Jill Green, NB minister of transportation and infrastructure
The governments of New Brunswick and Nova Scotia are promising to push for federal funding to help them raise dykes about 2 metres to 10.6 metres and improve aboiteau drainage to protect the Chignecto Isthmus transportation corridor — a project that would cost an estimated $190 to $300 million and take 10 years to complete.
“I know we’re committed to moving forward with this project and so is Nova Scotia and we’re going to work away at it as fast as we can,” Jill Green, New Brunswick’s minister of transportation and infrastructure (DTI) told reporters today after releasing a long-awaited study on how to protect the isthmus, the TransCanada Highway and the CN Rail line from the rising seas of the Bay of Fundy.
When asked about the urgency of the situation and whether the isthmus and the towns of Sackville and Amherst are in imminent danger from saltwater flooding, Green replied that she has no crystal ball.
“This is a massive project, this is not going to happen overnight,” she said, adding that it will take about five years to negotiate funding arrangements among the three levels of government, to complete environmental assessments and to conduct further engineering work.
She said that means construction would not begin for about five years.
Kim Masland, Nova Scotia’s minister of public works said that aside from a catastrophic storm like the Saxby Gale of 1869, the current 7.5 to 8.5 metre dykes should give adequate protection, but she also emphasized that both provinces are committed to the project.
“We recognize the importance of implementing this project on an expedited basis and that’s how we are going to move forward,” she added.
Three options
The Chignecto study recommends three main ways of raising the dykes to 10.6 metres.
Option A would raise the existing dykes and require construction of a large water control structure at the mouth of the Tantramar River:
Option A would cost an estimated $200.2 million (click to enlarge) Option A detail from Chignecto Isthmus Climate Change Adaptation Comprehensive Engineering and Feasibility Study – Final Report
Option B would build new dykes along the existing alignment of the present ones.
Option B would cost an estimated $189.2 million (click to enlarge) Option B detail from Chignecto Isthmus Climate Change Adaptation Comprehensive Engineering and Feasibility Study – Final Report
The third, most expensive option, would raise existing dykes along their present alignment and install approximately 800 metres of Steel Sheet Pile (SSP) walls at selected locations. Water level control structures would be required downstream of existing bridges.
Option C would cost an estimated $300.8 million (click to enlarge) Option C detail from Chignecto Isthmus Climate Change Adaptation Comprehensive Engineering and Feasibility Study – Final Report
Other options
Wood Environment & Infrastructure Solutions, the main consulting firm that conducted the study, considered several other options, but ranked them much lower than Options A, B, and C.
The additional options included raising one or both lanes of the TransCanada Highway to 10.6 metres; building a new rail line to 10.6 metres next to the existing one; moving both the highway and rail line to new locations and building a bridge that would include both highway and rail line.
Costly project
N.S. Public Works Minister Kim Masland
“This is a very significant project with a very significant cost,” Kim Masland said, echoing comments made by her New Brunswick counterpart, Jill Green.
Both emphasized the need for federal funding to help the two provinces protect transportation links such as the TransCanada Highway and CN rail as well as electrical transmission lines and fibre-optic cables.
They said that raising the dykes would also protect the towns of Sackville and Amherst from saltwater flooding while safeguarding the $35 billion in annual trade and other economic benefits that depend on keeping the Chignecto Isthmus open.
“This is much bigger than our two little provinces,” Green said. “This is a federal project, this is a strategic corridor for Canada.”
To read more about the Chignecto study, click here.
Well thank goodness the condensed version of the Chignecto Isthmus Study has now been released.
It is great to see that the two lesser expensive Options, A and B, will give full protection to all of Sackville by means of a new gate structure at the mouth of the Tantramar River. The new gates will would act similar to the existing Tantramar River gates, those under the TCH near Exit 506, in that they will remain closed to salt water intrusion and only be opened when needed at low tide to allow for excessive fresh water drainage to enter the bay from upriver. This will not only protect the town, but will enable the newly installed aboiteau gates under the Carter’s Causeway (Rte 935) to be permanently removed and have the four pipes just act as a free flowing 24/7 fresh water culvert system. No more flooding down that way or on Rte 106 headed to Dorchester. And of course, there will be no flood waters headed towards Lorne Street, like when the past flooding was at its worst.
Unfortunately the more expensive, Option C, would continue to see the siltation occurring at the Carters Brook causeway aboiteaux, on the south side, because that is exactly what is happening now and no changes are proposed with this option only. So hopefully they delete Option C.
I guess the best part of all three options is that the Tantramar River, behind Russell Metals, will act as a MASSIVE water retention pond that will make the current retention pond on St James Street completely redundant and will mean that we certainly don’t have to think of building any more of them. Any runoff of storm water from the town will be able to drain directly into this fresh water only section of the Tantramar River on a 24/7 basis and there will be no need to restrict it by means of an aboiteau. Just a larger culvert will be all that is required. So, we can forget about spending $5 million dollars on more retention ponds. We just have to clean out the ditches and get this project done as soon as possible.
Should be a no brainer to complete this by the feds with our tax dollars. Just think what happens if it’s not fixed! But considering they want to dump 400 million for a new hospital for the prisoners in dorchester I wouldn’t be shocked if they pump the brakes and claim it’s too costly to fix this much bigger and needed project.