The Hatton road system was constructed +20 years ago using bulldozer construction, as was common during that era. There had been road prism failures in several places along the road system. Rudimentary deactivation performed in the early 1990's, before modern deactivation measures had been fully developed, had resulted in diversion of surface drainage, which had caused downslope instability in several gully systems. 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 Hatton Creek road system is located along an east-west ridge that is south of the Caycuse River. This older road system is estimated to be +20 years old. Post-logging ditching down the road prism appeared to have cause several creek torrents as this work concentrated and transported runoff in a crossslope direction. Some fillslope failures had occurred along sections where sidecast was over-steepened Area sediment is variable. A deep till dominates the lower Hatton Main and H-11, H-12, H-14 Roads. Due to the till sediment?s sandy composition it is prone to erosion. Colluvium is predominate along the higher elevation H-8 road system. A deep accumulation of fine rock clast sediment was observed downslope from the H-8 road, which is located along the southern hillslope. And this is believed to result from the rapid weathering of highly fractured andesite bedrock. The H-8C roads situated along the northern hillslope were dominated by a generally shallow colluvium consisting of fine sand-based matrix and larger rock blocks, which correlate with the granite bedrock common to the north hillslope. A large ditch along Hatton Main and H-14 that had been excavated during rudimentary deactivation during the early 1990's transported water laterally across the hillslope causing the concentration of runoff, which subsequently caused a number of torrents at the discharge points. This ditch was infilled and as a measure to restore the hillslope drainage.
Pollmer, A.. 2003. Deactivation of a portion of the Hatton Road system, Hatton Creek Drainage, South Island Forest District: project completion abstract. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2003MR104