RoofRainYield

Villa Park, IL rainwater: 31,737 gallons off a roof

How much rain a roof in Villa Park, IL collects

31,737gallons a year

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

In Villa Park, 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 Villa Park 1.0 Nw station (1.0 mi away). Villa Park, IL ranks 118th wettest of the 225 cities covered in Illinois.

Month by month in Villa Park

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.181,733
Feb2.221,764
Mar2.501,987
Apr3.803,02069
May4.683,720
Jun4.663,704
Jul4.003,17944
Aug4.173,31422
Sep3.262,591136
Oct3.532,806102
Nov2.622,082
Dec2.311,836

May is the wettest month (4.68 in, 3,720 gal off the roof); Jan the driest (2.18 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Which tank size is worth it in Villa Park

Best fit: one 55-gallon barrel, which delivers about 296 gallons to the garden in a normal year (79.4% 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 Villa Park's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal29630,300
110 gal29630,300
165 gal29630,300
275 gal29630,300
550 gal29630,300
1,000 gal29630,300
1,500 gal29630,300
2,500 gal29630,300
5,000 gal29630,300

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