Gainesville, FL rainwater: 43,388 gallons off a roof
Rainwater from a roof in Gainesville, FL
43,388gallons a year
That is a 1,500 sq ft asphalt roof under Gainesville, FL's normal 54.6 inches of rain, about 795 gallons for every inch that falls.
In Gainesville, FL 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 Gainesville 1.7 Se station (2.4 mi away). Gainesville, FL ranks 109th wettest of the 173 cities covered in Florida.
Month by month in Gainesville
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 3.57 | 2,837 | |
| Feb | 2.97 | 2,361 | |
| Mar | 3.61 | 2,869 | |
| Apr | 3.11 | 2,472 | 155 |
| May | 3.58 | 2,845 | 96 |
| Jun | 7.95 | 6,319 | |
| Jul | 7.06 | 5,611 | |
| Aug | 8.13 | 6,462 | |
| Sep | 6.19 | 4,920 | |
| Oct | 3.23 | 2,567 | 140 |
| Nov | 2.05 | 1,629 | |
| Dec | 3.14 | 2,496 |
Aug is the wettest month (8.13 in, 6,462 gal off the roof); Nov the driest (2.05 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 Gainesville?
Best fit: one 55-gallon barrel, which delivers about 336 gallons to the garden in a normal year (86.1% 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 Gainesville's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 336 | 41,942 |
| 110 gal | 336 | 41,942 |
| 165 gal | 336 | 41,942 |
| 275 gal | 336 | 41,942 |
| 550 gal | 336 | 41,942 |
| 1,000 gal | 336 | 41,942 |
| 1,500 gal | 336 | 41,942 |
| 2,500 gal | 336 | 41,942 |
| 5,000 gal | 336 | 41,942 |
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 Florida?
Legal. Florida approves onsite non-potable use of rainwater for landscape irrigation, vehicle washing, filling pools and fountains and, in some local jurisdictions, toilet/urinal flushing (Florida Plumbing Code). No state storage cap or registration for non-potable collection.
Checked against the current source on 2026-11-06. Source