RoofRainYield

Mooresville, NC rainwater: 36,935 gallons off a roof

Mooresville, NC: gallons off the roof each year

36,935gallons a year

That is a 1,500 sq ft asphalt roof under Mooresville, NC's normal 46.5 inches of rain, about 795 gallons for every inch that falls.

In Mooresville, 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 China Grove 4.4 W station (9.6 mi away). Mooresville, NC ranks 62nd wettest of the 91 cities covered in North Carolina.

Month by month in Mooresville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.602,861
Feb2.982,369
Mar4.383,481
Apr3.963,14749
May4.353,457
Jun4.083,24334
Jul4.053,21937
Aug4.243,37014
Sep4.203,33819
Oct3.332,647127
Nov3.312,631
Dec3.993,171

Mar is the wettest month (4.38 in, 3,481 gal off the roof); Feb the driest (2.98 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 Mooresville

Best fit: one 55-gallon barrel, which delivers about 226 gallons to the garden in a normal year (80.9% of its need).

Before you buy, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Mooresville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal22635,583
110 gal22635,583
165 gal22635,583
275 gal22635,583
550 gal22635,583
1,000 gal22635,583
1,500 gal22635,583
2,500 gal22635,583
5,000 gal22635,583

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