God Made Dirt, So Dirt Don’t Hurt…Except For My Dam Removal Budget
Dan DeVaun
GEI Consultants Inc.
Traverse City, Michigan
Dam removal is a growing trend in the United States. In many communities outdated and/or unsafe dams are being removed to restore river ecosystems and eliminate the risk to people’s lives and property from dam failure. Removing a dam is a complex process. One aspect of these projects is the management of impounded sediments. Sediment management is a critical aspect of dam removal projects, as the sediment stored in the impoundment may be covering the historical channel and habitat and the release of trapped sediments can have downstream impacts on water quality, floodplain restoration, infrastructure, and aquatic habitats.
Effective sediment management during dam removal requires a thorough understanding of the pre-and post-dam sediment conditions, including the volume and characteristics (quality and grain size) of sediment stored behind the dam, the downstream sediment transport dynamics, and the potential effects of sediment release on the river ecosystem.
A key consideration in sediment management is the establishment of appropriate sediment release rates to ensure that downstream resources are protected, while also allowing for the restoration of upstream habitats. Strategies such as active removal, staged releases, sediment retention structures, and sediment diversions can be used to manage the downstream transport of sediment and minimize impacts.
Over the past decade, several groups have prepared guidance documents on dam removal that consider approaches for sediment management. These documents will be reviewed in the context of completed projects. The documents include those published by the USSD, USBR, USEPA, and USACE.
In conclusion, sediment management during dam removal is a complex process that requires careful planning, monitoring, and collaboration among stakeholders. By understanding the pre- and post-dam sediment conditions, and employing effective sediment management strategies, dam removal projects can be executed in a manner that protects downstream resources and restores upstream habitats.
About Dan DeVaun
Dan DeVaun is a Senior Project Manager and Professional Civil Engineer at GEI working with clients to solve water resource challenges in an ever-changing environment. His career over the past two decades has included service as an engineering consultant and a regulator in Michigan’s Dam Safety Unit. His experience includes supporting development of policy and law, implementing regulations, and designing and managing projects for; dam rehabilitation, dam removal, river restoration, watershed analysis and planning, and stormwater management. Dan has worked on over 20 dam removal and river restoration projects around the Midwest, including several of Michigan’s largest dam removals. Dan resides in Traverse City, Michigan with his family and enjoys recreating in and around our treasured natural resources.
