Affinity and Thames gauge chalk stream health

Affinity Water and Thames Water have launched a new framework for measuring the health of chalk streams that will be used to identify problems and plan interventions.

The assessment framework, which includes a set of chalk stream health metrics, will be piloted in the River Chess catchment area.

The water companies said that as the majority of the world’s chalk streams are found in England they should be seen as part of the country’s heritage, in the same way the Amazon rainforest is for Brazil and the Great Barrier Reef in Australia.

However, these streams are at risk of extinction due to the impacts of climate change and increased demand for water from a growing population. Many are dry in long stretches and do not meet the objectives set out in environmental legislation.

The firms said revitalising chalk streams would allow various species of fish to thrive once more, including Brown Trout, Bullhead, Brook Lamprey and Atlantic Salmon.

“It may surprise people to know that, at the moment there is no clear definition of what a healthy chalk stream is and how it is measured,” said Affinity Water’s head of external communications Kevin Barton.

“Different stakeholders have different responsibilities and legal obligations, and our new systematic metrics approach takes this a few steps further.”

He said: “Our new assessment framework will use a clear set of metrics that will measure the health of the streams and will help to identify problems and plan new interventions where needed.

“While it’s great that people are enjoying our chalk streams more there are numerous ways in which they can be negatively impacted including the pressure of human needs such as agricultural activities and land use change. We need to balance the needs of nature with the needs of human activities and ensure their preservation long into the future.”

Affinity and Thames developed the framework in partnership with Arup and supported by expertise from Cambridge University, the Environment Agency, the River Restoration Centre and Chalk Streams First.

Among other things, they said the initiative would provide a new method for decision-making to achieve the best value remedies; set objectives and interventions in collaboration with catchment users; demonstrate the complexity of chalk streams as socio-ecological systems, including interdependencies; and find new ways to fund projects that fall outside of minimum regulatory requirements.

The water companies also held a number of meetings with key stakeholders, including MPs and local councillors, and convened an independent panel to scrutinise the framework.

Panel chair Sir Charles Walker said: “During the Covid-19 lockdown we have come to realise how important our countryside and rivers are for our physical and mental health and we must do more to improve and enhance them for this and future generations who benefit in all kinds of ways from them.

“Humans and wildlife should be able to share nature’s gifts and live side by side together and this new innovative metrics approach will at last be able to give us a proper measurement of the health of our chalk streams and a proper plan of how we can improve them.”

The new approach will be shared with catchment partnerships and river groups ahead of the River Chess pilot.

Arup global water leader Mark Fletcher said: “The next stage of development will pilot the metrics on the River Chess, providing invaluable feedback to help refine our approach as we move forwards.

“Collaboration has been at the heart of this project, and we look forward to continuing conversations over the coming phases of work.”

The framework will additionally form part of Thames’ Smarter Water Catchment initiative to protect the River Chess.

Catchments programme manager Helena Soteriou said: “At Thames Water, we’re already working with local groups across the Chess to set out our vision for restoring and enhancing this incredible river

“We’re excited to put the new metrics into practice, which will help us choose the best projects to improve the health of our chalk streams. They will also support the improvement of water quality in the River Chess and highlight the importance of increasing biodiversity and the benefits these rivers bring to the communities who use them. “

Thames Water sustainability director Richard Aylard said: “Restoring and protecting chalk streams requires a team effort and the new health metrics will help measure our collective activities to improve these important rivers and make a difference to how wastewater is managed across the Chilterns.

“At Thames Water, we think investment in water quality improvements for chalk streams is really important and we’re increasing capacity at Chesham sewage works by 39% over the next two years to treat the flows that arrive on site.”