Internal flooding

A situation in which a building (commercial or residential) has been flooded internally, i.e. water has crossed the threshold and entered the building. This includes;. Basements and ground level floors of the building; Garages/outbuildings if they are integral to the main occupied building. Garages adjacent or separate from the main occupied building are not included; […]


The Lead Local Flood Authority in Northamptonshire is Northamptonshire County Council.

Main River

Main rivers are a statutory type of watercourse in England and Wales and are usually larger streams and rivers. A main river is defined as such on the Environment Agency’s Main River map, and can include any structure or appliance for controlling or regulating the flow of water in, into or out of a main […]

Main Rivers

Use this map to see the watercourses that the Environment Agency have powers to do works on but are ultimately the responsibility of the landowner. All other watercourses not shown on this map are ordinary watercourses, which district councils have powers to do works on but are ultimately the responsibility of the landowner.


The National Planning Policy Framework sets out government’s planning policies for England and how these are expected to be applied. The framework acts as guidance for local planning authorities and decision-takers, both in drawing up plans and making decisions about planning applications.

Ordinary Watercourse

Any watercourse not defined by the Environment Agency as a main river. Ordinary watercourses are generally smaller than main rivers, and can include streams, ditches and piped watercourses. See our Flood Risk Map for a map of all Northamptonshire main rivers.

Preliminary Flood Risk Assessment

The Preliminary Flood Risk Assessment (PFRA) provides an overview of past floods and the possible harmful consequences of future floods, leading to the identification of Areas of Significant Risk. The floods to be included are those which had significant harmful consequences for human health, economic activity or the environment (including cultural heritage), or which would have significant harmful consequences for those matters […]

Residual Risk

Residual risks are those remaining after actions have been taken to mitigate or defend against flood risk. Examples of residual flood risk include: the failure of flood management infrastructure such as a breach of a raised flood defence, blockage of a surface water conveyance system, overtopping of an upstream storage area, or failure of a pumped […]

Riparian Owner/Responsibility

All landowners and tenants whose property has a watercourse within or adjacent to the boundaries of their land, are riparian owners of that watercourse. Riparian owners have a responsibility for maintaining the watercourse and bank, clearing debris and keeping any ditches or structures clear. This ownership extends to watercourses that are piped (culverted) under the […]

Risk of Flooding from Rivers

Use this map to see if you are in an area at risk of flooding from rivers. The risk shown includes the effect of any flood defences that may be in the area, which help to reduce the impact of flooding, but do not completely stop it.