Athens-Clarke County, GA rainwater: 38,906 gallons off a roof
Athens-Clarke County, GA: gallons off the roof each year
38,906gallons a year
That is a 1,500 sq ft asphalt roof under Athens-Clarke County, GA's normal 49.0 inches of rain, about 795 gallons for every inch that falls.
In Athens-Clarke County, 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 Athens Ben Epps Ap station (2.4 mi away). Athens-Clarke County, GA ranks 91st wettest of the 101 cities covered in Georgia.
Month by month in Athens-Clarke County
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 4.36 | 3,465 | |
| Feb | 4.36 | 3,465 | |
| Mar | 4.37 | 3,473 | |
| Apr | 3.52 | 2,798 | 103 |
| May | 3.28 | 2,607 | 133 |
| Jun | 4.88 | 3,879 | |
| Jul | 4.20 | 3,338 | 19 |
| Aug | 4.55 | 3,616 | |
| Sep | 3.89 | 3,092 | 57 |
| Oct | 3.34 | 2,655 | 126 |
| Nov | 3.77 | 2,996 | |
| Dec | 4.43 | 3,521 |
Jun is the wettest month (4.88 in, 3,879 gal off the roof); May the driest (3.28 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 Athens-Clarke County
Best fit: one 55-gallon barrel, which delivers about 363 gallons to the garden in a normal year (82.7% 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 Athens-Clarke County's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 363 | 37,418 |
| 110 gal | 363 | 37,418 |
| 165 gal | 363 | 37,418 |
| 275 gal | 363 | 37,418 |
| 550 gal | 363 | 37,418 |
| 1,000 gal | 363 | 37,418 |
| 1,500 gal | 363 | 37,418 |
| 2,500 gal | 363 | 37,418 |
| 5,000 gal | 363 | 37,418 |
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