RoofRainYield

Lisbon, WI rainwater: 28,557 gallons off a roof

How much rain a roof in Lisbon, WI collects

28,557gallons a year

That is a 1,500 sq ft asphalt roof under Lisbon, WI's normal 35.9 inches of rain, about 795 gallons for every inch that falls.

In Lisbon, 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 Sussex 0.8 Nne station (2.2 mi away). Lisbon, WI ranks 41st wettest of the 98 cities covered in Wisconsin.

Month by month in Lisbon

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.711,359
Feb1.611,280
Mar2.151,709
Apr3.803,02069
May3.923,11654
Jun4.753,775
Jul3.732,96577
Aug3.843,05264
Sep3.292,615132
Oct3.002,384168
Nov2.171,725
Dec1.961,558

Jun is the wettest month (4.75 in, 3,775 gal off the roof); Feb the driest (1.61 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 Lisbon?

Best fit: one 55-gallon barrel, which delivers about 433 gallons to the garden in a normal year (76.8% 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 Lisbon's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal43326,984
110 gal43326,984
165 gal43326,984
275 gal43326,984
550 gal43326,984
1,000 gal43326,984
1,500 gal43326,984
2,500 gal43326,984
5,000 gal43326,984

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