Michigan River Partnership
Once perceived as almost entirely beneficial, dams are seen more realistically today as having both positive and negative effects. Over the last decade, growing concern about dam safety, fisheries, environmental quality, and the aesthetic characteristics of rivers has become more widespread in the state. Moreover, reconnection of tributary rivers and their watersheds continues to emerge as a significant component of larger, regional initiatives that focus on Great Lakes restoration.
The purposes dams serve often evolve from their original intent, though most dams were constructed originally as local infrastructure projects to drive economic development activities. Despite their potential negative effects on natural river function, some dams still provide benefits to society. Some dams form reservoirs that provide vital water supply to municipalities and industries. Similarly, impoundments created by some dams provide valuable uses where water‐based recreational opportunities are otherwise lacking, such as boating and fishing. These amenities may increase property values, thus adding to the tax base for local governments. Impoundments in some areas also provide valuable wildlife habitat and refuge.
Nevertheless, many dam owners do not have the financial capability to maintain either the original function of the dam or its current purpose, or remove the dam. Dam owners are often required to repair antiquated structures without sufficient knowledge about potential removal options or finding the financial resources necessary to accomplish it. Likewise, public entities that own dams face similar financial constraints when considering dam removal or repair. In Michigan, a majority (93 percent) of the approximately 2,500 dams in the state were constructed more than 25 years ago. Since the average life expectancy of dams is 50 years, this suggests that over the next 25 years many of these dams will need to be removed or repaired due to their age. Some of these dams have already been abandoned by their owners, and others and may be abandoned if the costs for repair or removal are prohibitive.
Without dedicated state funds to assist municipalities and other dam owners whose dams are approaching the end of their lifespan, little progress will be made to avert this growing problem.