Planning Advice Note 79: water and drainage

PLANNING AND WATER INFRASTRUCTURE

8. The planning system plays a key role in identifying suitable development locations in the context of an overall settlement strategy set out in development plans. Development plans should be drawn up in accordance with the principles of sustainable development stated in SPP1, promoting development of the right quality in the right places. This includes promoting the full and appropriate use of land, buildings and infrastructure. The plan should therefore reflect and identify priorities for the provision of infrastructure.

9. In relation to the provision of housing land, SPP3 Planning for Housing states that key considerations should be: the efficient use of land and existing buildings, energy and infrastructure; co-ordination with improvements to infrastructure and other major proposals; good access to jobs and services; and protection and enhancement of the environment. Other SPPs make similar statements in relation to other land uses. The availability of existing water and drainage infrastructure is therefore a consideration in identifying land for development but it is not necessarily an overriding one in determining the suitability of a particular location.

10. Sites identified as appropriate for development can sometimes be constrained by a lack of water and waste water infrastructure or capacity, or deemed to be constrained by service deficiencies which require to be overcome before new development can be accommodated. Constraints can include:

• insufficient capacity in the strategic assets e.g. water treatment works or waste water treatment works;
• communities at risk of, or existing properties having experience of, sewer flooding;
• communities at risk of, or existing properties experiencing, poor pressure;
• watercourses at risk of detrimental impact from waste water discharges; and
• communities at risk of supply interruption below a minimum desired service level.

Whilst the optimum use of existing capacity is an important consideration, there is a need for the provision of expanded water supply and drainage networks to be responsive to demographic changes and new demands. Development planning has an important role to play in influencing and addressing these requirements.

11. If a proposed development is considered acceptable in a location where the current water or drainage infrastructure would be insufficient, stakeholders should work together to identify the best practicable option to accommodate the development. The provisions contained within various pieces of legislation are particularly relevant. For example the regulatory framework for Scottish Water includes mechanisms for funding the infrastructure requirements of new development (see annex B). This has a bearing on the viability and timing of the removal of constraints and is therefore a relevant planning consideration.

12. Where a development is proposed in an area already served by Scottish Water's network, connection to that network will be the preferred option. However, for
a variety of reasons developers may propose private schemes. There are advantages and disadvantages to this approach, which the planning authority must weigh up within the context of sustainability considerations and other policy objectives. Individual proposals should not impede the wider development of waste water infrastructure in the area. Specific advice on private schemes is contained at paragraphs 50-53.

13. The allocation of land in a development plan or the granting of planning permission does not negate other statutory procedures and consents relating to water and drainage. Neither does it imply that such consents will be forthcoming. SPP1 states that the planning system should not be used to secure objectives which are more properly achieved under other legislation. Therefore, in considering proposals for development it is not necessary for the planning authority to address every aspect of the provision of water and drainage infrastructure. However, where other legal or administrative measures exist for controlling a particular activity the issues which they address can still be a planning consideration to which weight is given. For example, whilst the planning authority may not be concerned with regulations relating to financing the provision of water infrastructure, they will need to be satisfied that proposals would not have an adverse impact on water quality or the environment. Further information on the planning interaction with environmental regulations is set out within PAN 51 Planning and Environmental Protection.

14. The interaction between sewers, local watercourses and water bodies (including groundwater), means that planning authorities must also consider arrangements for surface water drainage and whether the risk of flooding is an issue. SPP7 Planning and Flooding sets out national policy on this matter. ¹