Clarkston, GA rainwater: 43,730 gallons off a roof
Rainwater from a roof in Clarkston, GA
43,730gallons a year
That is a 1,500 sq ft asphalt roof under Clarkston, GA's normal 55.0 inches of rain, about 795 gallons for every inch that falls.
In Clarkston, 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 North Decatur 3.0 Nne station (3.1 mi away). Clarkston, GA ranks 15th wettest of the 101 cities covered in Georgia.
Month by month in Clarkston
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 4.87 | 3,871 | |
| Feb | 4.87 | 3,871 | |
| Mar | 4.87 | 3,871 | |
| Apr | 4.54 | 3,608 | |
| May | 3.78 | 3,004 | 71 |
| Jun | 4.38 | 3,481 | |
| Jul | 4.94 | 3,926 | |
| Aug | 5.28 | 4,197 | |
| Sep | 4.35 | 3,457 | |
| Oct | 3.67 | 2,917 | 85 |
| Nov | 4.38 | 3,481 | |
| Dec | 5.09 | 4,046 |
Aug is the wettest month (5.28 in, 4,197 gal off the roof); Oct the driest (3.67 in). Garden shortfall is what a 200 sq ft vegetable bed needs beyond the rain that lands on it, April to October.
Barrel or cistern in Clarkston?
Best fit: one 55-gallon barrel, which delivers about 129 gallons to the garden in a normal year (82.8% 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 Clarkston's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 129 | 42,431 |
| 110 gal | 129 | 42,431 |
| 165 gal | 129 | 42,431 |
| 275 gal | 129 | 42,431 |
| 550 gal | 129 | 42,431 |
| 1,000 gal | 129 | 42,431 |
| 1,500 gal | 129 | 42,431 |
| 2,500 gal | 129 | 42,431 |
| 5,000 gal | 129 | 42,431 |
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