Policy information sourced from Windsor and Maidenhead Local Plan

NR 1 Managing Flood Risk and Waterways

Flood zones are defined in the National Planning Practice Guidance and the Council’s Strategic Flood Risk Assessment (Level 1). Within designated Flood Zones 2 and 3 (and also in Flood Zone 1onsitesof1hectareor moreinsizeandinother circumstancesas setout inthe NPPF)development proposals will only be supported where an appropriate flood risk assessment has been carried out and it has been demonstrated that development is located and designed to ensure that flood risk from all sources of flooding is acceptable in planning terms.

The sequential test is required for all development in areas at risk of flooding, except for proposed developments on sites allocated in this Plan or in a made Neighbourhood Plan which accord with the provisions of those Plans so far as material to the application. In applying this test, development proposals should show how they have had regard to:

  • the availability of suitable alternative sites in areas of lower flood risk
  • the vulnerability of the proposed use and the Flood Zone designation
  • the present and future flood risk
  • the scale of potential consequences
  • site evacuation plan in the event of potential flooding.

Only water compatible uses and essential infrastructure development will be supported in the area defined as functional floodplain. The exception test will still apply.

The sequential approach should be followed by developers for all development so that the most vulnerable development is located in the lowest risk flood areas within a site, taking account of all sources of flood risk.

Development proposals should include an assessment of the impact of climate change using appropriate climate change allowances over the lifetime of the development so that future flood risk is taken into account.

In all cases, development should not itself, or cumulatively with other development, materially:

  • impede the flow of flood water
  • reduce the capacity of the floodplain to store water
  • increase the number of people, property or infrastructure at risk of flooding
  • cause new or exacerbate existing flooding problems, either on the proposal site or elsewhere.
  • reduce the waterway’s viability as an ecological network or habitat for notable species of flora or fauna.

Development proposals should:

  • increase the storage capacity of the floodplain where possible
  • incorporate Sustainable Drainage Systems in order to restrict or reduce surface water runoff
  • reduce flood risk both within and beyond sites wherever practical
  • be constructed with adequate flood resilience and resistance measures suitable for the lifetime of the development
  • where appropriate, demonstrate safe access and egress and incorporate flood evacuation plans

The exception test will need to be applied in accordance with national policy and guidance in the NPPF and PPG, including on sites allocated in the development plan. This should demonstrate how flood risk would be managed on the site, including that the sustainability benefits of the site outweigh the flood risk and that the development will be safe for its lifetime, taking into account the vulnerability of its users and that it will not increase flood risk elsewhere. Where possible, development will reduce flood risk overall.

Development proposals will be required to incorporate appropriate comprehensive flood risk management measures as agreed with the Environment Agency or the Council as Local Lead Flood Authority

Developmentproposalsnear rivers (includingculvertedrivers) shouldretainorprovideanundeveloped 8 metre buffer zone alongside main rivers and, where practicable and appropriate, ordinary watercourses. This buffer zone should be on both sides of the watercourse and be measured from the top of the river bank at the point at which the bank meets the level of the surrounding land.

Further development land associated with strategic flood relief measures will be safeguarded, includingtheproposed River Thames Schemeandthefloodrelief channel from Datchet to Wraysbury. Development should facilitate the improvement and integration of waterways in Maidenhead, including the completion of the Maidenhead Waterway Project.

For more information please see the Local Plan