Identification

Title

Event Duration Monitoring - Storm Overflows - Annual Returns

Alternative title(s)

Abstract

This Event Duration Monitoring (EDM) dataset relates to the performance of storm overflows in England. Data are provided by Water and Sewerage Companies (WaSCs) to the Environment Agency each year as part of their regulatory Annual Return, to fulfil their permitted conditions to discharge from these storm overflows under the Environmental Permitting Regulations. Data files are provided by year (2024, 2023, 2022, 2021 & 2020) and include a sheet for each of the 10 WaSCs with storm overflows in England. Each WaSC sheet shows how often and how long each monitored storm overflow discharged during that year. From 2021 onwards the dataset also includes reasons why event duration monitors (EDM) may have provided information for <90% of the relevant return period, and why an overflow may have high spill counts in that period. These data reflect the best available information held by the WaSC at time of submission. The data file for each year also contains key summary data tables. These include: number of storm overflows with EDM, number of storm overflows returning spill counts, average spill duration and average spill count for each WaSC. A dataset README guide is also provided which provides further information to help use and understand the data. A sixth data file contains the annual key summary data from respective years plus a table showing long-term trends from 2016-2024. Attribution statement: © Environment Agency copyright and/or database right 2025. All rights reserved.

Resource type

dataset

Resource locator

https://environment.data.gov.uk/api/file/download?fileDataSetId=c55e170e-3c75-49a5-8026-a961ff94c8e0&fileName=EDM_2020_Storm_Overflow_Annual_Return.zip

protocol: http

description: EDM_2020_Storm_Overflow_Annual_Return.zip download on Defra Data Services Platform

https://environment.data.gov.uk/api/file/download?fileDataSetId=c55e170e-3c75-49a5-8026-a961ff94c8e0&fileName=EDM_2021_Storm_Overflow_Annual_Return.zip

protocol: http

description: EDM_2021_Storm_Overflow_Annual_Return.zip download on Defra Data Services Platform

https://environment.data.gov.uk/api/file/download?fileDataSetId=c55e170e-3c75-49a5-8026-a961ff94c8e0&fileName=EDM_2022_Storm_Overflow_Annual_Return.zip

protocol: http

description: EDM_2022_Storm_Overflow_Annual_Return.zip download on Defra Data Services Platform

https://environment.data.gov.uk/api/file/download?fileDataSetId=c55e170e-3c75-49a5-8026-a961ff94c8e0&fileName=EDM_2023_Storm_Overflow_Annual_Return.zip

protocol: http

description: EDM_2023_Storm_Overflow_Annual_Return.zip download on Defra Data Services Platform

https://environment.data.gov.uk/api/file/download?fileDataSetId=c55e170e-3c75-49a5-8026-a961ff94c8e0&fileName=EDM_2024_Storm_Overflow_Annual_Return.zip

protocol: http

description: EDM_2024_Storm_Overflow_Annual_Return.zip download on Defra Data Services Platform

https://environment.data.gov.uk/api/file/download?fileDataSetId=c55e170e-3c75-49a5-8026-a961ff94c8e0&fileName=EDM_Long-term_Trends_Storm_Overflow_Annual_Return.zip

protocol: http

description: EDM_Long-term_Trends_Storm_Overflow_Annual_Return.zip download on Defra Data Services Platform

https://experience.arcgis.com/experience/c9b8f3ba094c429aa30e0e2b6eaf43ac

protocol: http

name: Storm Overflow - Spill Frequency Portal: Event Duration Monitoring (EDM) Data

description: The Event Duration Monitoring - Storm Overflows - Annual Returns dataset in spatial form.

Unique resource identifier

code

21e15f12-0df8-4bfc-b763-45226c16a8ac_resource

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

http://www.opengis.net/def/crs/EPSG/0/27700

Classification of spatial data and services

Topic category

environment

Keywords

Keyword set

keyword value

EDM

Event Duration Monitoring

Storm Overflow

environment

Keyword set

keyword value

sewerage system

originating controlled vocabulary

title

GEMET - Concepts, version 2.4

reference date

date type

publication

effective date

2010-01-13

Geographic location

West bounding longitude

-6.236

East bounding longitude

2.072

North bounding latitude

55.816

South bounding latitude

49.943

Temporal reference

Temporal extent

Begin position

2020-01-01

End position

2024-12-31

Dataset reference date

date type

creation

effective date

2021-03-30

date type

revision

effective date

2025-03-27

Frequency of update

annually

Quality and validity

Lineage

This annual summary Event Duration Monitoring (EDM) dataset relates to the performance of storm overflows. Data are provided by Water and Sewerage Companies (WaSCs) each year as part of their regulatory EDM Storm Overflow Annual Return. Summary data and long-term trends are produced from these returns by the Environment Agency.

Conformity

Data format

name of format

Open format | Portable Document Format - Unreferenced (PDF)

version of format

Constraints related to access and use

Constraint set

Use constraints

Open Government Licence

Constraint set

Limitations on public access

There are no public access constraints to this data. Use of this data is subject to the licence identified.

Constraint set

Use constraints

Constraint set

Limitations on public access

There are no public access constraints to this data. Use of this data is subject to the licence identified.

Responsible organisations

Responsible party

organisation name

Environment Agency

email address

DSPcustomerforum@environment-agency.gov.uk

web address

https://environment.data.gov.uk/support

description: Defra Data Services Forum

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

organisation name

Environment Agency

email address

DSPcustomerforum@environment-agency.gov.uk

responsible party role

pointOfContact

Metadata date

2025-03-27

Metadata language

eng