Waskasoo Creek Channel Improvements
One of the primary goals of this project is to implement bioengineering elements, which will assist in increasing fish habitat as well as retaining the natural appearance of the creek through the downtown area and in Barrett Park. Specifically, the bioengineering work will include stabilization of banks using soil wraps, live stakes, brush layers, and a mixture of natural rounded fieldstone and angular rip rap.
Tree Removal: starting March 20, 2017
Area A: Select mature trees will be removed in preparation for a 1-metre-high by 170-metre-long clay grass covered berm on the north bank of the creek to reduce the risk of flooding for adjacent properties.
Area D: Select mature trees will be removed in preparation for a 1-metre-high by 70-metre-long clay grass covered berm on the north bank of the creek to reduce the risk of flooding for adjacent properties.
Area H: Past high flow events led to an unstable embankment and landslide; trees on the failed embankment are falling over, posing a safety risk. Damaged and falling trees will be removed to ensure a safe working environment for construction workers. Some additional trees will be removed to construction a temporary bridge and roadway to access the creek for repairs. Coniferous trees will be re-used as large woody debris to help naturalize the area.
Civil Work: Early August to late October 2017
Area A: A one-meter berm will reduce the risk of flooding on the north bank of the creek. Live stakes and an in-stream riffle will enhance fish habitat. A backflow prevention valve will be installed to prevent flood waters from flowing into the City’s sewer system.
Area B: Existing bridge protection and built up sediments will be removed and the bank will be repaired using large slabs of limestone, riprap and landscaping.
Area C: Repairs are needed at the area where Piper Creek enters the Waskasoo Creek; they intersect at a sharp angle, which is causing erosion on the north bank of Waskasoo Creek. 50m of the Piper Creek channel will be realigned to reduce the angle and to prevent further erosion; this area, as well as the north bank of Waskasoo Creek, will be repaired using earthworks, riprap, fieldstone, soil wraps, live stakes and landscaping. In addition, a backflow prevention valve will be installed to keep flood waters from flowing back into the City’s sewer system. In-stream pools and riffles will enhance fish habitat.
Area D: A 1 meter berm will help to reduce the risk of flooding. Live stakes will stabilize the creek while landscaping further enhances the area.
Area E: Due to the build-up of sediments in the culverts below 48 Ave, the creek has begun to shift south toward 43 St. Built up sediments will be removed from the culverts; the creek bank will be realigned to its original position and reconstructed with soil wraps and live stakes. Pools and riffles will be incorporated to improve fish habitat.
Areas F & G: 50m of failed creek bank will be reconstructed using riprap, soil wraps, live stakes and brush layers. Pools and riffles will be incorporated to improve fish habitat.
Area H: Previous high flow events led to a landslide on a high embankment in this area. Work in this area will stabilize the failed slope and protect the creek banks from future high flow events using riprap, fieldstone, soil wraps and live stakes. A temporary bridge and roadway will be constructed to provide safe access for crews working in the affected area. A pool and riffle, as well as woody debris from coniferous trees removed from the area in March, will enhance fish habitat. The existing concrete drainage channel will be reconstructed using fieldstone.
Bio-Engineering Element Descriptions
Riffle consists of gravel and rocks placed in a shallow stream to create rough water, which oxygenates water for fish residing in the stream.
Live staking reintroduces plant life directly into a stream by inserting stem cuttings from dormant trees directly into the stream bank. The stem cuttings eventually grow into new trees, which establish a root network in the stream bank, helping to prevent further erosion.
Rip rap is a foundation or sustaining wall of stone used to help prevent erosion.
Soil wraps are often made with a biodegradable cloth and are used to stabilize the soil and prevent erosion.