The Hemmingsen 2000 road system was constructed +40 years ago using bulldozer construction, as was common during that era. There had been road prism failures in several places along the road system. Prior to this project there was high potential for additional failures in the road prism and downslope. This project involved deactivating a portion of the road system. It was done to improve the road prism and downslope stability, and to return subsurface and surface runoff to pre-road conditions. The Hemmingsen 2000 road system is located on west-aspect mid-slopes above Hemmingsen Creek. Area sediment is comprised of a sandy, silty till with localized rubbly colluvium from debris torrents and debris flows. Along the road system, the tills are present generally as mantles and blankets. This road system is estimated to be +40 years old. Because of the cut and fill dozer construction, used at the time, a number of natural and logging-related landslides had occurred along the road. Several wooden culverts were in imminent danger of collapse, with potential debris flows resulting. The objective of this deactivation work was to return subsurface and surface runoff to its original pattern, and to stabilize the road prisms.
Adams-Hughes, Ken. 2003. Hemmingsen 2000 road system deactivation Hemmingsen Creek Drainage, South Island Forest District: project completion abstract. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2003MR105