Aging Watershed Projects
Since 1950 local project sponsors (with Natural Resources Conservation
Service assistance) have constructed over 10,000 small flood control dams in
America. Many of the dams are nearing the end of their design life.
Rehabilitation of these dams is becoming a major issue for many people who are
effected by a watershed project.
The primary purpose of these dams is flood control but many also are
multipurpose dams and are used for water supplies, recreation, and wetland
wildlife habitat.
Some of the issues that must be addressed for these aging projects include:
- Replacing deteriorating components.
- Dealing with unanticipated urban development below or near dams, which
increases the potential for loss of life and increased property development.
- Dealing with sediment that has accumulated in reservoirs to the point that
the dams can no longer properly function.
- Upgrades to meet current state dam safety regulations.
- Meeting natural resource needs not previously addressed, such as water
quality, wetland restoration and wildlife habitat.
In Maine there have been 16 dams built within six Public Law-566 Project Areas (see
map for project locations). The first of these dams was built in 1965 and
the last in 1975. All structures have performed as designed and have
provided flood control and protection for many areas.
In addition to flood control, three dams have permanent pools that provide
recreational opportunities such as fishing, boating and swimming. The
other 13 dams are "dry" and are strictly for flood control during
storm events.
Periodic inspection of these dams by Maine NRCS engineers show that they are
generally in good condition. However, all of them have reached at least
the halfway point of their 50-year design life expectancy. We need to
reinvest in these structures where necessary to extend the life of the
structures and address any safety and health issues. For example, in 1999
at Hanson Dam near Presque Isle a downstream toe drain was installed to
intercept excessive seepage. This $204,000 project will maintain the
integrity of this multipurpose flood control structure.
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