Monday, March 26th, 2007 @ Florence Filberg
Author’s Disclosure: This is a summary of the presentation of the risk assessment study of Comox Lake. It is not intended as a complete summary of the study or the meeting itself. It is intended to be an overview of some key components and key risks to the Comox Valley Water System. To access the completed reports, please refer to the Technical Memorandum’s found at
http://www.comoxstrathcona.bc.ca/1.0. Presentation of risk assessment studyThe Regional District of Comox Strathcona presented to a roomful of over 200 hundred people the findings of a report produced by engineering firm CH2M Hill that had investigated risks to the Comox Lake drinking watershed. 38,000 residents rely on Comox Lake as their water source.
The
primary goal of the Comox Lake watershed risk assessment was to identify the major risks to the Comox Lake water source so that a future program to mitigate these risks could be developed with the major stakeholders in the area. The watershed assessment followed the sections of the Province of British Columbia’s proposed Comprehensive Drinking Water Source to Tap Assessment Guideline that includes the characterization of the water source, an inventory of the potential contaminant sources, a description of the water supply system, and the characterization of the risks posed to the water source.
The
methodology used in the study incorporated the following:
Likelihood that the event will occur;
Consequences of the event if the event occurs; and
Vulnerability of the watershed to the event.
Risk to the watershed was measured by two variables of the time it would take to enter the intake pipe and the proximity to the intake pipe, which has been categorized as the time-to-impact barrier. The closer the risk event occurs in time and distance to the intake pipe the less time the regional district has to respond.
Very High Risks include:
Vehicular traffic over the bridge close to the Comox Lake outlet
Transportation on roads adjacent to Puntledge River
Boating on Puntledge River upstream of penstock
Intentional harm to the water source
High risks include:
Logging within 300 metres of the Puntledge River between Comox Lake outlet and penstock intake
Transport on roads 1km of the Puntledge River upstream of the penstock
Wildlife contamination between outlet and penstock (Eastern portion of lake)
Potential aircraft crash in Comox Lake or near Puntledge River
Lakeshore cabins and camping in undesignated areas (Eastern portion of lake)
Boating and fishing (Eastern portion of lake)
Flooding
The Regional District will be working to address the very high and high risk categories first and as funding permits will move down the list. For a complete guide to all of the identified the risks refer to Technical Memorandum #4 at
http://www.comoxstrathcona.bc.ca/1.1. Role of the Regional District and our water supply
The role of the Regional District is to provide a reliable source of safe, high-quality
drinking water to homes and businesses within some of its member municipalities and
electoral areas. This includes acquiring and maintaining the water supply, treating it to
ensure quality, and delivering it-all at a reasonable cost. Areas serviced include:
Comox Valley Water System: water originates in Comox Lake and is taken from the Puntledge River (delivers water to over 38,000 people);
Black Creek Water System: water originates in the groundwater wells and from the Oyster River (delivers water to 2,600 people & in the summertime up to 6,000)
Oyster Bay - Buttle Lake (Area 'D') Water System: water originates in John Hart Lake (delivers water to 2,700 people)
Denman Island Water System: water is drawn from wells (delivers water to 30 people)
According to Graeme Faris, General Manager of Operational Services with the Regional District, the district has no regulatory authority over water access and use; BC Hydro holds the majority of the water use licenses. The Comox Valley Water System (originating in Comox Lake) serves the largest number of users in the region. This particular watershed is 56,591 hectares and includes Comox Lake, Puntledge River, and Brown’s River. It receives 1,500 – 2,000 millimetres of rain annually. The intake system has three significant points:
Comox Dam, located at the outlet of the 461-km² Comox Lake Watershed into Puntledge River
Puntledge Diversion Dam, the inlet of the penstock is located 3.7 km downstream of the Comox Dam, with an additional 14 km² watershed (total of 475 km²). This is the last open surface water point in the system where the gravity intake from the penstock is used
Puntledge River Pump Station, located 6.6 km downstream of the Puntledge Diversion Dam, at the BC Hydro Power Generating Station, with an additional 115 km² of contributing area that includes the Browns River Watershed (total of 590 km²). Water for the Comox Valley Water Supply System is taken from this location only for a few weeks during the year.
The Regional District takes water for this system out of the Puntledge River downstream of Comox Lake, through a water license agreement with BC Hydro and the government of BC. Water taken from Comox Lake totals a flow rate of 35m³/second (equivalent to filling our aquatic centre pool twice in one minute). This volume is primarily shared amongst three groups: BC Hydro uses 28m³/second; Department of Fisheries and Oceans uses 5.7m³/second; and for drinking water purposes the Regional District uses 0.3m³/second.
Currently, the volume of water used from the Comox Lake watershed is 17,000 m³ in the wintertime, tripling to 55,000 m³ in the summertime. The Comox Valley holds the title of largest water consumer in the province at over 600 litres per capita per day with the national average at 390 litres per capita per day.
The only method of water treatment for the Comox Valley Water System is chlorination.
1.2. Role of Health Authority
While the Regional District is the water purveyor it is the Vancouver Island Health Authority with jurisdiction over water quality under the Drinking Water Protection Act of 2003. According to this act, the health authority officer has the ultimate legal powers to stop actions on or near watersheds should they be deemed as an immediate threat to the safety of our drinking waters.
Responsibilities of Drinking Water Officers include:
The Drinking Water Program is administered locally by Drinking Water Officers, Public Health Engineers and Medical Health Officers, who are responsible for direct service delivery in BC's Health Authorities.
Drinking Water Officers provide surveillance and monitoring of drinking water systems which may affect the public's health. They also administer and enforce the Drinking Water Protection Act, the Drinking Water Protection Regulation and the Health Act and provide interventions to minimize health and safety hazards.
Drinking Water Officers and Public Health Engineers are also the people who should be contacted prior to the creation or alteration of drinking water systems. Drinking water systems require construction permits and operating permits to ensure that water systems are created and maintained to ensure the safety of the drinking water supplied to customers.
1.3. Comox Lake user groups
Comox Lake supplies water to 38,000 residential customers and has sixteen user groups that include some of the following: TimberWest Forest Corporation, Hancock Timber Resource Group, Comox Lake Land Corporation, Comox Timber, Courtenay and District Fish and Game Protective Association, BC Hydro, Crown land, and private land owners. TimberWest Forest Corporation is the largest land shareholder around the lake. All user groups are being asked to draft strategies for mitigating risk to the watershed to submit to the regional district. The regional district will be asking for a commitment but will have no enforcement powers to hold the user groups accountable to their proposed strategies.
1.4. Future goals
This was the second meeting in a three-part series. The next step will be to develop strategies to meet existing demand, to identify growth and water availability for the future development of the area, to look at ways to protect the water source, and to promote water conservation, in part through public awareness raising.
1.5. References
Ministry of Health, http://www.healthservices.gov.bc.ca/protect/dw_index.html
Public Information session, March 26, 2007, Florence Filberg Centre, Courtenay BC, speakers: Graeme Faris and Russ Hostenpiller
Regional District of Comox Strathcona,
http://www.comoxstrathcona.bc.ca/