FAQ’s for the Black Creek-Oyster Bay Water System - September 2, 2014
This update notice is to provide some clarification to the homeowners connected to the Black Creek-Oyster Bay water system regarding the current situation and the Comox Valley Regional District’s (CVRD) plan to resolve the issues.
The Black Creek-Oyster Bay (BCOB) water system utilizes water from two ground water wells and from one river well. The two groundwater wells are typically used from October through June after which time they are shut down due to lower water levels in the summer. The system switches to the river well from July to September. Normally the ground water wells and the river wells do not run at the same time (although they can, for a limited time, if required).
The river well is essentially an intake of water from the Oyster River. The river well is located on land but is tied to an infiltration gallery (a perforated pipe that is buried several feet below and extends under the Oyster River). Water flows through the bed of the river into the infiltration gallery and then to the well for pumping to the treatment plant. This system has historically produced high quality and high volume water for summer supply. However in late July this year, the water in the river well became turbid (dirty) and the flow reduced. The CVRD responded by bringing the two groundwater wells back on line to supply the system and by shutting down the river well to determine the issue. A blockage could not be found so the infiltration gallery was flushed and brought back on line. A remote operated video camera (ROV) has been ordered to inspect the full length of the infiltration gallery and this work should occur in the next few weeks as the camera is not immediately available.
In the meantime, the river well is online again; however, the CVRD has reduced the supply from the river well and blended that water with water from the two groundwater wells. This is not a normal summer operating condition, and in order to ensure water supply for essential purposes (drinking and firefighting) we placed a water use restriction on the system. The CVRD does not plan to lift these restrictions until the infiltration gallery has been fully inspected and reestablished. The water restrictions will likely extend through the rest of summer and fall after which time the CVRD will switch back to the groundwater wells only and shut down the river well.
Frequently Asked Questions
Q. Why has there been a reduction in the flow of water?
A. The reduction in flow is due to a lack of available water in the infiltration gallery and is not due to a lack of water in the river. This is an important distinction. In the past, the river has been lower than it is now and the infiltration galley has had greater flow than it has now. Although we could not find a blockage on first inspection, the remote operated video (ROV) camera may show more. It is also possible that the infiltration gallery holes (small holes that allow water from the river into the gallery) could be blocked, which would be difficult to see on internal inspection.
Q. When will the inspection be done with the ROV camera and what will it provide?
A. The camera system will provide a variety of good and useful information but may not be conclusive. The CVRD anticipates that the camera inspection will be completed in the by mid–September so it is not likely the river condition will change before then. The long term forecast is for dry weather. Additional inspection work may be required, including possible work in the river.
Q. Is there a cohesive approach within the CVRD on future and present development to address significant implications with respect to water?
A. The engineering services branch continues to work closely with planning and development about the capacity usage at the Black Creek-Oyster Bay water system.