This layer of the map based index (GeoIndex) shows sites where regularly monitored rest water level data are available, usually covering a long time period. The data shows seasonal fluctuations in the water table and responses to periods of high or low rainfall. This layer is only available at specific zoom levels. Please zoom to a larger scale to interrogate the map.

This layer of the map based index (GeoIndex) shows sites where regularly monitored rest water level data are available, usually covering a long time period. The data shows seasonal fluctuations in the water table and responses to periods of high or low rainfall.

The Groundwater Vulnerability Scotland dataset forms part of the BGS Hydrogeological Maps of Scotland data product. This product is comprised of three datasets: Bedrock Aquifer Productivity Scotland; Superficial Aquifer Productivity Scotland; and Groundwater Vulnerability Scotland. The Groundwater Vulnerability Scotland dataset version 2 (2015) shows the relative vulnerability of groundwater to contamination across Scotland. Groundwater vulnerability is the tendency and likelihood for general contaminants to move vertically through the unsaturated zone and reach the uppermost water table after introduction at the ground surface. The groundwater vulnerability dataset was developed as a screening tool to support groundwater management at a regional scale across Scotland, and specifically to aid groundwater risk assessment. The data can be used to show the relative threat to groundwater quality from contamination, by highlighting areas at comparatively higher risk of groundwater contamination. The dataset is delivered at 1: 100 000 scale; the resolution of the dataset being 50m and the smallest detectable feature 100 m

The Environment Agency and Natural Resources Wales have updated its groundwater vulnerability map to reflect improvements in data mapping, modelling capability and understanding of the factors affecting vulnerability. Two new maps are available which show the vulnerability of groundwater to a pollutant discharged at ground level. The potential impact of groundwater pollution is considered using the aquifer designation status which provides an indication of the scale and importance of groundwater for potable water supply and/or in supporting baseflow to rivers, lakes and wetlands. This dataset for Wales has shared intellectual property (IP) between Natural Resources Wales and British Geological Survey.

This dataset is available for use for non-commercial purposes only on request as AfA248 dataset Groundwater Vulnerability Maps (2017). For commercial use please contact the British Geological Survey.

The Groundwater Vulnerability Maps show the vulnerability of groundwater to a pollutant discharged at ground level based on the hydrological, geological, hydrogeological and soil properties within a single square kilometre. The 2017 publication has updated the groundwater vulnerability maps to reflect improvements in data mapping, modelling capability and understanding of the factors affecting vulnerability Two map products are available: • The combined groundwater vulnerability map. This product is designed for technical specialists due to the complex nature of the legend which displays groundwater vulnerability (High, Medium, Low), the type of aquifer (bedrock and/or superficial) and aquifer designation status (Principal, Secondary, Unproductive). These maps require that the user is able to understand the vulnerability assessment and interpret the individual components of the legend.

• The simplified groundwater vulnerability map. This was developed for non-specialists who need to know the overall risk to groundwater but do not have extensive hydrogeological knowledge or the time to interpret the underlying data. The map has five risk categories (High, Medium-High, Medium, Medium-Low and Low) based on the likelihood of a pollutant reaching the groundwater (i.e. the vulnerability), the types of aquifer present and the potential impact (i.e. the aquifer designation status). The two maps also identify areas where solution features that enable rapid movement of a pollutant may be present (identified as stippled areas) and areas where additional local information affecting vulnerability is held by the Environment Agency (identified as dashed areas). Attribution statement: © Environment Agency copyright and/or database right 2017. All rights reserved.Derived from 1:50k scale BGS Digital Data under Licence 2011/057 British Geological Survey. © NERC.

The hydrogeological map indicates aquifer potential in generalised terms using a threefold division of geological formations:those in which intergranular flow in the saturated zone is dominantthose in which flow is controlled by fissures or discontinuitiesless permeable formations including aquifers concealed at depth beneath covering layersHighly productive aquifers are distinguished from those that are only of local importance or have no significant groundwater. Within each of these classes the strata are grouped together according to age or lithology.The 1:625 000 scale data may be used as a guide to the aquifers at a regional or national level, but should not be relied on for local information.Data from the British Geological Survey's GeoIndex hydrogeology theme are made available for viewing here. GeoIndex is a website that allows users to search for information about BGS data collections covering the UK and other areas world wide. Access is free, the interface is easy to use, and it has been developed to enable users to check coverage of different types of data and find out some background information about the data. More detailed information can be obtained by further enquiry via the web site: www.bgs.ac.uk/geoindex.

The Environment Agency has updated its groundwater vulnerability map to reflect improvements in data mapping, modelling capability and understanding of the factors affecting vulnerability. Two new maps are available which show the vulnerability of groundwater to a pollutant discharged at ground level. The potential impact of groundwater pollution is considered using the aquifer designation status which provides an indication of the scale and importance of groundwater for potable water supply and/or in supporting baseflow to rivers, lakes and wetlands. This dataset has shared IP (Intellectual Property) between Environment Agency and British Geological Survey. It supersedes the previous Groundwater Vulnerability 100k data released by EA.

This national dataset brings together sixteen national datasets to create a GIS product that provides the information necessary to determine the extent to which the ground is suitable for infiltration sustainable drainage systems (SuDS). It includes derivations of the following datasets: soluble rocks, landslide hazards, groundwater flooding susceptibility, made ground, shallow mining hazards, geological indicators of flooding, depth to water table, superficial thickness, compressible ground, collapsible ground, swelling clays, running sands, predominant flow mechanism, permeability indices and the Environment Agencys source protection zone dataset. All datasets have been reclassified and reattributed (with text descriptions and a score field indicating the suitability of the ground for infiltration) and feature in the end product both as single entities, but also in derived 'screening' maps that combine numerous datasets.

The hydrogeological map indicates aquifer potential in generalised terms using a threefold division of geological formations: those in which intergranular flow in the saturated zone is dominant, those in which flow is controlled by fissures or discontinuities and less permeable formations including aquifers concealed at depth beneath covering layers. Highly productive aquifers are distinguished from those that are only of local importance or have no significant groundwater. Within each of these classes the strata are grouped together according to age or lithology. The 1:625 000 scale data may be used as a guide to the aquifers at a regional or national level, but should not be relied on for local information.

Source Protection Zones (merged) have been created as public facing boundaries where discrete groundwater bodies within Source Protection Zones (SPZ) have been dissolved on zone number where common boundaries and overlaps have been removed. SPZs are defined around large and public potable groundwater abstraction sites. The purpose of SPZs is to provide additional protection to safeguard drinking water quality through constraining the proximity of an activity that may impact upon a drinking water abstraction. This is part of an initial screening process in assessing impacts to groundwater resources. Zones around location sites are defined by groundwater travel time to an abstraction. This is determined through applying Environment Agency groundwater flow models run at the location of abstractions, inputting parameters such as flow direction, geology type, rainfall and hydrological boundaries. SPZs provide a visual representation of the increased risks as you get closer to the abstraction. The following subdivisions are defined within SPZs: Zone 1: (Inner Protection Zone) - This zone is defined by a travel time of 50-days or less from any point within the zone at, or below, the water table. Additionally, the zone has as a minimum a 50-metre radius. It is based principally on biological decay criteria and is designed to protect against the transmission of toxic chemicals and water-borne disease.Zone 2: (Outer Protection Zone) - This zone is defined by the 400-day travel time from a point below the water table. Additionally this zone has a minimum radius of 250 or 500 metres, depending on the size of the abstraction. The travel time is derived from consideration of the minimum time required to provide delay, dilution and attenuation of slowly degrading pollutants. Zone 3: (Total catchment) - This zone is defined as the total area needed to support the abstraction or discharge from the protected groundwater source. A further Zone 4, or ‘Zone of Special Interest’ was previously defined for some groundwater sources. These zones highlighted areas (mainly on non-aquifers) where known local conditions meant that potentially polluting activities could impact on a groundwater source even though the area is outside the normal catchment of that source. In future this zone will be incorporated into one of the other zones (1, 2 or 3), whichever is appropriate in the particular case.Defra Network WMS server provided by the Environment Agency. Download the full dataset from the Spatial Data Catalogue.

OverviewThis dataset provides the measurements of raw water storage levels in reservoirs crucial for public water supply. The reservoirs included in this dataset are natural bodies of water that have been dammed to store untreated water.Key DefinitionsAggregation The process of summarising or grouping data to obtain a single or reduced set of information, often for analysis or reporting purposes.CapacityThe maximum volume of water a reservoir can hold above the natural level of the surrounding land, with thresholds for regulation at 10,000 cubic meters in England, Wales and Northern Ireland and a modified threshold of 25,000 cubic meters in Scotland pending full implementation of the Reservoirs (Scotland) Act 2011.Current Level The present volume of water held in a reservoir measured above a set baseline crucial for safety and regulatory compliance.Current Percentage The current water volume in a reservoir as a percentage of its total capacity, indicating how full the reservoir is at any given time.Dataset Structured and organised collection of related elements, often stored digitally, used for analysis and interpretation in various fields. Granularity Data granularity is a measure of the level of detail in a data structure. In time-series data, for example, the granularity of measurement might be based on intervals of years, months, weeks, days, or hours. ID Abbreviation for Identification that refers to any means of verifying the unique identifier assigned to each asset for the purposes of tracking, management, and maintenance. Open Data Triage The process carried out by a Data Custodian to determine if there is any evidence of sensitivities associated with Data Assets, their associated Metadata and Software Scripts used to process Data Assets if they are used as Open Data. Reservoir Large natural lake used for storing raw water intended for human consumption. Its volume is measurable, allowing for careful management and monitoring to meet demand for clean, safe water.Reservoir TypeThe classification of a reservoir based on the method of construction, the purpose it serves or the source of water it stores.Schema Structure for organising and handling data within a dataset, defining the attributes, their data types, and the relationships between different entities. It acts as a framework that ensures data integrity and consistency by specifying permissible data types and constraints for each attribute.Units Standard measurements used to quantify and compare different physical quantities.Data HistoryData OriginReservoir level data is sourced from water companies who may also update this information on their website and government publications such as the Water situation reports provided by the UK government. Data Triage ConsiderationsIdentification of Critical InfrastructureSpecial attention is given to safeguard data on essential reservoirs in line with the National Infrastructure Act, to mitigate security risks and ensure resilience of public water systems. Currently, it is agreed that only reservoirs with a location already available in the public domain are included in this dataset.Commercial Risks and AnonymisationThe risk of personal information exposure is minimal to none since the data concerns reservoir levels, which are not linked to individuals or households.Data Triage Review FrequencyAnnually unless otherwise requested. Data FreshnessIt is not currently possible to make the dataset live. Some companies have digital monitoring, and some are measuring reservoir levels analogically. This dataset may not be used to determine reservoir level in place of visual checks where these are advised.Publish FrequencyAnnuallyData SpecificationsData specifications define what is included and excluded in the dataset to maintain clarity and focus. For this dataset: • Each dataset covers measurements taken by the publisher. • This dataset is published periodically in line with the publisher’s capabilities.• Historical datasets may be provided for comparison but are not required.• The location data provided may be a point from anywhere within the body of water or on its boundary.• Reservoirs included in the dataset must be: o Open bodies of water used to store raw/untreated water o Filled naturally o Measurable o Contain water that may go on to be used for public supply ContextThis dataset must not be used to determine the implementation of low supply or high supply measures such as hose pipe bans being put in place or removed. Please await guidance from your water supplier regarding any changes required to your usage of water.Particularly high or low reservoir levels may be considered normal or as expected given the season or recent weather.This dataset does not remove the requirement for visual checks on reservoir level that are in place for caving/pot holing safety.Some water companies calculate the capacity of reservoirs differently than others. The capacity can mean the useable volume of the reservoir or the overall volume that can be held in the reservoir including water below the water table. For Wessex Water reservoir total capacity information is based on gross capacity of the reservoir. Current percentage full will be a percentage of this gross capacity.Level information is provided as meters below spillway. Where the water level is 0 m it is equal to the height of the spillway, which is equivalent to 100% of the total volume storage available.Supplementary InformationBelow is a curated selection of links for additional reading, which provide a deeper understanding of this dataset. 1. Uses of Reservoirs: https://britishdams.org/about-dams/dam-information/uses-for-reservoirs/2. Inventory of UK Reservoirs: https://catalogue.ceh.ac.uk/documents/f5a7d56c-cea0-4f00-b159-c3788a3b2b383. Reservoirs Act 1975 as applied in England: https://britishdams.org/assets/documents/Dam%20Legislation%20-%20England%20-%20October%202016.pdf4. Reservoirs Act (Northern Ireland) 2015: https://britishdams.org/assets/documents/Dam%20Legislation%20-%20Northern%20Ireland%20-%20October%202016.pdf5. Reservoirs (Scotland) Act 2011: https://britishdams.org/assets/documents/Dam%20Legislation%20-%20Scotland%20-%20October%202016.pdf6. Reservoirs Act 1975 as applied in Wales: https://britishdams.org/assets/documents/Dam%20Legislation%20-%20Wales%20-%20October%202016.pdf7. Monthly local reports on reservoir levels: https://www.gov.uk/government/publications/water-situation-local-area-reports

This dataset is not suitable for identifying whether an individual property will flood. GIS layer showing the flood hazard rating for flooding from surface water that could result from a flood with a 3.3% chance of happening in any given year. The flood hazard rating is defined as a function of simultaneous depth and velocity and grouped into 4 bands. This dataset is one output of our Risk of Flooding from Surface Water (RoFSW) mapping, previously known as the updated Flood Map for Surface Water (uFMfSW). It is one of a group of datasets previously available as the uFMfSW Complex Package. Further information on using these datasets can be found at the Resource Locator link below. Information Warnings: Risk of Flooding from Surface Water is not to be used at property level. If the Content is displayed in map form to others we recommend it should not be used with basemapping more detailed than 1:10,000 as the data is open to misinterpretation if used as a more detailed scale. Because of the way they have been produced and the fact that they are indicative, the maps are not appropriate to act as the sole evidence for any specific planning or regulatory decision or assessment of risk in relation to flooding at any scale without further supporting studies or evidence. Attribution statement: © Environment Agency copyright and/or database right 2015. All rights reserved.

Some features of this information are based on digital spatial data licensed from the Centre for Ecology & Hydrology © NERC (CEH). Defra, Met Office and DARD Rivers Agency © Crown copyright. © Cranfield University. © James Hutton Institute. Contains OS data © Crown copyright and database right 2015. Land & Property Services © Crown copyright and database right.