This campaign opposes Thames Water's TDRA scheme on environmental and social grounds.

The TDRA scheme is environmentally flawed

There will be a clear environmental and ecological impact on the River Thames. Green spaces are protected for a reason: for the protection of nature and for the benefits that access to nature can have on human health.

• The plan will abstract (remove) water from the River Thames at a unique location where the tidal river meets the freshwater river.
• This water will be replaced with treated sewage year round — every hour of every day. This is because to keep the mechanics, shafts and pipes clear, the scheme must run treated sewage into the river at 25% of capacity year-round. This is called a "sweetening flow."
• There will be a significant impact to putting treated sewage into the River Thames. See details below.
• There will be trees chopped down
• There will be badger setts disturbed
• Building compounds will cause earth compaction and change the soil biome
• Building compounds will interfere with the natural movement of mammals and birds which may damage their ability to flourish.

"In addition to the potential traffic impact, it is likely the TDRA would have a substantial negative impact onthe ecology of the Metropolitan Site of Special Interest for Nature Conservation that comprises Ham Lands. While I can acknowledge Thames Water’s stated commitment to biodiversity net gain and reconstruction, this does not discount the immediate impact the temporary destruction of acres of nature reserve would have on local flora and fauna. Once mature trees are felled, they cannot be replanted, and once badger setts are destroyed, and their occupants killed or driven off, they cannot necessarily be restored. These are two specific examples of the damage this project could do to the area, but Thames Water’s own documentation cites a potential impact on a wide array of wildlife."
Sarah Olney, MP for Richmond Park. Letter to Constituents, November 2023,.

The TDRA scheme is socially flawed

To construct the tunnels, shafts outfall and abstraction sites, Thames Water will be removing land from community use for a significant period of time, causing a high social cost.

Specifically in Ham Lands and Burnell Open Space

• The North Kingston construction site includes the pipeline shaft, the discharge structures, the abstraction structures and the connection shaft to the TLT tunnel. This means virtually the whole of Burnell will be a building site.
• In just over a mile (from near Ham House in the north to the Hawker Centre YMCA in the south) TDRA will mean the construction of five 10.5 metre shafts along with the new pipeline.
• The Burnell open space at the south of the scheme will be hoarded off for construction of the outfall structure and abstraction structure, as well as several ancillary kiosks.
• There are several primary and secondary schools within the area of construction along with thousands of residents
• Every day, there will be a huge impact on the thousands of walkers, runners, casual river users and swimmers that use the Burnell Open space and the Thames Path National Trail towpath.
• Some of the roads in Ham Lands can barely accommodate two cars at the same time. The more densely built areas of Isleworth and Moormeads will also suffer from extra thousands of HGVs and other construction traffic needed to build the new treatment facility at Mogden.

Specifically in Moormead:

• Created from wasteland, this lively park now plays host to a number of sports and community events and has a pleasant village green atmosphere. The park has numerous facilities including a children's playground, football facilities and tennis courts. All will be impacted during a long construction period.
• Local schools that do not have their own playing fields rely on Moormead Park to provide areas for sports.

Throughout residential neighbourhoods

• Construction will take place on roads that were never built for, and cannot sustain, continuous heavy construction traffic of the kind TDRA will require.
• Construction of each shaft may need 26 HGVs a day over an 8-month period.
• There will be issues of noise, air quality, building vibration, nighttime working, and construction traffic.
• The tunnels will be going under conservation areas with buildings that are already subject to subsidence. Many people in the areas of the conveyance route and the construction are very concerned about the impact of pipejacking under their houses, the impact of shaft construction vibration on their properties and also the sheer amount of construction traffic. These issues need to be addressed by Thames Water. There was no information for residents at the information events, despite Thames Water referring concerned residents to attend those meetings to get their questions answered.