Culvert - Environmental Impacts

Environmental Impacts

Safe and stable stream crossings can accommodate wildlife and protect stream health while reducing expensive erosion and structural damage.

Undersized and poorly placed culverts can cause problems for water quality and aquatic organisms. Poorly designed culverts can degrade water quality via scour and erosion and also restrict aquatic organisms from being able to move freely between upstream and downstream habitat. Fish are a common victim in the loss of habitat due to poorly designed crossing structures. Culverts that offer adequate aquatic organism passage reduce impediments to movement of fish, wildlife and other aquatic life that require instream passage. These structures are less likely to fail in medium to large scale rain/snow melt events.

Poorly designed culverts are also more apt to become jammed with sediment and debris during medium to large scale rain events. If the culvert cannot pass the water volume in the stream, the water may overflow over the road embankment. This may cause significant erosion, washing out the culvert. The embankment material that is washed away can clog other structures downstream, causing them to fail as well. It can also damage crops and property. A properly sized structure and hard bank armoring can help to alleviate this pressure.