Protecting the environment

Environmental aspects

At National Highways, we’re committed to minimising any negative impacts of our work and where possible enhancing the environment. Our design for the new road includes lots of environmental and wider community benefits, some of which we have listed below.

Wildlife and plants

We are limiting the impact on wildlife and plants by replacing habitats that have to be removed. New habitats will include 5 hectares of native woodland, 18 hectares of screen planting and over 6 miles of native hedges.

To enhance local biodiversity, we will be creating 30 hectares of wildflower grassland on the road verges, the embankments and around the five new drainage ponds.

We will protect existing vegetation and habitat that is not affected by the works by installing fencing around all trees, woodland and hedgerows.

Ecologists are helping to protect existing wildlife by completing surveys of local hedgerows for brown hairstreak butterflies (Thecla betulae), and conducting surveys of badgers, bats, great crested newts, reptiles, barn owls and birds.

During the building of the road, we will install nearly 2 miles of wildlife proof fencing to protect wildlife such as badgers and deer. Badger fencing will be also be installed to direct badgers to a specially designed wildlife tunnel under the new road to keep them away from the traffic.

To help replace lost habitats, we are talking to local landowners to agree locations along the road to install a bat house, 16 barn owl nest boxes, a barn owl perch and numerous small bat and bird boxes.

Ecologists will capture and remove reptiles from the working area and relocate them locally to two safe areas with suitable habitat and specially constructed refuges.

Where we need to remove hedgerows our ecologists will move the eggs of the protected brown hairstreak butterfly to hedgerows that won't be disturbed as part of the scheme. 


To minimise flood risk, we will be building five new drainage ponds. These ponds will store and control the flow of water that runs off during heavy rain. We have designed them to maximise biodiversity by planting reed and sedges on the banks.

We will also provide ditches along the new road to collect runoff water during storms. This will protect land at known flooding locations and keep road users safe.  

We are building 10 miles of permeable grass drainage channels which will visually blend in with the rural landscape.

Walkers, cyclists and horse riders

We have maintained or realigned the majority of the existing rights of way.

The new Steart Hill bridge and Hazlegrove underpass will provide two safe North-South road crossings for walkers, cyclists and horse riders.

A scheme for a bridleway connecting Eastmead Lane with the Southern side of the A303 via the Higher Farm Lane bridge near Podimore, has been approved by the Secretary of State.

Noise and light

We are deflecting traffic noise by building seven earth banks which will be nearly 1 mile in total length and sound absorbing fences nearly 0.4 mile in total length.

To minimise light pollution we will limit the new lighting we install as part of the build. When used it will be directed away from the properties and habitats.



We have produced a written heritage scheme outlining requirements for all archaeological works on site. This includes strip, map and record requirements for any archaeological deposits prior to construction, archaeological monitoring during the works, known as a watching brief, and how to manage any unexpected finds.

We will install fencing and buffer zones around Camel Hill scheduled monument and Downhead Manor Farm scheduled monument to protect them during the works. Other heritage assets such as the Royal Observer Corp observation post at Camel Hill, grade 2 listed B3151 milestone and grade 2 listed Eyewell cistern at Traits Lane will also be protected by fencing.

A grade II listed milestone at Canegrove Corner is currently missing. If it is found, we will record, store, restore and reinstate in its original location. We will also record, remove, store and then reinstate a section of Howell Hill stone wall.

Hazlegrove House Registered Park and Garden

Due to the new roads close proximity, 14% of the Hazlegrove House Registered Park and Garden's land will be needed to build the scheme. To compensate for this:

  • Veteran trees in the parkland will be protected and we will erect fencing to screen views into the works.
  • We’ll plant new trees along the route and sympathetically chosen trees will be established within the reinstated parkland area of Hazlegrove House Registered Park and Garden. We have carefully chosen trees and shrub to reflect those in the surrounding landscape and will be sourced locally where possible.
  • We’ll re-use topsoil containing the seeds from an area of felled woodland within the Hazlegrove House Registered Park and Garden, and use within the new areas of woodland being created.
  • We’ve designed a natural looking wildlife pond which will be constructed in the Hazlegrove House Registered Park and Garden.

RNAS Yeovilton

To protect aircraft using RNAS Yeovilton from bird strike, the five drainage ponds have been designed to reduce their attractiveness to birds by having a limited depth of water. Reeds will be planted within the ponds to break up the open water to disrupt bird landings and take off. We have also agreed a programme of measures with the Ministry of Defence to manage flocks of birds which might use the ponds.