RoofRainYield

Richfield, WI rainwater: 29,249 gallons off a roof

Rainwater from a roof in Richfield, WI

29,249gallons a year

That is a 1,500 sq ft asphalt roof under Richfield, WI's normal 36.8 inches of rain, about 795 gallons for every inch that falls.

In Richfield, 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 Richfield 3 Ssw station (2.3 mi away). Richfield, WI ranks 24th wettest of the 98 cities covered in Wisconsin.

Month by month in Richfield

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.741,383
Feb1.851,470
Mar2.131,693
Apr3.853,06062
May4.133,28327
Jun4.653,696
Jul4.183,32221
Aug3.692,93382
Sep3.302,623131
Oct2.932,329177
Nov2.251,788
Dec2.101,669

Jun is the wettest month (4.65 in, 3,696 gal off the roof); Jan the driest (1.74 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 Richfield?

Best fit: one 55-gallon barrel, which delivers about 396 gallons to the garden in a normal year (79.0% 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 Richfield's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal39627,817
110 gal39627,817
165 gal39627,817
275 gal39627,817
550 gal39627,817
1,000 gal39627,817
1,500 gal39627,817
2,500 gal39627,817
5,000 gal39627,817

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