Here, in Hertfordshire, we have a national and international responsibility for protecting our special chalk rivers, which have a unique ecology due to their clean, mineral-rich water and consistent flows. There are only 240 chalk rivers in the world and around 10% of those are in our county. Due to their rarity and significance for wildlife, these habitats are classified by DEFRA as Priority Habitats and were once included in Biodiversity Action Plans across the country.

Yet despite how precious chalk rivers are, they continue to face threats from a combination of factors such as changes in land-use, pollution, over abstraction and historic industry – all linked to a growing population. The impact of climate change is another factor that our rivers need to adapt to, as records show our weather conditions becoming hotter and drier in recent years. This has resulted in prolonged periods of drought and stress for our chalk streams. To ensure they are resilient in years to come, the ecological status of our chalk rivers needs improving.

Read on and explore four cases studies which demonstrate how the Trust’s Living Rivers project is partnering with landowners, local organisations and funders to tackle some of the issues associated with our chalk rivers and see the impact our work is having. 

River Lea and Seniors Lake Restoration in Hertford / near Stanstead Abbotts respectively

This project was funded by the Green Recovery Challenge Fund in 2022. In partnership with Red Spinners Angling Society and with support from the Environment Agency, fishery improvements were made on a 0.5km stretch of the River Lea to support natural spawning success of a range of fish species, including Barbel and Brown Trout. Trout have been lost from two thirds of their native UK range over the last 100 years, partially as a result of loss of spawning habitat. Work on the Lea to energise gravel beds and introduce woody habitat cover in the channel is helping to increase their breeding success.

Pond restoration work was also undertaken to support a Hertfordshire species of conservation concern (SON) – in this case, Crucian Carp. The project included four practical habitat days with club members, helping to build skills in the club for ecological fishery management and improving riparian habitat for Water Voles.

River Rib at Buntingford

This project in 2022 saw us partner with Buntingford Town Council, with funding from the Environment Agency and the Green Recovery Challenge Fund to restore 0.5km of the River Rib using specialist contractors, RJ Bull, and working with a team of local volunteers. In a concrete channel, riparian habitat was created using berms and large wood coppiced from bankside trees in need of attention! Nest boxes for Kingfisher, Yellow Wagtails and Daubenton Bats were installed and 20 local volunteers planted the river with 3,000 native plug plants, like Water Mint, Flag Iris and Gypsywort, but the work doesn’t stop there - our River Champion, Derrick Guy, has been supporting local landowners to tackle invasive non-native plants Himalayan Balsam and Giant Hogweed, on the upper Rib for the last two years. With funding from Affinity Water and support of their staff coordinated by Derrick, the seedbank of these plants has been greatly reduced and work will continue until they are fully eradicated over the next few years.

River Stort at Roydon

In January this year, we partnered with Stansted Bury to deliver the first stage of restoration work on the River Stort near Roydon. Funded by the Environment Agency, work was carried out to improve the river where it has been re-aligned after gravel was dug from the floodplain in the 1960s and the Rye Meads Sewage Treatment Works built. The project saw 0.5km enhanced through tree work to enable light in to a heavily shaded channel, berms and bank to create sinuosity in a straightened river, soft bank protection to safeguard a still water fishery and local wildlife site, as well as creation of Kingfisher nest banks using upturned willow rootballs. The work will not only benefit Water Voles recorded close by in 2022, but also a number of course fish species like Dace, Perch and Chubb, that use vegetation in the river to spawn. More work is to follow in autumn 2023 and spring 2024.

River Mimram at Digswell

Working in partnership and with funding from St Johns Primary School, we delivered work along a 300m stretch of the River Mimram to create an enhanced river corridor for wildlife and outdoor education area for the school. This will be followed by further work in 2024 to support the school in planting up the newly created riparian zone.

These examples are just some of the projects the Trust is undertaking to contribute to the major task of restoring these vital habitats. The lasting effects of which will be felt by wildlife and communities for many years to come. If what you have seen here inspires you to get involved, please check out our Living Rivers webpage.