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.