RoofRainYield

Glendale Heights, IL rainwater: 31,880 gallons off a roof

How much rain a roof in Glendale Heights, IL collects

31,880gallons a year

That is a 1,500 sq ft asphalt roof under Glendale Heights, IL's normal 40.1 inches of rain, about 795 gallons for every inch that falls.

In Glendale Heights, 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 Carol Stream 0.3 Sse station (2.7 mi away). Glendale Heights, IL ranks 109th wettest of the 225 cities covered in Illinois.

Month by month in Glendale Heights

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.191,741
Feb1.991,582
Mar2.461,955
Apr4.003,17944
May4.803,815
Jun4.343,4491
Jul4.103,25931
Aug4.273,39410
Sep3.322,639128
Oct3.452,742112
Nov2.772,202
Dec2.421,923

May is the wettest month (4.80 in, 3,815 gal off the roof); Feb the driest (1.99 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 Glendale Heights?

Best fit: one 55-gallon barrel, which delivers about 255 gallons to the garden in a normal year (78.1% 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 Glendale Heights's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal25530,424
110 gal25530,424
165 gal25530,424
275 gal25530,424
550 gal25530,424
1,000 gal25530,424
1,500 gal25530,424
2,500 gal25530,424
5,000 gal25530,424

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