RoofRainYield

Shelbyville, KY rainwater: 39,597 gallons off a roof

How much rain a roof in Shelbyville, KY collects

39,597gallons a year

That is a 1,500 sq ft asphalt roof under Shelbyville, KY's normal 49.8 inches of rain, about 795 gallons for every inch that falls.

In Shelbyville, KY 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 Shelbyville 1 E station (1.9 mi away). Shelbyville, KY ranks 22nd wettest of the 42 cities covered in Kentucky.

Month by month in Shelbyville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan4.153,298
Feb3.783,004
Mar4.653,696
Apr4.033,20340
May5.174,109
Jun5.244,165
Jul4.103,25931
Aug3.692,93382
Sep3.452,742112
Oct3.512,790105
Nov3.522,798
Dec4.533,600

Jun is the wettest month (5.24 in, 4,165 gal off the roof); Sep the driest (3.45 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 Shelbyville?

Best fit: one 55-gallon barrel, which delivers about 304 gallons to the garden in a normal year (82.1% 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 Shelbyville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal30438,078
110 gal30438,078
165 gal30438,078
275 gal30438,078
550 gal30438,078
1,000 gal30438,078
1,500 gal30438,078
2,500 gal30438,078
5,000 gal30438,078

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 Kentucky?

No rainwater harvesting regulations

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