Surrey Heath Draft Local Plan Issues Options/Preferred Options, 2018

Flood Risk and Water Quality

6.29 There are areas of Surrey Heath prone to flood risk from a variety of sources. The River Blackwater has been an historic source of flood risk affecting western areas of Mytchett, Frimley, Frimley Green and Camberley. The Addlestone Bourne and Mill Bourne also pose flood risks within the central and eastern areas of the Borough in particular Bagshot, Chobham and areas of West End. Other sources of flooding within the Borough have also caused disruption and damage to residential properties and businesses in the past. The 2015 Strategic Flood Risk Assessment undertaken by Capita identifies sources of flooding as Fluvial (river) flooding, surface water, sewer inundation, groundwater and possible breach of the Basingstoke Canal.

6.30 The Council commissioned a Strategic Flood Risk Assessment (SFRA) of the Borough in 2015. This identified river flooding and surface water run-off as the primary causes of flood risk in the borough with more urban areas also experiencing flooding from sewers. The risk from Groundwater flooding and breach of the Basingstoke Canal is identified as low risk.

6.31 Findings from the SFRA will enable the Council to apply a sequential test approach to sites allocated in the Local Plan to ensure that new development, unless an appropriate use under the Exceptions Test, is not located in areas of high or medium flood risk. The SFRA will also be used in the determination of planning applications for allocated and windfall sites. New development will need to minimise flood risk, including flood risk from surface water. Where appropriate applications will need to be accompanied by a Flood Risk Assessment. Any proposed development in areas of flood risk will require flood management, mitigation measures and demonstrate that the development is safe from flooding.

6.32 Managing surface water flooding at its source is one of the most effective ways to minimise run off from a site and prevent flood risk in the surrounding area. The Council will therefore seek the use of Sustainable Urban Drainage (SuDS) techniques to reduce flood risk, to the site and neighbouring areas, reduce pollution and provide landscape and wildlife benefits. In addition, SuDS should be designed to ensure they remain effective for storm events. Under national policy all major planning applications will require the inclusion of SuDS design.

6.33 With regard to water quality Surrey Heath, Hart and Rushmoor commissioned a Water Cycle Study (2017). This study reflects the objectives of the European Water Framework Directive and the Thames River Basin Management Plan. The Study sets out recommendations to ensure that any adverse impact of development on the water environment is minimised.


National Policy Context

6.34 In the preparation of this section regard has been had to paragraphs 18-22 of the National Planning Policy Framework (NPPF), 2012 which sets out the Government's approach with regard to the location of development and flood risk and to the 25 year Environmental Plan Policy Paper.

6.35 National Planning Guidance on Flood Risk and Coastal Change sets out strict tests to protect people and property from flooding and provides guidance on how to assess flood risk, avoid flood risk and manage and mitigate flood risk. It also includes guidance on SuDS.

Local Strategies and Evidence

6.36 The preferred policy approach would support the objectives set out in Surrey Heath's Five Year Strategy 2016-2021. One of the Councils principal objectives is to work with key partners to continue to keep the borough a very safe place to live.

View the full version of Surrey Heath's Five Year Strategy, located the Council's website.

6.37 The Surrey Heath Strategic Flood Risk Assessment (2015) takes into account statutory guidance to provide updated evidence on flood risk to assist the Council in selecting appropriate sites for allocation for housing, and other types of land use.

View the Surrey Heath Strategic Flood Risk Assessment which can be downloaded from the Flooding section of the Council's evidence base webpage.

6.38 The Hart, Rushmoor and Surrey Heath Water Cycle Study sets out approaches to water quality and supply.

View the Hart, Rushmoor and Surrey Heath Water Cycle Study which can be downloaded from the Council's evidence base webpage.

6.39 The following policies will be replaced in the new Local Plan (2016-2032)

Relevant Policies in the adopted Core Strategy & Development Management Policies DPD 2012

Policy CP2 Sustainable Development and Design

Policy DM9 Design Principles

Policy DM10 Development and Flood Risk


Draft Objectives for Flood Risk and Water Quality Policies

6.40 The following table sets out the draft objective for flood risk and water quality in the Issues and Options/Preferred Options consultation draft.

Objective G

To ensure that new development, unless appropriate development under the Exceptions Test, is not located in areas of high or medium risk of flooding and that development does not increase surface water run-off.


Policy Approaches to Flood Risk

6.41 The preferred policy approach and alternative approaches are set out below.

Preferred Policy Approach to Flood Risk

The aim of this policy approach is to minimise and reduce the risk of flooding and to ensure that Flood risk from all sources within the Borough is managed by:

Fluvial (River/Stream) Flood Risk

Having a policy that:

  • Restricts development in areas of fluvial (rivers/stream) flood risk.
  • Requires the sequential and exceptional tests to be applied in flood risk areas
  • Requires a site Flood Risk Assessment that demonstrates that the proposal would reduce risk both to and from the development
  • Requires flood resilient and resistant design and appropriate mitigation where risk have been identified

Surface Water

Having a policy that:

  • Requires all development to ensure, as a minimum, there is no net increase in surface water run-off. The use of SuDS to manage surface water will be required, unless it can be demonstrated that SuDs are not appropriate. In those instances an alternative approach to surface water management should be put in place such as a balanced system approach. The on-going maintenance and management of SuDS and other mitigation schemes will need to be demonstrated.

Water Quality and Supply

Having a Policy that:

  • Seeks to protect the Borough' water environment and where possible contribute to improvements to water quality.
  • To seek Building Regulations Optional Requirement for domestic uses and BREEAM 'good' standard for non-domestic uses.

Alternative Approaches to Flood Risk

With regard to flood risk and surface water management the Council considers that there is no reasonable alternative approach as the NPPF requires Local Plans to develop policies to manage flood risk from all sources.

With regard to water quality a proposed alternative approach is to not have a policy and rely on developers entering discussion with the Environment Agency at planning application stage.

With regard to managing supply a proposed alternative approach is to not have a policy and to use Building Regulations only.