RoofRainYield

Hope Mills, NC rainwater: 36,585 gallons off a roof

How much rain a roof in Hope Mills, NC collects

36,585gallons a year

That is a 1,500 sq ft asphalt roof under Hope Mills, NC's normal 46.0 inches of rain, about 795 gallons for every inch that falls.

In Hope Mills, 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 Hope Mills 0.6 Ese station (0.9 mi away). Hope Mills, NC ranks 70th wettest of the 91 cities covered in North Carolina.

Month by month in Hope Mills

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.262,591
Feb3.052,424
Mar3.542,814
Apr3.192,535145
May3.502,782106
Jun4.693,728
Jul4.943,926
Aug4.933,918
Sep5.104,054
Oct3.252,583137
Nov3.112,472
Dec3.472,758

Sep is the wettest month (5.10 in, 4,054 gal off the roof); Feb the driest (3.05 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 Hope Mills

Best fit: one 55-gallon barrel, which delivers about 325 gallons to the garden in a normal year (83.8% 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 Hope Mills's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal32535,194
110 gal32535,194
165 gal32535,194
275 gal32535,194
550 gal32535,194
1,000 gal32535,194
1,500 gal32535,194
2,500 gal32535,194
5,000 gal32535,194

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