RoofRainYield

Woodridge, IL rainwater: 31,745 gallons off a roof

Woodridge, IL: gallons off the roof each year

31,745gallons a year

That is a 1,500 sq ft asphalt roof under Woodridge, IL's normal 39.9 inches of rain, about 795 gallons for every inch that falls.

In Woodridge, 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 Bolingbrook 2.7 Ne station (0.5 mi away). Woodridge, IL ranks 116th wettest of the 225 cities covered in Illinois.

Month by month in Woodridge

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.101,669
Feb1.941,542
Mar2.552,027
Apr3.953,13950
May4.653,696
Jun4.353,457
Jul4.603,656
Aug4.163,30624
Sep3.262,591136
Oct3.642,89389
Nov2.712,154
Dec2.031,613

May is the wettest month (4.65 in, 3,696 gal off the roof); Feb the driest (1.94 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 Woodridge

Best fit: one 55-gallon barrel, which delivers about 242 gallons to the garden in a normal year (81.2% 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 Woodridge's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal24230,468
110 gal24230,468
165 gal24230,468
275 gal24230,468
550 gal24230,468
1,000 gal24230,468
1,500 gal24230,468
2,500 gal24230,468
5,000 gal24230,468

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