Working in partnership to improve the River Mimram
Source: gov.uk (2025-06-13)

Catchment based approach to improve a rare and precious chalk stream, Initiative to bring farmer and landowners together to benefit the Mimram.

Thanks to funding from the Environment Agency, Herts and Middlesex Wildlife Trust has appointed Heidi Mansell as the new Chalk Rivers and Farm Advisory Officer to lead crucial efforts to restore and protect the River Mimram—one of Hertfordshire’s rare and precious chalk streams.

The Mimram is a vital part of the local ecosystem, beginning near Whitwell in Hertfordshire, and flows through the villages of Kimpton, Codicote and Welwyn before joining the River Lea near Hertford. The River Mimram is being improved by removing unnecessary weirs, better land management etc, through a collaborative effort between various organisations and community groups.

The next exciting stage included bringing in a farm advisory officer - Heidi to look at a new approach with the Mimram. One that’s catchment-wide, considering the entire area of land that drains into the river and having a dedicated person to support work on the ground. It’s important because specific local issues, for example, the demand for water, pollution, or invasive species, may start in the wider catchment and those that affect or who are affected by them should be empowered to find the solutions.

After being in the role for a year, here is what Heidi has to say:

We recognise that for a number of years, different groups and stakeholders have been coming together to improve the Mimram, so now the aim is to consolidate on this good work and hopefully make further progress.

In these first few months, I have been meeting with and listening to landholders to understand the support that they would like and gathering existing data on the catchment. Already, 11 of those, with land right next to the Mimram have said that they would like to work towards improving the river, which is hugely encouraging. Over the coming months and years, we’ll work together to create and deliver restoration and management plans that address some of the reasons why the river is not achieving good ecological status, according to the Water Framework Directive.

Heidi is exploring further exciting new options that are now available through the Higher-Level Countryside Stewardship Scheme that may fund some of this work, with payments to farmers that sensitively manage riverbanks and water edge habitats and connect river and floodplain habitats.

As a result of this work, there is hope to see species such as the endangered Water Vole thriving once again, to find Brown Trout creating their nests on the riverbed, to see flashes of blue as Kingfishers dart along the river and waving strands of Water Crowfoot teetering on the water’s surface – all indicators of healthy chalk streams.

Elizabeth Walden, Chalk Catchment Coordinator for the Upper Lee at the Environment Agency, reflects on the collaborative efforts to restore and protect the River Mimram:

England is home to 85% of the world’s chalk streams. Despite their importance nationally and internationally, only 17% met good ecological status under the Water Framework Directive in 2019. The River Mimram is one of the many chalk streams currently falling short of this standard.

The problems facing chalk streams are complicated and costly to address. However, by working at a catchment-scale in close partnership with Heidi, we’re making meaningful improvements to the Mimram valley. By improving the use of water resources, restoring habitat, and enhancing the river’s resilience during periods of high and low flow, this project is helping to secure a healthier future for the River Mimram, and the communities that value it.

We are excited to see how this new collaborative approach with Herts and Middlesex Wildlife Trust develops and delivers lasting improvements in the years to come.

Notes to editors

For more information on the scheme: we have a YouTube Video Here – https://youtu.be/3YJUs56RiV4 (https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fyoutu.be%2F3YJUs56RiV4&data=05%7C02%7CAndrew.Turton1%40defra.gov.uk%7C46c76d90c87c4fefbc8d08dda734769c%7C770a245002274c6290c74e38537f1102%7C0%7C0%7C638850565939658407%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=MUmQiPAv76iT0UlsHoD84W88jRKHS3NEV8P7hXm3eUQ%3D&reserved=0) And a blog here - Working together to protect and restore the Mimram catchment – Creating a better place (https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fenvironmentagency.blog.gov.uk%2F2025%2F06%2F06%2Fworking-together-to-protect-and-restore-the-mimram-catchment%2F&data=05%7C02%7CAndrew.Turton1%40defra.gov.uk%7C46c76d90c87c4fefbc8d08dda734769c%7C770a245002274c6290c74e38537f1102%7C0%7C0%7C638850565939673865%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=VEHXDfFlN8L9zWd%2BMMeFCAohAkWRw1TQlV3NybMozcI%3D&reserved=0)