Glossary

 Assets: A flood risk management asset is usually an engineered structure but 

may also be a natural feature such as a grass embankment. Their purpose is to 

help manage the risk of flooding. These assets may be isolated structures, or 

they may work alongside others. Some structures may be located a significant 

distance from the communities they protect e.g., a flood storage area and 

associated embankments. 

 Attenuation: Refers to the reduction or slowing down of floodwater flow to 

manage flood risks. The goal of attenuation is to lessen the impact of flooding by 

controlling how and when water reaches vulnerable areas.

 Catchment: The area from which precipitation contributes to the flow from a 

borehole spring, river or lake. For rivers and lakes this includes tributaries and 

the areas they drain. In river basin management this can refer to the larger 

management catchments and the smaller operational catchments.

 Climate Change: The long-term shifts in global temperatures and weather 

patterns, primarily driven by human activities since the Industrial Revolution.

 Confluence: where watercourses join to become one

 Contingency: When we assess the risk of an asset being below required 

condition (BRC), we consider what, if any, measures need to be put in place to 

reduce the risk until we can return the asset to target condition. Some asset 

types must perform or there is an immediate risk e.g. pumps, sluice gates, tidal 

barriers, and our Strategically Important Assets. For these asset types we 

develop plans in advance to consider what measures would be needed if the 

asset was to fail.

 Conveyance: the flow, movement or transfer of water from one location to another

 Critical Drainage Areas (CDAs): Is considered to be an area contributing to surface water 

runoff, either as direct overland flow or from the existing sewer network, which causes flooding 

at locations within that area (final hotspots). The risk of flooding is thereby confirmed, either by historical 

evidence, or through numerical modelling or other detailed form of analysis. A CDA therefore 

has areas within it where surface water flood risk exists (final hotspots) and 

areas where properties, although not directly at risk, contribute to that flood risk (upstream 

areas in a CDA directly affecting flood-prone areas)

 Culvert: A covered channel or pipe designed to prevent the obstruction of a 

watercourse or drainage path by an artificial construction.

 Decommissioning assets: Decommissioning is where we have identified a need to discontinue the Environment Agency undertaking managing, maintaining and using Flood and Coastal Risk Management (FCRM) assets.

 Dredging: Dredging in the Environment Agency means removing accumulated 

material in the river like gravel or soil (often referred to as silt) that has been 

washed into rivers from somewhere else, as well as rocks and plant life.

 FCRM - Flood and coastal risk management (or FCERM - flood and coastal erosion risk 

management): Activities to reduce the risks (likelihood and consequences) of 

flooding from rivers and the sea to people, property and the natural environment 

or any component in the assessment of a risk, and any activity to analyse, assess 

or alter the balance of factors combined in assessing the risk.

 FCERM GiA (grant-in-aid): Money provided by central government (through 

Defra) to fund FCERM. [Defra provides the majority of its funding for FCERM to 

the EA as Grant-in-Aid, which is the mechanism for financing Non-Departmental 

Public Bodies (NDPB), such as the EA. The EA spends this funding directly on 

managing flood risk, but it also passes some of this funding on as capital grants 

for flood or coastal erosion defence improvements to Local 

Authorities or Internal Drainage Boards].

 Final Hotspots: Areas within Critical Drainage Areas where surface water flood risk exists (flood prone areas within a CDA).

 Flood: Where land not normally covered by water becomes covered by water by, 

for example: heavy rainfall; a river overflowing its banks or being breached; a 

dam overflowing or being breached; tidal waters; groundwater; surface water 

from drainage or any combination of these factors.

 Flood groups: The Environment Agency does not own or manage any flood 

groups and therefore we do not hold a list of them. Our local operations teams 

may share advice and information with individuals or groups that support or 

represent their communities during flood events.

 Floodplain: An area of land over which river or sea water flows or is stored during 

a flood.

 Flood risk: Chance of a flood.

 Flood Risk Activity Permitting (FRAP): All flood risk activity permits are 

processed through the Environment Agency’s National Permitting Service (NPS). 

Local area teams provide pre-application advice to customers.

 Flood Zones: The Environment Agency publishes the Flood Zones and 

information on main rivers, flood defences and water storage areas on the Flood 

Map for Planning service. 

- Flood zone 1 = Very low (Less than 0.1% chance of a flood each year)

- Flood zone 2 = Low (Between 0.1% and 1% chance of a flood each year)

- Flood zone 3 = Medium (Between 1% and 3.3% chance of a flood each year)

- Flood zone 3b = High (More than 3.3% chance of a flood each year).

 Fluvial: Relating to rivers and their flows.

 Groundwater flooding: Groundwater flooding happens when levels of water in 

the ground rise above the surface. It can aƯect property and structures above 

and below the ground. It is most likely to occur in areas underlain by permeable 

rocks, called aquifers. These can be extensive, regional aquifers, such as chalk 

or sandstone, or may be more local sand or river gravels in valley bottoms 

underlain by less permeable rocks.

 Infiltration: The process by which water moves from the surface into the soil and sub-surface layers 

 Internal drainage board (IDB): A public body that manage 

water levels in an area, known as an internal drainage district, where there is a 

special need for drainage. IDBs undertake works to reduce flood risk to people 

and property, and manage water levels for agricultural and environmental needs 

within their district.

 Lead local flood authority (LLFA): The unitary authority for the area or if there is 

no unitary authority, the county council for the area. LLFAs have a leadership role 

on local flood risk management in their area. Lead Local Flood Authorities 

(LLFAs) are responsible for managing flooding from local flood risk (surface 

water, ordinary watercourses and groundwater). 

 Maintenance:  Regular scheduled works undertaken in a channel or to an asset to preserve conveyance or an asset's condition and function. We prioritise maintenance work on assets to provide the greatest flood risk reduction for people, homes, and businesses.

 Main river: Some watercourses in England are designated as ‘main rivers’. These 

tend to be larger rivers and streams with the highest flood risk, although in some 

cases they can be small watercourses, drainage channels or covered ‘culverts’.

 "Major development” in planning: Development involving any one or more of the following—

 Modelling: The Environment Agency uses flood modelling to understand the risk 

of flooding at a local and a national level. Our flood models use a range of 

information to help make them as reliable as possible.

 National Flood Risk Assessment (NaFRA2): The EA are developing a new 

national flood risk assessment to meet changing needs for flood risk 

information: 

- an indication of current and future flood risk to guide investment and 

development planning 

- scenarios to plan for, respond and adapt to flooding 

 - better and clearer information to help our customers and partners 

understand flood risk and take action to build resilience 

 National Flood Forum (NFF): The National Flood Forum (NFF) is a charity that 

supports those at flood risk or who have flooded. They operate across England 

and Wales.

 Natural Flood Management (NFM): Natural flood management (NFM) uses 

natural processes to reduce the risk of flooding. These processes protect, 

restore, and mimic the natural functions of catchments, floodplains and the 

coast to slow and store water.

 Net Zero: The Government’s long-term strategy to end the 

UK’s domestic contribution to man-made climate change by 2050. The 

Environment Agency’s main carbon footprint comes from constructing flood 

defences and pumping water to alleviate flood and drought. The emissions from 

these activities will need to significantly reduce to achieve net zero, which will 

require innovation as some of the technologies needed to achieve this do not yet 

exist. 

 Ordinary watercourse: Small or less critical watercourses are classified as 

"ordinary watercourses," and their management typically falls under local 

authorities, such as Lead Local Flood Authorities (LLFAs) or Internal Drainage 

Boards (IDBs). Riparian landowners also share responsibilities for maintaining 

ordinary watercourses to ensure natural water flow.

 Permissive Powers: The term permissive means that we have the power to 

undertake flood and coastal risk management works but are not legally obliged 

to provide such works. In using these powers we must also comply with 

European legislation particularly the Habitats and Birds Directives, the Floods 

Directive and the Water Framework Directive and any other legal requirements.

 Property Flood Resilience (PFR): Refers to measures that can be put on or in a 

property to help manage the impact that flooding has on homes and businesses.

 Regional Flood and Coastal Committees (RFCCs): RFCCs guide flood and 

coastal erosion risk management activities within their river catchments and 

along the coastline. There are 12 RFCCs in England.

 Riparian owner: Where a watercourse runs adjacent to or through your land you 

will be what is termed a ‘riparian owner’. - Your watercourse: rights and roles

 Risk Management Authority: These are the organisations responsible for managing the risk of flooding. They are each assigned their own source/s of flood risk for which they are responsible, as outlined by the National Flood and Coastal Erosion Risk Management Strategy for England. This strategy describes what needs to be done by the Risk Management Authorities (RMAs) in respect to all sources of flooding and coastal erosion for the benefit of people, places and the environment. The RMAs include:

• The Environment Agency
• Lead Local Flood Authorities (LLFAs)
• District Councils
• Internal Drainage Boards
• Highways Authorities
• Water and Sewerage companies

To see what source/s of flooding each RMA is responsible for - https://engageenvironmentagency.uk.engagementhq.com/leicester-city-flooding-information/widgets/135005/faqs#36238.

 Sandbags: The Environment Agency does not have a duty to supply or install 

sandbags, although we may use them as part of a range of measures to protect 

and bolster existing defences.

 Surface water flooding: Surface water flooding happens 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.

 Surface water runoff: Rainwater (including snow) on the surface of the ground 

which has not entered a watercourse, drainage system or public sewer.

 Telemetry: In situ collection of measurements. In the EA this refers to collecting 

data about river levels rather than rainfall.

 Throughflow: is the lateral movement of water through the soil layer, occurring after infiltration and often when the soil is saturated.

 Watercourse: A watercourse can be any stream of water flowing in a defined 

channel or through an underground pipe or culvert. It can be small or wide, 

natural, or artificial and includes channels that are dry for long periods of time 

and may not flow every year. A dry channel only filled during temporary flooding 

is not a watercourse.

 Water Storage: In some locations we know that the best flood management 

option is to store water on farmland. The Environment Agency creates flood 

storage areas whenever they are appropriate as part of flood risk management 

improvements