Infrastructure Renewal Project – Prince of Wales Bridge Culvert Replacement

30 Apr Infrastructure Renewal Project – Prince of Wales Bridge Culvert Replacement

Dear River Ward Residents,

I wanted to provide you with the following update on an infrastructure project that you will begin to see taking shape just south of the Fisher and Prince of Wales intersection.

The following update provides an overall project briefing. If you have any questions or concerns with the project, please contact the project manager Jonathan Knoyle at (613) 580-2424 x16436 or jonathan.knoyle@ottawa.ca,

Infrastructure Renewal Project

Prince of Wales Bridge Culvert Replacement

Existing Conditions:  Prince of Wales bridge structure is located on Prince of Wales Dr, about 0.15 km South of Fisher Ave. on the boundary between River Ward and Knoxdale-Merivale. Built in 1940, and last rehabilitated in 1960, the culvert is an open-footing Reinforced Concrete Frame (5.6m wide and approximately 3.1m high) on the downstream side with a corrugated steel pipe extension on the west end (4.0m wide and 4.3m high). The overall length of the culvert is 60m. The road is four-lanes wide with granular shoulders and a speed limit of 60 km/h.

1. Project Scope / benefits: 

• The existing bridge culvert structure is badly deteriorated and Asset Management branch has identified it as in need of replacement.  
• Some concern has been expressed regarding slope instability at the culvert outlet.  Slope stability is being monitored by the City’s AMB branch, as well as Golder (geotechnical engineers) until permanent restoration occurs in 2015, as part of the culvert renewal.
• The project includes the design of cycle path safety improvement measures on POW Drive at Fisher (originally a separate project scoped by Planning & growth Mgt that was incorporated into this project for efficiency and ease of coordination).
• The new bridge culvert will also be lengthened in order to accommodate the future widening of POW Drive.

2. Solution:  The renewal solution is to line the existing culvert with a concrete pipe and to tunnel a new pipe parallel to the existing culvert to provide the required hydraulic capacity.

3. Schedule:  Bridge culvert renewal was originally planned for 2013 however construction did not occur in 2013 or 2014 for the following  main reasons:

• The feasibility study that was done prior to the project being scoped to Design & Construction recommended that the culvert be replaced by open-cut construction.  Once Design & Construction took the project over, it became clear that open-cut construction was not feasible predominantly due to the severe traffic impacts.  Therefore, a trenchless approach was adopted.
• During the preliminary design phase, a high pressure, vital, gas main was discovered below the culvert inlet. This presented a significant conflict for construction and so to alleviate that risk, Enbridge relocated the gas main into the west shoulder of Prince of Wales Drive.  This work took place in 2014.
• Construction was schedule to occur over the winter 2014 / 15.  However, the Conservation Authority confirmed all work would need to be completed by March 15^th (start of fish spawning period) and this deadline was too tight.
• Additional funding was required and a budget adjustment was approved by Council in April 2015.

The project will go out to tender week commencing 4^th May 2015.  Construction is scheduled to begin shortly after July 1^st 2015 (the end of fish spawning period) and be completed by late fall 2015.  There might be a need to finalize surface reinstatements in spring 2016.

4. Anticipated Impacts and mitigation strategies:  Although the selected trenchless method significantly reduces public  impacts, the following impacts are anticipated:

• Traffic disruption due to lane shifts and the presence of construction equipment off to the side of the road.  Effectively, there will be no actual lane reductions, but some traffic disruption is anticipated.  The City will install variable message signs on POW Drive in advance, north and south of the construction zone.
• Environmentally sensitive work in Nepean Creek will require strict adherence to RVCA and Parks Canada permit conditions.
• Tree removal necessary at the culvert outlet.  Concern from resident of 16, Rideau Shore Court that “screen” will be removed.  A re-planting plan has been developed to restore the tree coverage, but it will take time to become established.
• Inherent risks associated with trenchless methods. A thorough geotechnical study has been undertaken and an independent 3^rd party technical review is being carried out prior to tendering.
• Noise and disturbance impacts to the resident at 16, Rideau Shore Court.  A temporary construction easement has been obtained from the resident.

5. Public Consultation: Other than commuter traffic (the impacts to which are anticipated to be minimal) the only residents that will be affected by construction are the two residents either side of the creek at the culvert outlet.  We have coordinated closely with both residences regarding the project and have obtained a written consent to proceed with the construction.  This was a requirement of Parks Canada.