August 30, 2016
John Lawson Park, on the waterfront in the Ambleside West Vancouver community was in danger of damage from ocean wave action during King Tides. Keystone Environmental worked with the District of West Vancouver to resolve this risk, while at the same time increasing the marine habitat productivity. Project constraints included:
- Maintain shoreline sediment transport while providing wave protection
- Achieve a net increase in marine habitat productivity for fish and fish habitat
- Works could not be performed between midnight and 8 AM, which coincided with the preferred low tides, due to noise by-law restrictions. Instead, works had to occur within a limited work window during mid-tide levels in order to complete the work in the dry
- Because the works occurred in a high-profile location adjacent to the West Vancouver seawalk, it was subject to close public scrutiny
The existing beach material was excavated to a 3 metre depth in 25 m2 stages and the excavation backfilled with glacial till. The glacial till was sourced from the municipal hall excavation, enabling its beneficial re-use rather than transport to a disposal or fill site. Approximately 10,000 m3 of foreshore sand, pebble and cobble was removed and placed back on top of the glacial till raising the level of the beach. Rocks were placed to strategically allow sediment transport to occur while breaking waves further off-shore through the combination of wave traps and individual rock clusters. Sediment transport was improved by mobilizing approximately 1,200 m3 of native beach material from the top 10 to 20 cm to help maintain 1,000 m2 of forage fish habitat at Ambleside Pier and the lower foreshore reefs. The foreshore was raised 0.5 m to 1.0 m. A net productivity increase of 151 m2 surface area was created for intertidal algae such as rockweed and sea lettuce.
The project was a recognized by the Environmental Managers Association, receiving the 2016 Remediation and Restoration Award.