Managing sediment during dam removal
to reduce downstream mussel impacts.
Nick Nelson, Andy Selle, Mike Burke - all with Inter-Fluve, Inc.
Abstract:
Dams are being removed around New England and the nation for a variety of reasons. The process of dam removal can be a long term benefit to fragmented mussel populations, provided a thorough understanding of sediment management has been developed. The management of sediment stored within the impoundment can be accomplished actively or passively, each having implications for mussels both within the impoundment and downstream of the dam. Active management focuses on removing or trapping sediment and limiting downstream transport whereas passive methods allow sediment to be exported from the impoundment as river headcuts progress upstream. This presentation will discuss mechanisms of downstream sediment transport and deposition, alternative sediment management strategies, and lessons learned. From a practitioner's standpoint, we will discuss the metrics used to identify appropriate sediment management strategies and minimize impact to aquatic organisms. We will draw on experience removing large and small dams in rural and urban environments to present lessons learned.
to reduce downstream mussel impacts.
Nick Nelson, Andy Selle, Mike Burke - all with Inter-Fluve, Inc.
Abstract:
Dams are being removed around New England and the nation for a variety of reasons. The process of dam removal can be a long term benefit to fragmented mussel populations, provided a thorough understanding of sediment management has been developed. The management of sediment stored within the impoundment can be accomplished actively or passively, each having implications for mussels both within the impoundment and downstream of the dam. Active management focuses on removing or trapping sediment and limiting downstream transport whereas passive methods allow sediment to be exported from the impoundment as river headcuts progress upstream. This presentation will discuss mechanisms of downstream sediment transport and deposition, alternative sediment management strategies, and lessons learned. From a practitioner's standpoint, we will discuss the metrics used to identify appropriate sediment management strategies and minimize impact to aquatic organisms. We will draw on experience removing large and small dams in rural and urban environments to present lessons learned.
Biography:
Nick Nelson is a fluvial geomorphologist and the MA office manager for Inter-Fluve, Inc., a river and wetland restoration firm. Nick has conducted geomorphic assessments on over 250 river miles and has been involved in dozens of river restoration and dam removal projects throughout the country. In the past five years, Inter-Fluve has removed six dams and a dozen other flow barriers as well as restored miles of stream and many acres of wetland in New England alone. Nick has a BA in geology from Williams College and an MS in fluvial geomorphology from Utah State University.