- Contact Phone: (509) 922-6497
- Contact Email: [email protected]
The design team is responsible for mapping out the specific goals and expected results of the project.
The Project is designed to help restore delta banks that have eroded on islands and shorelines; increase upland habitat; protect native riparian and wetland vegetation; and improve the quantity and quality of fish and wildlife habitat. The Project would add habitat complexity with large woody debris; promote diverse native riparian vegetation growth such as black cottonwood, dogwood, and willow; reduce nonnative invasive reed canarygrass; and control other invasive species.
The goal of the proposed restoration project is to protect, improve and restore key riparian and wetland habitats and their ecological function in the Clark Fork River delta. To meet this goal the project has two focuses:
- To protect existing areas within the delta from further erosion using environmentally compatible stabilization methods, and,
- To restore and enhance the edge and interior areas; restoration and enhancement activities will add habitat complexity with large woody debris; promote diverse native riparian vegetation growth such as black cottonwood, dogwood and willow; and reduce non-native invasive reed canarygrass.
Many of the protection and restoration techniques proposed within the proposed project have been implemented at sites nationwide and proven to be successful through other projects such as the Pack River delta project completed in 2009. The design is currently at an 90% level and includes computer design of the proposed ground surfaces. The 90% design also includes initial input regarding cultural resources from the Kalispel Tribe. The following types of activities are proposed in the project design to meet the project goal:
- Protect delta shorelines from erosion – A combination of “hard” (i.e., structures constructed with rock and vegetation) and “soft” (i.e., structures constructed with wood and vegetation) engineered structures and vegetated riprap would be constructed to protect saturated wetland soils along the delta shorelines from slumping into the water when Lake Pend Oreille is drawn down.
- Protect existing island areas from erosion and create protective “barrier” island areas – The front of leading islands in the delta would be reinforced with vegetated “hard” and “soft” breakwater structures to protect them against scouring wave action. The protection must have a vegetative component and the intent is to create protection that can withstand the wave force driven by a 5.8 mile fetch while still providing some wildlife habitat value.
- Increase physical habitat complexity – Portions of the delta island areas that are currently submerged in the summer months would be raised to restore and expand wildlife habitat lost due to inundation; portions of the submerged areas would also be excavated to provide the fill to the raised areas. Currently, in the winter months, these submerged areas are extensive mudflats when the lake is drawn down to below 2,055 feet in elevation. The project would change these mudflat areas to where the excavated areas would remain flooded during the winter providing open water to waterfowl and shorebirds. Any exposed root wads and other large woody debris present on the mudflat areas would be used in the construction of the raised areas to provide some habitat complexity; so the project would be removing woody debris from areas that are submerged in the summer and making these submerged areas deeper. Surrounding the open water areas, there would be the raised areas that are expected to support high-value habitat for numerous species of waterfowl and wildlife, year-round. It is also expected that the altered topography would create stilled and backwater areas that would minimize long-term loss of soil from erosion and result in a net gain of soil.
- Increase wetland habitat diversity – The presence of noxious and invasive weeds on and near the restoration project area would be reduced and controlled prior to and during construction to prepare the restoration site for the establishment of native species. After construction, the project areas would be seeded and plantings will be planned over a three year period. The project area would be annually surveyed and treated for any noxious weeds and invasive weed control methods implemented.
- Capture woody debris and encourage sediment deposition in the delta area – The project design would incorporate methods to increase sediment deposition within the delta area by constructing a combination of “hard” and “soft” engineered structures that can allow the capture of woody debris directed down the Clark Fork River, and by increasing the areas of wetland habitat cover. The project proposes to use the driftwood currently stored in the log yard by putting the wood on top of the newly raised areas to provide some habitat cover and complexity prior to the establishment of vegetative cover. Also, the USACE report that the agency is currently planning to update and replace the aging boom system that directs large woody debris to the log yard. The USACE anticipate that in the future the new boom system would be designed so it can be moved and the drift wood can be directed to certain areas within the proposed project area.