Glossary

Activities undertaken to reduce the impact of flooding. Actions in the plans describe where and how flood risk will be managed. These actions have been set by SEPA and agreed with flood risk management authorities and were subject to public consultation. Section 1.2.6 of the flood risk management plans describes how actions have been selected.

An adaptation plan is intended to inform medium to long term management of an area. This plan should investigate multiple potential climate change scenarios and identify the best route to flood management under each scenario.

Depending on its size or severity each flood will cause a different amount of damage to a given area. Annual average damages (AADs) are the theoretical average economic damages caused by flooding when considered over a very long period of time. It does not mean that level of damage will occur every year: in many years there will be no damages, in some years minor damages and in a few years major damages may occur. High likelihood events, which occur more regularly, contribute proportionally more to AADs than rarer events. Within the flood risk management plans AADs incorporate economic damages to the following receptors: residential properties, non-residential properties, vehicles, emergency services, agriculture and roads. They have been calculated based on the principles set out in the Flood Hazard Research Centre Multi-Coloured Manual (2016).

An annual cost of flooding is an assessment of the economic impact of flooding within an area. Depending on its size or severity each flood will cause a different amount of damage to a given area. See ‘annual average damages’.

The process of defining objectives, examining flood management options and weighing up costs, benefits, risks and uncertainties before a decision is made. The appraisal method used in the flood risk management plans is designed to set objectives and identify the most sustainable combination of actions to tackle flooding from rivers, the sea and surface water.

Public awareness, participation and community support are essential components of sustainable flood risk management. Improved awareness of flood risk and actions that prepare individuals, homes and businesses for flooding can reduce overall impact. SEPA and other responsible authorities have a duty to raise public awareness of flood risk. This is undertaken both individually and collaboratively by a range of organisations.

Bathing waters are classed as protected areas under Annex IV of the Water Framework Directive (WFD). There are 84 designated bathing waters in Scotland.

A benefit cost ratio summarises the overall value for money of an action or project. It is expressed as the ratio of benefits to costs (both expressed as present value monetary values). A ratio greater than 1:1 indicates that the economic benefits associated with an action are greater than the economic costs of implementation; therefore, this is taken as the threshold of economic viability. It should be recognised that it is not always possible to accurately estimate economic values for all elements of benefit, and benefit cost ratio is just one of a number of techniques used in appraisal.

Blue green infrastructure refers to use of green pathways to store or transfer excess water and includes sustainable drainage systems, swales (shallow, broad and vegetated channels designed to store and/or convey runoff and remove pollutants), wetlands, rivers, canals (and their banks) and all watercourses. See also green infrastructure.

Buildings that are not used for people to live in, such as shops or other public, commercial or industrial buildings.

All the land drained by a river and its tributaries.

Category 1 and 2 responders are defined as part of the Civil Contingencies Act 2004 which seeks to minimise disruption in the event of an emergency.

• Category 1 responders are ‘core’ responders: local authorities, police, fire and rescue services, ambulance service, NHS health boards, SEPA and the Maritime and Coastguard Agency.
• Category 2 responders are key co-operating responders in support of Category 1 responders. These include gas and electricity companies, rail and air transport operators, harbour authorities, telecommunications providers, Scottish Water, the Health and Safety Executive and NHS National Services Scotland.

Where work has been carried out on a river channel allowing an increase in the volume of water it can carry.

A description of the natural characteristics of catchments, coastlines and urban areas in terms of hydrology, geomorphology, topography and land use. It also includes the characterisation of existing levels of flood risk and activities to manage flood risk.

Coastal flooding is where the risk is from the sea. Flooding can result from high sea levels or a combination of high sea levels and stormy conditions. The term coastal flooding is used under the Flood Risk Management (Scotland) Act 2009, but in some areas it is also referred to as tidal flooding and covers areas such as estuaries and river channels that are influenced by tidal flows.

Combined sewers transport sewage from homes and industry and also carry surface water runoff from gutters, drains and some highways. Heavy or prolonged rainfall can rapidly increase the flow in a combined sewer until the amount of water exceeds sewer capacity.

Combined sewer overflows are structures designed to ensure any excess water from sewerage systems is discharged in a controlled way and at a specific managed location.

Within the plans the term ‘community facilities’ includes:

• Emergency services (police, fire, ambulance, coastguard, and mountain rescue)
• Educational buildings (crèche, nursery, primary, secondary, further, higher and special education premises)
• Healthcare facilities: hospitals, health centres and residential care homes

Community flood action groups are community-based resilience groups which, on behalf of local residents and businesses, help to prepare for and minimise the effects of flooding. They reflect the interests of their local communities and may differ in composition and remit. There are over 60 groups already established in Scotland. The Scottish Flood Forum provides support for both new and existing groups.

Where two or more rivers meet.

Conveyance is a measure of the carrying capacity of a watercourse. Increasing conveyance enables flow to pass more rapidly and reducing conveyance slows flow down. Both actions can be effective in managing flood risk depending on local conditions.

The Cross Border Advisory Group is a statutory group made up of representatives from the Environment Agency, SEPA, Scottish Water and the 4 local authorities located within the Solway-Tweed River Basin District. This group ensure coordination of plans across the border between England and Scotland.

Historic Environment Scotland maintains lists of buildings of special architectural or historic interest. These buildings are referred to as ‘listed buildings’. The highest level of designation is a World Heritage Site. Other designations included in this assessment are scheduled monuments, gardens and designed landscapes, and battlefields.

A pipe, channel or tunnel used for the conveyance of a watercourse or surface drainage water under a road, railway, canal or other obstacle.

Flood damages are categorised as direct or indirect i.e. as a result of the flood water itself, or subsequent knock on effects. Damage to buildings and contents caused by flood water are an example of direct damages, whilst loss of industrial production, travel disruption or stress and anxiety are indirect. Some damages can be quantified in monetary terms, and others can only be described.

The potential damages avoided by implementation of a flood risk management action are commonly referred to as the benefits of that action. When comparing the effectiveness of different actions, it is useful to consider estimated damages and damages avoided across the lifespan of the action. Within the plans, a 100-year appraisal period has been used as standard. This allows costs, damages and benefits across this time frame to be compared in present value terms. See also ‘annual average damages’

A temporary flood barrier is one that is only installed when the need arises, that is, when flooding is forecast. A demountable flood defence is a particular type of temporary defence that requires built-in parts and therefore can only be deployed in one specific location.

An assessment of the economic value of the positive and negative effects of flooding and/or the actions taken to manage flooding.

Flood embankments are engineered earthfill structures designed to contain high river levels or protect against coastal flooding. They are commonly grass-covered but may need additional protection against erosion by swiftly flowing water, waves or overtopping.

Emergency response plans are applicable for all types of flooding. They set out the steps to be taken during flooding in order to maximise safety and minimise impacts where possible. Under the Civil Contingencies Act, Category 1 responders have a duty to maintain emergency plans. Emergency plans may also be prepared by individuals, businesses, organisations or communities.

A change in the environment as a result of an action or activity. Impacts can be positive or negative and may vary in significance, scale and duration.

Environmental Impact Assessment (EIA) is a process which identifies the potential environmental impacts, both negative and positive of a proposal.

Areas formally designated for environmental importance, such as Sites of Special Scientific Interest (SSSI), Special Protection Areas (SPA) and Special Areas of Conservation (SAC).

A natural process leading to the removal of sediment from a river bed, bank, floodplain or coastline.

A coastal body of water usually found where a river meets the sea; the part of the river that is affected by tides.

A break or fracture in the earth's crust as a result of the displacement of one side with respect to the other. In Scotland the Great Glen Fault is a major geological fault line cutting diagonally across the Highlands from Fort William to Inverness.

A flood that occurs a short period of time after high intensity rainfall or a sudden snow melt. A sudden increase in the level and velocity of the water body is often characteristic of these events, leaving little time for issuing flood warnings or taking action to minimise the impact of flooding.

A 'flashy' river or watercourse has a short lag time (the delay between peak rainfall intensity and peak river discharge), high peak discharge, and quickly returns to average flow. Rivers with these characteristics can be prone to flooding and leave a short time for warning or actions.

In the terms of the Flood Risk Management (Scotland) Act 2009, ‘flood’ means a temporary covering by water, from any source, of land not normally covered by water. This does not include a flood solely from a sewerage system, as a result of normal weather or infrastructure drainage. A flood can cause significant adverse impacts on people, property and the environment.

A constructed retaining wall, embankment or dyke designed to protect against flooding to a specified standard of protection.

nfrastructure, such as flood walls and embankments, intended to protect an area against flooding, to a specified standard of protection.

The area that has been affected by flooding or is at risk of flooding for a particular likelihood of flooding.

SEPA operates a network of over 250 rainfall, river and coastal monitoring stations throughout Scotland that generates data 24 hours a day. This hydrological information is combined with meteorological information from the Met Office. A team of experts then predict the likelihood and timing of river, coastal and surface water flooding. This joint initiative between SEPA and the Met Office forms the Scottish Flood Forecasting Service.

The probability that a particular size/severity of flood will occur in a given year (see likelihood).

An adjustable, sometimes temporary, barrier used as a flood defence to control the flow of water within a water system or during a flood. Flood gates can also be part of operational flood defences or protect individual buildings or sites.

Flood guards cover a variety of types of door and window barriers that can be fitted to individual properties and operated by the owners / occupiers prior to a flood event. They act as a physical barrier to water entering the property and can provide protection against frequent and relatively shallow flooding.

In terms of the Flood Risk Management (Scotland) Act 2009, hazard refers to the characteristics (extent, depth, velocity) of a flood.

Flood hazard maps are required by the Flood Risk Management (Scotland) Act 2009 to display information on the nature of a flood in terms of the source, extent, water level or depth and, where appropriate, velocity of water. Flood hazard and risk maps are referred to collectively as flood maps and are available on the SEPA website.

An area of land that borders a watercourse, an estuary or the sea, over which water flows in time of flood, or would flow but for the presence of flood defences and other structures where they exist.

Floodplains naturally store water during high flows. Storage can be increased through natural or man-made features to increase flood depth or slow flows in order to reduce flooding elsewhere.

The Flood Prevention (Scotland) Act 1961 gave local authorities discretionary powers to build flood prevention schemes. It was superseded by the Flood Risk Management (Scotland) Act 2009.

A flood protection scheme, as defined by the Flood Risk Management (Scotland) Act 2009, is a scheme developed by a local authority for the management of flood risk. This includes defence measures (flood prevention schemes) formerly promoted under the Flood Prevention (Scotland) Act 1961.

Flood protection works can include the same flood defence measures that would make up a formal flood protection scheme but without the legal process, protections and requirements that would come with delivering the works as a scheme. These are generally smaller flood defence measures.

A measure of both the likelihood of flooding occurring and the associated impacts on people, the economy and the environment.

Flood risk assessments are detailed studies of an area where flood risk may be present. These are often used to inform planning decisions, may help to develop flood schemes and have also contributed to the national flood risk assessment.

The flood risk management legislation for Scotland. It transposes the EC Floods Directive into Scots Law and aims to reduce the adverse consequences of flooding on communities, the environment, cultural heritage and economic activity.

Under the Flood Risk Management (Scotland) Act 2009, flood risk management planning is undertaken in 6 year cycles. The first planning cycle was 2015-2021. The delivery cycle was lagged by approximately 6 months and was from 2016-2022. The second planning cycle runs from 2021-2027 and the delivery cycle from 2022-2028.

Local advisory groups are stakeholder groups convened to advise SEPA and lead local authorities during the preparation of the plans. The groups include representatives from a range of sectors, including government agencies like Transport Scotland, National Park Authorities, local authorities, non-government organisations, utility companies and land and asset managers.

Flood risk management plans set out a long-term vision for the overall management of flood risk, helping to target investment and coordinate actions across public bodies. They set objectives for tackling flooding in high risk areas and identify the actions needed to work towards those objectives.

The plans are published by SEPA and are approved by Scottish Ministers. They are prepared in collaboration with all 32 local authorities, national parks, Scottish Water and other organisations with a responsibility or interest in managing flooding. They are also shaped in consultation with the public.

The term used for the first set of flood risk management plans, which were published in December 2015. The strategies have since been replaced by the 2021 flood risk management plans. The term ‘flood risk management plan’ is consistent with the Flood Risk Management (Scotland) Act 2009 and other areas of the UK.

The risk map complements the flood hazard maps, providing detail on the impacts of flooding on people, the economy and the environment. Flood hazard and risk maps are referred to collectively as flood maps and are available on the SEPA website.

Flood studies aim to refine understanding of the hazard and risk associated with flooding in a particular area, catchment or coastline. They involve detailed assessment of flood hazard and/or risk and may develop options for managing flood risk.

A flood defence feature used to defend an area from flood water to a specified standard of protection.

A flood warning scheme is the network of monitoring on a coastal stretch or river which provides SEPA with the ability to issue flood warnings.

On the 1st of April 2019, Forestry and Land Scotland was formed to take forward the work previously undertaken by Forestry Commission Scotland and Forest Enterprise Scotland.

The European Commission defines green infrastructure as “the use of ecosystems, green spaces and water in strategic land use planning to deliver environmental and quality of life benefits. It includes parks, open spaces, playing fields, woodlands, wetlands, road verges, allotments and private gardens. Green infrastructure can contribute to climate change mitigation and adaptation, natural disaster risk mitigation, protection against flooding and erosion as well as biodiversity conservation.” See also ‘blue green infrastructure’.

This type of flooding is caused by water rising up from underlying rocks or flowing from springs. In Scotland groundwater is generally a contributing factor to flooding rather than the primary source.

In urban areas, the causes of flooding are complex because of the interactions between rivers, surface water drainage and combined sewer systems and tidal waters. Scottish Water works with SEPA and local authorities to assess these interactions through detailed studies.

The process undertaken by public authorities to identify, evaluate and decide on different options for the use of land, including consideration of long term economic, social and environmental objectives and the implications for different communities and interest groups.

A local authority responsible for leading the production, consultation, publication and review of a local flood risk management plan. A flood risk management plan and local flood risk management plan is produced for each of the 14 Local Plan Districts in Scotland.

The chance of flooding occurring:

• High likelihood: A flood event is likely in the defined area on average once in every 10 years (1:10). Or a 10% chance of happening in any one year.
• Medium likelihood: A flood event is likely in the defined area on average once in every 200 years (1:200). Or a 0.5% chance of happening in any one year.
• Low likelihood: A flood event is likely in the defined area on average once in every 1000 years (1:1000). Or a 0.1% chance of happening in any one year.

The local flood risk management plans complement the flood risk management plans and are published by the lead local authority for each Local Plan District every 6 years. The local plans provide more detail on how the actions set out in the flood risk management plans will be delivered including information on the funding, timing and co-ordination of actions.

A local nature reserve is a protected area of land designated by a local authority because of its local special natural interest and / or educational value. Local authorities select and designate local nature reserves using their powers under the National Parks and Access to the Countryside Act 1949.

A local nature reserve is a protected area of land designated by a local authority because of its local special natural interest and / or educational value. Local authorities select and designate local nature reserves using their powers under the National Parks and Access to the Countryside Act 1949.Geographical areas assigned for the purposes of flood risk management planning. There are 14 Local Plan Districts (LPDs) in Scotland.

Each Local Plan District has established a local partnership comprised of local authorities, SEPA and Scottish Water (and others as appropriate). These partnerships are distinct from the local advisory groups, and they retain clear responsibility for delivery of the flood risk management actions set out in the local flood risk management plans. It is the local partnership that makes decisions and supports the delivery of these plans.

Sections 18 and 59 of the Flood Risk Management (Scotland) Act 2009 put duties of watercourse inspection, clearance and repair on local authorities. In addition, local authorities may also be responsible for maintenance of existing flood protection schemes or defences.

The National Flood Management Advisory Group provides advice and support to SEPA and, where required, Scottish Water, local authorities and other responsible authorities on the production of flood risk management plans and local flood risk management plans.

The national flood risk assessment provides a high-level overview of flood risk in Scotland. First published in December 2011, the NFRA provides the information needed to take a strategic approach to flood management. Information from the national flood risk assessment on the level of risk across the country is used to determine the potentially vulnerable areas. (see potentially vulnerable areas). The NFRA was reviewed and updated for the second flood risk management cycle in 2018 and is available to view on the SEPA website.

A set of techniques that aim to work with natural processes (or nature) to manage flood risk.

On the 1st of May 2020 Scotland’s national nature agency, Scottish Natural Heritage changed its name to NatureScot.

Properties that are not used for people to live in, such as shops or other public, commercial or industrial buildings.

The objectives in the plans provide a common goal and shared ambition for managing flooding. The objectives have been set by SEPA and agreed with flood risk management authorities and were identified by considering the causes and impacts of flooding in each target area.

See ‘likelihood of flooding’ and ‘return period’

An options appraisal study identifies and assesses a range of options that achieve flood risk management objectives whilst delivering other economic, social and environmental benefits. This helps to inform the decision-making process and identify how options work together to identify a preferred option for managing flooding within an area.

Current national planning policies, Scottish Planning Policy and accompanying Planning Advice Notes restrict development within the floodplain and limit exposure of new receptors to flood risk. In addition to national policies, local planning policies may place further requirements within their area of operation to restrict inappropriate development and prevent unacceptable risk.

Potentially vulnerable areas are catchments identified as having the greatest potential risk of flooding. These areas are the focus of further assessment and may require a multi-agency response to manage the flood risk. 233 PVAs were identified in the 2018 national flood risk assessment.

A preferred option identifies the collection of flood management options which combined offer the most suitable way of managing flooding within an area, based on the economic, social and environmental benefits of the options.

Property level protection includes flood gates, sandbags and other temporary barriers that can be used to prevent water from entering individual properties during a flood.

Some responsible authorities may have a formal scheme to provide, install and maintain property level protection for properties.

Ramsar Sites are wetlands of international importance designated under the Ramsar Convention.

Refers to the entity that may be impacted by flooding (a person, property, infrastructure or habitat). The vulnerability of a receptor can be reduced by increasing its resilience to flooding.

The risk which remains after risk management and mitigation. This may include risk due to very severe (above design standard) storms or risks from unforeseen hazards.

The ability of an individual, community or system to recover from flooding.

Responsible authorities are designated under the Flood Risk Management (Scotland) Act 2009 and associated legislation. The current responsible authorities are local authorities, Scottish Water and the National Park Authorities. Responsible authorities, along with SEPA and Scottish Ministers, have specific duties in relation to their flood risk related functions.

A measure of the rarity of a flood event. It is the statistical average length of time separating flood events of a similar size. (See Likelihood).

Sloping structures placed on banks or at the foot of cliffs in such a way as to deflect the energy of incoming water

The Water Environment and Water Services (Scotland) Act 2003 transposed the European Water Framework Directive into Scots Law. The Act created the river basin management planning process to achieve environmental improvements to protect and improve our water environment. It also provided the framework for regulations to control the negative impacts of all activities likely to have an impact on the water environment.

Flooding from a river or other watercourse. The risk of flooding from rivers is usually due to heavy or prolonged rainfall causing a river to rise above the top of the bank. Water spreads out and floods nearby areas.

Actions within a catchment or sub-catchment to reduce the amount of runoff during rainfall events. This can include intercepting rainfall, storing water, diverting flows or encouraging infiltration.

The stakeholder forum on flooding set up by the Scottish Government to ensure legislative and policy aims are met and to provide a platform for sharing expertise and developing common aspirations and approaches for reducing the impact of flooding on Scotland’s communities, environment, cultural heritage and economy.

Sediment management covers a wide range of activities that includes anything from the small-scale removal of dry gravels to the dredging of whole river channels and the reintroduction of removed sediment into the water environment. Historically, sediment management has been carried out for several reasons, including reducing flood risk, reducing bank erosion, for use as aggregate and to improve land drainage.

Self help actions can be undertaken by any individuals, businesses, organisations or communities at risk of flooding. They are applicable to all sources, frequency and scales of flooding. They focus on awareness raising and understanding of flood risk.

Flooding as a result of the sewer or other artificial drainage system (e.g. road drainage) capacity being exceeded by rainfall runoff or when the drainage system cannot discharge water at the outfall due to high water levels (river and sea levels) in receiving waters

Scottish Water carry out an assessment of sewer flood risk within priority sewer catchments to improve understanding of the performance of the urban drainage network.

A shoreline management plan is a large-scale assessment of the coastal flood and erosion risks to people and the developed, historic and natural environment. It sets out a long-term framework for the management of these risks in a sustainable manner.

Sites of Special Scientific Interest are protected by law under the Nature Conservation (Scotland) Act 2004 to conserve their plants, animals and habitats, rocks and landforms.

Site protection plans are developed to identify whether normal operation of a facility can be maintained during a flood. This may be due to existing protection or resilience of the facility or the network.

The type of flooding. This can be coastal, river, surface water or groundwater.

Special Areas of Conservation are strictly protected sites designated under the European Habitats Directive. The directive requires the establishment of a European network of protected areas which are internationally important for threatened habitats and species.

Special Protection Areas are strictly protected sites classified in accordance with the European Birds Directive. They are classified for rare and vulnerable birds (as listed in the directive), and for regularly occurring migratory species.

All flood protection structures are designed to be effective up to a specified flood likelihood (standard of protection). For events beyond this standard, flooding will occur. The chosen standard of protection will determine the required defence height and / or capacity.

A feature that can be used to store floodwater, this can be natural in the form of low lying land or manmade such as a reservoir or modified landform.

A process for the early identification and assessment of the likely significant environmental effects, positive and negative, of activities. Often considered before actions are approved or adopted.

A strategic flood risk assessment is designed for the purposes of specifically informing the development plan process. A SFRA involves the collection, analysis and presentation of all existing and readily available flood risk information (from any source) for the area of interest. It constitutes a strategic overview of flood risk.

Strategic mapping improvement actions have been identified in locations where SEPA is planning to undertake additional modelling or analysis of catchments and coastlines, working collaboratively with local authorities where appropriate, to improve the national understanding of flood risk.

Watercourses and culverts can carry a limited amount of water. When they can no longer cope, they overflow, or ‘surcharge’.

Flooding that occurs when rainwater does not drain away through the normal drainage systems or soak into the ground but lies on or flows over the ground instead.

A plan that takes an integrated approach to drainage accounting for all aspects of urban drainage systems and produces long term and sustainable actions. The aim is to ensure that during a flood the flows created can be managed in a way that will cause minimum harm to people, buildings, the environment and businesses.

The management of flooding from surface water sewers, drains, small watercourses and ditches that occurs, primarily in urban areas, during heavy rainfall. Flood risk management plan actions in this category include: surface water management plans, integrated catchment studies and assessment of flood risk from sewerage systems (Flood Risk Management (Scotland) Act 2009, Section 16) by Scottish Water. These actions have been selected as appropriate for each target area

A set of techniques designed to slow the flow of water. They can contribute to reducing flood risk by absorbing some of the initial rainfall and then releasing it gradually, thereby reducing the flood peak and helping to mitigate downstream problems.

The sustainable flood risk management approach aims to meet human needs, whilst preserving the environment so that these needs can be met not only in the present, but also for future generations. The delivery of sustainable development is generally recognised to reconcile 3 pillars of sustainability – environmental, social and economic.

Target areas are based on communities at risk of flooding. These are situated within potentially vulnerable areas and should benefit from actions to reduce flood risk. Objectives and actions to manage flooding have been set for each target area in the flood risk management plans. To benefit the community, actions may be applied outside the target area.

The leading source of climate change information for the UK. It can help users to assess their climate risks and plan how to adapt to a changing climate. The high emissions scenario refers to the RCP8.5 emission scenario. See the UKCP18 climate change projections report for details.

A dialect term, common in place names and used to refer to a small bay or creek in Orkney or Shetland.

A measure of how likely someone or something is to suffer long-term damage as a result of flooding. It is a combination of the likelihood of suffering harm or damage during a flood (susceptibility) and the ability to recover following a flood (resilience).

Wave overtopping occurs when water passes over a flood wall or other structure as a result of wave action. Wave overtopping may lead to flooding particularly in exposed coastal locations.