RoofRainYield

Radford, VA rainwater: 33,382 gallons off a roof

Radford, VA: gallons off the roof each year

33,382gallons a year

That is a 1,500 sq ft asphalt roof under Radford, VA's normal 42.0 inches of rain, about 795 gallons for every inch that falls.

In Radford, VA 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 Radford 0.9 Wnw station (1.0 mi away). Radford, VA ranks 36th wettest of the 39 cities covered in Virginia.

Month by month in Radford

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.122,480
Feb2.642,098
Mar3.732,965
Apr3.752,98175
May4.423,513
Jun4.113,26730
Jul3.893,09257
Aug3.532,806102
Sep3.502,782106
Oct3.002,384168
Nov2.792,218
Dec3.522,798

May is the wettest month (4.42 in, 3,513 gal off the roof); Feb the driest (2.64 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 Radford

Best fit: one 55-gallon barrel, which delivers about 427 gallons to the garden in a normal year (79.3% 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 Radford's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal42731,725
110 gal42731,725
165 gal42731,725
275 gal42731,725
550 gal42731,725
1,000 gal42731,725
1,500 gal42731,725
2,500 gal42731,725
5,000 gal42731,725

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 Virginia?

Legal and promoted by the state. Va. Code 32.1-248.2 directs the Board of Health to set standards for rainwater harvesting systems, and the Department of Health with DEQ to promote rainwater use. No state storage cap; indoor/potable use must meet health regulations.

Checked against the current source on 2026-11-06. Source