The design and material used in forest road building may have strong impact on erosion risk and water quality in streams. Bridges or culverts used at stream crossings must be properly designed to minimise negative impacts on the aquatic environment. Poorly designed or poorly constructed stream crossings can lead to increased sediment mobilisation, changes in flow patterns and even flooding upstream if insufficient water is transported.
Properly designed stream crossings permit the free movement of fish and aquatic invertebrates and will not restrict peak flows. Ensuring that stream crossings do not restrict peak flows will help to reduce localised flooding and can ultimately be more cost effective as they will not need to be rebuilt following high flow events.
