Understanding Schedule 3 of the Flood and Water Management Act 2010

Last updated 07/03/23


Rising urbanisation, a growing population and intensified weather patterns driven by the climate crisis continue to overwhelm the UK’s traditional drainage systems. 

Without a more effective water management approach, instances of surface water and sewer flooding will increase in both frequency and severity, alongside hazardous discharges from storm overflows. 

In January 2023, the Department for Environment, Food and Rural Affairs (DEFRA) and Environment Minister, Rebecca Pow, announced the government’s decision to implement Schedule 3 of the Flood and Water Management Act 2010 in England to better control flooding and wastewater discharges. 

The schedule, which was excluded from the Act’s ratification 13 years ago, is expected to be implemented in 2024 and will provide a framework for the approval and adoption of sustainable drainage systems to regulate rainfall, decrease the volume of water flowing into sewers and storm overflow discharges. 

The implementation of Schedule 3 in England will follow that of Wales who commenced the schedule into law in January 2019. 

What are sustainable drainage systems? 

The core purpose of Schedule 3 is to make the incorporation of sustainable drainage systems (SuDS) into new developments mandatory.

According to the schedule, a sustainable drainage system is a structure, or part of a structure, which has been designed or exists to receive rainwater. The definition excludes public sewers and water courses such as a stream or river. 

From linear wetlands, swales and retention ponds to detention basins and vegetative filtration, SuDS come in various forms and can control water runoff in several ways. 

As a natural drainage solution, SuDS boast a wealth of benefits for local communities and the environment alike and, if the schedule is implemented, should aim to achieve the following: 

  • Reduce damage from flooding
  • Improve water quality
  • Protect and improve the environment 
  • Protect health and safety 
  • Ensure the stability and durability of drainage systems

How will Schedule 3 impact the planning process? 

The implementation of Schedule 3 of the Flood and Water Management Act will impact the planning process in several ways. 

One of the most notable proposals is for the introduction of SuDS approval bodies (SAB) whose duty it will be to adopt new drainage systems on the basis that they meet certain conditions. 

These bodies will be the unitary body for the area where the development is proposed to be built or, in the case that a location does not have a local authority, the SAB will be the county council or an authority designated by the Secretary of State for Environment, Food and Rural Affairs. 

To hit the criteria, developers and other property professionals must ensure they do the following: 

  • Build the drainage system in line with an approved drainage plan that complies with national standards 
  • Certify that the drainage system functions in line with the approved plan or non-performance bond if a certificate has been issued
  • Ensure the system is a sustainable drainage system as defined by the Secretary’s regulations 

There are exclusions to this duty though; sections 18 and 19 of Schedule 3 state that the SAB’s adoption duty does not apply to a drainage system which has been designed for a single property or publicly-maintained roads. 

Developers and other professionals involved in developments must ensure drainage approval is sought from a SuDS approval body before construction begins. 

Another change Schedule 3 will bring is to only allow construction work with drainage implications to go ahead if a drainage system for the development has been approved by the SAB. 

Part b of section 7, sub-paragraph 1 in the schedule declares construction work with drainage implications to be a structure or building which will impact the land’s ability to absorb rainwater. 

Furthermore, a development can only be approved by an authority if the drainage system complies with national standards for sustainable drainage, as outlined in the National Planning Policy Framework (NPPF) and the planning practice guidance (PPG). 

In addition to this, the SAB may only approve a development if they have consulted with relevant organisations or authorities. These are outlined in Schedule 3 as follows: 

  • A relevant sewerage undertaker
  • The Environment Agency or Natural Resources Body for Wales
  • The Canal and River Trust 
  • An internal drainage board 
  • A relevant highway authority

According to Schedule 3, SuDS approval bodies must consult these groups if the proposed development’s drainage system will be connected to a public sewer, will directly or indirectly discharge water into a watercourse, waterway, or ordinary watercourse in an internal drainage board’s district or if it will affect a road. 

Once these authorities have been consulted and after an application has been approved, the SAB must notify the applicant, the planning authority and any official body consulted. 

How will Schedule 3 impact existing laws?

The implementation of Schedule 3 will introduce some small changes to three existing laws. 

The first of these is section 106 of the Water Industry Act 1991 which states that the owner or occupier of any premises or private sewer is entitled to have their drains communicate with any public sewer and can subsequently discharge foul water and surface water into said sewer. 

Following Schedule 3’s commencement, a person may only exercise this right if their drainage system was approved by an SAB before construction and if a proposal for their drainage system to communicate with a sewer was included in their application for approval. 

Schedule 3 is also linked to the Building Act 1984 – section 59 of the latter gives local authorities the power to request that sustainable drainage systems in an unsatisfactory condition be renewed, repaired or cleansed. 

Section 84 of the Building Act additionally stipulates that local authorities withhold the right to request that impermeable surfaces around a building which don’t allow for the satisfactory drainage of its surface or subsoil be remedied. 

Following the implementation of Schedule 3, this section will specify that surfaces need to remove water in a manner deemed satisfactory to the local authority. 

Section 63 of the New Roads and Street Works Act 1991 will equally include a small change should Schedule 3 be enacted. 

Alongside the Secretary of State’s designation of criteria for a street to be regarded as having special engineering difficulties, Schedule 3 will also require designation under certain circumstances. 

What are the national standards for sustainable drainage systems? 

National standards for sustainable drainage systems in England are outlined in the National Planning Policy Framework and the planning practice guidance

Here is a breakdown of what is stated in each of these guidelines: 


According to paragraph 167 of the NPPF, when determining any planning applications, local planning authorities should ensure that flood risk is not increased elsewhere. Development should only be allowed in areas at risk of flooding where it can be demonstrated that it incorporates sustainable drainage systems, unless there is clear evidence that this would be inappropriate.

Paragraph 169 goes on to outline that major developments in particular should incorporate SuDS and that such systems should do the following:

a) take account of advice from the lead local flood authority; 

b) have appropriate proposed minimum operational standards; 

c) have maintenance arrangements in place to ensure an acceptable standard of operation for the lifetime of the development; 

d) where possible, provide multifunctional benefits.

Planning practice guidance 

Reflecting the NPPF, the PPG outlines the importance of including sustainable drainage systems and goes as far as determining a hierarchy for SuDS. 

SuDS that allow immediate infiltration into the ground were ranked as most desirable, followed by SuDS which transfer runoff to a surface water body, SuDS which transfer runoff to a surface water sewer, highway drain, or another drainage system and finally, SuDS that transfer runoff to a combined sewer. 

The guidance also states that to meet the criteria of the NPPF, applicants must submit a “sustainable drainage strategy containing proportionate information on the proposed sustainable drainage systems as part of their planning application.” 

Moreover, using a strategic flood risk assessment is further recommended in the PPG to identify how natural flood management techniques like SuDS can help to reduce the impacts of flooding. 

How can GeoSmart help you to meet the requirement of Schedule 3?

GeoSmart is a leading provider of sustainable drainage assessments and detailed drainage designs

If you are in the process of putting forward an application for a new development, ensuring you have effectively incorporated sustainable drainage systems will give you the best chance of satisfying your local authority or SAB. 

To request one of our products or find out more about them from our experts, contact us today