RoofRainYield

Statesville, NC rainwater: 37,078 gallons off a roof

How much rain a roof in Statesville, NC collects

37,078gallons a year

That is a 1,500 sq ft asphalt roof under Statesville, NC's normal 46.7 inches of rain, about 795 gallons for every inch that falls.

In Statesville, NC 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 Statesville 2 Nne station (1.9 mi away). Statesville, NC ranks 57th wettest of the 91 cities covered in North Carolina.

Month by month in Statesville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.712,949
Feb3.182,527
Mar3.993,171
Apr4.053,21937
May3.702,94181
Jun4.273,39410
Jul4.423,513
Aug4.913,902
Sep3.873,07660
Oct3.232,567140
Nov3.382,686
Dec3.943,132

Aug is the wettest month (4.91 in, 3,902 gal off the roof); Feb the driest (3.18 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 Statesville

Best fit: one 55-gallon barrel, which delivers about 265 gallons to the garden in a normal year (80.8% 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 Statesville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal26535,642
110 gal26535,642
165 gal26535,642
275 gal26535,642
550 gal26535,642
1,000 gal26535,642
1,500 gal26535,642
2,500 gal26535,642
5,000 gal26535,642

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 North Carolina?

Regulated through the Department of Environment and Natural Resources; allowed through state’s plumbing code; check county for local incentives

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