The Deh Cho Bridge is a cable-stayed bridge across a span of the Mackenzie River on the Yellowknife Highway (Highway 3) near Fort Providence, Northwest Territories. Construction began in 2008 and was expected to be completed in 2010 but faced delays due to technical and financial difficulties. The bridge officially opened to traffic on November 30, 2012. The bridge replaced the , the ferry in operation at the time of opening, and ice bridge combination used for river crossing.
Deh Cho (lit. "Big River") is the Slavey language name for the Mackenzie River.
History
NWT Highway 3 (or the Yellowknife Highway) must cross over a kilometre of open water or ice on the Mackenzie River south of Fort Providence. Since the highway opened in 1960 through November 2012, a seasonal ferry service was provided (roughly mid-May until December or January), with an ice road maintained across the frozen river from December to April. During the spring breakup season, due to hazards from floating or jammed ice there was a 3-4 week period (from mid-April to mid-May) between the closing of the ice road and the start of ferry service. No vehicles could cross during this period, and supplies for Yellowknife and other highway communities north of the river had to be relayed across by helicopter, sent by air freight, or wait until ferry operations begin. A similar but shorter freeze-up period used to occur in December/January between the end of ferry operations and the opening of the ice road, but since the early 1980s ferry operations had generally been able to extend until the ice road was open.
The closing of the crossing created added transportation inconveniences and costs for residents north of the river, especially for perishable items such as food. A bridge had been of interest since the highway was opened, but various proposals for a bridge had difficulty establishing financial feasibility given the limited traffic volumes and the estimated construction and maintenance costs involved.
On August 9, 2023, one of the suspension cables on the southeast side of the bridge let go due to a metallurgical defect. This led to the bridge being reduced to one lane, as well as load restrictions. Plans to replace all 24 cables are scheduled for summer of 2024. The bridge was repaired and both lanes open by February 2025. DCBC proposal Initial proposal and development
In 2000, the Fort Providence Combined Council Alliance (composed of the area's Dene, Metis and Fort Providence leaders) began considering whether to put together a bridge proposal. They obtained seed money from the territorial and federal governments, and by the end of 2001 had preliminary design and financing concepts. In 2002 a Memorandum of Intent was drafted between the Alliance and the Government of the Northwest Territories (GNWT). The Deh Cho Bridge Corporation (DCBC) was incorporated, and presented a proposal to the Government of the NWT to finance and build the bridge as a public–private partnership. The DCBC would arrange financing, construction and operation of the bridge, which would be leased back to the GNWT for a period of 35 years, in return for annual payments and the proceeds of a toll on commercial vehicle traffic crossing the bridge. After the lease period, ownership of the bridge would revert to the GNWT.
A feasibility study was commissioned, traffic analysis done,PROLOG Canada. Commercial Vehicle Traffic Forecast , September 2002. and a cost–benefit analysis studyNichols Applied Management. Benefit Cost Analysis , February 2003. based on this was undertaken for the GNWT during 2002–2003. Capital construction costs were estimated at $55 million.
The GNWT passed enabling legislation (the Deh Cho Bridge Act) in June 2003, allowing it to enter into concession agreements for a bridge. The DCBC obtained a $3 million funding commitment from the federal Indian and Northern Affairs Canada department in 2004, and initially hoped to complete agreements with the GNWT and begin construction in that year.
However, the bridge proposal required regulatory review from the Mackenzie Valley Environmental Impact Review Board, which was finalized in March 2005. Requirements for final engineering and financial plans further delayed a concession agreement with the GNWT. Tenders in 2005 and 2006 did not produce any offers at a suitable price. These delays also resulted in less than half of the $3 million federal contribution being obtained, as the remaining funding expired.
By 2007, citing inflationary increases in infrastructure construction costs, the proposed capital costs had risen to $165 million.Nichols Applied Management. Benefits-Cost Analysis Update , December 2007. This necessitated similar scale increases in the proposed annual payments from the GNWT to the DCBC over the life of the agreement to keep the project financially viable.
Concession agreement
After lengthy negotiation, in 2007 public statements by the GNWT and others indicated that final agreements were close with the DCBC. A ceremonial celebration occurred in Fort Providence in August 2007"Fort Providence Celebrates Decision to Proceed with Deh Cho Bridge" , GNWT Press Release, August 24, 2007 to mark the decision to proceed.
On September 28, 2007, the GNWT entered into the Deh Cho Bridge Project Concession Agreement with the DCBC. Further amendments were made February 22, 2008, although the document was not made public until after that time.
In 2010 the DCBC was declared in default by its lenders, the project was taken over by the GNWT, and the Concession Agreement was terminated.
Tolls The Deh Cho Bridge Act includes provision for tolls based on the (now terminated) Concession Agreement.Toll System Protocol, Supply & Management Agreement - Schedule 11 of the Concession Agreement Tolls are only charged to commercial vehicles that are travelling north and weigh over ; private vehicles do not pay tolls.
The original monthly fees were for three types of vehicles and the rates per month for "tractor-trains" of 7 axles or more was $275, "tractor-trailers" of 4-6 axles paid $150, and trucks with 2-3 axles paid $75. These rates were for registered users with transponders; single-use permits had an additional $16.25 service charge. The toll rates were later changed to cover four types of commercial vehicles based on the number of axles. Toll rates have increased based on inflation and as of April 1, 2016 the tolls had risen to $78 for 2 to 4 axles, $157 for 5 or 6 axles, $289 for 7 or 8 axles and $380 for 9 axles or more. The corresponding charges for single use are $97, $175, $307 and $398.
Design The original design was completed by JR Spronken and Associates Ltd. of Calgary in 2002. Following the GNWT's independent review, performed by its consultants BPTEC of Edmonton and T. Y. Lin International of San Francisco, recommendations for changes to the superstructure design were made. Infinity Engineering Group of Vancouver carried out the redesign and is now the design engineer firm on the project.
Infinity Engineering Group's project description says:
The bridge makes significant use of weathering steel and is not painted, reducing maintenance costs and extending the projected lifetime."The Use of Weathering Steel for the Deh Cho Bridge" It has fairly minimal lighting, citing dark-adaptation for drivers and reduced risk to migratory birds.
Stay cable measurements
Extreme weather conditions, seismic movements or corrosion can have a significant impact on cable force distribution, affecting the fatigue lifespan of stay cables. For maintaining stay cable bridges tension force measurements reveal such problems at an early stage so that they can be addressed properly.
A laser vibrometer provides long range, non contact, fast and accurate measurement of vibrating cables. Polytec, Inc. and Metro Testing Laboratories Ltd, British Columbia, Canada, have joined forces to analyze structural data to determine the tension force. Polytec's vibrometer was able to generate data for up to 10 cables of the Deh Cho Bridge per hour. These preventative measures and maintenance of structures are cost effective in the long run because they ensure the structural integrity of the cables.
Cost and financing The original construction budget was $169 million. This was mainly financed by the issuance in 2008 of $165.4 million in inflation-linked real return bonds, paying 3.17% plus inflation adjustment. The bonds will be repaid over a 35-year period from December 2011 (interest only was paid from 2008). This will amount to approximately $275 million in principal and interest costs over the 35 years, before the inflation adjustments.
With the construction difficulties that caused the GNWT to assume control of the project in 2010, another $15.9 million in financing was required, which was provided by the government in its 2012/2013 capital estimates and brought the construction budget to $182 million. A further $10 million announced as being required in June 2012, brought the construction budget to $202 million.N.W.T. to spend another $7M to $10M on Deh Cho Bridge - CBC.ca, June 6, 2012.
Some items are not included in this figure, including costs for building toll plazas and other toll infrastructure (estimated at $1 million), compensation for lost fish habitat, and environmental remediation. The cost of various remediation repairs to the original Atcon Phase 1 work is not included; this is being paid for by the $13.3 million construction bond funded by the Government of New Brunswick.New Brunswick money used for repairs - NNSL, Laura Busch, Feb 22, 2013. Also not included are the indirect costs of the most recent delay to 2012 in opening the bridge; a year's worth of uncollected tolls and additional ferry operation.
The bridge now having been built, annual expenditures by the GNWT will approach $9 million, including principal and interest repayment, toll collection costs, bridge maintenance and the Opportunities grant to Fort Providence community groups. Along with the tolls, the government will save an estimated $3 million annual savings in ferry costs, but is anticipating a further subsidy requirement of around $2 million annually, depending on traffic volumes.
Project and construction difficulties
Actual construction began in June 2008,"Construction underway on N.W.T. bridge over Mackenzie River", CBC News, July 9, 2008 with an opening date then estimated as late 2010. Work was completed on the approaches and support piers, although the final approved designs for the superstructure were not yet complete. The four piers on the south side were put in place in 2008, and the four northern piers during 2009.
Delay and redesign During final approval of the bridge plans by the GNWT and its outside technical advisors, inadequacies relating to the design of the superstructure were discovered. A delay in the construction schedule to allow for investigation of design changes was announced, and the opening date pushed back by a year to late 2011.
General contractor terminated As of December 30, 2009, Atcon Construction's role as general contractor for bridge construction was terminated by the DCBC,Atcon out of N.W.T. bridge project which announced that an agreement could not be reached on a price for the revised superstructure. Atcon Construction (as well as a number of other companies in the Atcon Group) were placed in bankruptcy receivership in March 2010; In October, the bankruptcy receivers submitted a termination claim for $5.3 million (including $650,000 of equity); the GNWT (which had superseded the DCBC) disputed many of the claims. In November 2012 an agreement was reached to settle all claims for $1.3 million, and the receiver filed with the bankruptcy court to approve this in April 2013.