Fort Walton Beach, FL rainwater: 50,701 gallons off a roof
Fort Walton Beach, FL: gallons off the roof each year
50,701gallons a year
That is a 1,500 sq ft asphalt roof under Fort Walton Beach, FL's normal 63.8 inches of rain, about 795 gallons for every inch that falls.
In Fort Walton Beach, 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 Mary Esther 0.6 E station (1.8 mi away). Fort Walton Beach, FL ranks 41st wettest of the 173 cities covered in Florida.
Month by month in Fort Walton Beach
| Month | Rain (in) | Off the roof (gal) | Garden shortfall (gal) |
|---|---|---|---|
| Jan | 5.20 | 4,133 | |
| Feb | 5.73 | 4,554 | |
| Mar | 4.91 | 3,902 | |
| Apr | 5.72 | 4,546 | |
| May | 3.24 | 2,575 | 138 |
| Jun | 6.38 | 5,071 | |
| Jul | 6.50 | 5,166 | |
| Aug | 7.49 | 5,953 | |
| Sep | 5.39 | 4,284 | |
| Oct | 3.91 | 3,108 | 55 |
| Nov | 4.45 | 3,537 | |
| Dec | 4.87 | 3,871 |
Aug is the wettest month (7.49 in, 5,953 gal off the roof); May the driest (3.24 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 Fort Walton Beach
Best fit: one 55-gallon barrel, which delivers about 168 gallons to the garden in a normal year (86.9% 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 Fort Walton Beach's roof water will pass straight through it.
| Tank | Water used (gal/yr) | Spills over (gal/yr) |
|---|---|---|
| 55 gal | 168 | 49,437 |
| 110 gal | 168 | 49,437 |
| 165 gal | 168 | 49,437 |
| 275 gal | 168 | 49,437 |
| 550 gal | 168 | 49,437 |
| 1,000 gal | 168 | 49,437 |
| 1,500 gal | 168 | 49,437 |
| 2,500 gal | 168 | 49,437 |
| 5,000 gal | 168 | 49,437 |
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