RoofRainYield

Effingham, IL rainwater: 35,695 gallons off a roof

Rainwater from a roof in Effingham, IL

35,695gallons a year

That is a 1,500 sq ft asphalt roof under Effingham, IL's normal 44.9 inches of rain, about 795 gallons for every inch that falls.

In Effingham, 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 Effingham Se station (1.4 mi away). Effingham, IL ranks 12th wettest of the 225 cities covered in Illinois.

Month by month in Effingham

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.822,241
Feb2.281,812
Mar3.212,551
Apr4.813,823
May4.903,895
Jun5.444,324
Jul4.373,473
Aug3.322,639128
Sep2.922,321178
Oct4.113,26730
Nov3.923,116
Dec2.812,233

Jun is the wettest month (5.44 in, 4,324 gal off the roof); Feb the driest (2.28 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 Effingham?

Best fit: one 55-gallon barrel, which delivers about 280 gallons to the garden in a normal year (83.2% 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 Effingham's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal28034,244
110 gal28034,244
165 gal28034,244
275 gal28034,244
550 gal28034,244
1,000 gal28034,244
1,500 gal28034,244
2,500 gal28034,244
5,000 gal28034,244

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