Overflow Map API

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How to Access our Near Real-time Data

Overview

Scottish Water’s Overflow Map provides near real-time data on monitored sewer overflows across Scotland.

We are being open and transparent, sharing our data exactly as we receive it, and have provided a public Application Programme Interface (API) that allows you to access and reuse this data in your application.

What the Near Real-time Overflow Map Shows

Our Overflow Map shows the locations of overflows on the Scottish Water network with Event Duration Monitoring (EDM). 

It provides near real-time information on monitor activations and is updated every 60 minutes. However, not all the overflows record data and update data at the same frequency.

EDM monitors do not confirm overflow events, they only indicate them. There may be times when errors occur, e.g. due to maintenance activity or movement close to the monitor, indicating the overflow is active, when it isn’t.

We can’t say there has been any pollution or promise the water is safe to swim in. Our information can help water users make more informed decisions, but this data is not advice on water quality.

The EDM monitors will indicate:

  • an overflow is currently occurring or has occurred in the last 48 hours
  • the total duration of overflow events in the last 48 hours
  • the date and time of the most recent and previous overflow events
  • the priority for planned future investment

About the API 

The Near Real Time (NRT) Application Programme Interface (API) allows users to connect to our Near Real Time (NRT) Overflow Map data.  The API can be used to integrate this data into your application.

How to Use the NRT API

  1. Access 
    The API is open for public use. No authentication is required, but users should respect rate limits and cache data where possible.
  2. Servers
     https://api.scottish-water.co.uk/overflow-event-monitoring/v1
  3. Endpoints

GET: https://api.scottish-water.co.uk/overflow-event-monitoring/v1/near-real-time

Responses: 

200: Successful response 
Content: application/json
Example: 
{
 "results": {

    "OVERFLOW_START_DATETIME_PREVIOUS": "2025-08-09T07:28:43.000Z",
    "OVERFLOW_END_DATETIME_PREVIOUS": "2025-08-09T08:04:56.000Z",
    "OVERFLOW_DURATION_MIN_PREVIOUS": 36.22,
    "OVERFLOW_START_DATETIME": "2025-08-10T22:13:22.000Z",
    "OVERFLOW_END_DATETIME": "2025-08-10T23:02:05.000Z",
    "OVERFLOW_DURATION_MIN": 48.72,
    "OVERFLOW_STATUS_ID": 15,
    "OVERFLOW_STATUS_DESCRIPTION": "NO - No Overflows",
    "ASSET_ID": "CSO001446",
    "ASSET_NAME": "WISHAW PLAYING FIELD PCSO NS795566",
    "LICENCE_NUMBER": "CAR/L/1026132",
    "SW_UNIQUE_MEASUREMENT_POINT_DESCRIPTION": "Wishaw, Playing Field CSO Event",
    "OVERFLOW_TYPE": "CSO",
    "RECEIVING_WATER": "South Calder Water",
    "DISCHARGE_OVERFLOW_LOCATION_GRID_REFERENCE": "NS 79568 56663",
    "DISCHARGE_OVERFLOW_LOCATION_POSTCODE": "ML2 7LD",
    "DISCHARGE_OVERFLOW_LOCATION_X": 279568,
    "DISCHARGE_OVERFLOW_LOCATION_Y": 656663,
    "DISCHARGE_OVERFLOW_LOCATION_LATITUDE": 55.788221,
    "DISCHARGE_OVERFLOW_LOCATION_LONGITUDE": -3.9221516,
    "LOCAL_AUTHORITY_NAME": "North Lanarkshire",
    "INVESTMENT_PRIORITY": "None",
    "IS_INVESTMENT_DRIVER_AESTHETIC": false,
    "IS_INVESTMENT_DRIVER_WATER_QUALITY": false,
    "IS_INVESTMENT_DRIVER_OPERATING_IN_DRY_WEATHER": false,
    "IS_INVESTMENT_DRIVER_EMERGENCY_STORAGE": false,
    "TOTAL_OVERFLOWS_DURATION_MIN_PAST_48_HRS": null,
    "LAST_TRANSMITTED_DATETIME": "2025-08-13T20:05:36.000Z",
    "DEVICE_LAST_TRANSMITTED_DATETIME": "2025-08-14T06:04:08.930Z"
  }
}
401: Incorrect key: only applicable when using an API key. If you experience this using the public API, please contact us.
500: An unexpected error occurred. If you experience this using the public API, please contact us.

This API data includes "OVERFLOW_STATUS_ID" which relate to the 4 current overflow statuses as follows:

  • 3 - Overflowing
  • 14 - Recent Overflow
  • 15 - No Overflows
  • 16 - No Data Available

A Note on Dates and Times

  • The data on the NRT Overflow Map on our website is in UK local time.
  • The data available via the NRT API is in Coordinated Universal Time (UTC).

Terms of Use

Other overflow maps may use different icons, colours, descriptions, and statuses. We are not responsible for how third parties may reuse our data. For accuracy, we advise you to refer to the data presented on the official Scottish Water website.   

  • Data is provided under an open license for reuse.
  • Scottish Water is not liable for third-party interpretations.
  • Users must cite Scottish Water as the data source.

Need Help?

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