RoofRainYield

Tinley Park, IL rainwater: 32,754 gallons off a roof

How much rain a roof in Tinley Park, IL collects

32,754gallons a year

That is a 1,500 sq ft asphalt roof under Tinley Park, IL's normal 41.2 inches of rain, about 795 gallons for every inch that falls.

In Tinley 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 Palos Park 1.3 Sw station (6.6 mi away). Tinley Park, IL ranks 55th wettest of the 225 cities covered in Illinois.

Month by month in Tinley Park

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan2.311,836
Feb2.161,717
Mar2.592,059
Apr4.113,26730
May4.623,672
Jun4.433,521
Jul4.543,608
Aug4.393,489
Sep3.422,718116
Oct3.632,88590
Nov2.772,202
Dec2.241,780

May is the wettest month (4.62 in, 3,672 gal off the roof); Feb the driest (2.16 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 Tinley Park?

Best fit: one 55-gallon barrel, which delivers about 184 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 Tinley Park's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal18431,400
110 gal18431,400
165 gal18431,400
275 gal18431,400
550 gal18431,400
1,000 gal18431,400
1,500 gal18431,400
2,500 gal18431,400
5,000 gal18431,400

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