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Road Stream Crossing Best Management Practices
Problem: Road/stream crossings that are poorly designed or outdated can contribute tons of sand to a stream channel, especially with rain and snowmelt. Typical problems at road crossings include:
- Undersized culverts
- Steep approaches on dirt roads
- Old bridges and culverts that are breaking down
- Steep embankments that are not vegetated well
- Excessive foot traffic at crossings to access streams
- The culvert or bridge is the “low spot”, thus causing runoff to pool and flow directly into the stream
Common BMP solutions include:
![rsc1_geotextile.gif rsc1_geotextile.gif](media/pages/rsc1_geotextile.gif)
- Paving and curbing to channel runoff and prevent erosion of the roadbed
- Spillways to channel runoff into nearby lowland areas
- Larger culverts to better
accommodate stream flows and channel widths
- Longer culverts to prevent steep, eroding embankments that may be difficult to revegetated
Bridges or bottomless culverts to allow for natural stream bottoms
- Fieldstone at inlets and outlets for slope stabilization
- Geotextile on embankments for revegetation
- Raising the roadbed so that the crossing itself is not the low spot.
- Berms to prevent runoff from running over the edge of the road
- Check dams and ditching
Culverts:
Culverts are commonly undersized to handle stream flows, and can cause big pools to form as a result.
![rsc3_culvert.gif rsc3_culvert.gif](media/pages/rsc3_culvert.gif)
Open Bottom Arch or Box Culvert:
Wider, longer, bottomless arch and box culverts are an ideal way to accommodate stream flows, especially during high water events.
![rsc4_archbox.gif rsc4_archbox.gif](media/pages/rsc4_archbox.gif)
Multiple Culverts:
Multiple culverts are not ideal as some of them can get easily blocked with branches and debris.
![rsc5_multiculvert.gif rsc5_multiculvert.gif](media/pages/rsc5_multiculvert.gif)
Bridges:
Bridges are the proper structure for crossings on larger rivers and streams.
![rsc6_bridge.gif rsc6_bridge.gif](media/pages/rsc6_bridge.gif)
Steep Dirt Approaches:
Steep approaches on dirt roads constantly dump sand into rivers with rain and snow melt.
![rsc7_steepdirt.gif rsc7_steepdirt.gif](media/pages/rsc7_steepdirt.gif)
Pavement and Curbing:
Pavement and curbing is the ideal way to prevent erosion of the actual roadbed into the stream.
![rsc8_pavecurb.gif rsc8_pavecurb.gif](media/pages/rsc8_pavecurb.gif)
Spillways:
Spillways with rock at the end of curbing allows runoff to filter into nearby low areas.
![rsc9_spillway.gif rsc9_spillway.gif](media/pages/rsc9_spillway.gif)
Check Dams:
Check dams are a series of rock piles placed in vegetated ditches that slows runoff and filters out sediment.
![rsc10_checkdam.gif rsc10_checkdam.gif](media/pages/rsc10_checkdam.gif)
Run Off:
Our transportation system can be a major source of sediment to our creeks and rivers.
![rsc11_runoff.gif rsc11_runoff.gif](media/pages/rsc11_runoff.gif)
This page last updated on 12/13/2011.