RoofRainYield

Richmond, KY rainwater: 38,246 gallons off a roof

Richmond, KY: gallons off the roof each year

38,246gallons a year

That is a 1,500 sq ft asphalt roof under Richmond, KY's normal 48.1 inches of rain, about 795 gallons for every inch that falls.

In Richmond, 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 Richmond State Police station (0.4 mi away). Richmond, KY ranks 28th wettest of the 42 cities covered in Kentucky.

Month by month in Richmond

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.662,909
Feb3.813,028
Mar4.353,457
Apr4.673,712
May4.963,942
Jun4.593,648
Jul4.993,966
Aug3.322,639128
Sep2.662,114211
Oct3.622,87791
Nov3.592,853
Dec3.903,100

Jul is the wettest month (4.99 in, 3,966 gal off the roof); Sep the driest (2.66 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 Richmond

Best fit: one 55-gallon barrel, which delivers about 367 gallons to the garden in a normal year (85.3% 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 Richmond's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal36736,709
110 gal36736,709
165 gal36736,709
275 gal36736,709
550 gal36736,709
1,000 gal36736,709
1,500 gal36736,709
2,500 gal36736,709
5,000 gal36736,709

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