Hillside Runoff, Grading & Swales in Missoula, MT

A slope sends water downhill even when the lawn looks dry. We follow the flow from the upper edge of the property to the first place where it spreads, cuts a rut, or pools. We check the driveway crown, retaining edges, foundation grade, fence line, and the low point that receives runoff. A shallow swale, regrade, level spreader, or protected channel may fit when the site has room and a lawful outlet.

Missoula County's environmental design standards encourage natural and vegetated systems such as swales, constructed wetlands, and bioretention cells. County Public Works reviews grading, drainage, and erosion control for work under its standards. We describe the proposed route and its upkeep. The owner still needs to confirm the current review path before moving soil near a waterway or floodplain.