South East Water environmental performance data report 2025
Published 29 October 2026
Applies to England
© Crown copyright 2026
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This publication is available at https://www.gov.uk/government/publications/water-only-companies-in-england-environmental-performance-report-2025/south-east-water-environmental-performance-data-report-2025
This report provides company specific data and information on the South East Water environmental performance report metrics. It contains current year and historic performance data (as reported at the time, based on data provided in part by the water only companies).
For an overview of water only company performance, please see the Water only companies in England: environmental performance report for 2025. This includes further information on what each metric means in the Environmental performance metric guide.
1. Serious pollution incidents (category 1 and 2) metric
Main facts
For 2025:
- 0 serious pollution incidents, a decrease of 1 since 2024
- 1 of 6 companies (out of 7) to have 0 serious pollution incidents
Table 1. Annual number of serious pollution incidents (category 1 and 2) from South East Water assets from 2023 to 2025
| Year | 2023 | 2024 | 2025 |
|---|---|---|---|
| Serious pollution incidents | 0 | 1 | 0 |
Table 2. Number of serious pollution incidents (category 1 and 2) from South East Water assets in 2025
| Asset type | Number of serious pollution incidents (category 1 and 2) |
|---|---|
| Water distribution system (water supply) | 0 |
| Water treatment works (water supply) | 0 |
| Other | 0 |
2. Total pollution incidents (category 1 to 3) metric
Main facts
For 2025:
- 57 pollution incidents – an increase of 19 since 2024
- 14,620 km water distribution network length – from financial year ending 2018 (this baseline is used in the performance assessment)
- most incidents (34) from the water distribution system (water supply asset)
- the highest amount of pollution incidents out of 7 water only companies
- 1 of 3 water only companies (out of 7) to have more than 30 total pollution incidents for 2025
Table 3. Annual number of pollution incidents (category 1 to 3) from South East Water assets 2023 to 2025
| Year | 2023 | 2024 | 2025 |
|---|---|---|---|
| Total pollution incidents | 17 | 38 | 57 |
Table 4. Total number of pollution incidents (category 1 to 3) from South East Water assets in 2025
| Asset type | Number of pollution incidents (category 1 to 3) |
|---|---|
| Water distribution system (water supply) | 34 |
| Water treatment works (water supply) | 21 |
| Other | 2 |
Table 5. Total number of pollution incidents (category 1 to 3) from South East Water assets in 2025, including category breakdown
| Asset type | Category1 to 3 | Category 1 | Category 2 | Category 3 |
|---|---|---|---|---|
| Water distribution system (water supply) | 34 | 0 | 0 | 34 |
| Water treatment works (water supply) | 21 | 0 | 0 | 21 |
| Other | 2 | 0 | 0 | 2 |
3. Self-reporting of pollution incidents (water supply) metric
Main facts
For 2025:
- 86% self-reporting of incidents
- self-reporting has improved since 2024, when it was 82%
- the third lowest self-reporting score out of 7 water only companies
Table 6. Annual self-reporting of pollution incidents (category 1 to 3) from South East Water assets (water supply) 2023 to 2025
| Year | 2023 | 2024 | 2025 |
|---|---|---|---|
| Percentage of incidents self-reported | 65% | 82% | 86% |
| Number of incidents | 17 | 38 | 57 |
Table 7. Number of pollution incidents self-reported and not self-reported by South East Water in 2025
| Year | 2023 | 2024 | 2025 |
|---|---|---|---|
| Number of pollution incidents not self-reported (category 1 to 3) | 6 | 7 | 8 |
| Number of pollution incidents self-reported (category 1 to 3) | 11 | 31 | 49 |
4. Delivery of the Water Industry National Environment Programme (WINEP) metric
Main facts
For the financial year ending March 2026 (cumulative progress years 1 to 5 of the WINEP):
- 62.5% of schemes completed within planned deadlines
- 5 water resources schemes delivered in year 1 of the current WINEP
Table 8. Annual delivery of the WINEP from South East Water for financial year ending 2026
| Financial year ending | 2026 | 2027 | 2028 | 2029 | 2030 |
|---|---|---|---|---|---|
| Asset Management Plan (AMP) | AMP8 | AMP8 | AMP8 | AMP8 | AMP8 |
| Percentage of WINEP complete within deadlines (to date) | 62.5 | No data | No data | No data | No data |
| Cumulative number of schemes completed during AMP period | 5 | No data | No data | No data | No data |
| Cumulative number of water quality schemes completed during AMP period | 0 | No data | No data | No data | No data |
| Cumulative number of water resources schemes completed during AMP period | 5 | No data | No data | No data | No data |
| Cumulative number of fisheries, biodiversity and geomorphology schemes completed during AMP period | 0 | No data | No data | No data | No data |