RoofRainYield

Bensenville, IL rainwater: 30,091 gallons off a roof

How much rain a roof in Bensenville, IL collects

30,091gallons a year

That is a 1,500 sq ft asphalt roof under Bensenville, IL's normal 37.9 inches of rain, about 795 gallons for every inch that falls.

In Bensenville, 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 Chicago Ohare Intl Ap station (2.6 mi away). Bensenville, IL ranks 200th wettest of the 225 cities covered in Illinois.

Month by month in Bensenville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.991,582
Feb1.971,566
Mar2.451,947
Apr3.752,98175
May4.493,569
Jun4.103,25931
Jul3.712,94980
Aug4.253,37812
Sep3.192,535145
Oct3.432,726115
Nov2.421,923
Dec2.111,677

May is the wettest month (4.49 in, 3,569 gal off the roof); Feb the driest (1.97 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 Bensenville?

Best fit: one 55-gallon barrel, which delivers about 363 gallons to the garden in a normal year (79.3% 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 Bensenville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal36328,633
110 gal36328,633
165 gal36328,633
275 gal36328,633
550 gal36328,633
1,000 gal36328,633
1,500 gal36328,633
2,500 gal36328,633
5,000 gal36328,633

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