Jean-Yves Gilg

Editor, Solicitors Journal

Understand new drainage guidance to protect your clients

Understand new drainage guidance to protect your clients


Sustainable drainage solutions are a clear priority in guidance from planning authorities

Commercial lawyers gathered in the newly refurbished Salters' Hall in Central London on 9 June to find out about sustainable drainage systems (SuDS), their priority within the latest drainage guidance, and the implications for their clients' redevelopment sites.

Chaired by Stuart Pearce, the managing director of GeoSmart, the seminar was opened by Dr Paul Ellis, the innovation director, who outlined the mechanics of SuDS and how they mitigate local surface flooding.

Climate change is driving ever more frequent deluges, which conventional sewers cannot contain. New development simply amplifies flashy discharge of surface flooding into sewers, causing problems elsewhere. The solution now being embraced by many local authority planning teams ensures that, where conditions allow, surface water is discharged naturally into the ground, as if development wasn't there. This is now forming part of planning conditions ahead of development decisions underpinned by changing guidance and building regulations standards.

In his keynote address, John Bates, a barrister at Old Square Chambers, explored the new guidance, which he co-authored, and the case law that has paved the way for its release. The key points of his speech were as follows:

• Guidance from planning authorities now follows a clear drainage hierarchy, prioritising SuDS;

• Commercial lawyers need to understand site suitability to answer planning submission obligations;

• Developers in a flood risk area must not make situation worse elsewhere. SuDS mitigate their effects and their inclusion in a scheme is viewed positively by planners; and

• Surveyors and architects should note this but lawyers still have duty of care to advise their clients to meet operational compliance.

Solutions to support your duty of care

The first stage in identifying whether SuDS may play a role in a development application is through assessing the site suitability to include sustainable drainage.

Until now, this has been difficult to identify in a simple fashion. At the seminar, Chris Taylor, the product development director at GeoSmart, launched SuDSmart, the new drainage due diligence report for commercial property lawyers.

Meeting the new guidance on site suitability, SuDSmart identifies other potential risks and constraints and removes potential roadblocks at the planning stage. The easy-to-read report reveals the following key information:

• What the infiltration potential for surface drainage is on site;

• Whether there is a groundwater flood risk to the site;

• Whether there is a risk to the underlying aquifer; and

• Whether there is the potential to discharge to a surface water body or a sewer.

The simple traffic light system shows site suitability results, together with aerial photography, mapping, and expert analysis of soil geology and features adjacent to the site.

SuDSmart provides a comprehensive and bespoke report which meets the requirements of planning authorities in answering site condition questions for pre-planning or full planning submissions.

Growing influence of SuDS on development sites

Stephen Sykes, the chairman of the UK Environmental Law Association (UKELA), wrapped up the session with a call to read and understand the guidance note and educate colleagues so that SuDS site suitability becomes standard part of site due diligence.

A lively Q&A session followed, with questions from partners from some of the largest commercial law firms in the country. Among the main concerns for clients were the whole life cost of a SuDS, the maintenance obligations, and how these would need to be mapped out as part of due diligence.

There was some debate around a comparison to the contaminated land regime under part 2A of the Environmental Protection Act 1990. While it was important not to conflate the two together, it was clear that SuDS suitability and increased legislative pressure and policy in favour of SuDS across planning authorities would make this a more pressing issue in future months and years. SJ

GeoSmart Information supports property professionals, developers, house builders, insurance providers, lawyers, local authorities, and infrastructure owners in managing the impact of future risks to the environment, specifically climate change, on existing land and water

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