Presentation Slides: DEVELOPMENT PERMIT 2022/04 - 53 Knollwood Road

DEVELOPMENT PERMIT 2022/04

53 Knollwood Road

PURPOSE

• Development permit application to install retaining walls and landscaping to stabilize a slope within the Natural Watercourse and Shoreline Development Permit Area
• Variances are request to the height and separation of retaining walls

Background

• Land slip 1995

VARIANCE

1. Height of retaining walls from 1.2m to up to 2.0m tall. a. Geotechnically engineered for slope and provides some flexibility against a moving slope b. Plants to soften and strengthen wall c. Sea wall is in a mudflat environment with low wave energy erosion impacts even with sea level rise
2. Minimum height to horizontal separation ratio for unreinforced walls from 1:2 to 1:1.5 a. Geotechnical engineer inspection and certification

BIOLOGIST’S REPORT

The Biologist’s report provides recommendations to be incorporated into the development permit, including:

1. Work to be conducted during the summer Reduced Risk Fisheries Window for marine shorelines (July 1 to October 1)
2. The work will be conducted is such a way to minimize the impact to the shoreline and no permanent structures or land alteration are proposed below/past the Present Natural Boundary.
3. The patch of Lyngbye’s sedge on the west end of the shoreline will be protected during construction.

CONCLUSION

The proposal can be supported for the following reasons:

1. Total area of native plantings will increase. Approximately 425-485 m2 of native planting is proposed. This is roughly 85% of the DPA, exceeding the guideline target of 50%
2. The works will include invasive species removal
3. No large-scale negative impacts are expected to the marine environment
4. Gabion walls are low on the list of preferred soft-to-hard measures for stabilizing shorelines but are recommended by the project biologist and geotechnical engineer as the least invasive approach given the site context

RECOMMENDATION (1 of 2)

THAT Development Permit Application No. 2022/04 be approved as per the June 2, 2022 report from the Senior Planner titled “Environmental Development Permit No. 2021/04 – 53 Knollwood Road”;

AND THAT Development Permit Application No. 2022/04 include the following conditions:

1. Work in the development permit area is to be: a. monitored by a Registered Professional Biologist b. conducted in accordance with the report titled “Environmental Review for 53 Knollwood Road, Victoria, BC” prepared by Fish-KW Environmental, dated April 12, 2022 c. concluded with a letter of completion from the Registered Professional Biologist indicating how the recommendations of the Environmental Review were met.
2. Areas where storm water is to be conveyed downslope by pipe must be constructed and restored under the direction of a Registered Professional Biologist and a geotechnical engineer.
3. Retaining walls and other slope stability works are to be designed by a geotechnical engineer, inspected and certified that they will be safe for the use intended in accordance with the “Proposed Retaining Walls & Pool” report prepared by Ryzuk Geotechnical dated November 16, 2021 with updated plans dated April 12, 2022.
4. A security deposit for landscaping and protection of the natural environment must be provided prior to commencing alteration of land.

RECOMMENDATION (1 of 2)

AND FURTHER THAT Development Permit Application No. 2022/04 include the following variances:

1. Variance to Section 4.8.9 of Zoning Bylaw No. 900, 2014 to vary the maximum permitted height of retaining walls from 1.2m to 2.0m
2. Variance to Section 4.8.10 of Zoning Bylaw No. 900, 2014 to vary the minimum height to horizontal separation ratio for unreinforced walls from 1:2 to 1:1.5