Newnan, GA rainwater: 44,112 gallons off a roof
Rainwater from a roof in Newnan, GA
44,112gallons a year
That is a 1,500 sq ft asphalt roof under Newnan, GA's normal 55.5 inches of rain, about 795 gallons for every inch that falls.
In Newnan, 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 Newnan 2.6 W station (3.3 mi away). Newnan, GA ranks 13th wettest of the 101 cities covered in Georgia.
Month by month in Newnan
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 5.12 | 4,069 | |
| Feb | 5.74 | 4,562 | |
| Mar | 5.01 | 3,982 | |
| Apr | 4.70 | 3,736 | |
| May | 3.49 | 2,774 | 107 |
| Jun | 5.10 | 4,054 | |
| Jul | 4.83 | 3,839 | |
| Aug | 4.69 | 3,728 | |
| Sep | 3.54 | 2,814 | 101 |
| Oct | 3.35 | 2,663 | 125 |
| Nov | 3.92 | 3,116 | |
| Dec | 6.01 | 4,777 |
Dec is the wettest month (6.01 in, 4,777 gal off the roof); Oct the driest (3.35 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 Newnan
Best fit: one 55-gallon barrel, which delivers about 275 gallons to the garden in a normal year (82.6% of its need).
If you buy one, a 55-gallon barrel with a downspout diverter is the whole job. Check that the overflow points away from your foundation, because most of Newnan's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 275 | 42,576 |
| 110 gal | 275 | 42,576 |
| 165 gal | 275 | 42,576 |
| 275 gal | 275 | 42,576 |
| 550 gal | 275 | 42,576 |
| 1,000 gal | 275 | 42,576 |
| 1,500 gal | 275 | 42,576 |
| 2,500 gal | 275 | 42,576 |
| 5,000 gal | 275 | 42,576 |
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