Sewage Map

Blackwater (Test and Itchen) sewage map and spill data

2 storm overflows listed in the 2025 annual return name this water. All are operated by Southern Water. Check the latest company report for each outlet below.

2
Outlet records
126
Spills in 2025
1,542
Recorded hours
2
Linked to a live feed

Annual figures describe the whole of 2025, not today.

Official waterbody record ↗How spills are countedSearch the national map

Outlets on Blackwater (Test and Itchen)

Filter by the latest company report. The map follows the filters.

Filters apply to the map and list. Recent stops need a current report and a recorded stop time. They do not show whether water is safe.

Showing 2 of 2 outlets

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Most recorded spills in 2025

The highest 2025 counts among these outlets. A count is events, not volume or harm. Equal counts share a rank.

  1. 1
    West Wellow SSO - 115727

    Southern Water

    101spills
  2. 2
    Wellow Mill Blackhill CEO - 108499

    Southern Water

    25spills

Spills over time

The median outlet on Blackwater (Test and Itchen) recorded 63 spills in 2025, against 11 across England.

2 outlets have a comparable count for both 2024 and 2025, with the monitor working at least 90% of each year. 0 recorded more spills, 2 fewer and 0 the same. Together they went from 279 to 126 spills, a fall of 55%.

YearOutlets with a countTotal spillsMedian per outletEngland median
202521266311
20242279139.519
2023227013520
2022213768.513
2021215577.519

Earlier returns list fewer of these outlets, so totals are not comparable between years. The median per outlet and the like-for-like change are fairer comparisons. Counts are events, not volume.

All outlet records on Blackwater (Test and Itchen)

2 outlet records in alphabetical order. Each link opens the outlet page with its latest report and annual history.

Sources and dates

Outlet locations, waterbody links and spill figures come from the Environment Agency 2025 event duration monitoring annual return. The latest company reports come from each operator’s live feed and carry their own dates. Waterbody ID: GB107042016791. The official waterbody record is a source lookup; its classification is not imported here.

All sourcesHow the data worksReport pollution

Questions about Blackwater (Test and Itchen)

Which outlets are linked to Blackwater (Test and Itchen)?
The source links 2 outlet records to waterbody GB107042016791. The link comes from the annual return; it does not model where a discharge travelled.
How many spills were recorded for Blackwater (Test and Itchen)?
2 records report 126 spills in 2025 and 1,542 recorded hours. All listed records have a usable count. Outlets can discharge at the same time, so the hours are not the time the whole water was affected.
Who is responsible for the outlets on Blackwater (Test and Itchen)?
Southern Water operates every listed outlet. Contact the operator or the official pollution service if you see a problem in the water.
Which outlets on Blackwater (Test and Itchen) are linked to a live feed?
2 of the 2 records are matched to a monitor in a company live feed. A link does not mean the monitor is working now. Use the status filters above to see the latest report for each outlet, with its date. The rest show annual figures only.
How complete is the monitoring for Blackwater (Test and Itchen)?
Every record with a monitor operation figure shows 90% or more for 2025.
Does this show if Blackwater (Test and Itchen) is safe?
No. Event duration data does not measure bacteria, chemicals or current water quality. Use official local water-quality advice for that question.