Millers Homes have submitted a planning application for “Land at North Colwell Farm” (DM/25/0445) to Mid Sussex District Council to develop 80 homes on the site. In support of the application, they have included an Ecological Impact Assessment (EIA).
The EIA found the site to be of ‘county importance’ for one the UK’s rarest mammals, the endangered Hazel Dormouse (Muscardinus avellanarius), as well as finding rare bats, birds and reptiles. Hazel Dormice are a conservation priority species in the UK, assessed by Natural England as being vulnerable to extinction. A licence from Natural England is required to disturb and monitor Hazel Dormice.
The Land at North Colwell Farm site consists of three fields to the south of Lewes Road, between Colwell and Slugwash Lane. The fields have been left fallow since the 1980s, but deer and rabbits graze the meadows, which are bordered by Ancient Woodland and streams. With no footpaths or roads leading through them, the secluded location has allowed wildlife to flourish.
Lewes Road resident Ingrid Marson said she wasn’t surprised to see the EIA, as she has seen first-hand the high reptile, bird and invertebrate diversity in her garden, which is at the boundary of the site.
“Every year, we have Grass Snakes and Slow worms in our garden shed,” said Ingrid. “The Grass Snakes shed their skin in the shed, and we’ve even had nests of Slow worm babies. My children and their friends have loved seeing all this wildlife! It shows how vibrant the countryside around Haywards Heath is.”
According to local ecologists consulted by Ingrid Marson, the Land at North Colwell Farm is a rare south-facing microclimate. The site is one of the few remaining south-facing sites linking the South Downs National Park to the High Weald Area of Outstanding Natural Beauty. Most of the south-facing habitats of Haywards Heath have been lost to development over recent years.
The EIA found a living Hazel Dormouse and three Hazel Dormouse nests in the species-rich hedgerows bordering the fields. After doing a brief survey, the developers deemed the site of “at least regional importance” for bats with a wide range of species, including IUCN endangered species’ Leisler’s bat and Barbastelle, and other species including Noctule, Serotine and Soprano Pipistrelle bats.
The developers discovered a high bird diversity, including the Lesser Redpoll, which is on the UK RSPB Red List, and the Song Thrush and Dunnock, which are on the UK RSPB Amber List.
The developers also found Grass Snakes, Slow worms, Common Lizards, active Badger setts, and high potential for Hedgehogs. The site is in the amber risk zone for Great Crested Newts, indicating that there is suitable habitat and Great Crested Newts are likely to be present.
The developers propose to remove the majority of the grassland, and some of the hedgerows. Local ecologists state it would be impossible for the dormice to remain on the site if the grassland is removed due to the loss of microclimate, reduction in invertebrates and introduction of cats. These changes would also impact the bats, birds and reptiles.
Responses to the Millers Home plan can be submitted by visiting the Mid Sussex Planning Portal and searching for DM/25/0445. The deadline for public submissions is 28 March 2025.