The Tsitika River Project, Campbell River Forest District

Background

The Tsitika River Sediment Project began in 1991 to respond to concerns that sediment from the Tsitika River might adversely affect the killer whale rubbing beaches at Robson Bight Ecological Reserve. The initial objective for the project was to construct a sediment budget for the entire Tsitika River watershed and use it to determine the amount of sediment originating from forestry related activities.

Hydrometric stations were established at Russell and Catherine Creeks and were intended to represent logged (Russell) and unlogged (Catherine) sub-units at the scale of the Tsitika River watershed. Turbidity probes and sediment sampling equipment were added to the existing Water Survey of Canada station at Tsitika River below Catherine Creek. It was soon demonstrated that ocean currents carried sediment plumes from the Tsitika River away from the rubbing beaches. Despite this, concerns remained over forestry impacts on fisheries values within the watershed, thus research continued with a focus on creating sediment budgets within Russell and Catherine Creek watersheds.

Catherine Creek is entirely underlain by the basaltic Karmutsen Formation, whereas Russell Creek is dominated by granitic bedrock with only the upper 1/3 of the watershed in the Karmutsen. This made them unsuitable to act as paired watersheds, but provided the basis for comparative analysis of sediment production from the two bedrock types. It was decided that sediment budgets would be constructed for Russell and Catherine Creek watersheds separately, beginning with Russell Creek. In 1996 Forest Renewal BC (FRBC) funding was obtained for a period of three years for sediment budget research. The first year of this project was spent installing the monitoring sites and the storm sampling program, while the second and third years were spent primarily in data collection and analysis. The program was further extended under funding from the Forest Investment Account (FIA) from 2001 – 2003 to develop a sediment budget model.

Beginning in 2003 research within the Tsitika Watershed switched focus entirely on Russell Creek watershed. In co-operation with the University of British Columbia’s Forest Resources Management department, research began on subsurface preferential flow pathways at the hill-slope scale. In 2005 the meteorological station network within Russell Creek was expanded to examine the spatial variability of precipitation and temperature within the watershed. In addition, work began on a study to assess the role of interception recovery in the rain-on-snow zone of the watershed.

The overall purpose of continuing research within Russell Creek watershed is to determine the effects of forest harvesting on water quality and quantity. Completion of current projects, specifically related to sub-surface flow and canopy interception will be used in the creation of a physically based hydrological model. Model development is on-going, but when completed it will serve as a tool to aid in forest management decisions.

Click here to view the Russell Creek watershed with snow lysimeter and meteorological station locations.

Objectives

• To determine the effects of contemporary forest management on sediment delivery to surface water;
• To determine the effects of forest harvesting on peak flows in a watershed dominated by rain-on-snow events;
• To maintain current infrastructure for long term monitoring of stream flow and climate.

Publications

Technical Reports

Interpreting Turbidity and Suspended-Sediment Measurements in High-Energy Streams in Coastal British Columbia.

Storm based sediment budgets in a partially harvested watershed in coastal BC.

Comparative analysis of sediment production in two partially harvested watersheds in coastal BC.

Effects of forest harvesting and regeneration on peak streamflow in a Coastal watershed.