Water Environment and Flood Risk - Planning Guidance

Introduction

This Planning Guidance is intended to support implementation of the East Dunbartonshire Local Development Plan (LDP). The relationship between the LDP, Supplementary Guidance and Planning Guidance is established in Scottish Government Circular 6/2013 and summarised in the table below.

Document

Purpose and scope

LDP

Sets out the Council’s policies for the development and use of land, including community strategies, which identify opportunities for development, for the period up to 10 years from adoption.

This guidance supports LDP 2017 and LDP2. This guidance refers to

policies in LDP2 as the Council’s up-to-date policy position.

Supplementary Guidance

Supplementary Guidance is statutory as it forms part of the development plan, and has that status for decision-making. It is limited to the provision of further information or detail in respect of policies or proposals set out in the LDP. Supplementary Guidance will be adopted with the LDP and

lasts for the period of the plan.

Planning Guidance

Non-statutory planning guidance may be used to provide detail on a range of subject areas. This form of guidance should not be termed Supplementary Guidance and will not form part of the development plan. However, adoption of this guidance by the Council gives it formal status, meaning that it may be a material consideration in decision-making. Planning guidance can be updated as required and without the need for scrutiny by Scottish Ministers. Such updates are normally required where

a specific issue arises during the period of the plan.

Aims and Objectives

The aim of this document is to provide guidance on managing and enhancing the water environment through the appropriate siting, layout and design of development in East Dunbartonshire. It also explains how the Council will address flooding and development impact through the planning process. The guidance is intended for use by developers, landowners, planning practitioners and others involved in the development process. Key aims are as follows:

  • To assist applicants in addressing LDP2 Policy 18: Water Environment and Flood Risk within a development proposal, by providing technical guidance.
  • To provide guidance and best practice on flood risk to promote flood risk avoidance, mitigation or adaptation through development.
  • To provide information and guidance on the water environment in East Dunbartonshire, so that development can improve water quality and provide multi-functional benefits for the local water environment and green network, on or related to the site.
  • To establish a clear requirement for above ground Sustainable Drainage Systems (SuDS).
  • To clarify what supporting information is required for different scales of development.

Detailed guidance can be found below and this will be used to inform the development management decision-making process.

Jump to section:

What are the responsibilities of the planning authority in relation to the water environment?

Statutory Responsibilities

Under the Flood Risk Management (Scotland) Act 2009, the Council has a legal responsibility to manage flooding in a sustainable manner and to ensure the adoption of consistent principles and practices. The act takes a risk-based, sustainable and collaborative approach to flood risk management in Scotland. To help fulfil these responsibilities, the Council works with other local authorities in the city region to deliver the Clyde and Loch Lomond Flood Risk Management Plan [opens in a new window], which sets out how flood risk will be managed, co-ordinated, funded and delivered.

The Clydeplan Strategic Development Plan (2017) [opens in a new window] identifies these responsibilities in Policy 16: Improving the Water Quality Environment and Managing Flood Risk and Drainage, stating that Local Development Plans and development proposals should protect and enhance the water environment by:

  • Adopting a precautionary approach to the reduction of flood risk
  • Supporting the delivery of the Metropolitan Glasgow Strategic Drainage Plan
  • Supporting the delivery of the Glasgow and the Clyde Valley Green Network
  • Safeguarding the storage capacity of the functional floodplain and higher lying areas for attenuation.

In addition, the Water Environment (Controlled Activities) (Scotland) Regulations 2011 – more commonly known as the Controlled Activity Regulations (CAR) – and their further amendments of 2013 [opens in a new window] and 2017 [opens in a new window] – apply regulatory controls over activities which may affect Scotland’s water environment. This legislation arose from the European Community (EC)’s Water Framework Directive (WFD) [opens in a new window] becoming law in Scotland as the Water Environment and Water Services (Scotland) Act 2003 (WEWS Act) [opens in a new window].

The main aims of the regulations are to:

  • Prevent deterioration and enhance status of aquatic ecosystems, including groundwater
  • Promote sustainable water use
  • Reduce pollution
  • Contribute to the mitigation of floods and droughts.

The sustainable location and design of development can also contribute to climate change adaptation and mitigation, in line with the Climate Change (Scotland) Act 2009. This includes the protection and enhancement of biodiversity, and existing watercourses and water bodies. Achieving this will require effective management of the water environment through the planning process, in line with Policy 18 of LDP2.

Climate change mitigation and adaptation

Responsible management of the water environment is an important part of responding to the ongoing climate emergency. At a regional level, the Glasgow City Region Adaptation Strategy and Action Plan (Climate Ready Clyde, 2021) aims to ensure Glasgow City Region’s economy, society and environment is not only prepared for, but continues to flourish in the face of, the impacts arising from the climate crisis. A number of key risks to the water environment are identified, including:

  • Risk to soil stock from changes in temperature and water regime.
  • Risk to crops and livestock from changes to water regime.
  • Risk to freshwater biodiversity from pests, invasive species and disease.
  • Risks to new and existing business sites from river, surface water and coastal flooding.

In response to these risks, the Council has a responsibility to deliver nature-based solutions for resilient, blue-green ecosystems, landscapes and neighbourhoods.

The Council is also in process of preparing a local Climate Action Plan, which will commit the Council to placing climate change mitigation and adaptation, the green economy and biodiversity at the heart of its decision-making. This will include objectives relating to water management and the likely impacts of climate change on flooding and drainage.

Surface Water Management Plans

The aim of a Surface Water Management Plan (SWMP) is to reduce the risk of surface water flooding in the most sustainable way, as required under the Flood Risk Management (Scotland) Act 2009 (the ‘Flood Act’).

SWMPs set out the long-term vision for sustainably managing surface water flooding in an area and the actions needed to achieve that vision, and will take an iterative approach. Any proposed study area will be monitored, reviewed and updated within the timescales in relation to Flood Risk Management Planning cycles and new flood risk information.

To meet the Council’s responsibilities under the Flood Act and the vision of the Metropolitan Glasgow Strategic Drainage Partnership (MGSDP), the Council is undertaking studies to promote a number of SWMP measures across the Council area. Partnerships set up under the Flood Act allow the Council to work closely with Scottish Water to minimise flood risk from surface water sewers, which are the responsibility of Scottish Water.

SWMPs will include a range of measures to manage, attenuate and route surface water to less vulnerable areas, thus minimising the risk of flooding. In addition to water management, the use of SWMPs will aid the Council in meeting a number of other objectives with regards to climate change adaptation, green networks and place making.

Any development that will have a significant impact on local surface water systems or the water environment will be expected to support the objectives of the SWMP. The planning authority may request further information depending on the scale and nature of any proposal.

Where a development proposal represents an opportunity to deliver improvements or minimise surface water flood risk, developer contributions proportionate to the cost of the development itself may be secured to ensure these improvements are realised. Further information can be found in the Council’s Developer Contributions guidance note.

The Metropolitan Glasgow Strategic Drainage Partnership (MGSDP)

The Metropolitan Glasgow Strategic Drainage Partnership (MGSDP) [opens in a new window]) is a collaborative partnership formed by organisations involved with the operation of the sewerage and drainage network within the metropolitan Glasgow area. It is identified as a 'National Development' within National Planning Framework 3 (NPF3) - a nationally-significant exemplar of catchment-scale water and drainage infrastructure planning.

Graphic illustrating various components of the vision to 2060The MGSDP 2060 Vision is to transform how the city region manages rainfall to end uncontrolled flooding and improve water quality. The vision will be realised through partnership working and will be shaped by eight Guiding Principles:

  • Enhancement of our urban biodiversity and landscape
  • Reconnection of our waterways
  • Design for the severity of the rain
  • Presumption that surface water will be kept on the surface
  • Creation of an integrated system of blue- green networks
  • Integrated urban master planning and design
  • Sustainable and affordable drainage solutions
  • Climate-change ready.

Delivery of the MGSDP Vision and Objectives, in line with the Guiding Principles, will help to sustainably drain the Glasgow City Region, better service existing communities, unlock potential development sites and build greater resilience to long-term climate change, ensuring that aspirations for regeneration and growth are supported by improved infrastructure capacity.

Policy 18 of LDP2 aligns with these principles and applicants must ensure that the MGSDP Objectives and Vision are supported as part of the design process for all new developments. Further information can be viewed via the MGSDP website [opens in a new window].

River Basin Management Plan

The European Community Water Framework Directive (WFD) required the creation of River Basin Management Plans (RBMPs). Statutory objectives are set for Scottish waters through River Basin Management Planning. These objectives are based on ecological assessments and economic judgments. The plans cover all types of water body, e.g. rivers, lochs, lakes, estuaries, coastal waters and groundwater.

Each RBMP describes:

  • The current condition of the water bodies in the relevant river basin
  • Where ongoing or historic activities are reducing the quality of the water bodies
  • The actions required to ensure that ‘Protected Areas’ are up to required standards
  • The actions needed to deliver environmental improvements to water bodies over the following six years and in the longer term (up until 2027).

'Protected Areas' include drinking waters, shellfish waters, bathing waters, and waters designated for plants and animals (Special Areas for Conservation [opens in a new window] and Special Protection Areas [opens in a new window]).

The Scottish Environment Protection Agency (SEPA) is the lead authority to ensure compliance with WFD requirements. The overall aim is for 98% of Scotland’s waters to be in a good condition by 2027, progressively implemented through three RBMP cycles (2009-2015, 2015-2021 and 2021-2027).

The RBMP has identified the following key pressures on the water environment in Scotland:

  • Morphological alterations (e.g. modifications to beds, banks and shores as the result of historical engineering and urban development)
  • Diffuse source pollution (e.g. agriculture, urban development)
  • Point source pollution (e.g. the discharge of sewage, manufacturing and quarrying)
  • Abstraction and flow regulation (e.g. alterations to water flows and levels as the result of electricity generation and public water supplies)
  • Invasive non-native species.

East Dunbartonshire Council is designated as a ‘responsible authority’ and is required to:

  1. Exercise its designated functions to secure compliance with the water framework directive.
  2. In doing so, have regard to social and economic impacts, promote sustainable flood risk management and contribute to the achievement of sustainable development.
  3. As far as practical, adopt an integrated approach by co-operating with other responsible authorities to co-ordinate respective functions.

Actions to deliver the RBMP

The Town and Country Planning (Development Planning) (Scotland) Regulations 2008 require the development plan to have regard to the RBMP. In turn, decisions on planning applications are required to take account of the provisions of the development plan and any other material consideration. SEPA, in partnership with other public bodies, industry and land managers, has a key role to play in protecting and improving the water environment. This includes the regulation [opens in a new window] of activities that may affect it. SEPA also supports  planning  authorities  to align  and integrate  RBMP objectives  into land use planning [opens in a new window] and flood risk management [opens in a new window]. The main ways in which this can be achieved via the planning system include:

Any development that will have a significant impact on the water environment will be expected to support the objectives of the RBMP. The planning authority may request further data via the SEPA hub, depending on the scale and nature of the proposal.

Where a development proposal represents an opportunity to deliver improvements to water body status/potential, developer contributions proportionate to the cost of the development itself may be secured to ensure these improvements are realised.

RBMP Information Sources

Improvements put in place to protect and enhance the water environment can also deliver multiple benefits in terms of other key local authority objectives, e.g. extending and enhancing green networks, enhancing biodiversity, climate change and open space targets, reducing flood risk and making provision for recreation.

The planning authority will work with SEPA to ensure the achievement of these objectives through the development management process. More information about the actions or measures underway, or planned, in different areas is available on SEPA’s RBMP information sources page. This includes links to an interactive ‘Water Environment Hub’, which provides data on different aspects of the water environment at a local authority level. This includes data on the following:

  • Overall condition
  • Water quality
  • Physical condition
  • Access for fish migration
  • Water flows and levels
  • Freedom from invasive species

East Dunbartonshire’s water environment and flood risk

What causes flooding in East Dunbartonshire?

Flooding can occur for variety of reasons. The main cause is excessive rainfall within a limited period, which overwhelms the capacity of watercourses, particularly when the ground is already saturated. It can also occur when large volumes of rainwater flows over the ground before entering a natural or man-made drainage system. Other reasons include an overload of sewer capacity, groundwater flooding and coastal flooding. Key factors that can contribute to increased flood risk include:

Development being located on a functional flood plain, i.e. where there is a 0.5% or greater annual probability of flooding in any year (1:200 year flood)

  • Being located adjacent to a watercourse.
  • Poor maintenance of watercourses.
  • Poor maintenance of existing drainage systems.
  • Inadequate designs for drainage systems.
  • Increased surface water run off due to impermeable areas.
  • Rainfall events.
  • Breaches in flood defences
  • Ground water.

It is therefore important that both applicants and planning authorities consider the impact of new development on flood risk from all sources from the outset of the planning process (i.e. planning permission in principle).

Technical guidance relating to flooding and drainage can be found in the Council’s Flooding and Drainage Guidelines for Developers, 2015 document. This guidance sets out the Council’s technical requirements relating to flood risk, drainage design, construction, maintenance and operation. Additional technical guidance from SEPA is set out in their Technical Flood Risk Guidance for Stakeholders document.

The Council’s flooding and drainage officers will provide comment on, and review, any proposed development should the planning service deem that the proposals would have a significant impact on the local surface water systems or the water environment.

SEPA Flood Maps

SEPA’s flood maps [opens in a new window] provide information on river flooding, surface water flooding and coastal flooding throughout Scotland.

The flood maps help to identify whether a site sits within an area that is at risk of flooding and therefore if further assessment is needed before progressing with a development or application. Please note that the flood maps are not intended to ascertain flood risk to individual properties. This is because they were developed from a combination of national and local models that do not provide a precise or site- specific assessment of flood risk to any individual property.

In addition, SEPA’s flood maps do not cover all potential flood risks. There may be smaller scale and more localised flood risks, which can have significant consequences locally, which are not covered by SEPA's maps. Where available, other relevant information should be considered to establish the extent and impact of flooding from any source. Full terms and conditions relating to the Flood Maps are available upon opening the maps via the SEPA website (link above).

Water courses and water bodies in East Dunbartonshire

SEPA maintains a record of the status of each surface water body in Scotland, which is published via its water environment hubs [opens in a new window]. It provides information on each water body, pressures, measures and the objectives (targets) that have been set. The latest classification data can be found via the Water Classification Hub, hosted by SEPA [opens in a new window]. Data for water bodies in East Dunbartonshire shows that progress is being made overall towards the target status for 2021 and 2027. Of 15 surface water bodies, four have seen improvements since the base year of 2014, while 11 have remained constant. A summary of key information for the water bodies in East Dunbartonshire is shown in Appendix 3.

A summary of key information for the water bodies in East Dunbartonshire

How can flood risk be avoided or addressed?

Green and Blue Infrastructure

The priority when managing surface water and flood risk should be integrating features of the natural landscape into the design process. This can be achieved by establishing the potential contribution of green infrastructure networks to enable sustainable drainage. For example, the restoration, enhancement or creation of natural or existing features such as green spaces, wildlife corridors, flood plains, wetlands and woodland can help to restore more favourable run-off patterns and therefore reduce flood risk. Green infrastructure can also include water-based features such as swales, wetlands, rivers and canals (and their banks), and other watercourses. This is often referred to as ‘blue infrastructure’. These techniques typically protect, emulate or restore the natural processes which regulate flooding and erosion, by keeping water in areas where it will cause less damage. Examples of specific green and blue infrastructure measures applicants should consider include:

  • Improving water storage and capturing run-off by restoring, protecting or enhancing soil condition and woodland areas
  • Reconnecting floodplains, restoring wetlands or creating ponds and reservoirs to help store flood waters
  • Planting vegetation and managing hill slopes to help slow run-off
  • Restoring watercourses to a more natural channel form by removing culverts and other structures that constrain channels and contribute to flooding during high flows.

In urban areas, green roofs, rain gardens, permeable paving, flood and surface water attenuation ponds, opening up and realigning watercourses, and establishing green spaces and blue corridors are equivalent examples (further information on these measures is provided in the Sustainable Surface Water Management section below). The Council’s Supplementary Guidance on Green Infrastructure & Green Network identifies types of green infrastructure that can be used at different scales of development and provides guidance on delivery of green infrastructure and the green network in development.

Strengthening green and blue infrastructure networks has wider benefits for people and nature, including the provision of shelter, wildlife habitats, attractive public spaces, access and travel, pollution mitigation and food production as part of a wider ecosystem. The Scottish Government’s Green Infrastructure: Design and Placemaking also provides further information on this. The extract diagram below provides an overview of green and blue infrastructure techniques at different scales. This provides a useful starting point for applicants when thinking about the different measures that could be implemented through development, to enhance the overall water environment and adapt to climate change risk.

diagram providing an overview of green and blue infrastructure techniques at different scales

Flood Risk Framework

At a national level, the flood risk framework sets out three categories of coastal and watercourse flood risk. These are as follows:

  • Little or No Risk – annual probability of coastal or watercourse flooding is less than 0.1% (1:1000 years)
    • No constraints due to coastal or watercourse flooding.
       
  • Low to Medium Risk – annual probability of coastal or watercourse flooding is between 0.1% and 0.5% (1:1000 to 1:200 years)
    • Suitable for most development. A flood risk assessment may be required at the upper end of the probability range (i.e. close to 0.5%), and for essential infrastructure and the most vulnerable uses. Water resistant materials and construction may be required.
       
    • Generally not suitable for civil infrastructure. Where civil infrastructure must be located in these areas or is being substantially extended, it should be designed to be capable of remaining operational and accessible during extreme flood events.
       
  • Medium to High Risk – annual probability of coastal or watercourse flooding is greater than 0.5% (1:200 years)

May be suitable for:

  • residential, institutional, commercial and industrial development within built-up areas provided flood protection measures to the appropriate standard already exist and are maintained, are under construction, or are a planned measure in a current flood risk management plan;
     
  • essential infrastructure within built-up areas, designed and constructed to remain operational during floods and not impede water flow;
     
  • some recreational, sport, amenity and nature conservation uses, provided appropriate evacuation procedures are in place; and 
     
  • job-related accommodation, e.g. for caretakers or operational staff.
  •  

Generally not suitable for:

  • civil infrastructure and the most vulnerable uses

  • additional development in undeveloped and sparsely developed areas, unless a location is essential for operational reasons, e.g. for navigation and water-based recreation, agriculture, transport or utilities infrastructure (which should be designed and constructed to be operational during floods and not impede water flow), and an alternative, lower risk location is not available; and

  • new caravan and camping sites.

  • Where built development is permitted, measures to protect against or manage flood risk will be required and any loss of flood storage capacity mitigated to achieve a neutral or better outcome.

  • Water-resistant materials and construction should be used where appropriate. Elevated buildings on structures such as stilts are unlikely to be acceptable.

Further detail on what types of development may be permissible in flood risk areas can be found in SEPAs ‘Flood Risk and Land Use Vulnerability Guidance’.

Flood protection schemes 

Flood protection schemes can reduce flood risk, but cannot eliminate it entirely. Their primary purpose is to protect existing development from flood risk rather than to facilitate new development. For this reason the principle of avoidance should be adhered to for any proposed development in areas protected by such schemes.

Certain developments may be acceptable behind an existing or planned scheme in a built-up area. These fall into four main categories:

  1. Water-compatible developments and essential infrastructure that is designed to remain operational during flood events
  2. Development that does not increase overall flood risk
  3. The principle of the development has been established in an up-to-date, adopted development plan (including the National Planning Framework) with due consideration of flood risk
  4. The scheme is built to the minimum appropriate standard for the land use vulnerability category of the proposed development as defined below:

table showing the land use vulnerability categories

Formal flood protection schemes are those which have been/are being promoted through relevant legislation (i.e. Flood Prevention (Scotland) Act 1961 (as amended in 1997), the Flood Risk Management (Scotland) Act 2009 or Coast Protection Act 1949). Informal flood defences are proposals that have been/are being brought forward outwith this legislation. Any protection offered by informal flood defences would not be taken into account when considering development behind or benefitting from them. Such proposals would be considered within the context of the flood risk framework as if the scheme did not exist. This is because the structural condition and design standard of such schemes may be uncertain and they therefore pose a level of risk to any proposed development behind or benefitting from them.

Developments that introduce vulnerable uses will not be considered acceptable behind a flood protection scheme. These includes uses such as civil infrastructure, basement dwellings, nurseries and hazardous substance installations. The full classification of most vulnerable uses is detailed within SEPA's Flood Risk and Land Use Vulnerability Guidance [opens in a new window]. The consequences of any residual flood risk would be too significant for developments within this land use category.

Developing in areas with pre-existing flood risk

Applicants must ensure that the following principles have been met, for proposals within areas that are subject to existing flood risk:

  • Infrastructure and buildings should be designed to be free from surface water flooding in rainfall events where the annual probability of occurrence is greater than 0.5% (1:200 year) – see SEPA flood map.
  • Proposed developments with complex surface water hazards should ensure that the surface water flood risk is adequately assessed and managed within the site boundary (more strategic solutions are also acceptable, provided they are able to be secured via the land-use planning process).
  • Development must be located outwith the functional floodplain of nearby watercourses.
  • Development should not take place within a flow path (i.e. natural, modified or SuDS exceedance flow path), as this could increase flood risk to existing as well as any new development. Note also that any land raising in areas where surface water flows and ponds may only serve to increase flood risk to existing receptors by deflecting water towards them.
  • Land raising will not be permitted within the functional floodplain
  • Residential development in lower ground/basement floors should be avoided where surface water flood risk is significant and cannot be mitigated, as it can pose a risk to life. This is due to potential rapid inundation where water could pour in from above head height.
  • A Flood Risk Assessment should be used to inform the siting, layout, design and capacity of development on the site in a way that avoids an increase in flood risk on and off site and ensures that there is safe dry pedestrian access and egress at times of flood. This means the provision of a safe and flood-free route during the relevant flood probability event that enables the free movement of people of all abilities (on foot or with assistance) both to and from a secure place that is connected to ground above the design flood level and/or wider area.
  • Finished floor levels must be set 600mm above the design flood level where appropriate and practicable in order to provide an allowance for freeboard.
  • Buildings and other structures should be designed to be flood resistant and resilient. Flood- resilient buildings are designed to reduce the impact of flood water entering the building so that damage is minimised. In comparison, flood-resistant buildings are designed to prevent or minimise the entry of water into the building in the first place. The appropriate resilience and resistance measures will depend on the characteristics of the design flood; this includes the estimated flow velocity, inundation rate, depth that flood water will reach in the building and the duration of the flood event. Specific guidance on flood resilient and resistant construction techniques can be found in the CIRIA 2019 code of practice and guidance for property flood resilience.
  • Where development is a replacement for existing development of the same type, opportunities for flood risk betterment should be explored.

Further information on the above can be viewed in SEPA's ‘Flood Risk Standing Advice for Planning Authorities and Developers’ document.

Development affecting existing watercourses

Subject to agreement with the Council’s Flood Risk team, and in compliance with the relevant legislation, a culverted watercourse may be diverted. However, the final form and alignment of any diversion will be required to maintain existing pass-forward flows or flows specified by the Council and have a self-cleansing velocity. In addition, consideration should be given to the following design elements:

  1. Opportunities for day-lighting
  2. Removal of site-specific flow restrictions
  3. Improving access to the culvert for maintenance
  4. Opportunity to create multi-functional green infrastructure, including enhancements to landscape, habitats and access/recreation
  5. Removal of barriers to fish movement.

Developing residential extensions and outbuildings

Domestic extensions and alterations have the potential to impact on local flood risk, particularly in a cumulative sense. Similarly, small structures and outbuildings have the potential to impact upon flood risk elsewhere. This includes garages, sheds, conservatories, greenhouses and other buildings that are incidental to the enjoyment of a main residential dwelling houses. The Council will therefore expect the following flood design matters to be demonstrated. This applies to any residential extension or outbuilding, including the provision of new overnight accommodation/bedrooms, but excluding the formation of an entirely new dwelling:

  • The incorporation of flood resistant and resilient materials and design, and the raising of finished floor levels where practicable. The CIRIA 2019 code of practice and guidance for property flood resilience [opens in a new window] is a useful source of information and you may wish to consult with the local authority Building Standards team.
  • Safe and flood-free access and egress should be provided where possible. This means the provision of a safe and flood-free route during the relevant flood probability event that enables the free movement of people of all abilities (on foot or with assistance) both to and from a secure place that is connected to ground above the design flood level and/or wider area.
  • Finished floor levels should be set 600mm above the design flood level where appropriate and practicable in order to provide an allowance for freeboard. An allowance for climate change should be included when calculating the design flood level, independently of an allowance for freeboard, as per SEPA's Guidance on Climate Change Allowances for Flood Risk Assessment in Land Use Planning [opens in a new window].
  • A 6m minimum (for channels less than 1m in width and increasing proportionally to channel width) undeveloped buffer strip should be provided in perpetuity between all development types and watercourses, allowing space for natural fluvial processes to occur (as well as other attendant environmental benefits, not limited to but including biodiversity, open space, channel maintenance, pollution reduction and river restoration). It is important to highlight that buffer strips do not mitigate any identified flood risk that may exist at a site.

Full advice relating to a range of other development types can be found in SEPA's ‘Flood Risk Standing Advice for Planning Authorities and Developers (2020)' [opens in a new window]. This includes proposals for essential infrastructure, cemeteries, small-scale street furniture, walls and fences, footpaths and access tracks, car parks, open-sided agricultural buildings and temporary construction accommodation.

Riparian buffer strips

A buffer strip is an area between built development and the boundary of a watercourse where no development is permitted. It is maintained in permanent vegetation. Buffer strips can bring multiple benefits, including better soil and water quality. They ensure space for natural fluvial processes to occur and promote biodiversity including the provision of natural habitats. Other key benefits include: contributing to green networks and open space allocations; stabilising banks and reducing soil erosion; reducing pollution from surface water run-off; opportunities to undertake restoration of straightened or realigned watercourses in the future; and the delivery of RBMP and multiple benefits by providing a green-blue network.

The planning authority will seek a buffer strip of a minimum of 6m on either side of the watercourse, however, this should be proportional to the bank width. For example, wider rivers would have a larger buffer strip than a narrow burn. This will be measured from the top of the bank. Please note that 6m is a minimum and developers may be required to allow for a greater width where site-specific issues relating to site conditions, topography, flood risk, pollution-control pressures, physical condition, climate change mitigation, native species habitats, active travel and recreation are known to apply. The following table provides an indication of expected widths, as recommended by SEPA.1


table that provides an indication of expected widths, as recommended by SEPA

This strip should be kept free from any development in order to allow access to the water body for the purpose of assessment and maintenance, to ensure bank stability, and to aid water and ecological quality. Riparian buffer strips may be secured by a planning condition. Any request to reduce this requirement must be suitably justified to the satisfaction of the Council.

Sustainable surface water management and SuDS

Key Principles

All developments should include measures to safely manage rain and surface water run-off to avoid the risk of flooding to the new development, to adjacent developments and to any watercourses where surface water is discharged. This can be achieved by the use of Sustainable Drainage Systems (SuDS). These aim to mimic natural drainage and return excess surface water to the natural water cycle with minimal adverse impact on people and the environment. The CIRIA SuDS Design Manual (C753) details how SuDS should be designed and constructed to meet all requirements in relation to:

  • Managing water quantity and flood risk (up to the 1:200 year event plus climate change allowances)
  • Managing water quality
  • Providing benefits for people and place by being integrated into, and enhancing, the landscape quality and being considered part of the wider green infrastructure network
  • Providing benefits for biodiversity.

Principles of sustainable surface water management

Manage rain and surface water in a way that mimics natural systems, and protects and enhances both the built and natural environment.

Manage rainfall and surface water safely above ground, avoiding harm to people, homes, businesses and other adverse impacts of flooding. Maximise the use of permeable surfaces and plants, and convey water to watercourses using the natural topography. Avoid increasing surface water in the sewers as this can lead to flooding elsewhere. Reduce surface water in the sewers where possible.

Manage all rainfall events:

  • Everyday rain – manage rain locally at source, maximise infiltration and evapotranspiration by maximising use of permeable surfaces and plants. Water can be collected for use. There should be little or no surface water run-off in these frequent events.
  • Heavy rain - collect, delay and convey safely above ground to watercourses following the natural topography. Do not increase surface water in the combined sewers as this causes flooding elsewhere. Water can be collected for use.
  • Extreme rain - delay, store and convey safely above ground to watercourses following the natural topography.

Multi-functional – maximise all benefits:

  • People – integrate with, protect and enhance the urban landscape, provide attractive and inviting places for people to live, work and visit.
  • Drainage and flood management – manage all rainfall events, avoid flooding for people and buildings, avoid increasing flows to receiving watercourses and combined sewers.
  • Water quality – protect and enhance the quality and physical habitat of receiving watercourses. Collecting water for use can reduce the need to abstract water elsewhere.
  • Biodiversity – protect and enhance biodiversity, maximising permeable surfaces and plants to attract wildlife.
  • Adaptability to future change – help the urban environment adapt to future challenges of climate change (increasing rainfall, rising temperatures, etc) and mitigate the loss of green space.

 - Co-ordinate with other authorities and projects to maximise benefits and aid delivery (e.g. using footpaths and cycle paths as routes for infiltrating and conveying water, contributing to green and blue networks).

- Think of different spatial scales required to manage surface water (e.g. what can be done locally at building and street level, what regional and more strategic management is required and what connections between the different scales are required?).

Examples of Surface Water Management and SuDS

The table below sets out the variety of SuDS techniques and ways they can be implemented. In most cases, above-ground management of surface water will require a combination of these measures, including source control, conveyance and storage in all rainfall events.

Managing water on the surface

Potential Action

Description

Further information

Infiltration

For managing ‘every day rain’ – maximise the use of permeable surfaces and vegetation, allowing rain to infiltrate the ground and evaporate into the atmosphere where it falls, creating little or no surface water run-off.

Susdrain resource on sustainable drainage: 

 

CIRIA publications

 

  • CIRIA C753 (2015) -

The SUDS Manual

  • CIRIA C728 (2014)

Managing urban flooding from heavy rainfall – encouraging the uptake of designing for exceedance

  • CIRIA C713 (2012)

Retrofitting to manage surface water

  • CIRIA C635 (2006)

Designing for exceedance in urban drainage: good

practice

Conveyance

For managing ‘usual rainfall’ - collect, delay and convey rainfall and resultant surface water above ground to watercourses using green infrastructure techniques.

Storage

For managing ‘extreme rainfall’ - delay, store and convey surface water above ground to watercourses using green infrastructure techniques.

Restoring urban watercourses

Restore urban watercourses (e.g. restoring floodplains and de-culverting) to reduce flooding from the watercourse itself and provide more opportunities to convey surface water into the natural environment.

SEPA’s Natural Flood Management Handbook

Run-off reduction strategy

Develop what is typically a long-term plan for making whole urban areas more ‘green’ and permeable, whilst reducing impermeable and ‘grey’ engineered surfaces. This allows more rain to infiltrate the ground and encourages evapotranspiration, reducing run-off rates and volumes.

Sheffield City Council Grey to Green Project

Reducing surface water in the sewer

Identify opportunities to reduce surface water in sewers. Scottish Water is responsible for the sewer network and should therefore be contacted regarding any proposals.

Land management

Implement land management actions that reduce the rate and volume of run-off. Run-off from more rural land (‘the urban fringe’) can flood homes, businesses and infrastructure directly and, by significantly increasing flows to the urban area, drainage systems and watercourses can raise flood risk further downstream.

SEPA’s Natural Flood Management Handbook

Managing water below the surface

Potential Action

Description

Further information

Underground storage

Divert surface water to storage tanks or provide storage in the existing drainage/flood management network.

-

Underground conveyance

Increase capacity or build new underground pipes for surface water.

-

Modification of culverted watercourses

Increase the capacity of culverted watercourses or divert culverted watercourses.

-

Source: Surface Water Management Planning Guidance, Scottish Government (2018)

[DIAGRAM ILLUSTRATING BELOW TECHNIQUES]

Swales - Broad, shallow channels covered by grass or other suitable vegetation. Swales attenuate the surface water flow and allow time for filtration and sedimentation into sub-surface soil in areas where soil porosity is suitable.

Filter Strips - These are wide, gently sloping areas of grass or other dense vegetation that slow and treat run-off from adjacent impermeable areas.

Filter Drains - Filter drains are trenches that are filled with permeable material such as gravel. They work by providing capacity for attenuation. Surface water from paved areas flows into the trenches, is filtered and conveyed to other parts of the site. A perforated pipe may be built into the base of the trench to collect and convey the water.

Permeable Surfaces - Allow rainwater to pass through the surface into an underlying storage layer, where water is stored before infiltration into the ground. They can be designed to fit in with a variety of settings, e.g. permeable paving or gravel surfaces in car parks, garden paths, etc.

Infiltration Basins - Depressions created within the site to store run-off and allow filtration into the ground below.

Infiltration Devices - Dispose of surface water run-off into the ground. Both groundwater and ground conditions must be suitable to receive the volume and quality of water anticipated.

Extended Detention Basins - These are normally dry, though they may have small permanent pools at the inlet and outlet. They are designed to detain larger run-off volumes than infiltration basins as well as providing water quality treatment.

Ponds and Pools - Small but permanent water bodies which provide temporary storage for additional storm run-off above normally-expected water levels. Wet ponds may provide amenity and wildlife benefits, and a sedimentation process to reduce pollution to watercourses. Water may be retained for as long as two or three weeks.

Constructed Wetlands - These are ponds with shallow areas and wetland vegetation to improve pollutant removal and enhance wildlife habitat. They may also be landscaped to provide amenity value. Green Roof Systems - Cover a building’s roof (or walls) with vegetation. They are laid over a drainage layer, with other layers providing protection, waterproofing and insulation. Sedum rather than grass can minimise maintenance.

Below Ground Storage - Enables retention of water for irrigation of green infrastructure.

Exceptions

Please note that no SuDS features should be implemented within a functioning flood plain to avoid the risk of:

  • SuDS features becoming redundant during possible inundation from adjacent watercourses
  • Risk of contaminants from the development washing to the adjacent watercourses during such events.

Furthermore, any new developments must not impact on the storage capacity or functionality of an existing flood plain.

Levels of treatment

The level of surface water treatment required depends on the nature of the proposed development (for example, residential or non-residential), the size of development and the environmental risk posed by the development. As a minimum, the Council will expect the following levels of treatment to be provided. For mixed-use developments, the level of treatment required will be determined by the use with the highest sensitivity within the development.

  1. Residential developments of fewer than 50 houses and retail/commercial/business parks with car parks of 50 spaces or less require one level of treatment for all hardstanding areas including roads.
  2. Residential developments of 50 or more houses and retail/commercial/business parks with car parks of more than 50 spaces require two levels of treatment for all hardstanding areas including roads. An exception is run-off from roofs which requires only one level of treatment. As best practice, the second level of treatment should ideally be a basin or pond.
  3. Industrial developments require three levels of treatment for hardstanding areas and two levels of treatment for roads. An exception is run-off from roofs which requires only one level of treatment. As best practice, the second level of treatment should ideally be a basin or pond.
  4. All roads schemes require two levels of treatment. For technical guidance on SuDS techniques and treatment for roads please refer to the SuDS for Roads manual.
  5. For all developments, run-off from areas subject to particularly high pollution risk (e.g. yard areas, service bays, fuelling areas, pressure washing areas, oil or chemical storage, handling and delivery areas) should be minimised and directed to the foul sewer.

Please note that levels of treatment required may vary depending on other stakeholder and other statutory agency requirements. Further guidance regarding this matter can be found in SEPA’s Regulatory Method (WAT-RM-08) Sustainable Drainage Systems.

SuDS Case study

Sheffield’s Grey to Green SuDS project has transformed a redundant carriageway in the city centre into a network of sustainable drainage and rain gardens. This not only reduces the area generating surface run-off, but also provides the space to manage the remaining areas more robustly. Newly-created green infrastructure modified as a series of swale cells provides environments to capture, clean, infiltrate, move, and store water. It has improved the city’s resilience to climate change, enhanced the public realm and increased connectivity in the city centre. The project is now attracting investment in new and existing jobs.

Client: Sheffield City Council [opens in a new window];

Constructor: North Midland Construction

SuDS cascade through significant areas of level change, together with wetland planting SuDS cascade through significant areas of level change, together with wetland planting

Photo: SuDS cascade through significant areas of level change, together with wetland planting Image: Sheffield City Council)

SuDS cell visualisation used for consultation and interpretation (Image Credit: Sheffield City Council)

Figure - SuDS cell visualisation used for consultation and interpretation (Image Credit: Sheffield City Council)

Scheme overview – before and after (Image: Sheffield City Council)Figure – Scheme overview – before and after (Image: Sheffield City Council)

Before

After

Rainfall is drained quickly into pipes, for example via gullies in the road. This can add to flooding problems and in the case of roads can send pollutants such as oils, heavy metals and microplastics straight to rivers.

Rain is captured by the existing landscapes or new green infrastructure. Their design holds that water temporarily, even during extreme rainfall events. The everyday rain that washes pollutants from the roads is filtered and broken

down by soils and plants.

Urban areas disconnected from rivers and streams, where run-off is instead sent to the treatment works in sewers, mixed with foul water. During extreme rainfall events, many of these pipes overflow into rivers, causing

pollution.

Many new large developments now drain to rivers, but care needs to be taken with capturing and treating pollutants. Redirecting water back to the river, but making sure it is done sustainably, mimicking natural process – ‘clean

and slow flows’.

Rainwater was always seen as a nuisance to be got rid of. The pipes underground meant 'out of sight and out of mind'. To a large extent this was down to the problems of sanitation of the time

– needing to isolate people from water because it may contain disease.

Times have moved on - rainwater and the run- off it creates are seen as important things to manage to prevent flooding and pollution, but also that the landscapes that can do this are places to celebrate the visibility of rainwater. Rainwater is a resource that can irrigate our green networks, keep our urban areas cool and

build awareness of natural processes.

Source: Carbon Conscious Places, A&DS

Planning application procedures

Sustainable water management, including potential SuDS measures, must be considered at an early stage in project design in order to determine suitability. Pre-application discussion can be invaluable in developing a common understanding of what is proposed, and to assist the efficient and effective processing of applications. This includes discussions relating to maintenance responsibility. Developers are therefore strongly encouraged to approach the planning authority at the earliest possible stage to explore which combination of SuDS measures, if any, are most appropriate.

If a meeting is thought appropriate, then the developer should submit an outline development concept, in order that all parties to the meeting can come prepared to discuss the criteria for water quantity, quality and amenity issues related to the proposal. This may include related sites upstream and downstream on the relevant watercourses, sewerage systems or groundwater. For any SuDS discharge to the water environment, SEPA should also be consulted in order to provide the appropriate CAR approvals.

Level of information

The level of detail required as part of planning applications will be proportionate to the complexity of the flood risk mechanisms, the site location and the severity of the risk. Applicants must ensure that the information submitted clearly demonstrates that the proposed development is not at risk of flooding and will not increase flood risk elsewhere. The application must also include robust and sustainable drainage proposals. This information should be completed by an appropriate professional, as set out in this document. If the proposed development does not comply with this guidance document, the application may be refused.

Flood Risk Assessments

Detailed advice and guidance on flood risk is published by SEPA. This includes general guidance on flood risk and advice for an applicant and development management (see Appendix 1). The purpose of a Flood Risk Assessment (FRA) is to investigate the likely probability of flooding at a specific site and to assess the likely risk to the proposed development and to adjacent people and property.

The Council will request a FRA to support a planning application when:

  • The proposed development is located close to a watercourse
  • The Council has evidence of historical flooding issues relating to the proposed site
  • SEPA’s flood map shows the proposed site to be at risk of fluvial or pluvial flood or in close proximity to the inundation of a watercourse in the event of a year flood (plus climate change allowances).

The diagram below may be useful in determining whether a FRA is required. Where there is any doubt concerning the need for a FRA, applicants are strongly advised to consult with the planning authority at the earliest opportunity.

flowchart showing potential flood risk

The scope of an FRA will normally depend on the complexity of the flood risk mechanism(s), the site and the severity of the risk. FRAs should identify the source of potential flooding i.e. fluvial, coastal, surface water (pluvial) or combinations of sources of flooding. In some smaller cases, a more basic FRA may be appropriate where the risk is likely to be low. It is therefore advisable to consider the potential outcome of the assessment prior to investing in a detailed FRA. Applicants are strongly advised to use specialist and experienced professional consultants, preferably with experience of the local area.

It is recommended that an appropriate level of FRA be carried out as soon as the site is considered for development. The scope and detail of the FRA required should be discussed with the Council prior to submitting a planning application. The FRA should be completed by a professional with relevant experience in flood risk and drainage design.

Minimum requirements of a Flood Risk Assessment

Ref

Requirement

Check

1

Plans - description of the proposed development including location, size and

nature of surrounding area, watercourses and landscape.

 

2

SEPA flood risk map status.

 

 

Ref

Requirement

Check

3

Photos – showing area of proposed development relative to any watercourses or

water bodies. Time stamped.

 

4

Topographic information - existing ground levels, finished floor levels where appropriate, any land raising. Survey data used to assess flood routing/depths.

 

5

Cross sections - sections should be of an appropriate length to include the application site, the channel bed levels and bank levels of the opposite bank. Additional sections would also be required at keys areas of interest, including structures like bridges and culverts, significant changes in the channel or floodplain

width.

 

6

Structural information – details of any structures – such as culverts, bridges, weirs,

and croys – which may influence water levels, should be provided.

 

7

Other site specific information – overview of existing flood risk, consultation with SEPA and Scottish Water, provision of compensatory storage, results of hydrological modelling, details of proposed flood-resilient materials, existing

drainage infrastructure.

 

Additional technical guidance from SEPA is set out in their Technical Flood Risk Guidance for Stakeholders document [opens in a new window].

Drainage statements and impact assessments

Applicants should prepare and submit either a drainage statement or Drainage Impact Assessment (DIA), depending on the scale and/or type of proposal. This should be submitted as part of the planning application in principle. The purpose of this requirement is to demonstrate that the development can be effectively drained.

Drainage statement

All developments other than householder or changes of use will need to provide a drainage statement. This should describe the proposed drainage arrangements and connections to a surface water system or Scottish Water drainage network. Plans submitted with the application should include the proposed layout of the drainage proposals, which should include SuDS for attenuation and treatment of surface water.

Table 1 – Drainage statement essential documents checklist

Requirement

General description of the development, its size, location and surrounding

topography and land uses.

Description of existing drainage arrangements on-site and any sewers.

A concept drawing of the development and proposed/likely means of providing foul

and surface water drainage.

Evidence of proposed run-off rates and storage volumes for a variety of return

periods.

Drainage Impact Assessments

The need for a Drainage Impact Assessment (DIA) will be determined by the Council on a case-by-case basis, depending on the scale and type of proposal. A DIA is more detailed and should demonstrate the site-specific drainage issues relevant to a proposal and the suitable means of accommodating any identified drainage needs. A checklist setting out specific requirements is set out in Table 4.

In the case of masterplan developments involving more than one developer, the Council will expect all parties to adopt a joint approach to drainage, rather than individual approaches that may result in separate SuDS systems for each aspect of the wider development. The Council will expect this to be considered and agreed as a key part of the masterplan process.

Table 2 – Drainage Impact Assessment

Requirement

Completed?

Report including drawings/calculations/figures.

 

Description of existing drainage rights/arrangements on site.

 

Assessment of pre/post run-off rates, changes in impermeable areas.

 

Evidence of proposed run-off rates and storage volumes for a variety of return

periods.

 

Outline  drainage  design  showing  use/application  of  SuDS,  supported  by

calculations/model results.

 

Wastewater drainage proposals, including a letter of agreement from Scottish

Water to accept foul flows (if applicable).

 

Reporting of on-site infiltration tests (where suitable).

 

Proposals relating to discharge rate control methods, receiving water bodies,

structures, etc.

 

In the case of masterplans, all parties to demonstrate agreement of joint approach

to drainage.

 

The DIA should cover surface water and foul drainage. Early discussions with the Council, SEPA and Scottish Water are encouraged for applications of a significant scale. The drainage strategy should include:

  • An indication of the types of measures to be used
  • Which measures will be considered in the detailed design
  • Evidence of sub-soil porosity and suitability for use of infiltration SuDS
  • Pre and post-development run-off calculations to determine the scale of SuDS required
  • Assessment of flood risk where this is deemed appropriate
  • Proposals for integrating the drainage system into the landscape or required public open space
  • Demonstration of good ecological practice including habitat enhancement
  • Estimates of land take for different drainage options based on initial calculations carried out to size any significant drainage structures.

By the stage of submitting either a full or reserved matters planning application, a detailed drainage design will be required. Preparing such a design involves five steps:

  1. The planning authority will agree with the other regulatory authorities the type of information that needs to be included in the planning application and inform the developer accordingly
  2. The developer and drainage designer should liaise as necessary with the regulatory authorities to agree on appropriate criteria
  3. The drainage designer should follow the procedures in the SuDS Design Manual for selection of drainage techniques
  4. The developer should confirm with the regulatory authorities that the selected techniques are appropriate
  5. The drainage designer, in consultation with relevant disciplines as necessary, should follow the guidance in the design manual to produce designs for planning, building warrant, drainage and road construction applications, and to meet the needs of prohibition notices where appropriate.

Prior to the commencement of development works, the applicant will be required to submit to the Council a copy of the appropriate technical approval or consent to discharge to a Scottish Water asset. Technical guidance relating to drainage can be found in the Council’s Flooding and Drainage Guidelines for Developers, 2015.

Urban creep allowance

Urban creep is the conversion of permeable surfaces to impermeable over time. Common examples of this include the resurfacing of front gardens to provide additional parking spaces, extensions to existing buildings and the creation of large patio areas. This can significantly increase surface water run-off and flood risk over time. The consideration of urban creep will be assessed on a site-by-site basis, but is limited to residential development only.

It is important that the appropriate allowance for urban creep is included in the design of the drainage system over the lifetime of the proposed development. The allowances set out below should be applied to the impermeable area within the property curtilage:

Residential development density - dwellings per hectare

Change allowance % of impermeable area

<25

10

30

8

35

6

45

4

>50

2

Flats and apartments

0

Note - where the inclusion of the appropriate allowance would increase the total impermeable area to greater than 100%, 100% should be used as the maximum.

Climate change allowances

Climate change will increase the risk of flooding due to increased rainfall, rising sea levels and population growth. Therefore, a precautionary approach to flood risk that takes account of the predicted effects of climate change will be adopted by the Council. When designing proposals, allowance should be made for climate change as part of a Flood Risk Assessment.

A climate change allowance is a prediction of anticipated change in peak river flow, peak rainfall intensity and sea level rise caused by future climate change. The type of allowance used will depend upon the type of flooding being considered and, for river (fluvial) flooding, the size of catchment.

East Dunbartonshire lies within the Clyde Basin catchment area, which has a projected peak river flow allowance of 49% up to the year 2100 and a peak rainfall intensity allowance of 41% to the year 2100. Further information can be viewed in the SEPA ‘Climate Change Allowances for Flood Risk Assessment in Land Use Planning document (2022) [opens in a new window].

chart showing the type of flooding/location and the type of allowance to use

Source: Climate change allowances for flood risk assessment in land use planning (SEPA)

The role of SEPA

SEPA is responsible for regulating activities that are subject to the Water Environment (Controlled Activities) (Scotland) Regulations 2011 (as amended) (CAR). This includes discharges to the water environment (surface water and foul drainage), and engineering works that impact inland waters. For the most part drainage and other issues that fall within the remit of CAR are now subject to standing advice.

To minimise delay and the risk of complication planning permission and regulatory authorisation should be sought and progressed simultaneously. We recommend that applicants refer to the CAR Practical Guide and the water regulations section of our website in the first instance. Where an activity is subject to a General Binding Rules (GBR) it is incumbent on the applicant to ensure compliance.

The role of Scottish Water

Scottish Water is responsible for providing water and sewerage services across Scotland. It is accountable to the public through the Scottish Government and plays a key role in the land planning and development process in terms of ensuring appropriate connections to water and waste water infrastructure. The following paragraphs outline some key considerations where proposals may require liaison with Scottish Water.

Foul drainage

All developments requiring a foul discharge should be connected to the public sewerage system. The Council recommends that all applicants consult with Scottish Water at the earliest possible stage of the design development to ensure that sufficient capacity is available for connection.

Business and trade effluent

For all business and trade effluent discharges, the Council recommends that the applicant engages with an appointed licensed provider to Scottish Water.

Surface water drainage

If it has been identified that surface water should be discharged to either a combined or a surface water sewer, the Council recommends early engagement with Scottish Water. The applicant will be required to provide evidence of consultation and approval in principle from Scottish Water for the surface water discharge prior to the determination of a planning application.

Public water connection

For any development which will require a new connection to the public water network, the Council recommends that the applicant engages with Scottish Water at the earliest possible opportunity.

A list of Scottish Water’s legal responsibilities in relation to the water environment can be found in Appendix 2.

SuDS maintenance

Applicants will be expected to consider long-term ownership and maintenance responsibilities of the surface water drainage network and associated infrastructure. In particular, all SuDS features which provide a statutory function are adopted or vested by a relevant in-perpetuity body.

Within the curtilage of private properties, responsibility for surface water drainage lies with the owner. Outwith private properties (unless the site is served by a private sewer) statutory responsibility for surface water drainage is split between roads authorities - responsible for the drainage of adopted roads - and water authorities - responsible for drainage of roof run-off and curtilages/other land.

Local authorities (roads authorities) and Scottish Water may enter into agreements for shared drainage. Some agreements provide for a single shared drainage system to drain surface water from properties and from roads. While generally considered to apply to piped sewerage systems, it has been used as the basis for an agreement for maintenance of public above-ground SuDS (including swales or other ground depression features) being the responsibility of the local authority or other, whilst below ground SuDS will be the responsibility of Scottish Water.

Planning application checklist

The following checklist may be used to ensure that any planning application submitted addresses the key matters covered by this guidance:

Consideration

Yes/No

Does the proposal improve the physical environment of a watercourse/water body

and therefore improve its water quality?

 

Is the development site at risk of flooding from any source?

 

Will the development lead to increased flood risk elsewhere?

 

Has the need for a Flood Risk Assessment been established?

 

Does the proposal include details of how surface and groundwater from the site will

be sustainably managed* during construction and post-construction?

 

Has a drainage statement or Drainage Impact Assessment been undertaken to the

required standard?

 

Is it possible to provide safe access and egress during flood events?

 

Does the proposal include details of who will be responsible for the ongoing

management and maintenance of the SuDS?

 

Does the proposal explain how the development proposals will impact on the water environment in relation to any habitats, protected species and/or natural

environment designations?

 

Are there opportunities to enhance and connect with green or blue infrastructure, providing multiple benefits - including provision of shelter, biodiversity habitats and links, creating attractive public spaces, access and travel, pollution mitigation and

food production - while managing surface water?

 

* in line with the requirements of CIRIA SuDS guidance (currently CIRIA C753 The SuDS Manual) and CIRIA C768 Guidance on the construction of SUDS), the Water Environment (Controlled Activities) (Scotland) Regulations 2011 (CAR) (as amended), (refer to CAR practical guide), and Local Development Plan 2 Policy 18

Appendices

Appendix 1 – Further Information and Guidance

East Dunbartonshire Flooding & Drainage Development Guidance

The East Dunbartonshire Supplementary Guidance on Green Infrastructure & Green Network

Flood Risk Advice and Guidance, Published by SEPA

General advice and guidance on flood risk

Guidance on how our flood maps can be used to ensure new development avoids areas at flood risk

Guidance for using SEPA Flood Maps for Land Use Planning

An overview of SEPA's position on development protected by flood protection schemes

Planning information note on development protected by a flood protection scheme

A framework to assist the assessment of the vulnerability of different types of land use to the impact of flooding

Land use vulnerability guidance

Climate change allowances for flood risk assessment in land use planning

 

 

 

Climate change allowances for

flood risk assessment in land use planning

Explanatory note on the difference between planning guidance and future flood maps

Future flood maps explanatory note

Assessment of potential application of the reservoir inundation maps for land use planning purposes position statement (developed by SEPA and agreed with the Flood Risk Land Use Planning Working Group and the Scottish Government)

Reservoir Inundation Maps – potential use for Land Use Planning

Development management advice and guidance on flood risk

SEPA Flood Risk Standing Advice for Planning Authorities and Developers for lower risk applications, 2020

SEPA Flood Risk Standing Advic

SEPA Triage Framework: Guidance for Planning Authorities and SEPA

SEPA Triage Framework

Outlines methodologies that may be appropriate for hydrological and hydraulic modelling, and what information SEPA requires to be submitted as part of a Flood Risk Assessment, 2019.

Technical flood risk guidance for stakeholders

A checklist to help consultants ensure that all the necessary information is submitted to SEPA, in Microsoft Excel format 2020.

 

 

Flood Risk Assessment checklist

An overview of SEPA's requirements and recommendations for planning applications that may impact on flood risk, 2018

Development management guidance on flood risk

Provides more technical detail on how SEPA's development management guidance is applied and the reasons for its position, 2018

Land use planning background paper on flood risk

Appendix 2 – Local authority and key agency statutory responsibilities

The following sections outline the primary legal responsibilities for the planning authority, SEPA and Scottish Water. Full details can be found in the Surface Water Management Planning Guidance document (2018) developed by the Scottish Advisory and Implementation Forum for Flooding (SAIFF), which includes representatives of Scottish Government, local authorities, Scottish Water and the Scottish Environment Protection Agency (SEPA).

Planning authority

Flood Risk Management (Scotland) Act 2009

  • Section 56 gives local authorities general powers to manage flood risk (from all sources including surface water) in their area, including implementing actions set out in local flood risk management plans, flood protection schemes or any other flood protection work. The definition of flooding under the FRM Act does not include flooding solely from a sewerage system. Flooding solely from a sewerage system includes flooding from the sewerage system under usual rainfall events (usual rainfall is currently interpreted to mean up to the 1:30 year rainfall event) and comes under the jurisdiction of Scottish Water. In reality, surface water flooding is often a complex interaction of flooding from many different sources, requiring close working between partner organisations to resolve. Many of the actions identified through the SWMP process can help to manage surface water flooding and flooding solely from a sewerage system.
  • Sections 17 and 18 require local authorities to map bodies of water and SuDS, assess bodies of water and prepare a schedule of clearance and repair works.
  • Section 59 requires local authorities to carry out clearance and repair works described in the schedule of clearance and repair works, in specific circumstances.
  • Section 1 requires all responsible authorities (including local authorities), when exercising their flood risk functions, to manage flood risk in a sustainable way and to co-operate with all responsible authorities.
  • Section 41 requires all public bodies and office-holders to have regard to flood risk management plans and local flood risk management plans, which often encompass surface water flooding, when exercising functions that affect a flood risk district.

Roads (Scotland) Act 1984

  • Roads authorities (including local authorities) have powers under the Roads (Scotland) Act 1984 to provide drainage of public roads (for normal circumstances) and for road safety. The latter may involve signage and traffic diversions in the event of flooding.
  • Section 31 gives roads authorities power to drain a public road or proposed public road, or Otherwise, to prevent surface water from flowing onto it.
  • Section 99 allows roads authorities to carry out works to prevent flows of water onto roads, where the owner or occupier of any land has failed to prevent the flow of water, filth, dirt or other offensive matter from, or any percolation of water through, the land onto the road.
  • Section 21 refers to the need for consent for anybody other than a roads authority to build a new road. Where a developer is seeking to petition the roads authority, any proposed layout and construction of roads, including road and surface water drainage, must satisfy current design standards.

Sewerage (Scotland) Act 1968

  • Section 7 allows roads authorities (including local authorities) and Scottish Water to enter into agreements on providing, managing, maintaining or using their sewers or drains for conveying water from the surface of a road or surface water from premises.

Town and Country Planning (Scotland) Act 1997

  • This act gives planning authorities (including local authorities) powers to grant or refuse planning applications.

Planning etc. (Scotland) Act 2006

  • Part 2 requires the planning authority to exercise its planning function with the objective of contributing to sustainable development.
  • Part 2 also states that a strategic development plan should set out the infrastructure of the area concerned, including communications, transport and drainage systems, and systems for the supply of water and energy.
  • Part 2 further states that where land is not within a strategic development plan area, a local development plan should set out the infrastructure of that area, including communications, transport and drainage systems, and systems for the supply of water and energy.

Town and Country Planning (Development Management Procedure) (Scotland) Regulations 2008

  • Regulation 25 and Schedule 5 require that planning authorities consult SEPA where a development is likely to result in a material increase in the number of buildings at risk of damage by flooding. Planning authorities must take into account SEPA’s advice, along with the development plan and other material considerations, when determining planning applications incurring flood risk.
  • The regulations require key agencies, including SEPA, to co-operate with strategic development plan authorities and planning authorities when compiling main issues reports, strategic and local development plans, and action (including proposed action) programmes.

The Town and Country Planning (Miscellaneous Amendments) (Scotland) Regulations 2011

  • These regulations came into force on 1 April 2011. They amend The Town and Country Planning (Development Planning) (Scotland) Regulations 2008 to include reference to flood risk management plans and local flood risk management plans. When preparing strategic development plans and local development plans, planning authorities must have regard to any approved or finalised flood risk management plan that impinges on the strategic or local development plan area.

The Town and Country Planning (Notification of Applications) (Scotland) Direction 2009

  • This requires planning authorities to notify Scottish Ministers of any application where SEPA has either advised against granting planning permission or recommended conditions concerning flood risk which the planning authority does not propose to attach to the planning permission.

Coastal Protection Act 1949

  • Section 4 allows the competent authority to carry out coastal protection works to protect land from coastal erosion and to regulate works carried out by others within their authoritative boundary.

Civil Contingencies Act 2004

  • Local authorities are a Category 1 responder under this act.
  • Part 3 places duties on Category 1 responders to assess risk of an emergency occurring, including surface water flooding.
  • Part 4 requires Category 1 responders to maintain plans and arrangements to warn, inform and advise the public in the event of an emergency under Section 14.
  • Such assessments and plans are to provide a framework of contingency actions, enabling the Council and partner agencies to construct a co-ordinated and flexible response to mitigate the effects of flooding emergencies, including surface water flooding.

Water Environment and Water Services (Scotland) Act 2003

  • Section 16 requires every public body and office-holder including local authorities, in exercising their functions, to have regard to the River Basin Management Plan.

Building (Scotland) Act 2003

  • Section 8 refers to the issuing of building warrants for construction work and, in conjunction with Part 3, covers compliance and enforcement.
  • Under Building (Scotland) Regulations 2004, Mandatory Building Standard 3.6, which is subject to review as part of local authorities issuing building warrants, requires every building and hard surface within the curtilage of a building to be designed and constructed with a surface water drainage system that will:
    • Ensure that surface water is disposed of without threatening the building and/or the health and safety of the people in and around it
    • Have facilities for separating and removing silt, grit and pollutants. SCOTTISH WATER

Flood Risk Management (Scotland) Act 2009

  • Section 16 requires Scottish Water to assess flood risk from sewerage systems.
  • Section 1 requires all responsible authorities (including local authorities), when exercising their flood risk functions, to manage flood risk in a sustainable way and to co-operate with all responsible authorities.
  • Section 41 requires Scottish Ministers and every public body and office-holder to have regard to flood risk management plans and local flood risk management plans, which will include surface water flooding.

Sewerage (Scotland) Act 1968

  • Sections 1 to 8 state that Scottish Water must design and fully maintain public sewers to ensure that they remain capable of effectively draining surface water.
  • Section 12 sets out Scottish Water’s right to refuse permission to or impose conditions on a private owner to connect with and drain into public sewers.
  • Section 21 specifies that Scottish Water must vet building applications to ensure that no building that could interfere with or obstruct a sewer is constructed over it.
  • Other sections (as amended by the Water Environment and Water Services Act 2003 and in particular Schedule 3) give Scottish Water responsibility for maintaining SuDS, which are defined as facilities that attenuate, settle or treat surface water from two or more premises (whether or not together with road water), where they have been designed and completed to a required standard.
  • Section 7 allows roads authorities and Scottish Water to enter into agreements for providing, managing, maintaining or using their sewers or drains for conveying water from the surface of a road or surface water from premises.

Water Industry (Scotland) Act 2002

  • Section 50 states that Scottish Water must, in exercising its functions, seek to ensure that its resources are used economically, efficiently and effectively.
  • Section 51 compels Scottish Water to act in a way that contributes to achieving sustainable development.
  • Under Section 53, Scottish Water must have regard to protecting cultural heritage, natural beauty/flora/fauna and geological sites of special interest.
  • Under Section 54, Scottish Water must consult Scottish Natural Heritage (SNH) and National Park authorities (NPAs) when carrying out works that could affect designated sites or NPA land.

Water Environment and Water Services (Scotland) Act 2003

  • Section 16 requires every public body and office-holder including Scottish Water, in exercising their functions, to have regard to the River Basin Management Plan.

SEPA

Flood Risk Management (Scotland) Act 2009

  • Section 9 requires SEPA to produce the National Flood Risk assessment.
  • Section 13 requires SEPA to identify Potentially Vulnerable Areas (PVAs).
  • Section 19 requires SEPA to map artificial structures and natural features.
  • Section 20 requires SEPA to assess the potential for Natural Flood Management.
  • Section 21 requires SEPA to prepare flood hazard and risk maps for PVAs.
  • Section 27 requires SEPA to prepare flood risk management strategies.
  • Section 72 requires SEPA to provide advice on flood risk to the planning authority when requested.
  • Section 74 requires SEPA to make available flood warnings. Planning etc. (Scotland) Act 2006
  • The act gives SEPA (as a key agency) the duty to co-operate in preparing development plans.

Water Environment and Water Services (Scotland) Act 2003

  • Section 10 requires SEPA to prepare River Basin Management Plans.
  • Section 9 requires SEPA to set objectives for the quality of the water environment and identify actions to achieve them.

Civil Contingencies Act 2004

  • SEPA is a category 1 responder under this Act.

Appendix 3 – Summary of status of water bodies in East Dunbartonshire

(Source: SEPA Water Environment Hub)

Water Body

Catchment

Length (km)

Genre

Current Status

Target Status 2021

Target Status 2027

Comments

Allander

Water

River Kelvin

18.042

Heavily modified

water body

Moderate

Moderate

Good

Flood risk

present

River Carron

River Carron

6.258

Surface water

Good

Good

Good

 

River Kelvin – Glazert Water to Tidal Limit

River Kelvin

22.017

Heavily modified water body

Poor

Poor

Good

Historic flood issue, but strategic flood defence scheme now

in place

River Kelvin – Auchinstarry to Glazert

River Kelvin

 

Heavily modified water body

Poor

Poor

Good

 

Luggie Water

– Kelvin to

Mollins Burn

River Kelvin

8.166

Heavily modified water body

Moderate

Moderate

Good

 

Bothlin Burn – Garnkirk Burn to Luggie confluence

River Kelvin

4.744

Heavily modified water body

Moderate

Moderate

Good

 

Board Burn

River Kelvin

7.409

Surface water

Moderate

Moderate

Good

 

Craigmaddie Burn

River Kelvin

7.837

Surface water

Good

Good

Good

 

Garrel Burn

River Kelvin

9.181

Heavily modified water body

Poor

Bad

Good

 

Glazert Water/Finglen Burn

River Kelvin

15.136

Surface water

Poor

Moderate

Good

Flood risk present

Kirk Burn

River Kelvin

5.519

Surface water

Moderate

Good

Good

 

Stand Burn/Park Burn

River Kelvin

8.134

Heavily modified water body

Poor

Moderate

Good

 

Forth and Clyde Canal – Mountblow to

Maryhill

Glasgow Coastal

9.895

Artificial water body

Good

Good

Good

Flood risk at Bishopbriggs

Forth and Clyde Canal – Glasgow to Kirkintilloch

River Kelvin

9.811

Artificial water body

Good

Good

Good

 

Forth and Clyde Canal – Kirkintilloch to

Kelvinhead

River Kelvin

14.105

Artificial water body

Good

Good

Good

 

Campsie Bedrock and localised sand and gravel

n/a

n/a

Bedrock

Poor

Poor

Good

n/a

 

Water Body

Catchment

Length (km)

Genre

Current Status

Target Status 2021

Target Status 2027

Comments

aquifers

(groundwater)

 

 

 

 

 

 

 

Clydebank and Kirkintilloch bedrock and localised sand and gravel aquifers

(groundwater)

n/a

n/a

Bedrock

Good

Good

Good

n/a

East Campsie bedrock and localised sand and gravel aquifers

(groundwater)

n/a

n/a

Bedrock

Good

Good

Good

n/a

Kelvin Valley sand and gravel (groundwater)

n/a

n/a

Bedrock

Good

Good

Good

n/aa