Water Stewardship Information Sources

Citation Epps, D and Phippen, B. 2011. Water quality assessment and objectives for Comox Lake, Technical Report. BC Ministry of Environment.
Organization BC MoE
URL http://www.env.gov.bc.ca/wat/wq/comox/comox-technical-may2011.pdf
Abstract/Description or Keywords This document presents a summary of the ambient water quality of Comox Lake, British
Columbia, and proposes water quality objectives designed to protect existing and future
water uses. The water quality assessment for the lake and an evaluation of the watershed
form the basis for the objectives.
Comox Lake is a large lake, with a surface area of 2,100 ha, located near the village of
Cumberland, BC. Drinking water supply is an important water use of this watershed.
The Comox Valley Regional District withdraws drinking water from the Puntledge River
downstream from Comox Lake, and the water quality of Comox Lake has a large
influence on the quality of Comox Valley drinking water. BC Hydro has a dam at the
outlet of Comox Lake. The lake water levels are controlled to ensure sufficient flows for
the hydroelectric project, drinking water use and fisheries use downstream in the
Puntledge River. Comox Lake also provides significant recreational opportunities
(fishing, swimming, camping and boating) and fish and wildlife habitat. These activities,
as well as forestry, residential and historical mining activities, all potentially affect water
quality in Comox Lake.
Water quality monitoring was conducted between 2005 and 2008. The results of this
monitoring indicate the lake is oligotrophic and the overall state of the water quality is
very good. All chemical, physical and biological parameters meet provincial water
quality guidelines with the exception of microbiological indicators which exceeded
drinking water guidelines on occasion in the outlet basin. A microbial source tracking
study prepared for the Comox Strathcona Regional District in 2005 found that the
predominant sources of fecal coliforms near the lake outlet were attributable to deer, dogs
and seagulls (Clayton, 2005).
In order to maintain and protect the water quality in Comox Lake, ambient water quality
objectives were set for temperature, dissolved oxygen, water clarity (Secchi depth), total
phosphorus, chlorophyll a, turbidity and E. coli. Future monitoring recommendations include attainment monitoring at all three deep basin
sites, every 3-5 years, depending on available resources and whether activities, such as
forestry or development, are underway within the watershed. This monitoring should be
conducted for one year on a quarterly basis and also include microbiological indicators at
the seven perimeter sites during the summer low flow and fall flush period (five weekly
samples in 30 days). In addition, future monitoring should be conducted downstream of
Comox Lake in the Puntledge River at the CVRD water intake location.
Information Type report
Regional Watershed Vancouver Island South
Sub-watershed if known Comox Lake
Aquifer #
Comments
Project status
Contact Name Deborah Epps
Contact Email [email protected]