Road Culverts Water Level Control Devices for Beaver
If a decision is made to install a water-control device in a road culvert, the device must be able to handle at least the same amount of water as the road culvert to avoid road flooding and liability problems. In Figure 1, the water level control device passes water directly into the screened-off culvert. The screening is easily plugged leaving only the device, which is much smaller than the road culvert, to handle the flow.
If the water control device does not handle the water flow, the fenced off enclosure will act as an emergency spillway.
More information can be found in the publication Managing Nuisance Beaver Along Roadsides (PDF) (250 kB).