Hertfordshire's Rare Chalk River Restored to Natural Glory

As of October 2025, the Herts and Middlesex Wildlife Trust has successfully completed an ambitious 8-year project to restore a 4.3-mile stretch of the rare chalk River Ash to its original course. The landmark scheme, undertaken on the Easneye Estate near Hertford, is one of the largest of its kind in the county.

The restoration work included creating natural "wiggles" in the previously straightened river, reconnecting it to the floodplain, and adding over 3,000 tons of gravel to the riverbed. More than 300 woody debris features were also installed to provide shelter for fish. Additionally, 15 new ponds were created as part of the project.

According to Sarah Perry, the river catchment coordinator for the trust, the restoration will not only help protect the area from flooding but also "help to maintain the ecosystem balance" that the River Ash's unique chalk-based system supports. The river is home to vulnerable and endangered species like water voles, wild brown trout, and kingfishers.

Despite being one of only around 260 chalk rivers in the world, these precious waterways have historically faced significant challenges from human activities, including pollution, over-abstraction, and the growing impacts of climate change. The Herts and Middlesex Wildlife Trust's landmark project on the River Ash aims to provide hope for the recovery of this rare and unique ecosystem.