Building a watery nursery for young coho salmon is no small task.
It took 120 large boulders, 34 logs, a specialized excavator and countless hours of work by dedicated volunteers.
But for Glen Parker, project manager for the North Shore Streamkeepers, recent work to restore habitat for juvenile coho in a natural channel of Lynn Creek is worth the effort.
If the project is successful, it could increase the number of coho returning to Lynn Creek each year from the hundreds to the thousands, said Parker.
鈥淚t鈥檚 one of the bigger restoration projects that has been done on the North Shore in a while.鈥
The restoration project has been a long time coming.
Lynn Creek, the third largest salmon-bearing river on the North Shore, is a fabulous river for fish, said Parker 鈥 it鈥檚 cool and well-aerated 鈥 just the type of water salmon love.
But like many urban rivers, Lynn Creek has been 鈥渉eavily armoured鈥 with rocks and reinforcements along its sides to protect nearby land against flooding. For young coho, that鈥檚 bad news, said Parker, because those reinforcements also tend to destroy smaller back channels that are essential for the juvenile salmon. Unlike some other salmon species, young coho spend a year in the river before heading out to the sea.
Smaller channels and pools give the fish a more protected environment as they mature, said Parker.
The work will also help the buffer the salmon from impacts of climate change which can include large floods in winter and drier-than-normal conditions in summer, he added.
Several reports have pointed to the need for work on a Lynn Creek channel over recent decades, said Parker. But it was Port of 麻豆传媒映画staff who pointed that out to the local streamkeepers. The port also provided the lion鈥檚 share of funding to get initial engineering work done on the project.
That was essential, said Parker, because the project had to be built to withstand the force of a serious flood that might happen only once in 200 years 鈥 ensuring that rocks and boulders in the channel won鈥檛 come loose and be carried downstream.
Essentially the project involved creating four 鈥減ools鈥 in the natural channel 鈥 each about four metres in diameter 鈥 with the use of logs and boulders.
Boulders and logs were moved into place with a spider excavator capable of picking up and placing five-tonne rocks 鈥渨ith the precision of doing needlework,鈥 said Parker.
To ensure the logs don鈥檛 move, each of them had to be held down with four boulders, attached with cables. 鈥淭hey鈥檒l be there for hopefully a long time,鈥 said Parker.
The total cost of the project was about $100,000. Of that, almost half was contributed by 鈥渋n-kind鈥 donations of goods and volunteer labour. The Port of 麻豆传媒映画was the largest cash donor while the Pacific Salmon Foundation also contributed a significant sum. Logs and boulders were donated by the Tsleil-Waututh Nation. Northwest Hydraulic Consultants were also instrumental to the project, said Parker.
Work in the river 鈥 about half a kilometre upstream from where Highway 1 crosses the creek at the bottom of the Cut 鈥 started Aug. 21 and wrapped up Monday.
The work in the channel should help both the natural coho population and salmon enhancement efforts by the Morton Creek hatchery upstream, which also releases a small number of young coho into the creek, said Parker.
鈥淚f they have good places to live they have a better chance of survival.鈥