RoofRainYield

Bowling Green, KY rainwater: 39,820 gallons off a roof

Bowling Green, KY: gallons off the roof each year

39,820gallons a year

That is a 1,500 sq ft asphalt roof under Bowling Green, KY's normal 50.1 inches of rain, about 795 gallons for every inch that falls.

In Bowling Green, 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 Bowling Green Warren Co Ap station (1.0 mi away). Bowling Green, KY ranks 18th wettest of the 42 cities covered in Kentucky.

Month by month in Bowling Green

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.642,893
Feb4.073,235
Mar4.543,608
Apr4.813,823
May5.033,998
Jun4.513,585
Jul4.263,38611
Aug3.893,09257
Sep3.642,89389
Oct3.632,88590
Nov3.732,965
Dec4.353,457

May is the wettest month (5.03 in, 3,998 gal off the roof); Oct the driest (3.63 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

What size rain barrel for Bowling Green

Best fit: one 55-gallon barrel, which delivers about 198 gallons to the garden in a normal year (80.2% 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 Bowling Green's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal19838,377
110 gal19838,377
165 gal19838,377
275 gal19838,377
550 gal19838,377
1,000 gal19838,377
1,500 gal19838,377
2,500 gal19838,377
5,000 gal19838,377

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