For this reason, avoid leaving excess amounts of woody debris in stream channels where it can float downstream and lodge in culverts. Maintenance is especially important in areas where beavers are present. Undersized culverts can become plugged with sediment A culvert not installed at the existing stream gradient can degrade the stream channel. Install riprap to prevent erosion at the inlet to a culvert pipe. The streambed has a firm rock or coarse gravel bottom, and the approaches are low and stable enough to support traffic.
Traffic is limited to low volumes of light vehicles.
Water depth is less than 3 feet. If corduroy, coarse gravel, or gabion is used to create a driving surface, it should be installed flush with the streambed to minimize erosion and to allow fish passage. Crossings should be at right angles to the stream. Stabilize the approaches by using nonerodible material. The material should extend at least 50 feet on both sides of the crossing.