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Glan Llyn by St. Modwen Developments Ltd,

SK Environmental Solutions and Pleydell Smithyman

Shortlisted for Best Biodiversity Enhancement on a Brownfield Project


Biodiversity net gain for habitats

Biodiversity net gain for rivers and streams

Western Park Lake at Glan Llyn where Cetti’s warbler and water vole habitats are located

St. Modwen acquired the 600-acre former Llanwern Steelworks in 2010.  Since then, St. Modwen has transformed the brownfield site into a high quality and sustainable community development set within a landscape brimming with nature.  The site required extensive remediation to treat a legacy of contaminants including polyaromatic and petroleum hydrocarbons, heavy metals and high pH.


Working with Newport City Council, to date St. Modwen has delivered over 850 homes, a primary school, pub, a large park, linear green spaces and reens, along with footpaths and cycle routes throughout the development. The development includes three new lakes, extensive parkland across more than 80 acres, and the enhancement of the wildlife-rich pond area designated a Site of Interest for Nature Conservation (SINC). The environment provides a range of habitats for wildfowl and wetland creatures many native to the nearby Wentlooge Levels, including waterfowl, reedbed nesters and woodland animals and allows schoolchildren and residents to enjoy the nature on their doorstep.

St. Modwen is also currently creating an ecology park on the western edge of the development by enhancing an existing wildlife-rich area for the benefit of the wider community who will have access to part of the area.  The ecology park is designated by the Wales Biodiversity Partnership as highly prized from a wildlife perspective and is designated as a SINC.


In partnership with SK Environmental Solutions (ecologist), Pleydell Smithyman (landscape architect) and the wider design team, St. Modwen has been delivering ambitious plans for Glan Llyn through the design of new reens and lakes planted with wildflowers and wetland plants suitable for water voles, carder bees and reed nesting birds (such as Cetti’s warblers) in particular. Two of the reens will be completed this year and work already has started on the central lakes.  Plantations of native trees with a high percentage of hazel have been completed this spring in the north west corner of the site to enhance the existing dormouse habitat and link to the ecology park.

St. Modwen’s corporate commitments:


St. Modwen’s Responsible Business approach includes ambitious goals in six strategic areas where the company can make a sustained difference to society and the environment: net carbon reduction; biodiversity and sustainable environments; diversity and inclusion; education and future skills; health and wellbeing; and responsible operational practices and partnerships. This includes an aim to be operationally net zero carbon by 2025, and fully net zero carbon by 2040, and a pledge to invest 1% of cash profits annually into education partnerships.


Ellen’s Reen at Glan Llyn


Glan Llyn currently

Biodiversity net gain

With a biodiversity net gain for habitats of 21.84% and 41.29% for rivers and streams, the development will exceed the 10% net gain target set by Government, once complete.  This will be primarily achieved through retaining and enhancing existing areas of biodiversity interest, as well as converting large areas of hardstanding to green space.  In addition, new streams and ditches have been created, with existing streams enhanced through measures like opening up previously culverted watercourses.


Long term management and monitoring over 30+ years is crucial to fulfilling St. Modwen’s aims for Glan Llyn and as such, a long-term habitat management plan has been put in place.


Residual effects on all habitats and linear features by site

Water Voles

Historic watercourses (reens) across the former steelworks were heavily polluted prior to the start of the remediation and would have been unsuitable to support species such as water voles.  No evidence of water voles had been recorded across the site in surveys before 2021.  A strong population of water voles now exists within the Ecology Park reen and two small remnant populations are present within Glan Llyn and adjacent commercial St. Modwen Park, Newport.  St. Modwen and SKE have brought together a team of highly skilled, experienced ecologists to apply to Natural Resources Wales for a translocation licence.  These works are currently underway with survey work starting in May 2022.

Following site completion, St. Modwen aims to extend the excellent water vole habitat across the entire site, including the commercial area to the east.  This will help connect the existing populations of water vole across the Gwent Levels following the recent re-introduction programme undertaken by Gwent Wildlife Trust.

Shrill (and Brown Banded) Carder Bee

Shrill carder bees are only known to occur in one or two sites across south Wales. The species is present at Glan Llyn and has been recorded in a number of areas in the 2021 survey season for ground nesting birds. Works are in place to incorporate suitable habitat to create ecosystem resilience for this species across Glan Llyn.  This includes the planting of native hedgerows along the periphery of open spaces which will be maintained on a rotational basis to extend the season for nectar rich hedgerow blossom and planting appropriate wildflower meadows within open spaces and on the embankments of the reen network and lakes to provide food and nesting habitats.


Cetti’s Warbler

Evidence of Cetti’s warbler has been recorded across the wider Newport area and the Gwent Levels. To encourage Cetti’s warbler and other similar specie to breed at Glan Llyn, St. Modwen has created new habitats along reen systems and waterbodies, including Julian’s and Ellen’s Reen and the central lakes which are being planted up this year with areas of willow scrub, and marginal wetland vegetation. This species has been a particular priority for St. Modwen as it has been in decline over the last couple of decades.

Ground Nesting Birds

Ground nesting bird species such as lapwing, ringed plover and little ringed plover have all been recorded across the site, where earthworks have inadvertently created suitable breeding habitats for these species.


A novel approach has been pursued to protect these species, using gabion baskets placed over the nests when eggs have been laid. These gabion baskets are manipulated in such a way to allow the adult birds to freely come and go from the nest, whilst preventing predators such as corvid species (carrion crow, jackdaw etc) and mammalian predators, such as foxes, from predating upon the eggs.


The purpose is to maximise the potential brood success of these species, as once these species have a successful brood, they will not try again and will quickly move away from the site once the eggs have hatched and the juveniles have become mobile.  If these species are unsuccessful, they will continue to try multiple times until they have reared a successful brood or the breeding season is over.


By maximising the success of the early broods, the constraint posed by ground nesting birds to earthworks is minimised in terms of time and ground nesting birds are afforded protection from predation.  As the little ringed plover is a Schedule 1 species, it required a licence from Natural Resources Wales, which was granted at the beginning of the works in 2021.


Gabion basket and ringed plover nest

Engaging and educating communities – delivering social value

Engaging and educating communities around nature and biodiversity is a priority for St. Modwen to help encourage everyone to work together to protect and enhance our natural surroundings through sustainable behaviour.  All events are free to participate in and open to all, including those who don’t live at Glan Llyn.


In March 2022 at the Glan Llyn spring event, residents celebrated the launch of the development’s nature trail, with Gwent Wildlife Trust on hand to provide insight on local flora and fauna.  Junior nature enthusiasts were challenged to guide themselves through the trail from the development’s Western Pools to Western Park, using an activity sheet (see below) to identify some of the diverse wildlife on their doorstep.


Children enjoyed interacting with an expert from the Gwent Wildlife Trust, who St. Modwen partners with at Glan Llyn.  After considering a variety of bird books, children were then able to put their new-found knowledge into action at a wildlife-themed craft table, with a bird-drawing activity producing plenty of creative and colourful images.

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Green-fingered residents at Glan Llyn took part in a tree planting for the Queen’s Green Canopy, a nationwide initiative to mark Her Majesty’s Platinum Jubilee.  Supported by St. Modwen, the community was encouraged to play their part in enhancing the environment in their local area, with 14 trees planted at Glan Llyn.


Families who live at Glan Llyn helped plant the development’s new sensory garden, under the guidance of a landscape gardener.  Designed to stimulate residents’ senses with objects and plants drawing on touch, sight, scent, and hearing, the garden will be a calming space for the community to enjoy for years to come.


Additional engagement with the community around biodiversity is planned by St. Modwen to ensure residents and the wider community can experience, learn and enjoy spending time in nature at Glan Llyn.  This includes a summer event, a Glan Llyn in Bloom competition for residents to celebrate their gardens, and further activity in partnership with Gwent Wildlife Trust.


Local press coverage

Wildlife trail activity sheet for children

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