Dam Name: | H. Neely Henry |
---|---|
Other Name: | HENRY |
NID ID: | AL01416 |
Longitude: | -86.05334 |
Latitude: | 33.78333 |
Map Section: | S30 T14S R6E |
County: | CALHOUN, ST CLAIR |
River: | COOSA RIVER |
State: | AL |
Nearest City: | OHATCHEE |
Distance: | 3.00 miles |
Owner Name: | ALABAMA POWER COMPANY |
Owner Type: | Public Utility |
Private Dam? | No |
Core: | Homogeneous Dam (Position) Earth (Type) Known (Certainty) |
Foundation: | SK |
Purposes: | Hydroelectric |
Year Completed: | 1966 |
Dam Length: | 4705 feet |
Dam Height: | 104 feet |
Structural Height: | 104 feet |
Hydraulic Height: | 53 feet |
Maximum Discharge: | 340000 cu ft/sec |
Maximum Storage: | 121860 acre-feet |
Normal Storage: | 121860 acre-feet |
Surface Area: | 11235 acres |
Drainage Area: | 6600 square miles |
Hazard Potential: | High |
Emergency Action Plan? | Yes |
Inspection Date: | 2012-07-18 |
Inspection Frequency: | 1 |
State Regulated Dam? | No |
Spillway Type: | Controlled |
Spillway Width: | 300 feet |
Outlet Gates: | T6; |
Volume of Dam: | 1500000 cubic yards |
Federal Funding Agency: | HENRY |
Federal Regulatory Agency: | |
Federal Inspection Agency: | |
Source Agency: |
Dam Safety For Boats
A large amount of water can be released from a dam without any warning at any time and by any means. For example, when the demand for electricity is high, the turbines at a dam may be turned on automatically, resulting in a significant increase in the downstream flow of water in only a matter of seconds.
If there's a need to release water through the sluiceways (outlets at the base of the dam), this operation can also create a great swell of discharged water downstream.
During flood operations, any or all spillway gates across the width of a dam can be opened to release upstream flood water that needs to pass to the next downstream reservoir. Upstream or downstream, even the most experienced boater with the strongest motor is no match for this strong flow of water plunging over a spillway of a dam. Even if you're boating far downstream of a spilling dam, recirculating current can pull a powerful boat upstream toward plunging water that could shred any boat.
Some dams equipped with navigation locks create turbulent water as well. When vessels pass through, strong flow is released near the exhaust ports of the wing wall of the lock.
Warning Systems At Dams
To warn reservoir users of potential danger, warning devices are installed at many dams:
- Horns: Horns are sounded before water is released from the powerhouses, sluiceway or spillways. When you hear these horns, leave the areas upstream and downstream of the dam immediately.
- Strobe Lights: Strobe lights are activated before the hydro plant begins generating electricity at the powerhouse or releases water through the spillway or sluiceway. When you see these strobe lights flash, leave the areas upstream and downstream of the dam immediately.
- Warning Signs: Signs direct visitors to stay clear of hazardous areas and warn of rapidly rising water and sudden spillway and turbine water surges. Take them seriously—obey all warnings!