RoofRainYield

Jacksonville, NC rainwater: 44,914 gallons off a roof

How much rain a roof in Jacksonville, NC collects

44,914gallons a year

That is a 1,500 sq ft asphalt roof under Jacksonville, NC's normal 56.5 inches of rain, about 795 gallons for every inch that falls.

In Jacksonville, 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 New River Mcaf station (2.1 mi away). Jacksonville, NC ranks 7th wettest of the 91 cities covered in North Carolina.

Month by month in Jacksonville

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan3.963,147
Feb3.502,782
Mar3.793,012
Apr3.352,663125
May4.203,33819
Jun5.244,165
Jul6.184,912
Aug7.485,945
Sep7.455,921
Oct4.133,28327
Nov3.552,822
Dec3.682,925

Aug is the wettest month (7.48 in, 5,945 gal off the roof); Apr the driest (3.35 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 Jacksonville?

Best fit: one 55-gallon barrel, which delivers about 142 gallons to the garden in a normal year (83.1% 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 Jacksonville's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal14243,557
110 gal14243,557
165 gal14243,557
275 gal14243,557
550 gal14243,557
1,000 gal14243,557
1,500 gal14243,557
2,500 gal14243,557
5,000 gal14243,557

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