Updates to the Royal Borough of Windsor and Maidenhead Local Plan

The Royal Borough of Windsor and Maidenhead (RBWM) are expected to adopted a new Local Plan in the next few weeks. The Borough Local Plan (BLP) was recommended for adoption by an independent planning inspector on 26th January 2022, and Aegaea understand that Full Council will be recommended to formally adopt the plan at an extraordinary meeting on 8th February 2022. Aegaea have reviewed the BLP to understand the impact of this Local Plan update on flood risk policies within RBWM. The key change is that Adopted Policy F1 has been superseded by Emerging Policy NR1.

What was RBWM Policy F1?

In 2004, the Royal Borough of Windsor and Maidenhead (RBWM) adopted Supplementary Planning Guidance (SPG) titled Policy F1 (Areas Liable to Flooding). The SPG document provided guidance for assessing development within areas at risk of flooding, specific to the RBWM area. Policy F1 was applicable to all development within areas liable to flood as defined in the SPG. When the SPG was first published in 2004, the ‘areas liable to flood’ were derived from the EA ‘2001 Indicative Floodplain Maps’ which have evolved and been superseded over time. These maps showed an estimated extent for a 1%AEP (1 in 100 year) event. However it should be noted that the application of Policy F1 evolved and was based on the most up to date flood modelling and thus the areas liable to flood may have changed since the adoption of Policy F1 in 2004.

What did Policy F1 state and how would it affect my development?

Policy F1 states that:

“new residential development or non-residential development, including extensions in excess of 30m2 will not be permitted unless it can be demonstrated to the satisfaction of the Borough Council that the proposal would not of itself, or cumulatively in conjunction with other development:

1) impede the flow of flood water; or

2) reduce the capacity of the floodplain to store flood water; or

3) increase the number of people or properties at risk from flooding”.

While the policy notes that extensions or increases in footprint of greater than 30sq. metres would not be accepted unless the above criteria can be met, it is important to note that the 30sq. metres is taken to include additions to properties since September 1978. Therefore, for example, if a property was already extended by 25sq. metres in 2008, any new extension proposed that exceeded 5sq. metres would trigger the policy requirements of Policy F1.

The application of Policy F1 on a development restricted what is possible on site from a flood risk perspective.

What is Policy NR1 and how does this differ from Policy F1?

Aegaea have been informed that on the 26th January 2022, an independent Planning Inspector found that the RBWM Borough Local Plan (BLP), incorporating the Main Modifications, was sound and that it be brought forward for adoption. As such, RBWM have advised that the BLP incorporating the Main Modifications is therefore a material consideration for decision-making to which very substantial weight should be given. RBWM have advised that the 30sq. metres rule as part of Policy F1 is no longer being considered for applications in Flood Zones 2 and 3.

However, Policy NR1 of the Borough Local Plan does still require all applications in Flood Zones 2 and 3 to be supported by a Flood Risk Assessment. This now applies to all current and future applications. Emerging Policy NR1 states that:

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

a. impede the flow of flood water

b. reduce the capacity of the floodplain to store water

c. increase the number of people, property or infrastructure at risk of flooding

d. cause new or exacerbate existing flooding problems, either on the proposal site or elsewhere…

Therefore, a Flood Risk Assessment will still be required for developments in Flood Zones 2 and 3, but the 30sq. metres constraint will no longer apply. The RBWM website states that Full Council will be recommended to formally adopt the plan at an extraordinary meeting on 8th February.

The team have extensive project experience in RBWM and have reviewed the Emerging Policy NR1 requirements in detail. We would be happy to discuss how we can support your proposals. Please get in touch with Nick Darling-Drewett via the details below to discuss your site and ways forward.

e: nick@aegaea.com t: +44 (0) 20 8164 0550