Water Quality

Phosphorous Sources in the Upper Chimney Creek Basin

Background

The Upper Chimney Creek Basin is located approximately 30 minutes west of Williams Lake in the central interior of British Columbia. Two significant waterbodies in this area are Chimney and Felker Lakes. These lakes feed Chimney Creek, which flows into the Fraser River southwest of Williams Lake. Due to their proximity to Williams Lake the lakes have become a popular recreational area as well as a highly valued residential area. The water quality of the area has long been an issue and, with the increased domestic use, remains in the forefront with permanent residents. Spring overturn measurements have shown significant increases in total phosphorus (P) since 1979 and algal blooms and decreased water clarity have also been noted. Potential contributors to increased P loadings include forestry activities, residential lakeshore development and agricultural practices.

Residential development along Chimney (left) and Felker (right) Lakes

In response to water quality concerns, the Chimney Felker Water Quality Committee proposed a study with assistance from the Ministry of Environment, Lands and Parks [MELP] (now called Water, Land and Air Protection [WLAP]). This proposal included the following:

• complete a detailed scientific study design for monitoring the lakes;
• take sediment cores from the lake bottoms to determine historical water quality trends;
• determine P retention abilities of soils and quantify P loading from residential onsite sewage systems;
• survey homeowners to document fertilizer and household chemical use and determine the potential loading;
• survey agricultural practices and determine the potential P loading;
• review forest harvesting and road building practices and determine the potential P loading;
• estimate natural internal lake P loading;
• estimate P loading resulting from sediment disturbance from boats;
• review existing data on the lake; and
• develop recommendations with actions designed to reduce or prevent nutrient loading from the sources.
  
  

The Ministry of Water, Land and Air Protection [WLAP], formerly MELP, is continuing to support this work.

Cattle grazing in the upper portions of the watershed above Chimney Lake

The Study

In 1999, a consultant was contracted to study the P loading in Chimney and Felker Lakes. The objective was to evaluate various sources of P, both natural and man-made, and their potential levels of contribution to the lakes. The Chimney Felker Water Quality Committee played a key role in this study, spending numerous volunteer hours collecting valuable information from lakeshore residents. Assistance was also provided by the ranchers who utilize the watershed, Ministry of Forests' staff and the forest licencee operating within the study area. Data collection and map production was provided by MELP (now WLAP) staff from the Cariboo regional office in Williams Lake.

The Upper Chimney Creek Basin (shaded portion)

The results of this work were reported in Phosphorus Sources in the Upper Chimney Creek Basin (Hart, 2000). Export coefficients for individual land uses were estimated and the area of land affected by each land use was multiplied by the appropriate coefficient to estimate the P loading. The sum of these estimates provided an estimate for the entire watershed.

Key findings of the report include the following:

• P loadings over the past 30 years from onsite sewage systems was estimated to increase from 1 kg/year to 10.7 kg/year in Felker Lake and from 5.9 kg/year to 33.0 kg/year in Chimney Lake;
• the loading from onsite sewage systems is approximately 4% of the total annual P loading for both lakes from all sources;
• it is anticipated that P loadings from onsite sewage systems will increase in the long-term due to soil saturation of P binding sites.
• residential development, not including onsite sewage systems, accounts for about 3% of the total P loading for each of the lakes;
• livestock wintering and hay field fertilization accounts for about 5% of the total P loading to Chimney Lake and about 3% for Felker Lake;
• all agricultural activities account for about 15% of the total P loading for each lake;
• forested land, including logged areas, wetlands, small lakes and ponds contributes about 58% of the total P loading to Chimney Lake and about 49% to Felker Lake. These figures are due largely to the size of the land base rather than the harvesting practices which are mostly selective cutting with few clearcuts; and
• although analysis of initial increases in lake P concentrations for Chimney Lake suggest a correlation with winter precipitation, WLAP staff feel there are not sufficient data to make any conclusive statements.
  
  

Based on these findings, recommendations were made to either minimize the impact of P or prevent further P loading. An implementation plan was developed by MELP (now WLAP) to address the recommendations and presented to the Chimney Felker Water Quality Committee for their input on priorities and tasks.

Anglers on Chimney Lake

 

Objectives of the Implementation Plan

The Implementation Plan was designed to meet and address phosphorus issues in the Upper Chimney Creek Basin and minimize further P introduction. The plan includes restorative measures as well as research projects to reduce data gaps and monitor future conditions.

The report recommendations are grouped as either short-term or long-term depending on the type of work required and predictions of available funding and personnel. The recommendations are then addressed individually with a suitable procedure that considers the goals of minimizing P loadings and feasibility for completion.

Some of the actions involve enforcement of legislation and the use of best management practices. Others rely on increasing public awareness to encourage a voluntary change in everyday activities and assist in the maintenance of good water quality and environmental management.

 

The Future

A final plan has recently been completed and the tasks to be completed in the upcoming year are underway. These include:

• providing lakeshore residents with information on reducing phosphate inputs through the use of environmentally friendly products;
• providing lakeshore residents with information on environmentally friendly approaches to landscaping;
• examining the use of power boats on Chimney Lake; and
• discussing methods to minimize P inputs to the lakes with ranchers, the forest licencee and Ministry of Forests staff.
  
  
  

Felker Lake

 

Back to NPS homepage

Back to Project Profiles