ADMINISTRATIVE REPORT
Date: December 19, 2002
Author/Local:K. Mulji/6069
RTS No. 02811
CC File No. 8205
Council: January 14, 2003
TO: |
Vancouver City Council |
FROM: |
General Manager of Engineering Services in Consultation with the Director of Current Planning and the Manager of Parks and Recreation |
SUBJECT: |
Concord Beach Neighbourhood Area 1 - Revised Design of the Shoreline Protection Works |
RECOMMENDATION
THAT Council approve the revised design of the shoreline protection works as shown in Appendix B.
CITY MANAGER'S COMMENTS
The City Manager RECOMMENDS approval of the foregoing.
COUNCIL POLICY
On July 27, 1999, Council approved the design of the shoreline protection works and the pedestrian/bicycle pathway for Area 1 Beach Neighbourhood.
On April 2, 1996, Council approved the rezoning of Beach Neighbourhood East - Area 1B, and on April 29, 1999, Council approved the rezoning of Beach Neighbourhood West -Area 1A. As a condition of rezoning, the developer is required to design and construct shoreline protection works and a waterfront pedestrian/bicycle path.
On October 24,1991, Council approved the report Conceptual Shoreline Design, Coal Harbour and False Creek North and requested that with respect to detailed design, Council only review issues which represent changes to the approved proposals and principles.
PURPOSE
This report seeks Council's approval of the revised design of the Concord Area 1 (Beach Neighbourhood) shoreline protection works as shown in Appendix B.
BACKGROUND
The original 1991 concept design for the Area 1 shoreline protection works consisted of a deck on pile system with louvres, or precast concrete panels extending from the underside of the deck to the rip rap slope. Subsequently, for maintenance, aesthetic and public health reasons, the deck on piles with louvres was replaced with a stresswall (retained earth wall).
The current design of the shoreline protection works, approved by Council in July 1999, is illustrated in Appendix A. The design contains significant sections of stresswall, similar to the precast stresswall panels constructed in the Roundhouse and Quayside areas.
The Department of Fisheries and Oceans (DFO) had requested that the design of the shoreline protection works be reviewed area by area to ensure that the final design and construction is consistent with the latest habitat management policies and objectives. In reviewing the City approved design, the DFO had strong concerns regarding the use of stresswalls as they determined the walls would result in a loss of habitat.
Concord was required to complete a habitat assessment for review by the DFO. Upon review of this assessment, the DFO concluded that the stresswall design resulted in a loss of water area and habitat, and have therefore asked that in some segments of the Area 1 seawall, the stresswall be changed to pile and deck. The pile and deck system would provide productive habitat below the structure and would reduce the loss of fish habitat (Figure 1).
Figure 1. Typical pile and deck construction (Bayshore).
DISCUSSION
Staff prefer the stresswall design, approved by the City in 1999, as it results in lower maintenance costs, enhances the vertical appearance of the shoreline at low tides, reduces rodent harbouring opportunities, and presents a "hard" edge characteristic of highly urbanized waterfronts. However, recognizing that the DFO will not accept a stresswall design, and that DFO approval is required to allow Concord to start seawall construction, staff support the revised design shown in Appendix B.
The revised design converts three sections, totalling 260 m in length, back to deck on pile construction. In this scheme, the piles would be screened from view by precast concrete fascia panels. Staff are currently working with Concord on a detailed panel design that would cover each pile down to the rip rap slope and direct attention away from the under deck area. The objective is to achieve an attractive final pile and deck design that reflects the marine environment, complements the adjacent land and water uses, and meets with the approval of the DFO.
It should be noted that the revised design would still accommodate the standard 10.67 m. wide walkway/bikeway in all segments, with a 4.5 m. wide walkway, a 4.5 m. wide bikeway and a 1.67 m. landscaped separation between the two.
CONCLUSION
Staff recommend that Council approve the revised shoreline protection design in Area 1-Beach Neighbourhood, to replace some sections of the stresswall with a pile and deck system, as shown in Appendix B. The revised design is expected to meet the DFO's requirements and would allow Concord to gain the necessary approvals to start the construction of the Area 1 shoreline in April 2003.
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