Flood risk management basically interacts with spatial planning in two main ways:

1. Using the planning system to avoid locating unnecessary new development in areas of high flood risk.

2. Mitigating the surface water run-off impacts of new development on downstream areas through planning policies.

Specific policy relating to flood and water management in Northamptonshire is set out in our Local Flood Risk Management Strategy. This establishes the responsibilities of local authorities and the developers themselves with regards to flood risk and sets out the co-ordinated approach to the management of all local flood risks in Northamptonshire.

Local Plans

The National Planning Policy Framework (NPPF) explains how Local Plans should take account of flood risk. A local plan should set out the strategic priorities and policies for an area, including those to deliver the infrastructure for flood risk.

Local Planning Authorities can develop policies which contribute to the active management of flood risk and can include:

  • Allocating new development outside areas of high flood risk or securing of flood protection measures;
  • Protecting watercourse corridors and green networks;
  • Avoiding new culverting of watercourses;
  • Actively encouraging the de-culverting of watercourses;
  • Requiring  sustainable drainage systems (SuDS) in new developments;
  • Using Section 106 agreements from the Town and Country Planning Act  or community infrastructure levy (CIL) to secure suitable surface water drainage arrangements and;
  • Encouraging the use of in-built property level resistance and resilience measures.

Strategic Flood Risk Assessments

Section 10 of the NPPF and its supporting Technical Guidance, state that Local Plans should be supported by Strategic Flood Risk Assessments (SFRAs). Local Plan policies and allocations for new development should be considered in light of these assessments.

SFRAs consider the risk of flooding from all sources, taking into account climate change and are normally prepared in consultation with the Environment Agency, relevant Water and Sewerage Companies (WASCs) and other relevant flood risk management bodies including emergency planning and drainage teams. To find out what SFRAs have been carried out in Northamptonshire, please see Appendix 4 of the Northamptonshire Local Flood Risk Management Strategy.

Water Cycle Studies

Water cycle studies and Strategies (WCS) identify any tensions between new development proposals and infrastructure and environmental requirements in relation to water supply and drainage and identify appropriate solutions.

They are used to inform:

  • housing allocations and numbers;
  • phasing of development;
  • where developer inputs may be required for new infrastructure.

To find out what WCSs have been carried out in Northamptonshire, please see Appendix 4 of the Northamptonshire Local Flood Risk Management Strategy.

Surface Water Management Plans

Surface Water Management Plans (SWMPs) set out how local floods can be managed at a district level. Their purpose is to take into account the risks of all types of surface water flooding and ways to mitigate it. Each of the seven districts within Northamptonshire will have a SWMP and these are due for completion in the near future.

Development Management/Control

Local Planning Authorities (LPAs) must take the probability of flooding from all sources and the risks involved into account when determining planning applications.

For guidance on consulting Northamptonshire County Council as Lead Local Flood Authority in relation to surface water drainage, please refer to the LPA Consultation Guidance.

LPAs should:

  • Publicise the benefits of their pre-application service;
  • Screen all planning applications at the validation stage for flood risk from all sources – river, groundwater and surface water flood risk;
  • Ensure that all relevant information sources have been utilised by the applicants – has the Lead Local Flood Authority, the Environment Agency and all relevant Water and Sewerage Companies been contacted for site specific information?
  • Ensure that the sequential and exception tests have been applied correctly;
  • Ensure that an appropriate Flood Risk Assessment has been submitted, which demonstrates that the development will be safe for the lifetime of the development, has safe access and egress in times of flood, will not increase flood risk elsewhere and will deliver clear opportunities.

Northamptonshire County Council has published local guidance to support Local Planning Authorities in considering surface water drainage proposals in Northamptonshire, and to assist developers in the design of all surface water drainage systems. The guide sets out the standards that we apply in assessing all drainage proposals, as well as the information we require to be submitted as part of the planning application. This guidance is a ‘live’ document which will be continually updated and improved – the current version is: v1.3 August 2016 (Updated September 2017). For more information, please download the Local Standards and Guidance for Surface Water Drainage in Northamptonshire.

Northamptonshire County Council, supported by ESI Ltd, has undertaken a study to assess the risk of flooding from groundwater across the County. This data should be used to support LPAs determination of applications in areas which may be at risk of groundwater flooding. For guidance on how to apply this data, please refer to the Guidance For Planners on Groundwater Flood Risk in Northamptonshire or view the full study report in the Flood Library.

Neighbourhood Plans

Communities can also ensure that new development adequately plans for flood risk.  Neighbourhood planning provides a powerful set of tools for local people to ensure that they get the right types of development for their community.

Your development will require consultation with the Environment Agency; they maintain the consistency and compliance of a flood risk strategy at the planning stage of developments.