Submitting a surface water drainage strategy: guidance

A surface water drainage strategy shows how surface water will be managed within a development so it does not increase flood risk elsewhere.

You’ll need to include this with your planning application for any:

• minor developments (fewer than 10 dwellings) within an area liable to flood from surface water or groundwater or that are likely to increase flood risk locally
• major developments (over 10 dwellings)
• developments that need sustainable drainage solutions to be provided

They are not required for householder development.

View our guidance for submitting a surface water drainage strategy.

We offer pre-application advice on surface drainage water matters relating to your planning application.

We offer advice on:

• minor developments - 3 to 9 dwellings or 250m2 to 499m2 commercial floor space
• small major developments - 10 to 24 dwellings or 550m2 to 999m2 commercial floor space
• medium major developments - 25 to 199 dwellings or 1000m2 to 4999m2 commercial floor space
• larger major developments - more than 200 dwellings or more than 5000m2 commercial floor space

You can request:

• written advice
• a 1 hour virtual meeting with written advice
• a site visit with written advice

For the application form you will need to make sure you have:

• the location of the site (including National Grid Reference)
• a brief description of the proposed development
• a site plan
• site details including total site area, existing impermeable area and proposed impermeable area
• type of application you intend to submit (outline, reserved matters, full discharge of conditions)
• drainage layout
• information on the method of surface water disposal (for example ground investigations)

We recommend that you also include the following information if available:

• existing drainage plans including overland flow paths
• a topographical survey (meters above ordnance datum mAOD)
• details of site constraints
• surface water drainage strategy
• flood risk assessment (if applicable)
• any further information you think we should be aware of

Request pre-application advice for surface drainage water matters.

We aim to acknowledge pre-application advice requests within 5 working days. View our terms and conditions to view timescales for the services listed above.

You’ll need to submit a surface water drainage strategy with your planning application, via the planning portal.

The Local Planning Authority will consult the sustainable drainage team for their advice.

They are required to return their decision on the strategy within 21 days to the planning team.

This advice is based on:

If the strategy meets the necessary policies and guidance, we’ll recommend that the development is approved on surface water drainage grounds.

There may be planning conditions associated with these approvals. This is to make sure that the detailed design of the surface water drainage scheme meets the appropriate standards.

If the strategy does not meet the necessary policies and guidance, we’ll recommend the development be refused on surface water grounds.

Under guidance from the planning team, we’ll work with applicants to resolve these concerns where possible.

In determining an application, the planning team must be satisfied that surface water drainage strategy has:

• appropriate proposed minimum operation standards
• maintenance arrangements in place to ensure an acceptable standard of operation for the lifetime of the development
• provision for multifunctional benefits (where possible)

As the LLFA, we’ll comment only on surface water drainage matters.

Other sources of flood risk are the responsibility of other statutory consultees. For example, the Environment Agency will advise the LPA on planning applications on fluvial flood risk grounds for sites within Flood Zone 2 and 3.

To understand the statutory consultees for other sources of flood risk, review Schedule 5 of the Town and Country Planning (Development Management Procedure) (England) Order 2010).

Other risk management authorities may comment on a planning application if it falls within their administrative boundaries, but they are not statutory consultees. This may include water companies and the Internal Drainage Board.

If you have any questions, email [email protected].

We have a focus on incorporating sustainable drainage (SuDS) into new developments. This is in line with Paragraph 169 of the National Planning Policy Framework (2021) and local policy.