Branch T4000 was constructed approximately 30 years ago using conventional side cast methods. Through air photo (1969) interpretation it appears much of the Three Arm Creek watershed was logged from this road system.
The construction method resulted in significant volumes of fill material deposited on moderately steep to steep gradient slopes and into pronounced gullies particularly gullies A, B and C. Drainage disruption and concentration was evident throughout the lower section of road (1+040m-1+645m).
During November 2006 storms debris flows occurred that impacted Branch T4000, Three Arm Creek, and Three Rivers Main.
Discussions with road construction personnel with experience int his geographical area indicate the lack of readily available bedrock and type and material compostion posed a significant challenge during construction.
Observations made during the course of deactivation indicate the bedrock generated in cut was moved back for construction purposes rather than sidecast (initial assumption).
Unwin, Lyle. 2009. Three Arm Creek Road Deactivation. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2009MR213
Topic: FLNRORD Research Program
Keywords: Forest, Investment, Account, (FIA), British, Columbia
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