Klamath River Gravel Augmentation

Klamath_Gravel_AugmentationAs part of the Klamath Hydroelectric Project Settlement Agreement, PacifiCorp Energy committed to a series of Interim Measures that would improve habitat for resident trout, and potentially, future salmon (post dam-removal). These included the removal of a sidecast rock barrier to improve fish passage and the strategic placement of spawning gravels downstream of the J.C. Boyle hydroelectric project to enhance spawning habitat, macroinvertebrate habitat, and channel geomorphic processes.

PacifiCorp engaged MB&G to prepare an Environmental Assessment of these proposed actions, which are located on Bureau of Land Management lands. The Environmental Assessment addressed the project’s impacts on hydrology, channel characteristics, aquatic and terrestrial species, and recreational use of the river. In addition to the NEPA document, MB&G completed permitting for gravel addition, prepared a Gravel Augmentation Plan, and implemented a monitoring program to gage effectiveness and gravel transport. Gravel augmentation, begun in 2011, will be conducted through 2017, with applications at pre-selected sites each year. Gravel is applied based on the timing of fish, wildlife, and recreational use of the Klamath River.

PacifiCorp’s relicensing studies for the Klamath Hydroelectric Project included an analysis of sediment input and transport in Project-affected reaches of the Klamath River. These studies led to a recommendation by a technical oversight committee to develop a gravel augmentation program for the Klamath River between the J.C. Boyle dam and Copco Reservoir. Under contract to PacifiCorp, MB&G led a consultant team tasked with the design, permitting, and implementation of this program.

Addition of spawning gravels to the Klamath River downstream of J.C. Boyle will enhance aquatic resources, including:

  • Current spawning habitat for resident trout
  • Future spawning habitat for anadromous fish, if Klamath dams are removed
  • Macroinvertebrate habitat
  • Channel geomorphic processes (e.g., gravel bar formation for aquatic and riparian species).

Working with the Klamath Field office of the Bureau of Land Management, MB&G developed a NEPA Environmental Assessment for this project. Other state and federal permits obtained include:

  • Clean Water Act Section 404/401
  • OR State Removal/Fill
  • Oregon State Scenic Waterway/Federal Wild and Scenic River
  • Section 106 of the National Historic Preservation Act
  • Federal Endangered Species Act.

Gravel augmentation began in 2011 and was conducted through 2017, with applications at pre-selected sites each year. Gravel was applied based on the timing of fish, wildlife, and recreational use of the Klamath River.

Client

PacifiCorp Energy