Florida Lake Management Society Annual Conference, Naples, Florida, June 4 – 7, 2007
ENVIRONMENTAL CHALLENGES FOR A SUSTAINABLE WATER AND ENERGY FUTURE
Virgil Hobbs U.S. Army Corps of Engineers Savannah, GA
All industry is faced with meeting environmental challenges and standards. As the only reliable and environmentally friendly power generation mode, it is essential the Hydropower Community lead the field and actively pursues environmental enhancement opportunities. The U.S. Army Corps of Engineers has made great improvements to water quality downstream of federally owned, operated and maintained hydropower facilities in the Southeastern United States.
The majority of lakes in the Southeastern United States and other temperate regions of the world experience a phenomenon known as thermal stratification. In the summer months, as surface waters warm, the differences in density between the surface and bottom water restrict the vertical circulation of the lake. Reservoir-based hydroelectric water intakes are typically oriented such that they draw water from low in the water column. The lower portion of a thermally stratified lake is practically void of dissolved oxygen. Releasing low dissolved oxygen water into the tailrace can seriously impact downstream fish habitat. The U.S. Environmental Protection Agency (EPA) has published dissolved oxygen criteria indicating levels of less than 5 mg/l can severely impair fish development in early stages of life.
The U.S. Army Corps of Engineers operates and maintains 24% of the hydropower in the United States and is the nation’s fifth largest electric power provider with almost 24 thousand megawatts of installed capacity. Three Corps facilities located in the upper Savannah River Basin have a combined capacity of 1,480 megawatts. In fiscal year 2006, these three Projects generated $66 million in revenue that was returned to the United States Treasury. All Corps Projects are designated multipurpose, balancing the demands of hydropower, navigation, recreation, flood damage reduction, water supply and environmental stewardship stakeholders.
Environmental stewardship is one of the U.S. Army Corps of Engineers’ primary missions. Within our environmental operating principles, the Corps strives to avoid impact and whenever possible restore or improve ecosystems neighboring our facilities. Man-made impoundments are easy targets for environmental concern and criticism. Private industry hydroelectric installations are required by the U.S. Federal Energy Regulatory Commission (FERC) to address all environmental issues associated with their facility prior to relicensing. Federal government powerplants are not currently subject to FERC oversight but public scrutiny will eventually focus on these facilities. When that time arrives, the Corps of Engineers will be able to display numerous positive and proactive environmentally conscientious strides.
Hartwell Project is the northwestern most facility and origin of the Savannah River, which forms the State border between South Carolina and Georgia. The rocky channel below the dam combined with the cool generation release water temperatures have created an unusual
Session 9 – Page 4