RoofRainYield

Winterville, NC rainwater: 41,815 gallons off a roof

Rainwater from a roof in Winterville, NC

41,815gallons a year

That is a 1,500 sq ft asphalt roof under Winterville, NC's normal 52.6 inches of rain, about 795 gallons for every inch that falls.

In Winterville, 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 Winterville 3.5 W station (3.4 mi away). Winterville, NC ranks 10th wettest of the 91 cities covered in North Carolina.

Month by month in Winterville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.412,710
Feb3.252,583
Mar3.712,949
Apr3.552,822100
May4.503,577
Jun5.424,308
Jul5.584,435
Aug5.804,610
Sep6.595,238
Oct4.023,19541
Nov3.232,567
Dec3.552,822

Sep is the wettest month (6.59 in, 5,238 gal off the roof); Nov the driest (3.23 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.

Barrel or cistern in Winterville?

Best fit: one 55-gallon barrel, which delivers about 114 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 Winterville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal11440,440
110 gal11440,440
165 gal11440,440
275 gal11440,440
550 gal11440,440
1,000 gal11440,440
1,500 gal11440,440
2,500 gal11440,440
5,000 gal11440,440

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