By Mike McKenzie Strategic Watershed Action Team Member
SWAT’s restoration efforts around southern Ontario-It has been a busy few months of stream restoration for the Ontario Strategic Watershed Action Team (SWAT). Our two-person team of Chris Borowski and Michael McKenzie have been traveling throughout southern Ontario working to improve coldwater streams that have become degraded. Though most of these systems face similar issues, such as widening of the waterway leading to too much sediment buildup and increasing water temperatures, each stream is different and no one method works everywhere. Here is a selection of the restoration projects the SWAT Crew has conducted this summer and the approaches they used.
Barrhead Creek and Armstrong Creek, two tributaries of the Rocky Saugeen near Markdale, have both become over widened from years of logging, gravel removal, and dam construction. They are both now slow-moving and full of sediment. To combat this, Chris and Mike built wooden structures that redirect and concentrate the flow back into the center of the stream which can help move the excess sediment, exposing gravel that Brook Trout need for spawning. Behind these structures, the crew created sediment traps by securing recycled Christmas trees under the water so that they slow the water and allow the sediment to settle and build up the new bank.
Large woody debris being used to stabilize banks, trap sediment and redirect flow into the creek channel
Working on a Bronte Creek tributary on the Niagara Escarpment, the SWAT Crew encountered a stream that was splitting off into smaller streams because of excess woody debris blockages that were impacting stream movement. Using some of this cleared woody material, Chris, Mike, and our friends at Conservation Halton narrowed a section of the stream by building a deflector, like the ones in Markdale. The creek however is a flashy system, meaning the simple structures from the Barrhead would be at risk of being washed away due to the amount of water that quickly enters the creek during a rain event. To combat this, the crew built a structure that was packed tight with logs, cedar branches, rocks, and mud until water couldn’t move through it. As a sturdy bank, it will slowly catch sediment during high flows and eventually become covered in mud and new vegetation.
Mike Mckenzie (TUC) and Mike Heyming (Conservation Halton) stuffing a sediment trap/deflector with cedar branches to trap sediment.
Other times during the summer, the crew returned to river systems where work had previously been conducted. Stream restoration is a slow process and streams regularly need upkeep to ensure they are continuing to progress in the right direction. Marden Creek has been a passion project for the Speed Valley Chapter ever since resident Brook Trout were found in 2004. Dam removals, riparian plantings, and channel narrowing have gone a long way in helping the population rebound. The construction of a new bridge over the creek left large rocks in the waterway, restricting flow and backing up the water until it flooded the previously built structures. Eventually, the stream had completely widened and was again warming the water, putting the Brook Trout at risk of overheating. Following the removal of these rocks, it became clear to the SWAT Crew what path the creek needed to be adjusted to, to avoid future flooding. This was completed using submerged logs to redirect the flow and building sediment traps. Finally, mud and sediment scooped from the bottom of the stream were thrown onto the trees because the mud contained lots of seeds that would grow into plants that would stabilize the new banks.
The SWAT and Ignatius Jesuit Centre staff throwing seed laden sediment on a constructed Christmas tree sediment mat
Finally, Chris and Mike have been working on Washington Creek, just west of Cambridge, where previous SWAT Crews had conducted woody debris removal. Too many fallen trees had caused the stream to braid into many channels that could easily warm up. Now that the stream has carved itself into a single channel, it was time to reintroduce some habitat structures for the local fish populations. These methods provided shaded spots for fish to hide from predators, while they wait for their next meal to flow down the river to them.
By paying close attention to the behavior and specific needs of each river system, the Strategic Watershed Action Team has designed and implemented restoration structures that will help protect our aquatic ecosystems.
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