Following a year in the making, last November, the Trust delivered a large-scale habitat creation project at Hilfield Park Reservoir Nature Reserve, working in partnership with site owners and project funders, Affinity Water. The works form part of the Trust’s conservation management plan to improve wetland margins on the site, which sits between Elstree and Bushey, and represents the most significant habitat creation project on a nature reserve that the Trust has managed in a decade.

Here, Josh Kalms, People and Wildlife Officer (Affinity Water Sites), who led the project, tells us more about the work that has taken place and the wildlife that will benefit from the new wetland features on the reserve.

Hilfield Park Reservoir Nature Reserve is an undisturbed wetland site that is hugely valuable for local and visiting wildlife. In partnership with Affinity Water, since 2018, we have delivered a suite of ambitious conservation projects on the site, including the creation and maintenance of scrapes, ditches, creeks and lagoons and these most recent works have further enhanced its value to wildlife. This project really highlights the importance of partnerships in creating and conserving nature rich, resilient habitats, and with that, our knowledge and the support of our many volunteers, we can make headway in reversing the gloomy nature statistics, when, according to the State of Nature 2023 report, one in six species in the UK are at risk of extinction.

Time Capsules Ready to Burst into Life...

The landscaping work undertaken at Hilfield has been extensive. We have reshaped the ground to allow bigger, better and more connected reedbeds to form, whilst maximising the most productive areas in new wetlands by creating vast lengths of all-important shallow margins. Perfect for dragonflies, aquatic beetles, fish and everything that feeds on them. Disturbing the ground in this way has formed tracts of exposed but damp mud in the ‘drawdown zone’, which is an essential habitat, proved at Hilfield to contain the seeds of previously locally-extinct wetland plants, like time capsules ready to burst into life!

We’ve formed lagoons, sheltered by islands, where we hope rare Black-necked Grebes will breed once the margins vegetate. We have pushed overshading and invasive trees into the water to create ample submerged woody habitat; great for invertebrates, fish and nesting birds. Pollarding trees has generated supercharged sunlit reservoir margins, all these are important features for wetland systems to ecologically function.

We are hoping that as well as protecting the wildlife that thrives in this special place, new species will be attracted to the site too. Flocks of Lapwing have already been recorded using a newly scraped area, though as the enhanced reedbed becomes established, to see wintering Bittern here would not only be thrilling, but would reaffirm, that these habitats are suitable for a great variety of species.

Two large ponds were also created, one of which catches water flowing down a flush line and promises to be home to Downy Emerald, expanding its range into Hertfordshire, this locally rare dragonfly was observed in 2023 egg-laying in our ponds.

Harnessing the Expertise of Local People

To assess the value of the project, volunteer recorders will be on the lookout for which dragonflies, damselflies and birds arrive at the new habitats and will be monitoring how these, and other species, make use of the wetlands. We are fortunate to share in the expertise of local people who dedicate much time to monitoring the wildlife at Hilfield Reservoir.

Following the success of previous habitat creation on site, we know that these wetlands will deliver in abundance for local wildlife. This project has transformed this area creating a better connected, rare and diverse suite of habitats where wildlife will thrive.

Visiting Hilfield Park Reservoir Nature Reserve

Access to Hilfield Park Reservoir Nature Reserve is for Herts and Middlesex Trust members only by prior arrangement – for more information, please visit www.hertswildlifetrust.org.uk/nature-reserves/hilfield-park-reservoir

The Trust’s events programme is open to the wider public and details of the latest schedule can be found at www.hertswildlifetrust.org.uk/events