FLOOD risk information is often required for many types of development proposals.

Last year, the Government consulted widely about amendments to its national planning policy guidance on development and flood risk.

The revised version of the guidance, called Planning Policy Statement 25: Development and Flood Risk, has now been published.

As anticipated, Annex D of the guidance clarifies aspects of existing policy by amending the definitions of: Flood Zone 3b The Functional Floodplain and; The Flood Risk Vulnerability Classification.

Flood zones are graded 1-3a based on their low to high probability of flooding.

Flood Zone 3b, the Functional Floodplain, has tended to be restrictive to many types of development as it covers land where water has to flow or be stored in times of flood.

Local planning authorities identify these areas, in agreement with the Environment Agency, taking account of local circumstances.

The guidance says these areas should not be defined “solely on rigid probability parameters”.

Land that floods typically between one and 20 times a year or is designed to flood in extreme conditions should be a starting point for discussion in identifying the functional floodplain.

The guidance for Zone 3b recommends that developers and local authorities should seek opportunities to: Reduce the overall level of flood risk through the layout and form of the development and the appropriate application of sustainable drainage techniques; Relocate existing development to land with a lower probability of flooding.

During the consultation amendments were proposed to the Flood Risk Vulnerability Classification (FRVC).

The FRVC categorises different types of land uses and developments in relation to their vulnerability to flooding as: essential infrastructure, highly vulnerable, more vulnerable, less vulnerable and water-compatible development.

Wind turbines are now included in essential infrastructure along with essential transport that has to cross an area at risk of flooding; utility infrastructure that has to be located in a flood risk area for operational reasons; and water treatment works that need to remain operational in times of flood.

Sewage treatment works remain classified as less vulnerable if adequate measures to control pollution and manage sewage during flooding events are in place.

There is also further clarification within the highly vulnerable classification for installations requiring hazardous substances consent with regard to bulk storage, and installations associated with energy infrastructure.

Although the basic policy approach remains unchanged, the amendments affect the interpretation of the policy and how it is applied.

■ Louise Oakley is a planning consultant with BHP Develop and can be contacted on 0191-221 0898.