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In recent years, the United Kingdom has witnessed a concerning increase in the frequency and severity of flooding events. From devastating storms to heavy rainfall, the impact of flooding extends beyond immediate property damage, causing disruptions to daily life, economic losses, and threats to public. Addressing this growing challenge has become a pressing priority and the government has taken significant steps towards improving flood risk management by recommending the implementation of mandatory Sustainable Drainage Systems (SuDS) for new developments.


DHA’s Drainage Expert Chris Smoker provides a brief overview of the historical background, recent developments, and considerations for developers seeking planning permission in light of these forthcoming regulations.

Historical Background


In response to the devastating floods in the summer of 2007, Sir Michael Pitt conducted a comprehensive review of flood risk management in England. This review led to the inclusion of recommendations in Schedule 3 of the Flood and Water Management Act, which received Royal Assent in April 2010. However, Schedule 3 was not enforced, as the government opted to promote the use of SuDS through planning policy starting from April 2015.

As a result, Lead Local Flood Authorities were established as Statutory Consultees, responsible for reviewing drainage strategies and surface water management provisions for major development projects. Currently, major development is defined as comprising 10 or more dwellings, commercial buildings with a floor space greater than 1000m², and development on sites measuring one hectare or more.


What is Schedule 3?


Schedule 3 of the Flood and Water Management Act 2010 provides a framework for the approval and adoption of drainage systems through a SuDS Approving Body (SAB). It establishes national standards for the design, construction, operation, and maintenance of Sustainable Drainage Systems (SuDS). Compliance with Schedule 3 is essential for obtaining approval to connect surface water runoff to public sewers and must be fulfilled before commencing any construction work. The SAB, situated within the unitary authority or County Council, plays a crucial role in reviewing and approving drainage strategies, ensuring proper implementation of SuDS, and maintaining high standards of design and construction.


Recent Developments


In October 2019, an independent review assessed the existing arrangements for determining responsibility for surface water and drainage assets. The review concluded that the planning-led approach alone was inadequate, recommending that non-statutory technical standards for SuDS should be made statutory. The ambiguity surrounding this issue had made it difficult for planning authorities to fulfill their roles effectively.

Building upon the findings of the independent review, the government conducted its own review, published in July 2021. This review strongly supported the mandatory implementation of SuDS and highlighted the absence of adequate checking regimes to ensure adherence to agreed-upon SuDS construction standards. It also underscored the challenges associated with maintaining these systems once the developers have completed their work.


The Importance of Schedule 3


The government's review emphasised the necessity of reconsidering the implementation of Schedule 3 from the Flood and Water Management Act 2010. This schedule provides a framework for approving and adopting drainage systems through a SuDS Approving Body (SAB). It also establishes national standards for the design, construction, operation, and maintenance of SuDS. Compliance with the schedule is a prerequisite for connecting surface water runoff to public sewers before commencing any construction work.


Role of the SuDS Approving Body (SAB)


The SAB will be located within the unitary authority or the County Council if there is no unitary authority present. Certain exemptions apply, such as permitted development under 100 square meters, single buildings under 100 square meters, and construction work carried out by an internal drainage board under the Land Drainage Act 1991. Nationally Significant Infrastructure Projects will also be exempted.


Considerations for Developers


Developers seeking planning permission must take several factors into account:

  1. SuDS will be mandatory for almost all new developments in England, except for specific exemptions.
  2. Detailed SuDS designs may need to be submitted during the pre-planning stage for approval by the SAB.
  3. The Lead Local Flood Authority (LLFA) will continue to act as a Statutory Consultee for major development projects and will eventually adopt the SuDS.
  4. Developers must submit an application to the SAB, separate from the Local Planning Authority approval process.
  5. A fee will be payable upon applying to the SAB, and there will be a right to appeal against refusals.
  6. SAB approval will entail additional conditions beyond those imposed by the planning consent.


Future Steps


A comprehensive analysis of the costs and benefits of implementing Schedule 3 to the Flood and Water Management Act 2010 is currently underway. This analysis will include a regulatory impact assessment that will be consulted upon after DEFRA's consultation. The document is expected to be released in 2024.


The forthcoming mandatory implementation of SuDS in 2024 marks a significant milestone in flood risk management and environmental protection in England. By incorporating sustainable drainage systems into new developments, the government aims to mitigate surface water flooding and reduce pollution. Developers must familiarize themselves with the requirements and consult with relevant authorities to ensure compliance with the new regulations.


DHA's infrastructure team is closely monitoring updates regarding the implementation of Schedule 3. If you have any questions or inquiries related to flood risk or drainage, please don't hesitate to contact Chris, or one of his team.

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