RoofRainYield

Matteson, IL rainwater: 33,461 gallons off a roof

Matteson, IL: gallons off the roof each year

33,461gallons a year

That is a 1,500 sq ft asphalt roof under Matteson, IL's normal 42.1 inches of rain, about 795 gallons for every inch that falls.

In Matteson, IL 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 Park Forest station (3.5 mi away). Matteson, IL ranks 26th wettest of the 225 cities covered in Illinois.

Month by month in Matteson

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.491,979
Feb2.151,709
Mar2.652,106
Apr4.023,19541
May4.573,632
Jun4.913,902
Jul4.733,759
Aug4.023,19541
Sep3.442,734113
Oct3.652,90187
Nov3.002,384
Dec2.471,963

Jun is the wettest month (4.91 in, 3,902 gal off the roof); Feb the driest (2.15 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

What size rain barrel for Matteson

Best fit: one 55-gallon barrel, which delivers about 222 gallons to the garden in a normal year (78.4% 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 Matteson's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal22232,070
110 gal22232,070
165 gal22232,070
275 gal22232,070
550 gal22232,070
1,000 gal22232,070
1,500 gal22232,070
2,500 gal22232,070
5,000 gal22232,070

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 Illinois?

Local government can regulate rainwater harvesting per state plumbing law

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