Approach
Streams and rivers are dynamic and sensitive to climate and land-cover, where changes are often reflected in physical alterations to the stream channel geomorphology (channel shape and pattern) and to fluvial processes (streamflow and sediment transport). More intense and variable seasonal precipitation is expected to increase the volume and rate of water entering streams, amplifying the risks of erosion, scour, and adjustment of channel dimensions, particularly bank full width, and depth. Warmer conditions and altered forest hydrology may combine to reduce low flows during the growing season, potentially fragmenting aquatic and terrestrial wildlife communities. Restoring stream channel form and function and preparing riparian systems to absorb additional climate-related stresses, may help reduce risks of erosion, channel instability, and degradation of aquatic habitat.
Tactics
- Remove anthropogenic “hard measures” that restrict channel flow and alter channel shape such as check dams, concrete armoring and undersized culverts; and replace with structures designed to accommodate a natural stream channel that allows for geomorphic
- Use in-stream restoration techniques to dissipate streamflow energy that enhances bank stability during and after large storm events, by using rock vanes, weirs, large boulders and large wood.
- Reduce disturbances related to impervious surfaces by placing facilities away from water bodies, improving road and ditch characteristics, decommissioning facilities, and by using temporary bridge stream crossing structures.
- Re-sculpt functioning ditches in agricultural areas to two-stage designs that mimic a floodplain providing more consistent fluvial form and process, greater channel stability and to slow delivery of water through watershed.
Strategy
Strategy Text
This strategy seeks to sustain fundamental watershed functions, addressing the maintenance of and restoration of soil-water connections and hydrologic function. A shift in climate may amplify and exacerbate existing ecosystem challenges resulting from land-uses that have fragmented, altered or obstructed water flow pathways. Sustaining hydrologic and ecosystem functions into the future is likely to depend on management planning that seeks to maintain the long-term conveyance of water through unobstructed hydrologic pathways, most notably actions that promote the enhancement of water infiltration by porous forest soils.
Shannon, P.D.; Swanston, C.W.; Janowiak, M.K.; Handler, S.D.; Schmitt, K.M.; Brandt, L.A.; Butler-Leopold, P.R.; Ontl, T.A. (in review). Adaptation Strategies and Approaches for Forested Watersheds. Ecological Applications.,