Boone, NC rainwater: 46,997 gallons off a roof
Rainwater from a roof in Boone, NC
46,997gallons a year
That is a 1,500 sq ft asphalt roof under Boone, NC's normal 59.1 inches of rain, about 795 gallons for every inch that falls.
Boone, NC gets enough rain in the growing season that a 200 sq ft garden rarely needs topping up, so a tank here is about saving the occasional dry spell, not a summer of watering.
Rainfall: NOAA 1991-2020 climate normals, the Boone 1 Se station (1.1 mi away). Boone, NC ranks 3rd wettest of the 91 cities covered in North Carolina.
Month by month in Boone
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 4.39 | 3,489 | |
| Feb | 3.64 | 2,893 | |
| Mar | 4.77 | 3,791 | |
| Apr | 5.52 | 4,387 | |
| May | 5.46 | 4,340 | |
| Jun | 5.59 | 4,443 | |
| Jul | 5.11 | 4,061 | |
| Aug | 5.56 | 4,419 | |
| Sep | 5.73 | 4,554 | |
| Oct | 4.69 | 3,728 | |
| Nov | 4.44 | 3,529 | |
| Dec | 4.23 | 3,362 |
Sep is the wettest month (5.73 in, 4,554 gal off the roof); Feb the driest (3.64 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 Boone
Best fit: a 5,000-gallon cistern, which delivers about 0 gallons to the garden in a normal year.
Before you buy, a single 55-gallon barrel is plenty here; spend the money on a first-flush diverter and a screen rather than more storage.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 0 | 45,542 |
| 110 gal | 0 | 45,542 |
| 165 gal | 0 | 45,542 |
| 275 gal | 0 | 45,542 |
| 550 gal | 0 | 45,542 |
| 1,000 gal | 0 | 45,542 |
| 1,500 gal | 0 | 45,542 |
| 2,500 gal | 0 | 45,542 |
| 5,000 gal | 0 | 45,542 |
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