 La Crosse

Best fit: one 55-gallon barrel, which delivers about 219 gallons to the garden in a normal year (79.5% 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 La Crosse's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal21928,513
110 gal21928,513
165 gal21928,513
275 gal21928,513
550 gal21928,513
1,000 gal21928,513
1,500 gal21928,513
2,500 gal21928,513
5,000 gal21928,513

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