Policy CC/IW: Integrated water management, sustainable drainage and water quality

1. All development proposals must adopt an integrated approach to water management which considers water efficiency, sustainable drainage, water quality, flood risk and biodiversity. Water management must be: 

  a. planned at a strategic level for the whole development; 

  b. incorporated into the design process at the earliest opportunity; 

  c. designed in such a way that does not prejudice the delivery of development at an adjoining site; and 

  d. designed in such a way that makes use of nature-based solutions wherever practicable. 

2. Evidence of a site-wide

Collaborative approaches to land use and water management that integrate social, environmental, and economic factors to deliver the coordinated management of water storage, water supply, water demand, wastewater, flood risk, water quality, and the role of water in the natural environment.

approach should be provided as part of a Sustainability Statement. 

Sustainable Drainage Systems 

3.

This refers to development in its widest sense, including buildings, and streets, spaces and places. It also refers to both redevelopment, including refurbishment, as well as new development.

proposals must demonstrate how adequate surface-water drainage will be achieved, following the surface water drainage priority order set out below: 

  a. Firstly, surface water runoff is collected for non-potable use; 

  b. Then discharged into the ground via infiltration; 

  c. Then discharged into a waterbody; 

  d. Then discharged into a surface water sewer; 

  e. Then discharged into a combined sewer. 

4. New development must incorporate Sustainable Drainage Systems (SuDS) as part of an

Collaborative approaches to land use and water management that integrate social, environmental, and economic factors to deliver the coordinated management of water storage, water supply, water demand, wastewater, flood risk, water quality, and the role of water in the natural environment.

approach to the design of the whole site.

This refers to development in its widest sense, including buildings, and streets, spaces and places. It also refers to both redevelopment, including refurbishment, as well as new development.

will be permitted provided that: 

  a. surface water is managed close to its source and on the surface where reasonably practicable to do so; 

  b. there is no discharge from the developed site for rainfall depths up to 5mm of any rainfall event; 

  c. SuDS have been designed to take into account climate change and the impact it may have over the lifetime of the development; 

  d. opportunities have been taken to integrate SuDS in ways that create amenity, enhance biodiversity, and contribute to a network of high-quality green and blue open space, whilst also ensuring the development responds positively to the local character and site-specific constraints; 

  e. all hard surfaces are permeable surfaces where reasonably practicable and having regard to groundwater protection; 

  f. any flat roof is a green or brown roof, provided that it is acceptable in terms of its context, its relationship with the historic environment, and the structural capacity of the roof if it is a refurbishment; 

  g. SuDS have been designed to manage water quality to minimise the risk of pollution and sediment entering watercourses; and 

  h. details of the future management, maintenance and adoption of the SuDS are provided to ensure they will function effectively over the lifetime of the development. 

5. The design and implementation of SuDS must be in line with the updated Construction Industry Research and Information Association (CIRIA) SuDS Manual and the National Standards for SuDS or successor documents and other best practice guidance. 

Water quality 

6. To protect and enhance water quality, all development proposals must demonstrate that: 

  a. there is capacity for wastewater treatment and adequate wastewater conveyancing infrastructure to serve the whole development, or an agreement is in place with the relevant service provider to ensure the provision of the necessary infrastructure prior to the occupation of the development (where development is being phased, this must be demonstrated for each phase before first occupation); 

  b. appropriate water treatment and pollution control measures have been incorporated into the proposed foul and surface-water drainage systems to minimise the risk of water pollution; and 

  c. the quality of ground water and water bodies will not be harmed by the construction or operation of the development, and that opportunities have been explored and taken to maintain or improve water quality, including through nature- based solutions. 

7. Foul drainage to a public sewer should be provided where possible. Where it is demonstrated that this would not be feasible, alternative facilities may be allowed provided they do not pose an unacceptable risk to water quality or quantity for the lifetime of the development. 

Collaborative approaches to land use and water management that integrate social, environmental, and economic factors to deliver the coordinated management of water storage, water supply, water demand, wastewater, flood risk, water quality, and the role of water in the natural environment.

(IWM) is a holistic approach to water management that considers water supply, wastewater, flood risk and water quality in a coordinated way with the aim of ensuring the long-term sustainability of water resources and ecosystems and helping to provide multiple benefits. The concepts of ‘water smart communities’ and ‘sponge cities’ have similar aims. A sponge city is designed to mimic natural processes by absorbing, storing and gradually releasing rainwater, much like a sponge soaks up water. Green infrastructure is used to manage rainwater runoff to prevent flooding and improve water quality. 

Figure 130 shows the interlinked components of an effective IWM system. Weather pattern changes and the increasing occurrences and intensity of flooding and drought events, all of which are being influenced by global climate change, are making effective IWM increasingly important for both urban and rural environments. Therefore, it is crucial that IWM is considered at an early stage in the design process of any development. Appropriate water management measures for a particular development will depend upon the scale and nature of the development, but even at a small scale, measures such as permeable paving, green roofs and water butts can slow down the discharge of water, enable the reuse of water, and enhance biodiversity. 

The surface water drainage priority set out in the policy begins with the collection of rainwater for non-potable use, which is in line with the requirements of this plan to make developments as water efficient as possible. However, the surface water drainage network must be designed without taking this into account as a form of attenuation, because at times rainwater storage could be at capacity, for example during the winter months. Infiltration should be maximised on site by way of sustainable drainage systems (see below) before moving further down the priority order where this is not possible. 

Sustainable drainage systems (SuDS) are a key component of IWM. SuDS re-create the benefits of natural drainage systems, allowing infiltration and storage of water and reduce the rate and volume of water entering fluvial systems following storms therefore reducing peak flood levels. They also provide other benefits such as water filtration, which can improve water quality. Infiltration SuDS help to recharge aquifers which support the baseflows of the chalk streams and reduce the flow peak and volumes entering the Fens, which is increasingly important due to climate change. They also provide biodiversity and amenity enhancements, which can have positive implications for both human and environmental health. Ensuring that there is space for SuDS and the creation of blue and green infrastructure needs to be considered early in the design process for new developments. Details of the management, maintenance and adoption of SuDS will be required to ensure that they function effectively over the lifetime of the development. This will include removal of debris and sediment to ensure that there are no areas of standing water which will lower the risk of vector borne diseases associated with climate change. 

Guidance on the design of SuDs and surface water management can be found in the SuDS Manual, National Standards for Sustainable Drainage Systems, Cambridgeshire County Council’s Surface Water Planning Guidance and the Cambridgeshire Flood and Water SPD. These documents (or their successor documents) should be referred to when designing an appropriate drainage strategy for a new development. For major development on land with surface water drainage issues, Cambridgeshire County Council, the Lead Local Flood Authority, must be consulted.

To further protect and enhance water quality, the policy also requires that development proposals demonstrate that there is adequate wastewater infrastructure to serve the development over its lifetime. Applicants will need to secure a connection with the service provider, Anglian Water. Appropriate water treatment and pollution control measures will need to form part of the surface drainage system / SuDS to prevent contamination of water on the site or downstream during the construction and operation of the development. 

• The combined areas of Cambridge District and South Cambridgeshire District Councils.

  A plan for the future development of a local area, drawn up by the local planning authority in consultation with the community. In law this is described as the development plan documents adopted under the Planning and Compulsory Purchase Act 2004. A local plan can consist of either strategic or non-strategic policies, or a combination of the two.

  : Climate Change Topic Paper (2025)

• The combined areas of Cambridge District and South Cambridgeshire District Councils.

  Collaborative approaches to land use and water management that integrate social, environmental, and economic factors to deliver the coordinated management of water storage, water supply, water demand, wastewater, flood risk, water quality, and the role of water in the natural environment.

  Study (2025)

We will consider all comments while developing the next version of the

A plan for the future development of a local area, drawn up by the local planning authority in consultation with the community. In law this is described as the development plan documents adopted under the Planning and Compulsory Purchase Act 2004. A local plan can consist of either strategic or non-strategic policies, or a combination of the two.

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All comments must be received by 30 January 2026 at 5pm.