Coastal Protection and Mitigation

The Issue

The decision not to proclaim or otherwise enact the Coastal Protection Act pushes the responsibility for setting rules to localities. For much of the Eastern Shore, this involves Halifax Regional Municipality (HRM). While I won’t get into the benefits or trials of amalgamated regions, this provincial decision means that those living on the shore should watch the HRM closely on a few points.

Two Impacts

Impacts can be “direct” or “indirect.” Direct impacts describe conditions where the event affects something itself. A flooded basement due to sea-level rise and storm surge falls into this. Indirect impacts are those that are the result of a second set of consequences that are tied to the effect of the event and not necessarily the event itself. For example, a disruption in emergency services because a road is flooded and ambulances can’t get through.

The Road Network

To describe the road network, I am using the “Toporama” website provided by the Atlas of Canada. Coastal regions tend to lack the resilience apparent along the main corridor (Halifax towards Truro). While not unexpected, it does leave certain communities vulnerable.

Along the Eastern Shore, Trunk 7 acts as the main route with several smaller roads branching off from it. Routes branching off towards the ocean are often “one-way-in-one-way-out” kinds of situations. For example, the route towards East Petpeswick and East Jeddore fall into this category. Other routes may loop back to the main route, but these offer little local resilience.

Fragmentation and Dissolution

The Province of Nova Scotia Coastal Hazard Map shows many locations fall prey to flooding. Fragmentation occurs where the road network is broken, leaving sections more difficult to get to. Dissolution occurs when fragmentation occurs to such a point that there are whole sections of network isolated from the main network with no recourse.

Road network fragmentation along the coast is highly possible, if not probable. Within the Eastern Shore, however, the lack of resilience within the road network leads to a significant possibility of road network dissolution. The sea level rise impacts certain key areas and intersections that would essentially isolate communities.

This scenario represents one in which the main intersection on Trunk / Highway 7 is disrupted as is the intersection on one of the roads heading off the main highway. In this case, the communities south of this disruption would be completely isolated from the main route. The Atlas of Canada Toporama website shows the scarcity of alternative routes.

The Goal

The goal of any transportation system is to ensure that persons and goods leave their point of departure and arrive at their intended destination on time, in acceptable condition, and for reasonable cost. The road network supports this by offering alternative routes that allow the movement to trade cost (usually in terms of fuel) and time (if less efficient) to help assure that it at least gets there.

The overarching goal would be to have a reasonably resilient road network that prevents communities from being cut off. This may involve building roads or bridges that rise above sea level or may involve building new roads on less susceptible ground.

We will post on this challenge in the future.