Senate Committee — TRCM — Brief — followup_sebastianweissenberger_e

TRCM / Brief / followup_sebastianweissenberger_e

Senate Committees

Sebastian Weissenberger Answers to the questions during the meeting Senator Miville-Dechêne: It’s all rather depressing. My first question is fairly pragmatic and is for Mr. Weissenberger and Mr. Ness. What can we do about all this? You mentioned asphalt, which seems to me to be a lower-cost solution than changing an entire road. Are there already places in Canada where builders are using a type of asphalt that can better withstand water, I imagine, or major storms? Is prevention already being done to that effect? Answer Many types of asphalt are used for roads.

Generally speaking, asphalt is a mixture of aggregates, sand and bitumen, which acts as a binder. Depending on the type of material used, the pavement’s physical properties can change, such as its durability, load resistance, skid resistance, deformation (which is why different types of asphalt are used for highways and secondary roads), and even the level of noise generated by tires rolling over it. Asphalt generally has very low impermeability. This means that a key factor in the longevity of asphalt is drainage, more than the composition of the asphalt itself.

There are, however, new types of porous asphalt (or open-graded asphalt) that can absorb significant quantities of water (see demonstration below). This type of asphalt is not necessarily suitable for all uses, and may not be more resistant in the event of heavy precipitation, but not in the event of coastal flooding. There are also durability considerations in cold climates, such as its ability to withstand freeze- thaw cycles, but some demonstrations have shown it is feasible (Zhang & Kevern, 2021). It would certainly be an option worth considering.

A good source of additional information would be the Centre d’expertise et de recherche en infrastructures urbaines (CERIU) (https://ceriu.qc.ca/) [AVAILABLE IN FRENCH ONLY]. Ness et al. (2021) also suggest increasing the depth of the base layer for roads to allow better drainage. • City of Burnsville, 2013. “City Demonstrates Porous Asphalt.” https://www.youtube.com/watch?v=_-5S9LIyYvQ&t=38s The main factor affecting pavement in southern Canada is temperature (Maadani et al., 2021; Mills et al., 2009).

Extreme heat affects the bitumen, causing damage to roads and leading to more frequent repairs, and it is the main factor in the anticipated increase in road spending (Ness et al., 2021). Ness et al (2021) estimate that updating building codes to reflect climate change could reduce additional costs associated with extreme temperatures, heavy precipitation and freeze-thaw cycles by 77%–84% by mid-century and 90%–98% by the end of the century (this figure does not, however, take into account coastal erosion). Often, it is not a question of the pavement itself, but of how the road is built.

When a washout occurs, the damage affects not just the pavement, but also the base layers of the road. Washouts can happen along the coast, but also along lakeshores, near rivers or wherever the road is laid on a loose substrate. In such situations, ideally before a washout occurs, the road’s base layers can be stabilized with rock armouring, concrete along the right-of-way, etc., which is of course expensive. References: Maadani, O., M. Shafiee, I.

Egorov (2021). “Climate Change Challenges for Flexible Pavement in Canada: An Overview.” Journal of Cold Regions Engineering 35, https://doi.org/10.1061/(ASCE)CR.1943-5495.0000262 Mills, B. N., S. L. Tighe, J. Andrey, J. T. Smith, K. Huen (2009). “Climate Change Implications for Flexible Pavement Design and Performance in Southern Canada.” Journal of Transportation Engineering 135, https://doi.org/10.1061/(ASCE)0733-947X(2009)135:10(773) Ness, R., D. G. Clark, J. Bourque, D. Coffman, D.

Beugin (2021). “Under Water: The Costs of Climate Change for Canada’s Infrastructure.” https://climatechoices.ca/wp- content/uploads/2021/09/Infrastructure-English-FINAL-Sep29.pdf Zhang, K., J. Kevern (2021). “Review of porous asphalt pavements in cold regions: the state of practice and case study repository in design, construction, and maintenance.” Journal of Infrastructure Preservation and Resilience 2, Art. 4. https://jipr.springeropen.com/articles/10.1186/s43065-021-00017-2 Senator Cardozo: Mr. Weissenberger, I have a couple of questions about two different situations in Quebec. […] .

The other area I keep thinking about is Highway 40 going into Montreal around Lac de la Montange. Looking on a map here, on Île aux Tourtes, just west of the bridge, there is a

section of maybe a kilometre that is close to water level. A couple of years ago, when the water level was high, it was only protected by a bunch of sandbags. That is a major highway going into Montreal. Whose responsibility would it be to deal with that piece of highway? Answer In April 2019, flood barriers were installed on Highway 40 in the Vaudreuil – Île aux Tourtes sector. The bridge through Bigras Island in Laval was also prepared for and emergency.

Most of the work was undertaken by the ministère des Transport of Québec, but also 800 members of the Canadian armed forces were mobilized in Quebec (as they had been in 2017). This is not the only event affecting highway 40 in recent years: - In July 2009, following heavy rainfall, a sector of Highway 40 near the Rond-Point de l’Acadie got flooded and several motorists had to be rescued.

This sector was flooded seven times between 2004 and 2010, and again in 2022. - In August 2020, access roads to Highway 40 were flooded in Trois-Rivières after 100 mm of rainfall. - Highway 40 is also very vulnerable in the Lac-Saint-Pierre area, where access roads are regularly inundated, e.g. 2017, 2019, 2021. Other highways also have vulnerable spots. Thus, Highway 50 was briefly flooded in the Gatineau sector, but reopened thanks to protective measures during the 2017 floods. Several Canadian and Quebec government buildings were closed as a precaution.

Flood barriers were again installed in the springs of 2022 and 2023 by the ministère des Transports du Québec. In May 2023, some accesses to Highway 50 in Gatineau were closed due to bloods. Highway 20 was closed in 2017 for two days between Île Perrot and Montreal (Galipeau bridge). Highway 40 in the same sector was not closed, but came close to be flooded in the Lac-Saint-Pierre area. The floods of 2017 and 2019 were exceptional. Both exceeded the 100-year return water level, in 2017 for five days, in 2019 for six days.

This mirrors the evolution in Western and Central Europe, where centennial floods have occurred in 2002, 2013 and 2021, which puts into question the meaning of those historical recurrence measures in the context of climate change, and what type of events we should prepare for. The responsibility for emergency measures is widely shared among municipal, provincial and federal (Canadian army) levels, and also includes a large number of volunteers.

Usually, the responsibility for numbered roads remains with the ministère des Transports du Quebec (including federal highways), that for unnumbered roads is delegated to municipalities. The ministry’s actions are guided by the “Plan ministériel de sécurité civile (PMSC)”. The Canadian government can be called for help in case provincial resources are not sufficient. The Emergency Management Strategy for Canada: Toward a Resilient 2030, dating from 2007 and updated in 2017 and 2019 guides the action of the Canadian government. Temporary dykes used in Quebec are made of concrete, polythene, and sandbags.

Other technologies exist, such as inflatable water bags, which are for example used by the cities of Calgary or Laval. “Aquadams” had also been installed on Highway 50 in 2019, but one was broken after a truck passed too close. Interestingly, in an interview led a few years ago, a municipal manager in New Brunswick said he had not heard about those solutions before being told about it by a peer from Calgary. Such structures have the advantage of being quicker to install and reusable, avoiding the disposal of thousands of sandbags (75 000 for the town of Trois-Rivière alone in 2019).

Various types of solid, inflatable or gel-filled bags exist. It would be useful to have better information for municipalities on what’s available and the advantages and drawbacks of the various techniques.

Document details

Collection	Senate Committees
Citation	TRCM / Brief / followup_sebastianweissenberger_e
Type	committee
Volume / chapter	441 / Brief / followup_sebastianweissenberger_e
Language	en
Format	pdf
Source	COMM_SEN
Identifier	7cda186da586ed721d34c6882485dea9b9496338

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