Approach
Infrastructure is often designed to efficiently drain water, by concentrating and diverting water flows to adjacent vegetation, ditches, surface waters, wetlands or stormwater systems. More frequent, intense, and heavy precipitation may result in excessive stormwater runoff. Concentrated stormwater runoff can cause adjacent areas to erode, and flood, destabilize stream channels, and impair water quality. Natural and low impact development techniques help to reduce stormwater conveyance, enhance groundwater recharge, and improve water quality by decentralizing flows and using soil and plants to capture and filter pollutants. This approach may be especially effective in areas with high percentages of impervious land cover and sensitive ecosystems.
Tactics
- Incorporate permeable surfaces into designs such as block pavers, porous asphalt and concrete to reduce hardening of surfaces and to increase infiltration of storm flows.
- Attenuate and treat stormflows in depressional areas, using bioretention systems to capture runoff, recharge groundwater, and reduce pollutant loads.
- Divert and disperse storm water off of impervious surfaces (such as walkways, roofs, roads, trails) to forests, densely vegetated areas, swales and filter strips to increase water retention on site and enhance filtering of water.
- Use vegetated shoulders and embankments of compacted soils to resist storm surge water flowing across a roadway.
- Strategically grade soil where needed and avoid disturbance of soils if unnecessary to preserve soil porosity and natural drainages.
- Use low water bridges and vented fords.
Strategy
Strategy Text
This strategy addresses actions for adapting infrastructure in forested watersheds, such as roads, skid trails, recreation trails, road-stream crossings, bridges, culverts, dams and other facilities associated with development. Infrastructure and transportation systems designs to avoid structural losses and damages by taking into account storm events and return periods documented in regional historical records. A changing climate may necessitate critical evaluation of past design concepts and criteria to minimize risks and safety concerns over the designed lifespan of the unit. Roads, skid trails, road-stream crossings, recreation trails, facilities, and other infrastructure are known to affect local landforms and hydrology, particularly where impervious surfaces concentrate water into flow pathways, generating high-velocity runoff and erosion. Added considerations in design may be necessary to accommodate altered hydrology and reduce risks of damage, failure or total loss. These considerations may be especially important near high-risk areas and where the consequences of lost infrastructure are unacceptable.
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.,