RoofRainYield

Leland, NC rainwater: 48,555 gallons off a roof

Rainwater from a roof in Leland, NC

48,555gallons a year

That is a 1,500 sq ft asphalt roof under Leland, NC's normal 61.1 inches of rain, about 795 gallons for every inch that falls.

In Leland, 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 Leland 5.7 Wsw station (3.1 mi away). Leland, NC ranks 1st wettest of the 91 cities covered in North Carolina.

Month by month in Leland

MonthRain (in)Off the roof (gal)Garden shortfall (gal)
Jan4.063,227
Feb3.772,996
Mar4.303,418
Apr3.342,655126
May4.553,616
Jun5.604,451
Jul7.606,041
Aug8.076,414
Sep7.556,001
Oct4.653,696
Nov3.672,917
Dec3.933,124

Aug is the wettest month (8.07 in, 6,414 gal off the roof); Apr the driest (3.34 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 Leland

Best fit: one 55-gallon barrel, which delivers about 101 gallons to the garden in a normal year (80.2% 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 Leland's roof water will pass straight through it.

TankWater used (gal/yr)Spills over (gal/yr)
55 gal10147,209
110 gal10147,209
165 gal10147,209
275 gal10147,209
550 gal10147,209
1,000 gal10147,209
1,500 gal10147,209
2,500 gal10147,209
5,000 gal10147,209

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