Dikes and Pump Stations Doing their Job during Rain Events

(February 7, 2018 - North Cowichan, BC) The week of January 28, North Cowichan received approximately 80mm of rain over 4 days. Despite this heavy downpour, there were minimal impacts to the community despite the flow volumes in the Cowichan River being higher than the flow volumes during the devastating flood of November 2009. In fact, we have not seen flows this high in the Cowichan River since 1960.

Last week, we heard from a number of people who believe that the dikes and pump stations were a waste of taxpayer money because we experienced some temporary road closures, says Mayor Lefebure. This is simply not true. Even with the dikes and pump stations functioning as intended, we cannot prevent some localized flooding from occurring in parts of the community during heavy rain events.

During the devastating flood of November 2009, about 300 homes were evacuated and a regional emergency operation centre was mobilized for 8 days. This emergency response and recovery process cost a significant amount of money, following which, the Province mandated that local jurisdictions install a 200-year flood protection system.

There are numerous reasons why we can continue to expect some localized flooding during heavy rain events: 

  • Our diking system has three gaps to accommodate traffic and roads: at Canada Avenue, the Trans-Canada Highway, and Lakes Road. There is a procedure in place to systematically close these gaps as waters rise. During last weeks rain event, we were fortunate that of these three major roads, only Canada Avenue needed to be closed. 
  • The area outside of the dike network is susceptible to flooding from streams or rivers that overflow. Last week, Holmes Creek, which runs adjacent to the RCMP station, experienced very high flows that caused a large volume of water to flow onto Canada Avenue.
  • Finally, culverts and drainage systems protected by the dike network can be blocked and prevent water from flowing into storm drains and flowing towards the pump stations.

Notwithstanding the above, North Cowichan is investigating the possibility of raising Canada Avenue in the Philip Street area to allow Canada Avenue to remain open south of Philip Street during a similar rain event. The Municipality will also revamp its traffic management plan for any future flooding on Canada Avenue to improve access to land that may be unaffected by flooding.

Anyone who has questions about the dike network or pump stations is encouraged to contact engineering@northcowichan.ca or call (250) 746-3128 to learn more.