Flood risk assessment

A flood risk assessment is an assessment of the risk of flooding, particularly in relation to residential, commercial and industrial land use.

England and Wales

In England and Wales, the Environment Agency requires a Flood Risk Assessment (FRA) to be submitted alongside planning applications in areas that are known to be at risk of flooding, planning permission is not usually granted until the FRA has been accepted by the Environment Agency. Flood risk assessments are also relevant to the maintenance and insurance of existing buildings. [ [http://www.floodrisk.org.uk/ Floodrisk Management Research Consortium] ]

PPS(25) legislation - England only

Flood Risk Assessments are required to be completed according to Planning Policy Statement (PPS)25: Development and Flood Risk. The initial legislation (PPG25) was introduced in 2001.Fact|date=April 2008

PPS(25) was designed to "strengthen and clarify the key role of the planning system in managing flood risk and contributing to adapting to the impacts of climate change." [ [http://www.communities.gov.uk/statements/corporate/planning-policy-flooding Planning Policy Statement (PPS) 25: Flooding - Corporate - Communities and Local Government ] ] and sets out policies for local authorities to ensure flood risk is taken into account during the planning process to prevent inappropriate development in high risk areas and to direct development away from areas at highest risk.

In its introduction, PPS25 states "flooding threatens life and causes substantial damage to property [and that] although [it] cannot be wholly prevented, its impacts can be avoided and reduced through good planning and management". [ [http://www.communities.gov.uk/documents/planningandbuilding/pdf/153740 PPS(25) pdf] ]

Composition of an FRA

For a flood risk assessment to be written information is needed concerning the existing and proposed developments, the Environment Agency modeled flood levels and topographic levels on site. At its most simple (and cheapest) level an FRA can provide an indication of whether a development will be allowed to take place at a site.

An initial idea of the risk of flooding to a local area can be found on the [http://www.environment-agency.gov.uk/subjects/flood/ Environment Agency flood map website] . However, the Environment Agency use low resolution flood mapping to create this flood map as a cautious estimate of flood risk, and therefore on the more local scale this mapping may not be accurate. [ [http://www.ggy.bris.ac.uk/research/hydrology/models/lisflood School of Geographical Sciences, University of Bristol ] ]

Longer FRAs consist of a detailed analysis of available data to inform the Environment Agency of flood risk at an individual site and also recommend to the developer any mitigation required for a planning application to be submitted. More costly analysis of flood risk can be achieved through detailed flood modelling to challenge the agency's modelled levels and corresponding flood zones.

The FRA takes into account the risk and impact of flooding on the site, and takes into consideration how the development may affect flooding in the local area. It also includes provides recommendations as to how the risk of flooding to the site can be improved or improved following development.

Other uses

Assessments can also be used to provide insurers with a more detailed assessment of flood risk at a location, and can act as a means of reducing insurance premiums.Fact|date=May 2008

References

ee also

*Flood warning
*Ambiental

External link

* [http://www.floodsmart.gov/prp US Government: Flooding Assesment in the United States]