Despite the bitterly cold wind, Spring does seem to have arrived.
Groundwater levels are dropping consistently, and although the sewers are still charged with groundwater, the risk of serious sewer flooding is reducing.
Now it's time to review what happened over the winter months, following the extensive work to the sewerage network carried out by Thames Water during 2025. Unfortunately, it's not an entirely satisfactory story.
Here are the key points:
- For the four months November to February, rainfall totalled 161% of long term average
- Groundwater levels were high. Higher than 2024/25, and similar to 2023/24
- The sewers in Lambourn, Eastbury and East Garston were full, and are still heavily charged
- Both Lambourn and East Garston ATAC filter units needed to be switched on
- Lambourn and Eastbury had sewage spilling out of manholes. East Garston had a minor spill but a few ground floor loos were having problems before the ATAC unit was switched on
- Great Shefford had no problems
- Tankers have been deployed at Weston to relieve pressure on the system and on the Sewage Treatment Works. The relining work was successful, but there is still infiltration from lateral and private drains
- East Shefford Sewage Treatment Works was discharging untreated sewage on a regular basis for about a month depsite both ATACs working and tankers running. This was partly due to groundwater levels but the situation was exacerbated by the excessive rainfall over the winter leading to above normal levels of surface water running into the system
- After the improvement seen in sewer flooding between winters of 2023/24 and 2024/25, the extensive remedial work carried out in 2025 does not seem to have had any significant impact on flooding levels
- TW have been unable to fully investigate the network due to the system being fully overloaded, but this will be done as soon as levels allow, to determine the next phase of relining
- The ATAC units have been suffering from excessive amounts of "wrong" stuff going down the pipes
On this final point, TW have shared with us some evidence of "sewer abuse" which led to blockages in the East Garston ATAC unit to a degree that has not been seen in the unit before. Wet wipes and various other items are clearly seen in this photograph which was taken only a day or two after the unit was switched on. Not surprisingly, the filters were soon blocked resulting in the unit shutting down.
As has been said many times before, wet wipes are the main cause of the problem of sewer blockages. Don't be fooled by the term "flushable". Yes, they will disappear when flushed down the loo, but most are plastic based and stay in one piece.
If anyone needs convincing, carry out this simple test:
Put a sheet of toilet paper in a jar half filled with water and give it a shake. It will disintegrate into a mushy pulp, which won't cause blockages.
Then do the same with one of your favourite brands of "flushable" wipes. You can shake it for as long as you like, it remains in one piece. Putting those down the loo is just asking for trouble.
The SAGLUV team are meeting with Thames Water fo a review later this month [April], after which, we will issue a further update.
SAGLUV Team
April 2026