The potential realignment of the coast is a danger

FAVOURITES  9 December 2009 – The  issue of potential damage to infrastructure is a late comer to climate concerns, and so too is the likely realignment of the coast itself argues, MWH’s Peter Fagan –

Much has been said about the global concern for climate change and the very real threat it poses to both the environment and business.  Most recently, concern has been expressed, particularly within local government, over the impacts that rising sea levels will have on coastal areas with regard to property and land use.

Most towns and councils seem to be more focused on land use planning issues in these “at risk” coastal regions rather than the potential costly damage to their existing infrastructure.

Issues of what coastal towns and councils ought to be doing about protecting these assets and minimising interruptions to water and wastewater services should also become a more important topic for planners and utility operators. This is an area which cannot afford to be overlooked given the potential for long-term, lasting damage.

As the wastewater systems of most coastal settlements have a tendency to flow toward the coast and to be close to the lowest point along the shoreline, these facilities and equipment are high-risk assets and that risk will only increase over time.

Apart from the threat posed by coastal erosion due to storm activity, seawater infiltration of sewerage systems can cause severe damage to infrastructure, resulting in interruptions to services and considerable repair and replacement costs. As the frequency of storm and sea surges increases, the associated problems will be compounded.

Additionally, an often forgotten consideration involves town and infrastructure planners not yet factoring in a shift in the direction of energy inputs to the coast due to shifts in the climate patterns. Simply put, our coasts have, over the last several thousands of years, aligned themselves in keeping with the direction from which the majority of the storm energy has come.

At a simplistic level, the impact of this can be seen on annual basis by the changing shape of our beaches between summer and winter, where sand movements occur and alter the size and shape of the intertidal and adjacent beach fronts.

A small, more permanent shift in the direction from which storms traditionally come, over and above the impacts of actual sea level rises, could more realistically mean the realignment of the coastline.

This would further increase the risk to a broad range of infrastructure assets from buildings, roads and bridges through to water and wastewater plants, pumps, pipelines and other related assets.

Rather than planning for simple rises in sea levels, councils need to consider the likely realignment of our coastline – a much more complex task.

Efforts need to be made to assess how the coastline could actually be altered and how infrastructure planning will need to be adjusted to effectively protect valuable assets.

Councils, utilities and planning authorities need to start planning for the adaptations that they will need to make to all their coastal assets, including water infrastructure, without delay.

The adaptive measures they will need to undertake will be varied in their style and approach and will cover community strategies to deal with short- to medium-term interruptions to services through to temporary adjustments to the operating regime, configuration of their current assets and replacement of assets.

Authorities also need to move quickly to develop the necessary quantitative methods required to better understand the dynamics of these coastal environments, as well as methods that will support the need for higher rates in order to ensure funds are available to pay for the required changes or maintenance.