RoofRainYield

Huntley, IL rainwater: 31,442 gallons off a roof

Rainwater from a roof in Huntley, IL

31,442gallons a year

That is a 1,500 sq ft asphalt roof under Huntley, IL's normal 39.6 inches of rain, about 795 gallons for every inch that falls.

In Huntley, 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 Algonquin 0.7 N station (7.0 mi away). Huntley, IL ranks 133rd wettest of the 225 cities covered in Illinois.

Month by month in Huntley

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.861,478
Feb1.831,454
Mar2.251,788
Apr3.572,83797
May5.064,022
Jun4.753,775
Jul4.453,537
Aug4.333,4422
Sep3.522,798103
Oct3.192,535145
Nov2.431,931
Dec2.321,844

May is the wettest month (5.06 in, 4,022 gal off the roof); Feb the driest (1.83 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 Huntley?

Best fit: one 55-gallon barrel, which delivers about 268 gallons to the garden in a normal year (77.0% 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 Huntley's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal26830,049
110 gal26830,049
165 gal26830,049
275 gal26830,049
550 gal26830,049
1,000 gal26830,049
1,500 gal26830,049
2,500 gal26830,049
5,000 gal26830,049

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