Glossary of Terms

ADA: Association of Drainage Authorities

Biodiversity Action Plan (BAP): A Biodiversity Action Plan provides a framework for habitat and species conservation, both highlighting threats and issues, and encouraging methods of best practice

Berm: A horizontal shelf cut into an embankment to break the continuity of a long slope to reduce erosion and provide beneficial habitat

Brownfield site: A redevelopment site, usually within an urban area

Catchment: The area adjacent to a watercourse from which water drains into it

Control Structure: A device to limit the flow of water Gravity System: A drainage system whereby flow is caused by the action of gravity

Culvert: A closed conduit or structure used to convey water through an obstruction for example an embankment or roadway.

DEFRA: Department for Environment, Food and Rural Affrairs

Dredge: The deepening of a watercourse through the removal of sediment or deposited material

GIS: Geographical Information System

Greenfield site: A new development, usually at the edge of an urban area

Headwall: A retaining wall placed either end of a pipe or culvert

IDB: Internal Drainage Board

Land Drainage Act: The Land Drainage Act was passed in 1991 and requires that watercourses are maintained be their owner so that the free flow of water is not impeded

Lead Local Flood Authority (LLFA): The body responsible for developing, maintaining, applying and monitoring a strategy for local flood risk management in its area (For more information on the role of LLFAs please see DEFRA’s Local Authority Factsheet

Outfall: The point where water discharges from a pipe, channel, or other conduit

Pile: A long, slender structure driven into a bank to improve its support and stability

Right to Accretion: A right to material deposited by the watercourse

Right to Boomage: A right of entry onto riperian land for the purpose of fastening of booms and boom sticks

Riparian: Anything connected with, or adjacent to a watercourse

Runoff: Water from precipitation that flows off a surface to reach a drain or sewer

Screen: A device used to retain or remove solids flowing in drains

Sluice: A sliding gate or door, which controls the flow of water (i.e. flow when the gate is open, no flow when the gate is closed)

Sustainable Drainage Systems (SuDS): Drainage techniques believed to be environmentally beneficial or causing little or no long-term detrimental impact

Weed Cutting: The process of removing weed from the channel

Weir: An overflow structure across a channel used to control upstream surface levels, reduce erosion or divert flow