Project to restore a precious chalk stream completed by Affinity Water and partners

0
781

A CHALK stream restoration project between Affinity Water, the Environment Agency, Luton Borough Council and catchment partners has been completed.

The Moor river improvement project in Luton is one of a number of projects that are part of the Revitalising Chalk Rivers partnership, in collaboration with the Environment Agency.

Kevin Barton, Head of External Communication for Affinity Water, commented on the news: “We are delighted that working with our partners, Affinity Water has been able to revitalise the Upper River Lea, just one of around 24 chalk streams in our catchment area.

“Chalk streams are globally rare habitats and as precious as the Bengali Tiger.

“There are just 240 of them in England, with 10 per cent located within our supply area, which the River Lea is a part of.

“We want to thank our partners the Environment Agency, Luton Borough Council, and the Luton Lea River Catchment Partnership too.

“This river restoration project has provided the ideal habitat for fish to be able to breed again.”

According to the Wildlife Trusts, chalk rivers are characterised by clear water and a diverse flora.

They emerge from the chalk aquifer, so the very pure water is rich in minerals and remains at a fairly constant temperature year-round.

This lets diverse aquatic plants grow, including various species of water-crowfoot and water star-wort.

The plant diversity and good water quality supports many invertebrate and fish species.

The river restoration work is part of a wider programme to restore globally rare chalk streams to their natural condition and help create sustainable habitats to allow fish, insects and plants to flourish.

Only 200 chalk rivers are known globally, 85% of which are found in the UK in southern and eastern England.

Classic examples include the rivers Itchen and Avon in Wessex and the river Wensum in Norfolk.

The programme will also help rivers across the southeast meet the EU Water Framework Directive of Good Ecological Potential by 2027.

Affinity Water Environmental Enhancement Programme Manager, David Watts, commented: “The River Lea is now more resilient to low-flows.

“We’ve carried out tree works to cut back overgrown trees along this stretch of the river.

“This allows sun light to reach the river and its banks to enable plants to grow again.

“We created new channel that meanders further into the park and constructed a bund to divert the river into the new channel.

“Berms, riffles and pools have been created in the new river channel to provide a mosaic of different habitats for insects, plants and fish.

“The old river channel now provides a wetland habitat and a buffer from road run-off pollution.

“By designing the new river channel and creating a buffer area this will reduce the amount of silt entering the river, as a result the gravel on the riverbed is now accessible to fish species, such as trout, and a wide range of invertebrates, providing the fish with an ideal habitat to breed.

“The river channel has also been designed to be resilient in times of low-flow and has increased the flood capacity in this area by 700m.

“Construction started on 6 January 2020, our contractor battled the storms of Ciara and Dennis and the subsequent high river levels to complete the project before the Coronavirus lockdown.”