Flooding is a natural hazard. The nature of the flood source can present a range of different risks, such as the speed of inundation, depth and the duration of different forms of flooding, which can vary greatly. With climate change, the frequency, pattern and severity of flooding is forecast to change and become more damaging.
Tidal flood risk
It is predicted that as a consequence of climate change, the incidence and severity of flooding will increase over time. This is as a result of rising sea levels and increased storminess producing higher intensity rainfall and increased run-off from land and buildings. The result will be increased vulnerability of Poole’s coastal and harbour areas to the risk of tidal flooding.
For the local area, information about flooding from the sea can be found in the Poole and Christchurch Bays Shoreline Management Plan 2.
The Environment Agency
The Environment Agency (the EA) has direct responsibility for the prevention, mitigation and remedying of damage caused by flooding from main rivers and the sea.
For coastal flooding, flood risk areas are mapped by the EA to a 1 in 200 year event (flood zone 3) and a 1 in 1,000 year event (flood zone 2). The EA’s flood maps for planning provide information relating to current day flood risk for a specific location by postcode.
The EA has produced Local Flood Risk Standing Advice specific to areas at current day and future risk of flooding in Poole. The advice contains guidance on the minimum levels of flood risk mitigation that would be required for various forms of development and is provided so that developers are aware of, and can incorporate, the measures necessary to mitigate flood risk affecting development proposals, prior to the submission of a formal planning application.
Revised strategic flood risk assessment levels 1 and 2
As part of the evidence base supporting the new Local Plan for Poole, the Strategic Flood Risk Assessment (the SFRA) has been updated (November 2017), in collaboration with the EA.
The level 1 SFRA provides an assessment of the extent and nature of flood risk from all sources and takes into account sea level rise as a consequence of climate change. It identifies areas at risk of flooding and outlines methods to minimise and manage that risk.
Evidence has established that Poole cannot meet its identified need for housing within areas at low risk of flooding. A level 2 SFRA has been undertaken to enable a detailed application of the sequential test and exception test, as required by the National Planning Policy Framework (the NPPF), on strategic sites in central Poole, at current and future risk of flooding, which have been allocated for development (i.e. Twin Sails regeneration area). The level 2 SFRA has been informed by a series of mapped climate change scenarios, incorporating predicted rises in sea level over time.
Future flood risk mapping
Flood modelling (for a 1 in 200 year event), has been produced for the Poole Local Plan to understand the scale and nature of future flood risk to 100 years beyond the end of the plan period i.e. 2133. Find out if your property falls within this future flood risk zone (due to the amount of data in the map it may take a while to load).
The NPPF requires the sequential test to be undertaken for new developments proposed in areas at higher risk of flooding. In accordance with paragraph 158 of the NPPF (July 2018), the SFRA should be the basis for applying the sequential test. The updated level 2 section of the SFRA provides details of the revised study area boundary for application of the sequential test. The study area includes those parts of central Poole which have been identified for growth and regeneration and within which strategic development sites will require flood defences. The sites located within the study area will not need to meet the NPPF sequential test requirements.
The council has produced a Strategic Housing Land Availability Assessment which identifies a deliverable five year supply of housing from sites within the town centre and parts of the borough in flood zone 1 (low flood risk). Given this, development proposals for a net increase in dwellings in areas of current and future flood risk, are unlikely to be able to meet the tests set out in the NPPF, particularly the sequential approach to site selection. Such development proposals are therefore likely to result in a refusal of planning permission.
Flood risk management strategy
The Flood Risk Management Strategy (published January 2011), is a strategic review of flood risk to determine realistic and workable options for defending Poole from tidal flooding, together with an estimate of the potential costs of providing flood defences. The final report is accompanied by a number of appendices:
Ground and surface water flooding
Preliminary flood risk assessment
Poole, as a lead local flood authority (LLFA), as defined by the Flood and Water Management Act 2010 and the Flood Risk Regulations 2009, is required to prepare a Preliminary Flood Risk Assessment (the PFRA). The PFRA has been produced in accordance with national guidance and should not be used on an individual household basis to measure flood risk. Further work will better inform flood risk at this level, but until that time the findings should not be used for insurance or other valuation purposes. The PFRA is a desktop analysis which collates past known flooding reports from local flood sources such as:
- surface water runoff
- ordinary watercourses
- canals and small impounded reservoirs
It considers the consequences that these forms of flood risk might have to people, properties and the environment, including cultural heritage and ecology, and will help to develop a strategy to manage local flooding in Poole.
Impact of the PFRA on insurance
The insurance industry will have access to the flood risk information produced as part of the PFRA, as will all members of the public, subject to certain restrictions. Insurers already have access to historic claims, models and commercial products similar to the EA's national surface water maps that show surface water flood risk information. They use this information to make decisions on risk in order to set premiums and excesses using a range of information.
The information in the PFRA is not suitable to assess risk to individual properties in all parts of the country in detail as we cannot know all details about all properties, for example how high the floor level is above ground level and how water might get into houses through doors, windows and airbricks. Insurers can therefore only use the information as a first stage in assessing the flood risk for a general location. The cost of insurance can vary according to the level of flood risk, market strategy by individual insurers and other factors, such as crime. For more information about flood risk and insurance, visit the Environment Agency website.
Poole's Local Flood Risk Management Strategy (the LFRMS)
On completion of the PRFA, Poole developed a strategy to manage flooding across the borough. The LFRMS considers the risks of flooding from all sources, measures to manage the risk and how the measures may have multiple benefits.
Make a report for flooding on:
Page last updated: 16 October 2019