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Lambourn Valley

We're improving our sewer network in the Lambourn Valley area. This includes the villages of Lambourn, East Garston, Eastbury and Great Shefford. 

The valley often floods during wet weather. After the wettest winter on record, the valley is currently flooded at many locations. We expect high groundwater levels to continue for several months.

 What we're doing

  • Daily clean-ups around the manholes to keep the area as tidy as possible
  • Using tankers at our sewage pumping station in Upper Lambourn 24 hours a day to help manage excess flows 
  • Filtering as much of the diluted discharge as possible, to minimise the impact on the river
  • Continually monitoring the river and carrying out regular water quality testing. The tests have shown minimal impact on the environment because the flows are heavily diluted by the groundwater and surface water runoff. We've been keeping the Environment Agency up to date with these tests
  • Continuing to investigate where groundwater and surface water are getting into the the sewer system
  • Writing to residents to remind them about what they flush - see more on our Bin it, don't block it page
Debris left after sewer flooding in Lambourn Valley

Some of the debris left behind after the flooding has cleared.


We've invested in an extensive programme of relining and sealing works. So far, we've lined around 8.5km of sewers and sealed 83 manholes. We've applied a further 1.6km of lining and sealed 49 manholes since April 2023.

The lining and sealing work carried out to date is significant but we know there's more to do. 

We now have funding for a further 548m of lining and sealing of 13 manholes. This work will be carried out across Eastbury, East Garston and Great Shefford.  


The wet weather has overwhelmed our sewer network with groundwater, surface water and flood water. It comes from many sources, including infiltration into our sewers and manholes, as well as those owned privately.

Because rainwater soaks into the ground slowly, groundwater levels can continue to rise long after the rain has stopped. This means it will take a long time for the extra water to leave our system, even once the rain stops. 

This water shouldn't be in our sewers as they aren't designed to hold it. Once they reach capacity, the water, mixed with untreated sewage, overflows into properties and streets. Find out more about sewer flooding


Lambourn Valley sewer flooding ATAC unit to filter flood water

An ATAC unit which filters the excess flows before they are discharged to the river.


We're responsible for maintaining our sewer network and have a long-term plan for preventing sewer flooding. We're working towards reducing storm overflow usage to improve river health. Our storm discharge map shows where discharges are happening in near real-time. 

Local authorities and the Environment Agency (EA) are responsible for groundwater, river and surface water flooding. We'll be working with them to manage flood water entering the sewer system.