On a crisp Thursday morning last week, as the sun rose over the pond formed by Argo Dam in Ann Arbor, 25 owners and operators of small dams within the Huron River watershed gathered to discuss their management and responsibilities for the dams.
Here are some of the highlights:
Elizabeth Riggs provided background information and statistics about dams in the watershed, in Michigan and around the nation. The majority of dams in the watershed are more than 40 years old, which presents a significant maintenance issue across the watershed as these dams may be approaching (or passed!) their design life. Elizabeth also discussed the growing national trend of dam removal. She indicated that removal can be 3 to 5 times less expensive than dam reconstruction, and funding is available for removal, but not reconstruction.
Luke Trumble, environmental engineer with the Hydrologic Studies and Dam Safety Unit of MDEQ, spoke to the group about the state’s regulation of dams and how it impacts dam owners. He emphasized liabilities associated with dams and the importance of inspection for dam safety. He indicated that owners of high-hazard dams are about 95% compliant with inspection and maintenance regulations. MDEQ inspects state-owned and municipally-owned dams upon request. Private owners must hire private, licensed engineers.
Shawn Middleton, engineer with the Spicer Group, presented on dam inspection and maintenance considerations and the economics of dam management. He highlighted observable evidence of dam deterioration, what to do about it, and how to quantify and minimize cost. One interesting point of discussion was that most of the older dams were not designed for the flood sizes that can be expected in the near future. For example, storms have caused dam failure in western parts of the state in recent years.
Following the presentations, Laura Rubin facilitated a discussion with the attendees and speakers on topics such as restoring river systems following a long period as a dammed system; dam ownership and transfer; and hydropower cost vs. revenue. Cost/benefit analysis in Michigan is showing that converting to hydropower is a liability rather than a benefit financially.
Leading up to the seminar, HRWC has worked to inventory the dams in the watershed and collect information about the structures, their ponds, owners and management. Dam owners and operators were surveyed to update information in the dam database. During this process, more dams, many which are too small to be regulated by the state, were discovered. The large dam operators on the river mainstem recently formed an informal association to establish communication and share information. The smaller dam owners were invited to last Thursday’s seminar.
Presentations and Links of Interest are now available at www.hrwc.org/events/past-seminars.