We are fortunate that we can largely take the quality of the water in the lake for granted. For many years the lake has taken all we, and other users of the watershed, have thrown at it and still has high quality water. Climate and over use may be bringing us to the end of the free ride.
A 2007 Province of BC study of the lake identified only Forestry and residential septic fields as waste discharges that could cause water quality problems. The board often hears that recreational use can also degrade water quality. This section examines all of these issues.
- Our understanding of water quality in Shawnigan Lake is based on a number of studies done by the Province of BC over the last 30 years and recent testing done by Dr Mazumder of the University of Victoria. Learn more about recent water testing and future plans.
- Water testing has shown that sewage is leaking from septic fields around the lake, particularly with the first big rains each fall. Learn more about the current Liquid Waste Management study.
- The quality of lake water is also affected by watershed development in the private forest lands that occupy much of the watershed. The SRA tracks this activity and represents its members before the CVRD.
- The number of recreational users of the lake and the types of uses also affect water quality. Is it a problem? What should we be doing about it?
More about Water Quality:
The provincial government has done comprehensive testing of the water in Shawnigan Lake several times in the last 40 years.
Dr Mazumder of UVic
Dr Mazumder and his group at UVic have been testing water quality in lakes around BC for many years. His presentation, given to the Shawnigan Watershed Watch group, is a little more pessimistic than the following Provincial reports.
Shawnigan Lake Water Quality Study 1984
This provincial study says, in the Summary: "Data were collected from 1977 to 1979 for a variety of parameters of water chemistry and biology at two deep water stations (main basin and south basin), as well as several shallow water stations, and the inflow streams."
Shawnigan Lake Water Quality Study 2004
A second provincial study has a series of recommendations:
- Ministry of Water, Land and Air Protection (WLAP) staff should continue spring overturn sampling, including water chemistry at multiple depths and biological parameters (chlorophyll a, phytoplankton, zooplankton).
- WLAP staff should conduct additional bacteriological sampling in 2004 to confirm results noted in this study. Efforts should be concentrated to areas in the lake within 10 m from domestic intakes as well as McGee Creek and the Shawnigan Creek inflow. Samples should be collected a minimum of five times in a 30-day period.
- WLAP should review and formalize the water quality objectives for Shawnigan Lake proposed by Nordin and McKean (1984).
- Support should be provided to organized lake stewards to continue with basic water quality sampling through the BC Lake Stewardship Society. Other activities for lake stewards could include monitoring of aquatic macrophyte growth and distribution, and tracking sportfishing catches to monitor fish populations, especially bass and trout.
- The Cowichan Valley Regional District should ensure residential and commercial land development within the watershed take into account the potential impacts on the water quality of any such activities. Appropriate best management practices and planning techniques should be applied to protect Shawnigan Lake for domestic purposes and other current and future water uses.
Water Quality Assessment and Objectives for Shawnigan Lake 2007
A second provincial study provided a series of water quality objectives - measured levels of nutrients, bacteria, cloudiness, etc - that if met would indicate that Shawnigan Lake water quality is satisfactory. We reproduce parts of the overview of that document. The report said that all measurements at that time fell well within the objectives.
Liquid Waste Management
The Cowhichan Valley Regional District has been doing Liquid Waste Management study of the South Sector, which includes Shawnigan Lake (also known as Area B). Liquid waste means sewers and septic fields; solid waste means garbage and recycling.
This current study will replace a study done in 1998. While dated and soon to be replaced by the new study, this older study does cover the basic problems we face.
In summary, the 1998 report recommends:
- A central sewer system should be installed to service:
- Shawnigan Village;
- Shawnigan Lake Shoreline;
- Mill Bay Core;
- Mill Bay Shoreline; and
- Cobble Hill Village.
- A common treatment plant should be located in Mill Bay with an outfall to Satellite Channel located north of Hatch Point.
- The wastewater converyance system should be essentially a conventional gravity system using low pressure mains and STEP systems as required.
There is no current document on the CVRD web site for the new Liquid Waste Management study.
With cutbacks in Provincial spending in the current downturn, this new study could well be delayed for some years.
The trailer park on South Shawnigan Lake Road has installed a waste water treament facility capable of handling 150 homes at a cost of less than $2 million. The treated water from this plant is released on crown land well away from the lake.
The option of using small facilities like this, with several located around the lake handling waste for all homes within 200 metres of the lake (homes that cannot locate their own septic field more than 200 metres from the lake), may be an alternative to the central facility in Mill Bay.
This would be particularly true for properties on the south east and wouth west sides of the lake. It may even make sense for all properties more than 1 to 2 kilometres from Shawnigan Village (the current sewage collection area).
The provision of a sewage system, even on of this limited size, would have side effects we must consider. Right now density is pretty well limited for all areas NOT served by a sewer system - all those on septic fields. If we install any type of sewer system the pressure for higher densities would increase. This would mean applications for lot subdivision would be much more common. Some might be approved, particularly if these applications were considered by the CVRD as whole rather than an incorporated Area B.
Water Quality Documents
- 1984 Shawnigan Lake Water Quality Study
- 1985 BC Water Level Study
- 1996 Fecal Coliforms in Shawnigan Lake
- 1996 State of Water Quality of Shawnigan Lake 1976-1995
- 2000 Shawnigan Creek Watershed - A Fisheries Perspective
- 2004 Shawnigan Lake Water Quality Assessment 1976-2004
- 2006 Shawnigan-Goldstream Water Allocation Plan
- 2007 Water Quality Assessment and Objectives for Shawnigan Lake-Overview
- 2007 Water Quality Assessment and Objectives for Shawnigan Lake
- 2009 CVRD South Cowichan Water Plan
- 2010 CVRD State of the Environment Report
- 2010 BC Water Act Modernization Report
- 2011 Shawnigan Lake Community Water System & Watershed
- 2015 Ecosystem-based Conservation Plan for Shawnigan Lake Watershed
Water quality depends in part on how many people live in the watershed, as well as the number and types of businesses and industrial uses.
Residents are often surprised to see new developments. When were these developments approved? What was the approval process?
Development within the watershed should be governed by the current Official Community Plan and current zoning. The current OCP is 20 years old.
The CVRD has used consultants to help prepare a new Official Community Plan, one component of which applies to the Shawnigan Lake Watershed. Work to date has involved a consultant, several members of the Shawnigan Lake community, and CVRD staff. There have been a number of OCP Open Houses, but many people are still not aware of the OCP and the work done to date. The work on a Draft of the OCP is currently being done by CVRD staff. The CVRD has a page on the OCP.
The closer a new development is to the water the more the development will affect water quality. Most current development is taking place well back from the water. In the hills at the southern end of the lake we have
- an existing and a new industrial park near the rail crossing on South Shawnigan Lake Road,
- the subdivision on Stebbings Road,
- the community on the Elkington Lands,
- the trailer park on South Shawnigan Lake Road, which has now become The Estates at Shawnigan Station with strata title,
- a gravel pit and possible a golf course south west of the lake,
- the new houses on the south western ridge.
There could be more. There could be many more.
The number of recreational users of the lake and the types of uses also affect water quality. Is it a problem? What should we be doing about it?
Questions we are looking into:
- seasonality - high and low season use
- direct pollution from boats - 4 stroke, 2 stroke
- sediment and boats - how to limit speeds in very shallow areas so sediment does not ruin drinking water quality (assuming it is a problem)
- bank erosion - is it a problem? if so, how to reduce?
- carrying capacity - how much usage can the lake tolerate?
Fast and Loud Boats
While most of the boats on the lake are driven with care and attention there are a few boats that appear now and then that are either traveling too fast, making too much noise, or both. How can we control speed and noise?
Noise comes in two forms - boats with noisy engines and boats with loud music. While there are few lakes boats with noisy engines, now and then we get a visitor with a very loud engine. Often the boat is unmuffled - a boat designed to be very noisy. These boats are also often designed to be fast and often speed.
Is there a problem that we need to address? Do we have these fast loud boats often enough to take action? Send us your views.
Wake boats are a recent arrival on the lake - in the past 4 or 5 years. While not fast and not necessarily loud (although loud music seems to be a large part of the wake boat experience), wake boats have effects greater than their numbers would suggest.
Wake boats are certainly much harder on docks than any other recreational boat. Many docks will require new mooring mechanisms or more frequent mooring maintenance. Many docks are impossible to use when wake boats are in the area - the wakes move the docks around far too much for comfort.
Wake boats are much harder on the shoreline than regular water ski boats. Higher erosion rates and more disturbed sediment affect water quality (turbidity) negatively.
Do we need controls on wake boats? Send us your views.