RoofRainYield

Canton, IL rainwater: 31,403 gallons off a roof

How much rain a roof in Canton, IL collects

31,403gallons a year

That is a 1,500 sq ft asphalt roof under Canton, IL's normal 39.5 inches of rain, about 795 gallons for every inch that falls.

In Canton, 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 Canton station (1.8 mi away). Canton, IL ranks 137th wettest of the 225 cities covered in Illinois.

Month by month in Canton

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan1.461,160
Feb1.941,542
Mar2.732,170
Apr4.143,29026
May5.674,507
Jun4.473,553
Jul4.133,28327
Aug3.582,84596
Sep3.762,98874
Oct2.902,305181
Nov2.692,138
Dec2.041,621

May is the wettest month (5.67 in, 4,507 gal off the roof); Jan the driest (1.46 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 Canton

Best fit: one 55-gallon barrel, which delivers about 335 gallons to the garden in a normal year (82.9% 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 Canton's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal33530,063
110 gal33530,063
165 gal33530,063
275 gal33530,063
550 gal33530,063
1,000 gal33530,063
1,500 gal33530,063
2,500 gal33530,063
5,000 gal33530,063

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