Backwater restoration in the Maidenhead to Teddington catchment

Battlemead Common, Maidenhead in Berkshire.

A backwater is a part of a river where the water is stagnant or flows slowly, often isolated from the main flow. These areas can be created naturally or artificially and typically occur in bends, oxbow lakes, or behind natural or man-made barriers. Backwaters are characterised by:

  • Slower water movement: Compared to the main river channel, backwaters have minimal flow, making them relatively calm.
  • Habitat diversity: They provide unique habitats that support diverse aquatic life, including fish, macrophytes (aquatic plants), and macroinvertebrates.
  • Nursery and spawning grounds: They serve as important nursery and spawning grounds for fish and other aquatic species.
  • Ecological importance: Backwaters contribute to the overall health of a river ecosystem by offering refuge and foraging areas for wildlife, including critically endangered species, like the European eel.

Issues facing backwaters in the UK include:

  • Pollution: agricultural runoff, urban wastewater, and industrial discharge contribute to the pollution of backwaters. This leads to poor water quality, which can harm aquatic life and disrupt ecosystems.
  • Eutrophication: the accumulation of nutrients, particularly nitrogen and phosphorus, from agricultural fertilisers and sewage can cause algal blooms. These blooms deplete oxygen levels in the water, creating dead zones where aquatic life cannot survive.
  • Hydrological alterations: Changes in water flow, due to damming, water extraction for agriculture and industry, and flood management practices can reduce the connectivity of backwaters with the main river. This impacts water exchange, habitat quality, and the overall health of these ecosystems.
  • Sedimentation: increased sediment load from erosion and land-use changes can smother habitats, reduce water depth, and impact water quality.
  • Lack of awareness and management: insufficient knowledge and lack of targeted conservation efforts can result in inadequate protection and management of backwaters.

In order to address these challenges, Thames21 has worked with our partners to map and assess backwaters throughout the Maidenhead to Teddington Catchment. Through the mapping tool, opportunities and priority areas were identified, enabling targeted restoration efforts.

The mapping tool was completed in March 2024 and can be found here:

Thames21 is now in the second year of the project and as per the recommendations of the first year, two prioritised backwaters will be restored in the Maidenhead to Teddington Catchment.

Please contact project officer Jo Goad for more information by clicking link here: jo.goad@thames21.org.uk