Five years after the devastating flood of 2013, now seems like a suitable time to take stock of what has been accomplished so far with regard to flood mitigation and of what remains to be done.
Most of the projects completed so far, and those still being worked on, have focused on mitigation against flooding caused by local rainfall. Much of the flooding in our community in 2013 was caused by backup from storm sewers which were overloaded and unable to discharge into the river when the outfall gates had to be closed.
Completed work includes: installation of remote power valves for B47/B48/B48A outfalls, and a rebuild of the 3rd Street Sanitary Lift Station. Work in progress includes: A new stormwater pump station (Pump Station #1) east of the Curling Club, for November 2019; a rebuild of stormwater Pump Station #2 at 5A Street and 1 Avenue, for the fall of 2019; the Upper Plateau Separation project, to discharge water from the top of the hill directly into the river instead of into our community's stormwater system – for 2021/2022; two new pump stations in Hillhurst, Pump Station #3 and #4, after 2022; and various piping improvements, for 2018 – 2022.
By 2022, when nearly all of these projects will have been completed, we will be in good shape for protecting against flooding from the stormwater system. However, the threat from river water remains unaddressed. In 2013, heavy rainfall in the mountain catchment areas caused the terrifyingly high water levels and flow rates that Calgary experienced on the Bow and Elbow rivers. In 2013 there was overtopping of the berm running along Memorial Drive, and it's not difficult to imagine a river level not all that much higher than the peak in 2013 resulting in an overwhelming inundation of water laying to waste large swaths of our community. Between local rainfall and berm overtopping it is the latter which has, by far, the greater potential for causing flooding much worse than what happened in 2013.
The City's plan for countering the threat of flooding from the rivers involves a combination of two components – upstream mitigation by means of dams and local mitigation by barriers along the river banks. With the dams being outside the City's jurisdiction, the City is working with the Province on that part of the solution. There was some good news recently when the Province announced, among other things, that conceptual design of three different options for upstream mitigation on the Bow is underway. Feasibility studies will be the next phase. However, with all the hurdles that will have to be jumped over before upstream mitigation can be built we may be waiting about 15 years before we see a new dam on the river. In the meantime, we are at the mercy of the berm and temporary barriers.
Unfortunately, what we have heard so far from the City about their plan for the berm in Sunnyside gives us serious concerns which we have made known to them. The City is proposing only a small increase in the height of the berm, just at certain low points, and not an overall increase in height all the way along the berm. Because of things which have been done since 2013 – among them, the reinforcement of the Prince's Island Causeway, and the fortifications being built on the other side of the river to protect Eau Claire and the downtown – we would need our berm raised all along its length just to give us the same level of protection that we had in 2013. The goal is to be prepared for the next, possibly bigger flood, but with regard to the berms it seems we're fighting to even catch up with the preparedness we had in 2013.
If our berm is lower than that on the other side of the river, then in some easily foreseeable flood event we might have Sunnyside catastrophically flooded while Eau Claire and the downtown are unharmed. Of course, protection of the downtown always has to be the number one priority for Calgary, but it would not be fair to sacrifice Sunnyside in order to save the downtown. We are asking for our hundred year-old community to get the same level of protection that is being provided on the other side of the river.
Through our continuing advocacy, we have obtained a commitment from the City that before finalizing their plans for the berms along the Bow they will seek public engagement. The fall of 2018 is when this will probably take place. We want to host a meeting at the HSCA Community Centre and our objective would be to have a room full of residents, all well informed and respectfully asking all the right questions. This will likely be our last opportunity to advocate for the berm that could save our community from destruction. Please watch out for announcements so that you can mark your calendars!
There is further detail about the now and future flood mitigation in an information sheet written by Charlie Lund for the HSCA's April 2018 AGM. The document may be found on https://www.hsca.ca/eparc-presentations under the 2018 Update section.
On behalf of the HSCA Emergency Planning and Response Committee (EPARC) - David Brindle, Chair.