Klamath River Dam Removal Study: Sediment Transport DREAM-1 Simulation

Document Details:

Title: Klamath River Dam Removal Study: Sediment Transport DREAM-1 Simulation
Category: Technical Report
File: Stillwater_2008_0232_Klamath-River-Dam-Removal-Study.pdf
Updated Date: 16.05.2017
Author(s)/Source(s): Stillwater Sciences
Publication Date: 2008-Oct
Focal Topic: Dam Removal, Sediment & Geomorphology
Location: Klamath Basin
Watershed Code: 180102

Iron Gate, Copco 1, Copco 2, and J.C. Boyle dams, located on the Klamath River in Oregon and California downstream of Upper Klamath Lake, are under consideration for possible removal. Data collected to date indicate that 11.5 to 15.3 million m3 (15 to 20 million cubic yards) of deposits are stored within the four reservoirs (Eilers and Gubala 2003; GEC 2006). Unlike the other mid- to large-sized dam removal projects in the U.S. (e.g., Marmot Dam on the Sandy River, Oregon; dams on the Elwha River, Washington; Matilija Dam on Ventura Creek, California; and San Clemente Dam on Carmel River, California), the deposits in the above four reservoirs on the Klamath River have a high water content (~ 80% by volume), and the majority of the sediment particles are fine-grained (i.e., in the silt and clay range), while the composition of the Klamath River channel bed downstream of these dams are cobble sized (e.g., Stillwater Sciences 2004; Cui et al. 2005; GEC 2006; Shannon and Wilson Inc. 2006). As a result, if the deposits are released downstream, high suspended sediment concentrations and their associated biological impacts due to the quick release of fine sediment will most likely be the major concern (GEC 2006), while concerns for downstream sediment deposition common to other dam removal projects will be minor, as demonstrated by the “worst-case-scenario” assumption analyses conducted in Stillwater Sciences (2004).

Keyword Tags:
Dam removal, Sediment Transport, DREAM-1 Simulation