Statutory Main Rivers Map is a spatial (polyline) dataset that defines statutory watercourses in England designated as Main Rivers by the Environment Agency.

Watercourses designated as ‘main river’ are generally the larger arterial watercourses. The Environment Agency has permissive powers, but not a duty, to carry out maintenance, improvement or construction work on designated main rivers.

All other open water courses in England are determined by statute as an ‘ordinary watercourse’. On these watercourses the Lead Local flood Authority or, if within an Internal Drainage District, the Internal Drainage Board have similar permissive powers to maintain and improve.

This is a view service of the CEH 1:50k rivers dataset. This is a river centreline network, based originally on OS 1:50,000 mapping. There are four layer: rivers; canals; surface pipes (man-made channels such as aqueducts and leats) and miscellaneous channels (including estuary and lake centre-lines and some underground channels).The dataset was produced within a long-term project of the Institute of Hydrology (now CEH) between the mid-1970s and the late 1990s. The project digitised, (either manually or using 'laser scanners') the "blue line" layer of the Ordnance Survey's 1:50,000 2nd series (Landranger) maps. The dataset consists of all the single blue lines from the source maps, plus centre-lines from double sided rivers, lakes and estuaries. All gaps in the source material have been closed, using local knowledge where necessary, to give a river network that is continuous from source to mouth

This dataset comprises river centrelines, digitised from OS 1:50,000 mapping. It consists of four components: rivers; canals; surface pipes (man-made channels for transporting water such as aqueducts and leats); and miscellaneous channels (including estuary and lake centre-lines and some underground channels). This dataset is a representation of the river network in Great Britain as a set of line segments, i.e. it does not comprise a geometric network.

The Statutory Main River Map Variations dataset defines proposed changes to the Statutory Main River Map.

Statutory Main Rivers Map defines statutory watercourses in England designated as Main Rivers by Environment Agency.

Watercourses designated as ‘main river’ are generally the larger arterial watercourses. The Environment Agency has permissive powers, but not a duty, to carry out maintenance, improvement or construction work on designated main rivers.

All other open water courses in England are determined by statute as an ‘ordinary watercourse’. On these watercourses the Lead Local flood Authority or, if within an Internal Drainage District, the Internal Drainage Board have similar permissive powers to maintain and improve.

The Environment Agency notifies the public and interested parties of our intentions to make a change to the statutory main river map and decides which watercourses are designated as Main Rivers following a legal process to determine and publish changes.

The change, or variation, to the Statutory Main River Map is either a deletion (also known as a demainment) or an addition (also known as an enmainment).

There are two reasons for a change to the Statutory Main River Map - Designation and Factual.

Designation changes are required when we make a decision to lengthen or shorten the section of a river designated as a 'main river'. These changes will determine which risk management authority may carry out maintenance, improvement or construction work on the watercourse. These changes result also in differing legislation applying to the riparian owner and others with an interest.

Factual changes may be required to update the map to represent the real position of the watercourse. They do not involve any changes of authority or management. Typical examples of factual changes are when: a watercourse has changed course naturally, a watercourse has been diverted or a survey of a culvert shows a different alignment.

A change to the Statutory Main River Map goes through the following stages (identified as Status within the data):

• Draft
• Consultation
• Pending Determination
• Determination
• Appeals
• Pending Appeals
• Pending Implementation
• Implemented (Month and Year)

Available for England, Scotland and Wales as a Network, polygon and line representation in a number of Ordnance Survey (OS) products: MasterMap Water Network Layer, Open Rivers, Open Names, MasterMap Topography Layer, Vector Map Local and Vector Map District. Small-scale cartographic representations are also available. All data is collected by Ordnance Survey. Culvert data within OS MasterMap Water Network Layer is sourced from Scottish Local Authorities. as part of their role as the National Mapping Agency of Great Britain. This data is often used for environmental monitoring and risk assessment, navigation, statistical analysis. Keywords: Hydrography, Rivers, Streams, Watercourses

Data shows the location of Priority Habitat Chalk rivers and Streams. Replaces the existing 1:50,000 scale data.Based on Environment Agency Detailed River Network (DRN) version 3. All fields from DRN have been retained. This subset of chalk rivers uses the old 1:50,000 Biodiversity Action Plan (BAP) chalk river data, BGS geology, WWF report "The State of England’s Chalk Streams" and stakeholder knowledge to produce an updated chalk river network for England.Full metadata can be viewed on data.gov.uk (to follow).

The Flood Map for Planning (Rivers and Sea) includes several layers of information. This layer and documentation covers Flood Zone 2. It is the Environment Agency's best estimate of the areas of land at risk of flooding, when he presence of flood defences are ignored and covers land between Zone 3 and the extent of the flooding from rivers or the sea with a 1 in 1000 (0.1%) chance of flooding each year. This dataset also includes those areas defined in Flood Zone 3.This dataset is designed to support flood risk assessments in line with Planning Practice Guidance ; and raise awareness of the likelihood of flooding to encourage people living and working in areas prone to flooding to find out more and take appropriate action. This dataset is republished by the West of England Combined Authority for supplementing information within our Local Nature Recovery Strategy. If you are using it for statutory purposes, you should refer to the Environment Agency's canonical version, linked in the Attributions field below as this is likely to be more current.

Keyword: Rivers OS MasterMap Water Network Layer offers one of the worldâ s most detailed, heighted water networks â showing the flow and precise course of every river, stream, lake and canal in Great Britain.

One of the two datasets that make up the Priority River Habitat Map. Consists of rivers and streams that exhibit a high degree of naturalness. The naturalness classification used to map priority river habitat is based on recent work to review the river SSSI series. It evaluates four main components of habitat integrity: hydrological, physical, physico-chemical (water quality) and biological. An additional classification of the naturalness of headwaters (defined as streams with a catchment area of <10km2 to coincide with WFD typology boundaries) uses land cover data as a surrogate for direct information on river habitat condition (information which is generally lacking on headwaters). Streams and rivers operating under natural processes, free from anthropogenic impact and with a characteristic and dynamic mosaic of small-scale habitats that supports characteristic species assemblages (including priority species), are the best and most sustainable expression of river ecosystems. Key elements are: a natural flow regime; natural nutrient and sediment delivery regimes; minimal physical modifications to the channel, banks and riparian zone; natural longitudinal and lateral hydrological and biological connectivity; an absence of non-native species; low intensity fishery activities. These conditions provide the best defence against climate change, maximising the ability of riverine ecosystems to adapt to changing conditions. They also provide the most valuable and effective transitional links with other priority habitats, including lakes, mires and coastal habitats. In English rivers and streams, high levels of naturalness are rare.Full metadata can be viewed on data.gov.uk.

"One of the two datasets that make up the Priority River Habitat Map. Consists of rivers and streams that exhibit a high degree of naturalness. The naturalness classification used to map priority river habitat is based on recent work to review the river SSSI series. It evaluates four main components of habitat integrity: hydrological, physical, physico-chemical (water quality) and biological. An additional classification of the naturalness of headwaters (defined as streams with a catchment area of <10km2 to coincide with WFD typology boundaries) uses land cover data as a surrogate for direct information on river habitat condition (information which is generally lacking on headwaters). Streams and rivers operating under natural processes, free from anthropogenic impact and with a characteristic and dynamic mosaic of small-scale habitats that supports characteristic species assemblages (including priority species), are the best and most sustainable expression of river ecosystems. Key elements are: a natural flow regime; natural nutrient and sediment delivery regimes; minimal physical modifications to the channel, banks and riparian zone; natural longitudinal and lateral hydrological and biological connectivity; an absence of non-native species; low intensity fishery activities. These conditions provide the best defence against climate change, maximising the ability of riverine ecosystems to adapt to changing conditions. They also provide the most valuable and effective transitional links with other priority habitats, including lakes, mires and coastal habitats. In English rivers and streams, high levels of naturalness are rare. "

PLEASE NOTE: This dataset has been retired. It has been superseded by https://environment.data.gov.uk/dataset/04532375-a198-476e-985e-0579a0a11b47. Links to this data will be removed after April 2025. We encourage users to download this Flood Zones dataset if you would like to retain a comparison ability beyond this date.

The Flood Map for Planning (Rivers and Sea) includes several layers of information. This dataset covers Flood Zone 2 and should not be used without Flood Zone 3. It is our best estimate of the areas of land at risk of flooding, when the presence of flood defences are ignored and covers land between Zone 3 and the extent of the flooding from rivers or the sea with a 1 in 1000 (0.1%) chance of flooding each year. This dataset also includes those areas defined in Flood Zone 3.

This dataset is designed to support flood risk assessments in line with Planning Practice Guidance ; and raise awareness of the likelihood of flooding to encourage people living and working in areas prone to flooding to find out more and take appropriate action.

The information provided is largely based on modelled data and is therefore indicative rather than specific. Locations may also be at risk from other sources of flooding, such as high groundwater levels, overland run off from heavy rain, or failure of infrastructure such as sewers and storm drains.

The information indicates the flood risk to areas of land and is not sufficiently detailed to show whether an individual property is at risk of flooding, therefore properties may not always face the same chance of flooding as the areas that surround them. This is because we do not hold details about properties and their floor levels. Information on flood depth, speed or volume of flow is not included.

Each layer consists of specific singular content portraying Path and Track, Rail or Water network information which can be queried using Geographic Information Systems as part of wider planning and asset management

Paths/Tracks have been published: see https://data.gov.uk/dataset/walking-paths-routes Water network has been published: see https://data.gov.uk/dataset/river-maps Rail remains unpublished

The objective of the priority habitat map in England is to:• help organisations protect the most natural remaining examples of rivers from further impacts on natural processes, and • highlight any aspects of habitat integrity (hydrological, chemical, physical, biological) that could most usefully be improved. The priority river habitat map that has been produced is an English interpretation of the UK definition of priority river habitat, focusing on naturalness as the principal criterion in recognition of the vital importance of natural processes in delivering sustainable riverine habitats and supporting characteristic biodiversity.Full metadata can be viewed on data.gov.uk.

Location of manmade barriers, mostly weirs, and natural features, such as waterfalls, on river courses in England and Wales. This dataset is known as 'Potential Sites of Hydropower Opportunity' and has been created under the EA project 'Opportunity and environmental sensitivity mapping for hydropower in England and Wales'. The dataset shows the location of opportunities for hydropower and the basic environmental sensitivity, which considers the presence of fish species and whether the site has been designated as Special Area of Conservation (SAC), associated with exploiting them. Besides their location, the dataset includes information on river level height, up and downstream the barrier.

One of the two datasets that make up the Priority River Habitat Map. Under the UK BAP definition all headwaters potentially form part of the priority habitat definition. The headwater resource can be a significant proportion of the river habitat network, accounting for the large majority of total river length. The headwater areas selected as most natural by land cover comprise a relatively large proportion of the upland headwater resource but a very small proportion of the lowland resource. The headwater analysis is the least certain component of the naturalness analysis – for example, highly natural headwater streams running through very small catchment areas, often wooded, would not be detectable by the analysis that has been undertaken. Equally, land cover is a crude measure of naturalness and various types of impact on river habitat are not well correlated with it (e.g. abstraction pressure, point source pollution). These issues can only be addressed through local interpretation of the final priority habitat map. Attribution statement: © Natural England copyright. Contains Ordnance Survey data © Crown copyright and database right [year].

This dataset consists of an interactive map (and supporting guidance) containing background information that informs how we understand flood risk across the Severn River Basin District. The map shows the River Basin District, component river basins and the coastline together with layers showing land use and topography.

This dataset together with equivalent datasets for each River Basin District, supports the Preliminary Flood Risk Assessment for England report which has been written to meet the requirements of the Flood Risk Regulations (2009) - to complete an assessment of flood risk and produce supporting maps of river catchments. Attribution statement: © Environment Agency copyright and/or database right 2018. All rights reserved. © Crown copyright and database rights 2018 Ordnance Survey 100024198 © Bluesky International Ltd/Getmapping PLC. Some features of this map are based on digital spatial data from the Centre for Ecology & Hydrology, British Antarctic Survey and British Geological Survey. © NERC (Centre for Ecology & Hydrology; British Antarctic Survey; British Geological Survey).
Contains public sector information licensed under the Open Government Licence v3.0.

Introduction

The Strategic Flood Map (Coastal) map service is a multi layered predictive flood mapping product providing a strategic overview of areas across Northern Ireland that could be affected by coastal (or sea) flooding. The Strategic Flood Map (Coastal) includes the following layers of information for both present day and climate change epochs: • Floods with a medium probability

Purpose of the data The dataset has been designed to raise awareness among the public, Government Departments, local authorities and other organisations of the likelihood of coastal flooding, thus supporting a more proactive and co-operative approach to flood risk management. By being aware of the land estimated to be at risk of flooding, authorities can develop strategies to better manage flood risk through their planning, flood prevention, and emergency planning functions.

Data Coverage Around the coast of Northern Ireland.

Data Format

OGC (Open Geospatial Consortium) compliant Web Mapping Service in WGS 1984 projection, accessible via secure website (requires authentication by user specific username and password).

Data content

Extreme Sea Level Strategic Coastal Floodplain o Coastline Strategic Coastal Floodplain (Present Day) o Medium Probability Floods (0.5% AEP) Strategic Coastal Floodplain (Climate Change 2030) o Medium Probability Floods (0.5% AEP)

AEP is Annual Exceedance Probability e.g. the 0.5% AEP flood extent shows areas of land with an annual probability of flooding of 0.5% (or 1 in 200 chance) in any year.

There are 49 rivers in England and 31 rivers in Wales that regularly support salmon, although some of the stocks are very small and support minimal catches. Of these, 64 rivers were designated ‘principal salmon rivers’ on the basis of the prospect of annual rod catches of at least 50 fish around the time (~1996) of the development of Salmon Action Plans (SAPs*).These data are recreated from SALMON STOCKS AND FISHERIES IN ENGLAND AND WALES, 2021 figure 1 using OS Open Rivers. Attributes include if a river has a SAP and if it is designated as a Special Area of Conservation (SAC) in which salmon must be maintained or restored to favourable conservation status (SALMON STOCKS AND FISHERIES IN ENGLAND AND WALES, 2021 Table 1).These data are intended for visualisation only and should not be used for statutory purposes or connectivity modelling.*Salmon Action Plans in Wales are now referred to as ‘Know Your Rivers’ reports.

Submerged river terraces located in UK coastal Waters. Obtained from the digitalisation of a georeferenced map. This dataset is associated with a series of digital maps/spatial information layers that are designed to help identify Marine Conservation Zones (MCZs) in UK waters. (see Project MB0102: 'Accessing and developing the required biophysical datasets and datalayers for Marine Protected Areas network planning and wider marine spatial planning purposes' - Report No.8, Task 2a Mapping of Geological and Geomorphological Features)

Flood Map shows the areas across Wales that could be affected by flooding from rivers or the sea. It also shows flood defences and the areas that benefit from them. Flood Map is designed to raise awareness among the public local authorities and other organisations of the likelihood of flooding and to encourage people living and working in areas prone to flooding to find out more and take appropriate action. The Flood Map includes several layers of information, this layer is: Flood Zone 2, which is NRWs best estimate of the areas of land between Zone 3 and the extent of the flood from rivers or the sea with a 1000 to 1 chance of flooding in any year. It includes those areas defined in Flood Zone 3.

An online viewable version of this dataset is available via the NRW website.