Name: Event Duration Monitoring - Storm Overflows - 2025 (England and Wales)
Display Field: waterCompanyName
Type: Feature Layer
Geometry Type: esriGeometryPoint
Description: This Event Duration Monitoring dataset relates to overflow performance in England and Wales. Water and Sewerage Companies (WaSCs) submit this regulatory return annually to the Environment Agency or Natural Resources Wales to meet discharge conditions outlined in the Environmental Permitting Regulations. The English data were downloaded from environment.data.gov.uk (accessed 27th March 2025). Sewer Storm Overflow EDM Annual Returns Data for Wales were downloaded from the Dŵr Cymru/ Welsh Water and Hafren Dyfrdwy websites. For England, the dataset also includes reasons why event duration monitors may have provided information for <90% of the relevant return period, and why an overflow may have high spill counts in that period. What doesn't this dataset show?There are a significant but unknown number of overflows which are not included in this dataset because the WASCs and the Environment Agency don't know where they are within the sewer network. If you spot signs of sewage pollution please report this to the Environment Agency on 0800 80 70 60 or Natural Resources Wales on 0300 065 3000 so that these unmapped discharges can be pinpointed. Emergency overflows in England and Wales are not included in this dataset as the Environment Agency and Natural Resources Wales only require storm overflows to be included in the EDM returns, though some WASCs do record this information. Emergency overflows do have permits but these are for use in the event of mechanical issues, for example pump failure. We do publish the emergency overflows for England and Wales in the consented discharges dataset, but we don't have spill duration data for them. You can find out more about environmental permits for storm and emergency overflows for England here and Wales here. Quality ControlThe Rivers Trust has endeavoured to clean, check and interpret the data, but cannot be held responsible for any missing or inaccurate data. Points in the sea may be long-sea outfalls or they may be errors in the data. Water companies, citizen scientists and map users are welcome to contact us to notify any known data errors on specific overflows and we will flag these in the map popups and pass on to the regulators. We are providing feedback to the Defra storm overflows taskforce about how to improve transparency around sewer storm overflows, and would welcome feedback and suggestions.Contact us at data@theriverstrust.org
Copyright Text: Produced by The Rivers Trust. © Environment Agency copyright and/or database right 2024. All rights reserved. © Dŵr Cymru/Welsh Water. © Hafren Dyfrydwy.
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Supported query Formats: JSON, geoJSON, PBF
Use Standardized Queries: True
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XMin: 88684.670536947
YMin: 10650.3870908587
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Spatial Reference: 27700 (27700)
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Fields:
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- waterCompanyName (type: esriFieldTypeString, alias: Water Company Name, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- siteNameEA (type: esriFieldTypeString, alias: Site Name (EA Consents Database), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- siteNameWASC (type: esriFieldTypeString, alias: Site Name (WaSC operational name) (if applicable), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- permitReferenceEA (type: esriFieldTypeString, alias: EA Permit Reference (EA Consents Database), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- permitReferenceWaSC (type: esriFieldTypeInteger, alias: WaSC Supplementary Permit Reference (if applicable), SQL Type: sqlTypeOther, nullable: true, editable: true)
- activityReference (type: esriFieldTypeInteger, alias: Activity Reference on Permit (if >1 discharge on permit), SQL Type: sqlTypeOther, nullable: true, editable: true)
- assetType (type: esriFieldTypeString, alias: Storm Discharge Asset Type, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- outletDischargeNGRmappedRT (type: esriFieldTypeString, alias: Outlet Discharge NGR, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- outletDischargeNGRoriginal (type: esriFieldTypeString, alias: Outlet Discharge NGR Original (if different), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- wfdWaterbodyID (type: esriFieldTypeString, alias: WFD Waterbody ID (Cycle 3) (discharge outlet), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- wfdWaterbodyName (type: esriFieldTypeString, alias: WFD Waterbody Catchment Name (Cycle 3) (discharge outlet), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- recievingWaterName (type: esriFieldTypeString, alias: Receiving Water / Environment, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- shellfishWater (type: esriFieldTypeString, alias: Shellfish Water (if applicable), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- bathingWater (type: esriFieldTypeString, alias: Bathing Water (if applicable), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- totalDurationAllSpillsHrs (type: esriFieldTypeDouble, alias: Total Duration (hrs) all spills prior to processing through 12-24, SQL Type: sqlTypeOther, nullable: true, editable: true)
- countedSpills (type: esriFieldTypeInteger, alias: Counted spills using 12-24h counting method, SQL Type: sqlTypeOther, nullable: true, editable: true)
- treatmentType (type: esriFieldTypeString, alias: Treatment Type, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- edmOperationPercent (type: esriFieldTypeDouble, alias: EDM Operation - % of reporting period EDM operational, SQL Type: sqlTypeOther, nullable: true, editable: true)
- edmOperationReason (type: esriFieldTypeString, alias: EDM Operation - Primary Reason <90%, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- edmOperationAction (type: esriFieldTypeString, alias: EDM Operation - Action taken / planned - Status & Timeframe, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- highSpillOperationalReview (type: esriFieldTypeString, alias: High Spill Frequency - Operational Review - Primary Reason, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- highSpillOperationalReviewLongTerm (type: esriFieldTypeString, alias: High Spill Frequency - Operational Review - Primary Reason Long Term, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
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- edmNumberofYearsOperational (type: esriFieldTypeInteger, alias: EDM Number of Years Operational, SQL Type: sqlTypeOther, nullable: true, editable: true)
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- riversTrustErrorFlag (type: esriFieldTypeString, alias: The Rivers Trust Error Flag, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- riversTrustComments (type: esriFieldTypeString, alias: The Rivers Trust Comments, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
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- Northings (type: esriFieldTypeInteger, alias: Northings, SQL Type: sqlTypeOther, nullable: true, editable: true)
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- constituencyWestminster (type: esriFieldTypeString, alias: Constituency (Westminster), SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- cabaCatchment (type: esriFieldTypeString, alias: CaBA Catchment, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- eaWaterMgmtArea (type: esriFieldTypeString, alias: EA Water Management Area, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- eaPublicFaceArea (type: esriFieldTypeString, alias: EA/NE Public Face Area, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- riverBasinDistrict (type: esriFieldTypeString, alias: River Basin District, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
- sourceDB (type: esriFieldTypeString, alias: Source Database, SQL Type: sqlTypeOther, length: 8000, nullable: true, editable: true)
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Is Data Versioned: false
Has Contingent Values: false
Supports Rollback On Failure Parameter: true
Last Edit Date: 4/29/2026 3:01:57 PM
Schema Last Edit Date: 4/29/2026 3:01:57 PM
Data Last Edit Date: 4/14/2026 3:57:47 PM
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