Installation of a Trumer debris net to protect the residential and commercial population from catastrophic river debris flow events.

Work Site

  • Remote riverbed, adjacent to waterfall in a steep 90o canyon with heavy treed canopy
  • limiting or negating helicopter operations
  • Extremely sensitive environmental conditions with potential effects of native species of aquatic wildlife
  • Rapid, and unpredictable fluctuations in river water levels
drilling 1 - mosquito creek


Check scaling, drilling, anchor installation, transportation of fence materials to site, installation of debris net


Fluctuating water levels, extreme environmental sensitive area, and requisite controls for river work.  With no possibility of crane, helicopter access, or road access, all materials were carried by hand 1km up access trail

GRA used advanced rope access highline techniques for rigging and materials transport systems, and developed specially designed site specific environmental control procedures.

GRA’s deep understanding and experience in challenging access remote work locations, expertise in minimizing environmental impact/footprint proved essential in managing unpredictable and urgent water levels required for a successful and safe installation.


Described by debris net material supplier, Trumer as ”most difficult installation conditions they have seen”, GRA was more than up to the task to successfully complete this project to the Client’s satisfaction.