The Corps of Engineers' Woodruff Lock & Dam
This is the end of the line for the 'hooch. In Lake Seminole, behind the Jim Woodruff Dam here, the Chattahoochee and Flint Rivers join to make the Apalachicola River. From here the Apalachicola flows another 100 miles or so to Apalachicola Bay and into the Gulf of Mexico. The dam is close to Chattahoochee, FL. Normal pool for Lake Seminole is 77 feet MSL, and the lake covers 37,500 acres at that level.
The GA/FL state line crosses the eastern side of the dam. It's a wonder that Sonny and Jeb don't have armed troopers here protecting "their" water...
The lock here is 82 feet wide by 450 feet long, with a maximum lift of 33 feet. The ACF (Apalachicola-Chattahoochee-Flint) system is navigable to Columbus on the 'hooch, and to Bainbridge on the Flint. The waterway is not used that much, and as such is a source of controversy, especially the dredging required to maintain the channel.
The powerhouse has three units rated at a total of 36 Megawatts at normal head of 30.5 feet, or 6 Megawatts at minimum head of 9 feet. Hydraulic capacity is 18,300 cfs at normal levels.
This dam does not have Tainter gates. These are called Vertical lift split leaf gates; there are 16 of them and they are 40 feet wide by 30.5 feet high. There are two gantry cranes to operate the gates; and one of those is also used to operate the intake gates to the powerhouse as well.
"Don't pick at the dam!"
A view of the dam from the bridge over the Apalachicola downstream. Its difficult to determine the size stats for the dam. Besides the gated spillway at 766 feet long, there is a fixed crest spillway (elev 79 feet) for another 1634 feet, and an earthen overflow dike (elev 85 feet) at 2,130 feet. According to the pertinent data, the 100 year flood puts the lock underwater, the "biblical" flood puts the whole project under water! I wondered if it was a typo: the "spillway design flood" has the tailwater elevation at 96.73 feet, and the headwater elevation at 96.1 feet... which I guess means water is flowing in from the Gulf! Not too hard to imagine, though, after what we saw Katrina do...