Holly Springs, GA rainwater: 42,554 gallons off a roof
Holly Springs, GA: gallons off the roof each year
42,554gallons a year
That is a 1,500 sq ft asphalt roof under Holly Springs, GA's normal 53.5 inches of rain, about 795 gallons for every inch that falls.
In Holly Springs, GA 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 Holly Springs 1.0 Nne station (1.3 mi away). Holly Springs, GA ranks 35th wettest of the 101 cities covered in Georgia.
Month by month in Holly Springs
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 4.88 | 3,879 | |
| Feb | 4.80 | 3,815 | |
| Mar | 5.13 | 4,077 | |
| Apr | 4.37 | 3,473 | |
| May | 4.00 | 3,179 | 44 |
| Jun | 4.12 | 3,275 | 29 |
| Jul | 5.04 | 4,006 | |
| Aug | 4.22 | 3,354 | 16 |
| Sep | 4.11 | 3,267 | 30 |
| Oct | 3.62 | 2,877 | 91 |
| Nov | 4.27 | 3,394 | |
| Dec | 4.98 | 3,958 |
Mar is the wettest month (5.13 in, 4,077 gal off the roof); Oct the driest (3.62 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 Holly Springs
Best fit: one 55-gallon barrel, which delivers about 169 gallons to the garden in a normal year (80.7% of its need).
If you set one up, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Holly Springs's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 169 | 41,155 |
| 110 gal | 169 | 41,155 |
| 165 gal | 169 | 41,155 |
| 275 gal | 169 | 41,155 |
| 550 gal | 169 | 41,155 |
| 1,000 gal | 169 | 41,155 |
| 1,500 gal | 169 | 41,155 |
| 2,500 gal | 169 | 41,155 |
| 5,000 gal | 169 | 41,155 |
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 Georgia?
Legal. Outdoor irrigation use is unrestricted; indoor non-potable systems must follow Appendix I 'Rainwater Recycling Systems' of the Georgia amendments to the state plumbing code. No state storage cap; potable use depends on local rules.
Checked against the current source on 2026-11-06. Source