Presenter/s: Joshua Chenoweth
Symposium Session: 2022 - 08 Beyond Dam Removal: Ecological Restoration of the Klamath Basin
Topics covered: adaptive management and monitoring, community involvement, instream structure (culvert/bridge/dam), riparian, terrestrial species, and uplands
The removal of four dams on the Klamath River will expose nearly 2,000 acres of uplands, riparian habitats, tributary, and main stem river channels that will be devoid of vegetation and critical aquatic habitat. The goal of the project is to create a free-flowing river; allow for access to over 400 stream-miles of historic spawning area upstream of the dams to salmon, steelhead, and lamprey; and to enhance riparian and upland habitats. Dam removal also is expected to lower fall water temperatures and alleviate poor ecological conditions that contribute to fish diseases below the dams.
Currently, there is an estimated 13 million cubic yards of fine sediments deposited in the reservoirs. A majority of the sediments are expected to remain and will require establishing a strong foundation of native vegetation and biological conditions to promote physical processes and place the Klamath on a positive ecological trajectory. A detailed restoration plan is outlined in the Reservoir Area Management Plan, a collaboration of multiple organizations including Resource Environmental Solutions (RES) and the Yurok and Karuk Tribes under Klamath River Renewal Corporation’s leadership. Ecological restoration is informed by the latest scientific guidance and requires a careful coordination of Invasive Exotic Vegetation (IEV) management, revegetation, and in-channel habitat monitoring and restoration. The surrounding landscape harbors abundant populations of IEV poised to dominate the dewatered reservoir landscapes. IEV requires pre-dam removal management, a robust early detection and rapid response plan post-removal, and aggressive revegetation strategies. Revegetation will consist of seeding native species, and planting native bare root plants, live cuttings and herbaceous plugs. Seeding native grasses and forbs immediately during and after dam removal will minimize erosion of fine sediments, preclude IEV species, and enhance natural regeneration while residual moisture from the reservoirs is available. Bare root plants will be installed in priority tributary habitats and in select, concentrated upland areas in dense patches referred to as facilitation patches.
In addition to revegetation efforts there will be volitional fish passage restoration work in high priority tributaries designed to improve habitat conditions. Current restoration designs target five tributaries including: Spencer, Jenny, Camp, Scotch, and Beaver Creek areas. Restoration actions include large wood placement, strategic grading to promote fish passage, in-channel and off-channel habitat enhancement, sediment evacuation, and wetland development. In-channel restoration will occur during drawdown and after dam removal to allow for natural river processes and restore connectivity the upper watershed. All ecological revegetation and restoration actions will be coordinated and implemented together based on field observations and monitoring during the drawdown process.
Restoration on the scale of the Klamath project requires multiple years of preparation. Seed collection from genetically appropriate native species began in 2018 and is ongoing. To date nearly 2,000 lbs. of seed from 80+ species has been collected and used to establish over 37 acres of seed increase fields that produced over 25,000 lbs. in 2020. The next few years are critical for revegetation preparation to ensure native plant materials are ready for this monumental project.