Increase resilience of road system infrastructure to higher peak flows

Approach

Tactics

Increase size of drainage structures; plan for greater than 100-year events.
Install more bridges and open bottom culverts and use venting fill in floodplains.
Plan for more decommissionings and re-routings; review historical closures/decommissionings for adequacy.
Reduce hydrologic connectivity of roads to the stream system by outsloping, increasing rolling dips and cross culverts; improve surfacing, especially at approaches to crossings.

Sensitivity

• Higher and earlier peak flows will lead to higher risk of damage to transportation infrastructure (roads and trails) and to stream channel function.

Strategy

Design and modify infrastructure to match future conditions