GSTARS3-HTC Model Development and Evaluation as Part of the Lewis and Clark Lake Sediment Management Study

The deposition of hydraulically transported sediments occurs in all flow impoundments, whether they be naturally occurring or man-made. The natural system way of managing the deposition is to fill the impoundment with sediment until a point is reached where the flow of water finds a new path requiring less energy. This is very often caused by an impoundment completely or nearly full of sediment. If left in the current flow regime, Lewis and Clark Lake will eventually fill with deposited sediment, albeit more than 150 years in the future. The man-made reservoir, Lewis and Clark Lake, formed by Gavins Point Dam, has existing uses that preclude merely allowing the reservoir to fill up. The lake is used for hydropower, navigation re-regulation, recreation, water supply, and flood storage. In an effort to find ways to maintain all of the interests on the lake, management of the deposited sediments in the reach is vital. While the specific management process for the reservoir is yet to be determined, the Lewis and Clark Lake Sediment Management Study aims to develop tools to evaluate a wide variety of possible management proposals.