Understanding risk essential at time of climate change and rising tide of claims
Rita Gavin helping her sister Marian Gavin and her nephew Jack Gavin clear water from their basement apartment on Ballybough Road, Dublin, after flooding in July 2009 photograph:: alan betson
Background:We must become much more aware of coastal erosion and rising sea levels
It is more than six years since Hugh McElvaney, leader of the Fine Gael group on Monaghan County Council, was told that land proposed for rezoning outside Ballybay was located in a floodplain, and he responded by suggesting that houses could be “built on stilts”.
Now the policy is that development in areas with a high probability of flooding “should be avoided and/or only considered in exceptional circumstances, such as in city and town centres” or essential infrastructure that cannot be be located elsewhere.
“Understanding flood risk is an essential step in managing the associated impacts of flooding,” according to the Planning System and Flood Risk Management guidelines issued in November 2009 by then minister for the environment John Gormley.
“The effects of climate change, such as more severe rainfall events and rising sea levels, will increase these risks and may put other areas at risk that may not have flooded in the past ... Adapting to the reality of climate change, therefore, requires us to be even more vigilant.”
The guidelines warn that rising sea levels and more frequent and more severe coastal storms will “significantly increase” the risk of flooding. The consequential economic impacts “are expected to multiply over the next century” in Dublin and other coastal areas.
For example, the flooding that happened in Dublin in 2002, when a one-metre surge coincided with one of the highest spring tides of the year, “could change from a relatively rare to a more common occurrence”. Therefore, “a precautionary approach should be adopted”.
According to the guidelines, “development should be designed with careful consideration of possible future changes in flood risk,including the effects of climate change and/or coastal erosion so that future occupants are not subject to unacceptable risks”.
Furthermore, it is up to applicants for planning permission for development to “identify and assess all sources of flood risk”, including the impact of their plans on surface water drainage. They may also be required to submit an “appropriate flood-risk assessment”.
The guidelines note that transport and utilities can be particularly vulnerable to flooding – “a key lesson learned from recent floods in Ireland when national primary roads and railway lines were flooded”, and the summer 2007 floods in Britain which disrupted water supplies.
Indeed, the Association of British Insurers said large areas of the UK were likely to become uninsurable because of the higher risk of flooding due to climate change. In several areas affected by coastal erosion the policy was now one of “planned retreat”.
In Ireland €1.2 billion has been paid out on weather-related claims over the past four years, according to the Irish Insurance Federation (IIF).
This includes the two largest insurance losses on record – for the flooding in November 2009 (€244 million) and the “ice period” in late 2009/early 2010 (€297million).
“Whatever side you’re on in the climate change debate, we’re seeing more frequent costly weather-related claims”, said the IIF’s Michael Horan.
Asked if parts of Ireland could become uninsurable due to repeated flooding, he replied: “Insurance is the business of covering risks, not inevitable events.”
Otherwise, “premiums would skyrocket”, he warned. “In some areas of the country where we have inevitable flooding, flood insurance is increasingly unviable. But we’re working with the Office of Public Works so that insurance companies can take flood defences into account in assessing risk.”
The report of the Flood Policy Review Group, approved by the government in 2004, highlighted “the need to pro-actively manage floodrisk”.
This led to the OPW becoming the lead agency for implementing flood-risk management policy and devise appropriate responses – including flood defences.
Under the EU floods directive the OPW is developing a series of river catchment-based flood-risk management plans in partnership with local authorities, the Environmental Protection Agency and other relevant departments to give “strategic direction” to the efforts (see cfram.ie).
The 2009 planning guidelines aim to avoid “inappropriate development” in areas at risk of flooding as well as new developments that could increase flood risks elsewhere and to “ensure effective management of residual risks for development permitted in floodplains”.
“By retaining open spaces for storage and conveyance of flood water, flood risk to both upstream and downstream areas can be more effectively managed without reliance on flood defences.
“This is an important element of the ... philosophy of ‘leaving space for water’.”
The new buzz term in flood management is sustainable drainage systems (SuDS), which are designed to reduce run-off so that surface water drains do not become overloaded, as well as improving water quality and contributing to local amenity.
Referring to the trend of paving front gardens to provide off-street car parking, the Department of the Environment pledged to to review exempted development regulations “to ensure that only those complying with sustainable drainage principles will be exempted”.
However, a spokesman said this review “has not been prioritised” by the department. Instead it concentrated on street design in residential and mixed-use areas to promote pedestrian and cycle use, and a new Design Manual for Urban Roads and Streets is to be published next month.
Apart from providing ponds and swales to contain excess water, the guidelines cite a “small-scale yet practical example” of SuDS in using permeable pavements – rather than concrete or Tarmac – to reduce run-off rates and the volumes of water flowing from car parks and access roads.