An Ohio-based developer, Low Head Hydro, has filed multiple applications for preliminary permits to study the feasibility of its proposed hydroelectric projects at lock and dam sites owned by the U.S. Army Corps of Engineers (USACE) along the Mississippi River.
The applications were filed for proposed projects at Mississippi Lock and Dam 21, located on the Mississippi River, in Adams County, Illinois, and Marion County, Missouri; and Mississippi Locks and Dam 11, a project proposed to be located at the Mississippi Lock and Dam located on the Mississippi River, near Dubuque, Iowa.
The proposed Mississippi Locks and Dam 21 Hydroelectric Project would consist of:
- A new hydropower structure located approximately 100 feet downstream of the existing Corps submersible dam, connected to the west side of the dam via a new proposed access road;
- 30 Very Low Head (VLH) turbine-generator units located in concrete channels (turbine bays) within the hydropower structure, each rated with a capacity of 500 kilowatts providing a total rated capacity of 15 megawatts;
- A new unlined earth intake channel located upstream of the powerhouse which will convey flow from the upper pool to the turbine bays;
- A 150-foot-long guide wall proposed on both sides of the new intake channel;
- A new unlined earth excavated tailrace with stone riprap proposed to be 300-foot-wide and 300-foot-long;
- A 150-foot-long guide wall proposed on both sides of the new tailrace channel;
- A new 14-foot-wide concrete deck proposed to connect the approach dam on the west side to the existing Corps operation yard on the east; and
- A control building and substation on the west river bank connecting the transmission line to an interconnection point. The proposed project would have an estimated annual generation of 71,400 megawatt-hours.
The proposed Mississippi Locks and Dam 11 Hydroelectric Project would consist of:
- An impoundment approximately 19,613 acres with a storage capacity of 170,000 acre-feet;
- A 200-foot-long and 300-foot-wide intake area located upstream of the powerhouse;
- A 120-foot long and 276-foot-wide powerhouse located adjacent to the left bank of the existing Corps’ dam;
- Nine vertical Kaplan turbine-generators rated at 1.57 megawatt (MW) each installed in the new powerhouse, for a total installed capacity of 14.13 MW;
- A 13-megavolt-ampere, 4.16/69-kilovolt (kV) three-phase step-up transformer located adjacent to the powerhouse in a new, 50-foot-wide by 60-foot-long substation;
- A1.52-mile-long, single overhead three-phase 69-kV line extending from the substation to the interconnection point;
- New concrete guide walls constructed upstream and downstream of the powerhouse;
- A 276-foot-wide and 400-foot-long unlined earthen excavation tailrace area having stone riprap placed in the areas of higher velocity; and (9) appurtenant facilities. The proposed project would have an estimated annual generation of 91 gigawatt-hours.
On Tuesday, the Wisconsin Department of Natural Resources filed a motion to intervene in the Mississippi Locks and Dam 11 Hydroelectric Project, but a reason was not provided in the filing.
The sole purpose of a preliminary permit, if issued, is to grant the permit holder priority to file a license application during the permit term. A preliminary permit does not authorize the permit holder to perform any land-disturbing activities or otherwise enter upon lands or waters owned by others without the owner’s express permission.
