Milton, GA rainwater: 42,554 gallons off a roof
Milton, GA: gallons off the roof each year
42,554gallons a year
That is a 1,500 sq ft asphalt roof under Milton, GA's normal 53.5 inches of rain, about 795 gallons for every inch that falls.
In Milton, 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 (10.4 mi away). Milton, GA ranks 33rd wettest of the 101 cities covered in Georgia.
Month by month in Milton
| 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.
Which tank size is worth it in Milton
Best fit: one 55-gallon barrel, which delivers about 169 gallons to the garden in a normal year (80.7% 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 Milton'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