Citation | Millard, T. 2001. Transport of logging slash and sediment in S5 and S6 streams near Boston Bar, Chilliwack Forest District. Forest Research Technical Report TR-012, Vancouver Forest Region. |
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Organization | FLNRO |
URL | https://www.for.gov.bc.ca/rco/research/georeports/tr012.pdf |
Abstract/Description or Keywords | Under the Forest Practices Code of British Columbia, a forest reserve may not be required alongside S5 and S6 streams. S5 and S6 streams are non-fish streams outside of community watersheds. In S5 and S6 streams that have harvesting adjacent to their banks, deposition of additional quantities of woody debris (logging slash) into the stream may occur. Removal of this logging slash (usually referred to as stream cleaning) is often done to prevent increased transport of woody debris and sediment into fish streams connected to the S5 or S6 stream. This report investigates the transport of logging slash and sediment in “slashfull” streams. This study is the second phase of a project initiated in 1999 to examine the effects of logging slash in channels, and to provide recommendations to assist in the decision of whether stream cleaning would be beneficial. The first phase of the project examined streams near Nitinat Lake, in southwestern Vancouver Island (Millard, 2000). This second phase of the project examined streams within the Anderson River watershed, on the east side of the Fraser Canyon near Boston Bar. The project has two objectives: 1. To determine how channels respond if logging slash is left in the stream, and, 2. To identify stream parameters that can be used to predict the likelihood of channel disturbance and downstream transport of logging slash and sediment. Forty-three stream reaches were surveyed, with the data from 42 streams analysed. Most of the streams were logged from 1986 to 1993, with two additional study reaches logged in 1997. Most of the channels were located in thick, fine-grained till sediments. The following response variables were measured: size of woody debris transported, the size of woody debris jams that developed in the study reach, the size of sediment wedges that developed in the study reach, and the overall level of disturbance in the channel. Bankfull channel width was shown to be the most significant predictor variable for all of these response variables. The size of sediment transported in the study reach was another significant predictor variable. Based on the results of this study and Millard (2000), recommendations for stream cleaning of S5 and S6 streams were developed. |
Information Type | report |
Regional Watershed | Lower Fraser |
Sub-watershed if known | |
Aquifer # | |
Comments | |
Project status | complete |
Contact Name | Tom Millard |
Contact Email | [email protected] |