RoofRainYield

Moline, IL rainwater: 30,950 gallons off a roof

Moline, IL: gallons off the roof each year

30,950gallons a year

That is a 1,500 sq ft asphalt roof under Moline, IL's normal 38.9 inches of rain, about 795 gallons for every inch that falls.

In Moline, 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 Moline 0.9 N station (1.1 mi away). Moline, IL ranks 161st wettest of the 225 cities covered in Illinois.

Month by month in Moline

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.571,248
Feb1.811,439
Mar2.622,082
Apr3.522,798103
May4.933,918
Jun5.254,173
Jul4.693,728
Aug4.163,30624
Sep3.232,567140
Oct2.942,337176
Nov2.331,852
Dec1.891,502

Jun is the wettest month (5.25 in, 4,173 gal off the roof); Jan the driest (1.57 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 Moline

Best fit: one 55-gallon barrel, which delivers about 362 gallons to the garden in a normal year (81.8% 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 Moline's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal36229,492
110 gal36229,492
165 gal36229,492
275 gal36229,492
550 gal36229,492
1,000 gal36229,492
1,500 gal36229,492
2,500 gal36229,492
5,000 gal36229,492

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