Thank you very much. Good morning, everyone.
L'Organisme de bassin versant de la Yamaska was commissioned by the Yamaska committee, comprised of mayors from Mr. Simon‑Pierre Savard‑Tremblay's riding, to conduct a review of literature on the effects of wake boats and the speed of motor boats on shoreline erosion and sediment suspension in certain sections of the Yamaska River. Today, I will present the conclusions of our review that can also be applied elsewhere.
There are a few concepts to define, including eutrophication, i.e., the aging of waterways. Waterways age like humans, but they are increasingly doing so at a much faster rate. That is what is worrisome.
Next, I would like to talk about the movement and effect of waves, known as wake. When watercraft produce waves, each wave is charged with kinetic turbulence energy, and therein lies the problem. The faster a wave breaks on the shore, the more energy it discharges, not in the water, but on the shore.
Wake sports boats are designed to produce large waves of a particular shape using their ballast system. This technology is used for certain water sports such as wake boarding and wake surfing, which other witnesses have talked about.
To assess the effect of waves generated by boats, including wake boats, you have to be able to show that there is a difference between the energy of a wave resulting from wind and natural processes and that of waves produced by boats. If wave energy received on the shoreline is higher when produced by boats than in so-called natural waves, it is reasonable to believe that shorelines and riverbeds will have more damage from waves generated by boats. Then, of course, you have to show that this difference in energy will have a marked effect on erosion and sediment disturbance.
Generally speaking, boats passing at normal speed contribute little to wave energy compared to wind. On the other hand, waves generated by wake sports boats have a bigger impact on the shore. These boats generate waves that transfer more energy to the shore than wind, paddle boats, flat-bottom boats, trolling engines or high-speed boats. We're talking about four to twelve times more energy, depending on the studies we reviewed. It is therefore reasonable to say that the regular passage of boats that create big wakes accelerates shoreline erosion.
Some of those same studies also indicate a positive correlation between turbidity and suspended phosphorus. This shows that increasing wave energy generated by boats can lead to greater phosphorus concentration in water through the disturbance of various bottom sediments and the release of nutrients, which will obviously accelerate eutrophication.
Added to this is navigation speed, which is known to influence shoreline degradation. You've heard it before. Studies show a significant reduction in shoreline erosion when boats travel at low speeds, i.e., 10 kilometres an hour.
As part of our study, we also identified other impacts on ecosystems related to the passage of wake sports boats. First, there is the increased risk of invasion by alien species of the body of water. You've heard how important it is to clean boats. With the ballast system, you have to clean the inside of the boat, not just the outside, or you can run into problems. Then there is the disruption and degradation of aquatic grass beds and wildlife habitats through turbulence, as well as the disruption of bird nesting caused by noise and wave impact.
As a result, wake sports boats shouldn't get close to the shore. The distance between them and the shore, according to the studies we consulted, varies between 90 and 190 metres. Since many parts of the Yamaska, like other areas and bodies of water, aren't wide enough to provide that kind of a buffer zone, our recommendation is to prohibit this type of boat, and therefore the practice of activities such as wake boarding and surfing, and to limit the speed of boat traffic to 10 kilometres an hour.
We believe that with the knowledge we've gained and will gain in the future, we can provide a better framework for aquatic activities and a better way to share our waterways.