Another flurry of letters calling for a third vehicle crossing off 29 St. and across the estuary, as a reaction to recent flooding events, requires a response.
The building of a bridge/causeway to cross the estuary is a non-starter on a number of fronts, including ecological, cultural, and economic to name but a few.
The root causes behind Courtenay’s flooding issues have also been raised in several letters. I agree with those that point out that the removal of mature forests from our watersheds is more than likely a contributing factor to the problems we face. It has been the case in other areas that mature, forested hillsides have evidenced a much better ability to retain heavy rainfalls and so prevent the rapid, turbulent runoff which occurs on logged-off slopes. Road developments with hard surfacing, culverts and ditches, which all channelize water runoff, can also create problematic drainage issues: the more water that accumulates, the bigger the problem. The excessive turbidity created in our drinking watershed (Puntledge River/Comox Lake), which has necessitated the recent extensive “boil water advisory” can also be attributed, at least in part, to these factors.
Of course, had the city not extended development onto an historical floodplain, this problem would not exist. Extensive channelization through the now-developed floodplain has been done in an attempt to route the runoff from three major watersheds through a pinch-point at the 5th St. bridge. This is not good hydrological thinking. Huge water flows after heavy rain events are denied their historical relief route over the floodplains (the agricultural lands) and into the estuary.
These issues could possibly be addressed by raising the arterial/emergency routes, such as Highway 19A, Ryan Road and the Old Island Highway, as required, which would allow for water movement underneath via box culverts and/or bridges. Secondary streets, such as Puntledge, Tsolum and Rye Roads, could be lowered to allow for these flows to reach their historical flooding areas and then drain into the Komoks Estuary through Dike Slough and/or under an elevated Comox Road.
Continued attempts to tame extreme flooding events by further channeling with concrete and steel when we should be attempting to work with nature and traditional flow patterns makes no long-term sense. Let’s learn from the City of Calgary (watch bit.ly/1oBxt3C), by practising floodplain retreat and making “Room for the River”.
Extreme weather events, a changing climate and sea-level rise around the planet are part of the “new normal” and we had best get back to learning how to live with nature.