RoofRainYield

Shively, KY rainwater: 39,716 gallons off a roof

Shively, KY: gallons off the roof each year

39,716gallons a year

That is a 1,500 sq ft asphalt roof under Shively, KY's normal 50.0 inches of rain, about 795 gallons for every inch that falls.

In Shively, 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 Pleasure Ridge Park 0.6 Nnw station (3.5 mi away). Shively, KY ranks 19th wettest of the 42 cities covered in Kentucky.

Month by month in Shively

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.642,893
Feb3.512,790
Mar4.933,918
Apr4.943,926
May5.214,141
Jun4.623,672
Jul4.303,4186
Aug3.492,774107
Sep3.722,95779
Oct3.682,92584
Nov3.622,877
Dec4.313,426

May is the wettest month (5.21 in, 4,141 gal off the roof); Aug the driest (3.49 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 Shively

Best fit: one 55-gallon barrel, which delivers about 230 gallons to the garden in a normal year (83.5% 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 Shively's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal23038,301
110 gal23038,301
165 gal23038,301
275 gal23038,301
550 gal23038,301
1,000 gal23038,301
1,500 gal23038,301
2,500 gal23038,301
5,000 gal23038,301

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