A county board may undertake stream clearing and brush removal on free flowing streams in the county, with the consent of adjacent landowners holding title to the stream bed or to land needed for access to the stream. “Brush removal” for this purpose includes, but is not limited to, cutting of dead trees or brush on stream banks and any open burning of such trees, brush or other natural materials necessary to the cleanup of such a stream. With the approval of the county engineer or superintendent of highways, equipment used by the county highway department may be used in connection with such stream cleanup.