Policy information sourced from Runnymede Local Plan
EE13: Managing Flood Risk
New development will be guided to areas of lowest flood risk from all sources of flooding through the application of the sequential test. A sequential approach to the layout on individual development sites will also be expected to be followed to minimise flood risk. The exception test will continue to be applied where national planning policy advises that this is necessary.
Any development proposed in either flood zone 2, flood zone 3, on sites over 1ha in flood zone 1, or in a dry island (all types of development excluding minor development in a dry island), must be accompanied by a site specific Flood Risk Assessment, proportionate to the scale of development that demonstrates that all forms of flooding have been taken into account (as detailed in the Council’s Strategic Flood Risk Assessment). Managing flood risk over the lifetime of the development must be addressed, taking into account the following:
- The impacts of climate change, and
- Where practical to do so, it will be expected that developments will be constructed with adequate flood resilience and resistance measures suitable for the lifetime of the development, in line with Environment Agency advice and advice contained in the Runnymede Strategic Flood Risk Assessment.
Where national planning policy requires the exception test to be applied and passed, and when a site is located in a dry island, applicants will be expected to consider the onset and duration of a flood, the vulnerability and willingness of occupiers to evacuate the site in a flood event and the ability of the site to operate an effective flood evacuation procedure.
For new development where at least 1 net additional residential unit is proposed or for all other types of development, where a net additional floorspace of 250sqm is proposed, development must not materially:
- Impede the flow of flood water;
- Reduce the capacity of the floodplain to store water;
- Cause new, or exacerbate existing flooding problems, either on the proposed development site or elsewhere.
Development proposed will be required to attenuate surface water run-off so that the run-off rate is no greater than the run-off prior to development taking place or, if the site is previously developed, development actively reduces run-off rates and volumes. All new development is required to ensure that sustainable drainage systems are used for the management of surface water unless demonstrated to be inappropriate. All new developments in areas at risk of flooding must give priority to the use of sustainable drainage systems. The Council supports proposals for strategic flood relief measures (and associated enabling works), including the emerging flood relief measures and channel through Runnymede as part of the wider River Thames Scheme. The land which may be required for the River Thames Scheme, as shown on the Policies Map is safeguarded for this purpose. The Environment Agency will continue to engage and consult with landowners affected by or immediately adjacent to the scheme of works, to inform future planning proposals to ensure the River Thames Scheme proposal is compatible with existing and future development. Any loss of the approved compensation scheme at Thorpe Park as a result of the River Thames Scheme construction works would be reprovided in agreement with the Council.
For more information please see the Local Plan