Environmental Engineering Reference
In-Depth Information
tions. In many cases, no amount of compensation can replace ancestral and cultural attachments
to places that have spiritual value to a displaced population. Historically and culturally important
sites can be flooded and lost. Some of these may have religious significance (Armaroli and Bal-
zani 2011, 234).
Decommissioning
Decommissioning of a hydroelectric facility involves removal of the dam structure and powerhouse
from the river on which it was built. For small hydro facilities, this can generally be accomplished
through use of bulldozers, trucks, and shovels similar to those used in road construction. Somewhat
durable in construction, no large hydro power plant has ever been decommissioned in the United
States, so cost estimates for large facilities are not available.
Hydroelectric facilities must be licensed and relicensed by the U.S. Federal Energy Regulatory
Commission (FERC) every fifty years. Since the 1980s, the environmental amenities of many
existing small hydroelectric generating sites have increasingly been viewed by the public as more
valuable than the small amount of electricity they generate. This stimulated public participation in
FERC relicensing proceedings and demands for removal or substantial alteration of numerous dams
and reservoirs. The vision of a free-running river, interruption of migratory patterns for fish such
as salmon—some of which are endangered species—and injury or death to fish passing through
turbines attracted the attention of sports fishing enthusiasts and recreational users of rivers, who
pushed for removal of some small dams and installation of fish ladders at others.
In the early 1980s, the state of Maine adopted a comprehensive plan for the lower Kennebec
River that established a goal of restoring several species of migratory fish to the lower Kennebec
and specifically called for removal of the Edwards Dam, a small hydro facility. In 1986, Congress
amended the Federal Power Act, which governs FERC's licensing of hydropower dams, by requir-
ing “equal consideration” of power and nonpower values such as fish and wildlife and recreation.
Coupled with FERC's obligation to license projects “consistent with comprehensive plans,” this
change in law opened the way for a new type of environmental advocacy focused on restoration
of America's rivers (Fahlund 2011).
The Kennebec River was once home to all ten species of migratory fish native to Maine—includ-
ing Atlantic salmon, American shad, several species of herring, alewife, and shortnose and Atlantic
sturgeon—along with several thriving commercial fisheries. Damming the river transformed the
natural landscape and ushered in an era of industrialization and pollution (Fahlund 2011).
Built in 1837, the Edwards Dam was 25 feet high and 917 feet wide, with an 850-foot spillway.
The timber and concrete structure rose approximately 20 feet above the water, creating a 1,143-
acre reservoir that extended 17 miles upstream to the next dam in Waterville. Sitting just at the
far reaches of tidal influence, the Edwards Dam was the first, and therefore most devastating,
obstruction encountered by large populations of sea-run fish on the way to their upstream spawn-
ing grounds, especially Atlantic salmon, striped bass, river herring, and sturgeon. (American
Museum of Natural History 2011)
The Edwards Dam generated only 3.5 MWh of electricity in 1995 (Fahlund 2011).
The Federal Energy Regulatory Commission's 1997 decision to order removal of Edwards
Dam was nationally significant because the federal government recognized that a free-flowing,
healthy river teeming with life can be more valuable than the electric power and private profit
it produces (Maine State Planning Office 2011). This was the first time that FERC ordered dam
 
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