Work begins on ‘super sewer’ aquatic ecology research project

Mar 10, 2017

BUG is delighted to be commencing work to support Tideway, the company tasked with delivering London’s Thames Tideway Tunnel, one of the largest infrastructure projects in the UK.

As part of this major infrastructure project; Tideway has commissioned BUG, in collaboration with ZSL (Zoological Society of London) and Steve Colclough (SC2), to conduct an aquatic ecology study within the tidal reaches of the River Thames to provide baseline data against which future improvements in water quality and ecology can be assessed.


Tideway’s ‘super sewer’ will be approximately 25km long and will run up to 65m below the River Thames (Source: Tideway).


Every year, tens of millions of tonnes of raw sewage enter the River Thames through Combined Sewer Overflows (CSOs), which release flows through discharge points at various locations along the tidal Thames. Historically, this would only occur once or twice a year; however, in recent times this has become a regular occurrence due to the increased demand on the Victorian sewage system.

Tideway’s solution is the construction of a 25km long and up to 65m deep ‘super sewer’, the Thames Tideway Tunnel, to intercept storm flows before they enter the river. These flows will be diverted through the tunnel to Abbey Mills Pumping Station near Stratford, where they will be transferred to Beckton Sewage Treatment Works via the Lee Tunnel, before being treated and discharged at the mouth of the estuary. This will help prevent the tidal River Thames from being polluted with untreated sewage which can stay in the river for up to three months before the ebb and flow of the tide finally takes it out to sea.


The Thames Tideway Tunnel will intercept Combined Sewer Overflows (CSOs) before they enter the River Thames (Source: Tideway).


How is BUG helping?

As part of this £4.2bn project, Tideway has commissioned an expert team of fisheries scientists from BUG, ZSL and SC2 to conduct an aquatic ecology research project over the next three years. The team will be investigating the temporal and spatial utilisation of the tidal Thames by larval and juvenile fish to help understand the current ecological functioning of this important river reach and to track any changes associated with improvements in water quality.


Scientists from BUG and ZSL trialling mid-channel juvenile fish sampling methods on the River Thames.


Scientists from BUG, ZSL and SC2 trialling marginal juvenile fish sampling methods on the River Thames.


The monitoring programme begins in mid-March 2017 and will continue over the next three years until 2019. Citizen Scientists will also be involved in collecting data for this comprehensive research project which, in addition to providing data to track changes associated with improvements in water quality in the River Thames, will also help to inform management decisions for future large infrastructure projects within estuaries throughout the UK and worldwide.

For more information on Tideway, visit

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