Ealing Council Planning Guidance

London Borough of Ealing Council planning policy for sustainable drainage reports, flood risk assessments and contaminated land risk assessment are driven by environmental conditions and the local authority policy.

Guidance for architects, and developers on flood risk, drainage and phase 1 contaminated land reports is summarised below with links to the key summary documents.

• Contaminated Land Guide to help developers meet planning requirements
• Local Flood Risk Management Strategy
• West London SFRA Level 1 – relevant docs
• Approach to SuDS Assessments

Ealing Council Contaminated Land

The Council holds some information on contamination in the Borough, mainly submitted during applications for planning permission.  If a proposed development concerns land where any past use may have caused contamination, the Council will normally require a site investigation as a condition of any approval.  Agreed remedial works will then have to be properly carried out before the development proceeds.

The developer and their environmental consultant, such as GeoSmart, will need to assess the potential risks from contamination on the basis of the proposed use and local circumstances.  This should normally be done before the formal planning permission is given for the development.  However, in some cases, permission can be granted subject to a condition, which will require developers to investigate whether there is any land contamination and, if necessary, devise a strategy to deal with it.

Where a developer is proposing to develop land that is suspected of being contaminated, it is advisable to contact the Contaminated Land Officer before submitting the planning application.  It is useful to do this as the Council may have additional information that you are unaware of, and may also be able to answer any particular questions that you have.

Procedure for dealing with land potentially affected by contamination:

• Step 1 – the desktop study. This should establish former uses of the site and adjacent buildings, include a site walkover survey, identify contaminants of concern, develop a site-specific conceptual model and compile conclusions and recommendations.
• Step 2 – detailed site investigation (when necessary). This should include the design of a sampling strategy and samples being taken (based on the conceptual model.) A quantitative risk assessment should be undertaken, comparing results of sampling with appropriate standard and should identify unacceptable risks. If necessary, it should identify appropriate remediation options available.
• Step 3 – remediation strategy (when necessary). Preferred remedial options should be selected and submitted for approval. Remedial works should be designed and implemented.
• Step 4 – validation report (where necessary). Following completion of works, developers should compile a validation report to demonstrate works have been carried out according to remediation strategy, and detail any changes that occurred.

Site Walkover Reconnaissance

Ealing Council request a site walkover is undertaken as part of the desktop study.

Ealing Council Flood Risk Assessment

The borough of Ealing is a heavily urbanised borough meaning that it has a high proportion of impermeable surfaces and reduced areas to store water. Impermeable surfaces do not allow water through and water which falls on these surfaces typically runs off quickly to local low points or into the drainage system. Because the surface water runs off so quickly, water can potentially overwhelm the local drainage network in these low points and result in flooding.

The biggest risk of river flooding in the borough comes from the River Brent. The other main river sections within the borough are the Osterley Park Boundary Stream and the Yeading Brook. Smaller watercourses are also at risk of flooding and causing disruption or damage to property or infrastructure. ‘Ordinary watercourses’ in the borough include the Costons Brook, Dormers Wells Stream, and Northolt Brook, in addition to additional smaller ditches across the borough. The Grand Union Canal is the only canal which flows through the borough of Ealing and, although split into two branches, is the longest stretch of the canal flowing through one borough.

The borough of Ealing has several areas where groundwater has the potential to cause flooding.

Ealing Council Sustainable Drainage SuDs

Following the enactment of the Flood and Water Management Act in 2010 and the Written Ministerial Statement published on the 18th December 2014, Lead Local Flood Authorities (LLFAs) will be a Statutory Consultees on major1 planning applications as of the 15th April 2015.  The designated LLFA is the Council. In brief, the LLFA will assess the proposed drainage designs for a development and provide comment to the Local Planning Authority.

The following is a list of the documents and information which the LLFA expect the applicant to submit as part of their planning application to the LPA. This information is what the LLFA will be using to assess the application against the above policies and standards in line with its Statutory Consultee duty.

• A completed Drainage Assessment Form – this is the document which will state the site’s characteristics, the calculated surface water runoff rates and required storage volumes, where the runoff is to be discharged to, the SuDS features proposed and the proposed methods of how the drainage system is going to be managed and maintained
• Detailed drainage design plans

GeoSmart can assist you with the above.

Please see Ealing’s Approach to SuDS Assessments document below for a flow chart of the steps and timescales relevant when dealing with major planning applications.

Ealing Council Groundwater Flood Risk

The borough of Ealing has several areas where groundwater has the potential to cause flooding, as identified in the increased Potential for Elevated Groundwater maps produced in the Council’s Preliminary Flood Risk Assessment, however groundwater flooding is difficult to assess due to unpredictability relating to where or when it may occur. Detailed work would need to be carried out locally to clarify the level of risk however the local geology can provide an initial indication as to whether an area may be more susceptible to groundwater flooding.