Thursday, June 4, 2015

What's to become of the Dalewood Bridge?

https://www.flickr.com/photos/dforbes/118822735/ taken 2006

Let's start with a little history, taken from a Letter to the Editor by Brian Gorrill, published in the St. Thomas Times-Journal on March 5, 2009:


From research in the newspaper from Tuesday, July 26, 1983, the then 88-year-old Dalewood bridge was slated for replacement because of rotted structural steel members.
"The concrete abutments have also deteriorated," noted the article.
To replace the structure at that time (1983), costs were pegged at $317,000, exclusive of any road construction.
Installed in 1983, the Bailey bridge (on loan from the Ministry of Transportation) is a military-type structure.
It is a temporary bridge, not a disposable bridge, has one lane and no load restrictions (cost $35,000).

. . . and more information taken from Ian's City Scope blog dated Nov. 14, 2014 :
A 30-YEAR TEMPORARY FIX
The agenda for the final meeting of this council isn’t exactly a fluff piece.
STTJ DALEWOOD BRIDGE 3  RC
Members will receive a report dealing with the future of the Dalewood Bridge — the 31-year-old Bailey bridge positioned over the Kettle Creek reservoir as a temporary route for Dalewood Dr.
Council will be asked to authorize an expenditure of $92,000 to complete a Class EA study to determine the future needs at the road crossing. The modular bridge was supplied by the provincial transportation ministry in 1983 as a temporary fix under a 20-year lease arrangement, with the city assuming ownership in 2003.
A report to council from city engineer John Dewancker lists possible options: maintain the status quo; a pedestrian-only crossing; a new, two-lane bridge; upgrade/rehabilitate the existing one-lane structure and alternative traffic routes.
Whatever the option chosen by the new council, it could prove a bridge over troubled waters for the new council.
And that brings us up to date.
Tonight at Monsignor Morrison Catholic School Gym here in St. Thomas there was a Public Information Centre regarding the Dalewood Drive Bridge Municipal Class Environmental Assessment.  According to the information sheet I was able to print from the internet (which of course I can't find the link now):
Public consultation is a vital part of the Environmental Assessment process . . . The first PIC will be hosted in order to provide an overview of the study process, identify potential solutions to address the problem, and solicit input from members of the public, community interest groups, and agencies.
Now for my notes which I will try and shorten to those necessary to understand what they were trying to tell us at this initial PIC (in my world anyway).
The purpose of the PIC is to describe the Municipal Class C Environmental Assessment, to identify problems and opportunities, to share alternative solutions being considered, and the evaluation of these solutions.
The Environmental Assessment is a process to promote environmentally responsible decision-making and involves public consultation as a vital part of that process.
The objectives of this EA are:
1.  To implement a cooperative and solution directed approach to reaching a consensus.
2.  To identify relevant natural, social, and economic issues and constraints.
3.  To discover alternative solutions and concepts, taking into account legislative planning strategies and policies, natural and social environmental constraints, utility and related infrastructure needs, property impacts, scheduling, and costs.
4.  Preliminary design for the preferred alternate.
5.  Summarize the environmental assessment process and preliminary design in an Environmental Study Report.
The short version of all this is that the objective of the Environmental Assessment is to involve all the stakeholders in the decision of what to do about the Dalewood Bridge . . . which I think everyone agrees something needs to happen there . . . and to identify all the pros and cons of each alternative plan until they are able to determine the preferred way to proceed.
A Schedule C Municipal Class Environmental Assessment has five phases:
  • Phase 1 – Problem or Opportunity - Identify and describe the problem or opportunity.
  • Phase 2 - Alternative Solutions - Prepare environmental inventory, identifying and evaluating alternative solutions to address the problem and establishing the preferred solution.
  • Phase 3 – Alternative Design Concepts - Examining alternative design concepts for the preferred solution and establishing a preferred design concept, as well as identifying measures to minimize any adverse effects
  • Phase 4 – Environmental Study Report - Prepare and file  Environmental Study Report which summarizes the rationale, planning, design and consultation process for the Project  Document phases 1-3 for public review.
  • Phase 5 – Implementation of the Project.

Right now we are in Phase 2 which involves presenting the alternative solutions to the problem for public and agency input.  And that is why there was a PIC tonight.  The next PIC is expected to be held in the Fall of 2015 - Phase 3 - when they will present preliminary recommended design solutions for public and agency input.

Overview of the Project 

Stantec Consulting Ltd has been retained by the City of St. Thomas to undertake a Schedule C Municipal Class Environmental Assessment for the Dalewood Drive Bridge.  Their task is to determine the feasibility of replacing, removing or rehabilitating the bridge.

The deficiencies of the bridge include safety, structural condition, performance, and applicable design standards.

The alternative solution should limit impact to Dalewood Resevoir, Kettle Creek, and the surrounding ecosystem.

As mentioned near the beginning of this post, the original Dalewood bridge was replaced by a temporary modular bridge supplied by the Ministry of Transportation in 1983.  It is a single lane structure.  Vehicles must yield in both directions and alternate crossing of the bridge. 

There is no accommodation for bicycles or pedestrians.  Overall safety is a concern for pedestrian and cyclist usage under current single lane conditions.

Structural Reports in 2014 and 2015 show that elements of the bridge are in urgent need of replacement, particularly the abutments and embankments.  The dams only function is to maintain an environmental area.  It does not act as flood control.

Does anyone else remember a few years back when Waterworks flooded so high that the water level reached the roof of the pavilions?

Existing Condition - Natural Environment

Dalewood Conservation Area is a candidate warm water fish habitat on both sides of the dam and a candidate significant wildlife habitat.  

(The Significant Wildlife Habitat Technical Guide (SWHTG) was developed to support the Provincial Policy Statement and the Natural Heritage Reference Manual and is a more detailed technical manual that provides information on the identification, description and prioritization of significant wildlife habitat.  It is a guide that is advisory in nature and intended to be used by ecologists, biologists, environmental planners and others involved in the development of strategies to identify and protect significant wildlife habitat in the municipal planning and renewable energy planning processes.)  

Kettle Creek is a candidate significant woodland and the Kettle Creek valley lands are candidate significant wildlife habitat.

Existing Condition - Traffic

Dalewood Drive is a major collector road with a speed limit of 50 km/h with reduced speed of 30 km/h at the bridge.  The annual average Daily traffic count is 2000.  The current structure is theoretically sufficient except during peak times where delays may occur.  Speed bumps are located at each approach to decrease speeds.

I asked the consultants about delays for emergency services if the bridge were not available.  Ambulance and fire generally use Burwell Road and Ron McNeil to access the Dalewood area.  There could be delays for police.

Bridge Closure Travel Delays


7.6 km = 9 minute delay


6.8 km = 7 minute delay

So here are the five alternatives suggested:

1.  Do nothing.  This does not address the issue of deterioration of the bridge.  No cost.

2.  Remove the bridge and don't replace it.  This would impact vehicle and pedestrian traffic as well as affecting accessibility to KCCA.  Low cost.

3a.  Rehabilitate the existing bridge for pedestrian use only.  Costs to rehabilitate the bridge is high and would require a significant amount to be spent on maintenance.

3b.  Rehabilitate the existing bridge for vehicle use only and modify the dam for pedestrian use.  Rehabilitation costs would be high as well as high maintenance costs.

4a.  Build a 2 lane bridge for vehicles and pedestrians in the current location.  This solution does not effectively address the problems.  High capital cost.  Low maintenance cost.

4b.  Build a combined bridge and dam crossing in the current location.  Next question becomes how long will the current dam last.  A long term solution would still need to be considered at the end of the dam's life.  It does provide the opportunity to reassess a storm water management function for the dam which currently does not serve this function.  High capital cost.  Low maintenance cost.

4c.  Build a new bridge in a new location.  The topography is not conducive to this alternative.  Roads would have to be realigned and there would be a negative impact on the Kettle Creek Conservation Authority areas.

5.  Reconstruct the dam for vehicle and pedestrian traffic.  The dam was not constructed for vehicle traffic.  The whole dam would need to be redesigned and reconstructed.  Dalewood Drive would need to be realigned through KCCA land.

So I've given you a very brief overview of the problem of Dalewood Bridge and some possible solutions presented this afternoon.

The entire presentation is supposed to be online in the next few days.  

If you wish to obtain additional information about the study, be included on the study mailing list, or provide input at any point during the study process, you can contact the Project Team members:

Corri Marr, H.B.Sc
Senior Planner
Stantec
Phone 519-645-2007
corrie.marr@stantec.com

Leslie Whiteman, P. Eng.
Special Projects Enginee
City of St. Thomas
Phone 519-631-1680, ext. 4260
lwhiteman@stthomas.ca

Don't you just love the sound the bridge makes as you drive over it?  Or does it seem just a little scary to you?