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Projects

We have worked on many varied projects, large and small, sometimes under CDM regulations. We have assisted our clients with many protected species trapping and translocation programmes including newt and reptile translocation. We have worked on a large variety of landscaping projects, as well as flood alleviation works.

We create and restore habitats for protected species, including wetland and large-scale pond creation, restoration of grassland including grassland seeding, badger sett closure and artificial badger sett creation, vegetation clearance, and woodland enhancements including hedge laying.

Building

Dormouse bridge construction

The brief

Surveys were carried out on the site of a new housing development, and dormice were found to be present in the hedgerows and adjacent woodland. We were asked to design and install a dormouse bridge to allow the dormice to move across the gap created by the development’s access road.

What Thomson Habitats did for the client

We constructed a dormouse bridge comprising a steel circular mesh tube wrapped in hessian and filled with hay. Using a MEWP (mobile elevated work platform) we installed the dormouse bridge over the housing development access road. It was suspended at a height of 6.5 metres to allow emergency vehicles to pass safely underneath.

The outcome

The bridge forms a link between the adjacent vegetation, creating a safe connecting route for dormice.

GCN mitigation and habitat creation works, Basildon

The brief

Redrow Homes asked us to carry out ecological mitigation and habitat creation works on a large residential development site in Basildon, Essex. We carried out extensive habitat creation and enhancement works to the adjacent designated receptor site and, working alongside a team of ecologists, we installed fencing and traps to trap and translocate the GCNs.

What Thomson did for the client

  • Created three ponds, and earth bunds of varying size and shape to provide diverse aquatic and terrestrial habitat for GCN.
  • Installed logpiles, stone hibernacula, and a brash corridor to provide suitable refuges and connectivity within the receptor site.
  • Planted over 2500 hedgerow whips (and fencing) to provide screening and a barrier between the development and the receptor site.
  • Sensitively cleared vegetation to facilitate wildlife fence installation using our low ground-pressure (LGP) track loader.
  • Installed 1.5km of semi-permanent fencing, o 2km of temporary GCN fencing, and 400 pitfall traps to enable the GCN to be moved from the works site.

Added value

We provided our client with added value by:

  • Bringing forward the vegetation clearance to avoid nesting birds, ensuring that there were no delays for our client.
  • Using our LGP track loader for the majority of the works in the receptor site to minimise ground disturbance, and also when clearing vegetation. This saved time and associated costs.
  • Using our interactive mapping software (TIM) and mobile mapping equipment to mark features on the ground, and so to assist with monitoring project progress.

The outcome

Working under ecological supervision, we completed the works on time, enabling the GCN trapping and translocation programme to begin without delay and guarantee that the main works were not delayed beyond what was planned.

Invasive species control, Stratford

The brief

On a site in East London which was soon to be redeveloped, we treated an area of Japanese knotweed.

What Thomson Habitats did for the client

  • Checked the site for underground services using a CAT scanner, and erecting temporary fencing to delineate the areas of Japanese knotweed.
  • Dug the ground and turning it over to expose it to a 0.5 metre depth using a mechanical excavator. Japanese knotweed stems and crowns were then cut down and broken up into smaller pieces and spread over the area to encourage them to regenerate more stems.
  • Ensured that all machinery and equipment was cleaned before leaving the site to ensure that no Japanese knotweed could be spread to any other part of the site or off site.
  • When the plants had regrown, they were treated with Picloram and in later visits any new growth was sprayed with Glyphosate.

The outcome

By the next season only about ten stunted plants had regrown, which were then sprayed again with Glyphosate.

Japanese knotweed remediation, Wellingborough

The brief

Our brief was to move two large stands of Japanese knotweed (JKW) and contaminated soil to stockpiling locations outside the construction footprint, prior to construction works starting.

What Thomson Habitats did for the client

We began by clearing scrub and trees within the JKW areas being careful not to spread any fragments of JKW.

We installed Heras fencing, signage and foot washing stations which would act as bio-security measures for anyone entering or leaving the site.

We excavated the JKW into stockpiles using two 30 tonne 360° excavators. This was done under the supervision of a JKW clerk of works, who ensured that excavations continued to a point where rhizome fragments were no longer visible.

Two 25t articulated dumper trucks hauled over 12,000 tonnes of the JKW contaminated material to designated stockpiling locations, outside the construction footprint.

Contaminated material was stockpiled onto membrane which prevented it contaminating the ground underneath. The stockpiles were fenced off in order to ensure that contaminated material could not be reached and spread around the site.

The stockpiles were then allowed to grow and the JKW was subject to a spray regime.

The outcome

The JKW areas were successfully moved and stockpiled outside of the construction footprint.

Newt and reptile fencing on challenging terrain

The brief

We worked with our client, a housing developer, to assist them in preparing a site for a phased house-building project. The site in Burgess Hill, Sussex, was a decommissioned quarry that provided clay for a brick and tile works, also on site.

Our client was undertaking substantial remodelling of the quarry.  Before this could be done, any ecology issues had to be addressed. The main constraint was the presence of newts and reptiles, which are legally protected from killing and injury, so they had to be moved from site before the development works could begin.

What Thomson Habitats did for the client

  • Installed almost 2km of semi-permanent newt and reptile fencing around the perimeter of the site
  • Installed approximately 2km of temporary newt and reptile fencing within the site
  • Put down pitfall traps and carpet tiles to enable the trapping programme.

The outcome

The project was extremely challenging due to the difficult terrain. There were many steep slopes, and the ground was heavy clay, making operating on site difficult.

Despite the challenges, we completed the works within time and within budget!

Vegetation clearance, Silvertown Docks, London

The brief

We worked with our client, The Silvertown Partnership and their ecologists, AECOM, to facilitate the £3.5bn Silvertown Quays scheme.

The scheme involves the re-development of the iconic Millennium Mills, including the construction of a school, health centre, shops and an innovative new bridge. Upon completion, the scheme will have 3000 new homes, two million sq. ft. of commercial space and three million sq. ft. of 'brand spaces'.

Thomson Habitats was contracted to clear all on-site vegetation which had the potential for nesting birds. The works were undertaken outside of the nesting bird season and during reptile and bat hibernation periods. This was to ensure the minimum amount of disturbance to wildlife.

It was vital that all the works which were to be carried out caused minimum disturbance to the ground.

What Thomson Habitats did for the client

  • Sensitive vegetation clearance, using a low ground pressure tracked loader with a forestry mulcher attachment.
  • Any scrub that could not be safely removed by the mulcher was cleared by a chainsaw and brushcutter team with a 6” tracked wood chipper.
  • Removal of Cotoneaster as a Schedule 9 invasive species

The outcome

Despite a tight programme, and difficult ground conditions, we were able to meet the client’s requirements and carry out the clearance works sensitively and efficiently. The works were carried out to the satisfaction of the project ecologist, AECOM.

“From the initial point of contact, Thomson Habitats provided a prompt high quality service. They responded promptly to any risks, and ensured that all of the works were carried out with the utmost regard to health and safety. They worked effectively, and as result, we were able to commence the next phases on site without our programme being affected. I would not hesitate to use them on other schemes, or to recommend them to other clients.”

Andrew Pollard, Development Manager at First Base, on behalf of Silvertown Partnership

Flood and coastal

Badger sett closure and artificial sett creation, Shoeburyness, Essex

The brief

A coastal flood defence bund was to be built on the site of a badger sett in Shoeburyness, Essex, by the local borough council.

Under the Protection of Badgers Act 1992 it is an offence to interfere with or disturb an occupied sett, so Thomson Habitats were asked to close the sett under licence prior to the works commencing and encourage the badgers into a new artificial sett nearby.

What Thomson Habitats did for the client

  • Installed 50 one-way badger gates
  • Surrounded the existing setts with netting (pinned to the ground with posts) to prevent the badgers from entering
  • Constructed an artificial sett (covering an area of 1.2 hectares) consisting of eight nesting chambers, and connecting the chambers by a network of pipes. The sett was buried to a depth of at least 1250mm.

The outcome

Once completed, the sett was baited to encourage the badgers to use it. Photographic evidence showed that within just one week badgers were occupying the artificial sett.

Ecology mitigation works, Exeter flood defence scheme

The brief

We worked with our client, Team Van Oord, as part of their Water and Environment Management (WEM) framework, to facilitate Phase 1 of the Exeter Flood Defence Scheme.

The project costing £30m is aimed at reducing flood risk to 3000 homes and businesses in Exeter. Phase 1 of the works will involve deepening the existing flood relief channel, lowering the spill weir at the top of another flood relief channel and removing a check weir at the bottom of the channel. These works will increase the flow capacity of the main channel.

What Thomson did for the client

We were commissioned to undertake the initial ecological enabling works package as Principal Contractor under the Construction Design and Management (CDM) Regulations. To support these works we:

  • Undertook mechanised vegetation manipulation of the 6.5ha area to make the habitat unsuitable for reptiles
  • Enhanced a reptile receptor site by creating basking banks, log piles, egg-laying sites and basking areas
  • Mechanically cleared 4.4ha of Himalayan balsam using a combination of hand tools, mechanical flails and mulchers
  • Cut back 100m of existing hedgerow
  • Installed information signs about the works

Flood defence works, Whittlesey Washes

The brief

We worked with our client, Team Van Oord, to facilitate Phase 2 of the Whittlesey Washes flood defence scheme. The £26m scheme involves strengthening a 16km stretch of the south bank between Whittlesey and Stanground. The scheme is designed to protect 8,000 hectares of farmland, hundreds of homes, as well as infrastructure around Peterborough.

What Thomson Habitats did for the client

Thomson Habitats was commissioned to:

  • Supply and install 7km of demarcation fencing
  • Cut up to 26ha of ruderal grassland with a bat wing mower
  • Supply and install 3km of concrete post rabbit fencing
  • Supply and install 6.5km of concrete post stock fencing
  • Supply and install 10 stiles and 9 field gates
  • Hydroseed 5.5ha with flexterra
  • Conventional seed 37ha with a deep rooting grass mix

The outcome

Working closely alongside our client, we were able to mitigate the risk of potential programme delays and have worked collaboratively to ensure the delivery of the works.

Great crested newt (GCN) mitigation works, Steart Peninsula

The brief

Due to predicted changes in the West Somerset coastline caused by the rising of the sea level, wetland has been created to support local wildlife as well as helping manage the flood risk to the local community.

What Thomson Habitats did for the client

  • We installed 5km of temporary newt fencing in order to trap amphibians including great crested newts. Some of the newt fencing was installed around water-bodies
  • We undertook translocation of suitable pond material to a nearby great crested newt receptor site
  • We drained and in-filled six ponds
  • We installed log hibernacula to provide habitat for the great crested newts within the receptor site
  • We translocated over 2000 great crested newts
  • We completed chytridiomycosis swabbing and analysis

Hedge planting, flood defence works, Congresbury Yeo

The brief

We worked with our client, Team Van Oord, to facilitate flood defence works at Congresbury Yeo.

The £7.5m scheme involves the raising and widening of the existing flood defences. Three new sections of bank are being constructed, and the existing banks topped up to provide a 1 in 75 year flood defence protection to properties in Wester-super-Mare, Worle and Kingston Seymour.

Following our previous involvement on site, Thomson Habitats were asked to carry out hedgerow planting works. The works consisted of planting and re-instating hedgerows that had previously been cleared in order to ensure no loss of biodiversity.

The works involved significant constraints, including that all the planting works had to be completed by the 31st of October - the start of the wintering bird season.

What Thomson Habitats did for the client

Following careful planning with Team Van Oord, Thomson mobilised an eight man planting gang to site. Four km of native-mixed species hedgerow were planted in eight days.

The outcome

Despite the sometimes challenging weather and ground conditions, we have been able to complete the works within the deadline and with minimal disturbance to the ground.

“We gave Thomson Habitats a highly challenging brief. From the off-set, Thomson Habitats carefully planned the works with us and developed an understanding of our project deadlines. Thomson have delivered the hedgerow planting two days ahead of programme, with no compromise on quality or safety. They’ve done an outstanding job.” Construction Manager, Kier Construction

Himalayan balsam, Exeter Flood Defence Scheme Phase II

Following a competitive tendering process, we were awarded the Himalayan balsam remediation package by BMMJV (a joint venture between BAM Nuttall and Mott MacDonald), for works on the Exeter Flood Defence Scheme Phase II.

The £32m Exeter Flood Defence scheme for the Environment Agency will involve the construction of flood defences on both banks of the River Exe from Cowley Bridge to Countess Weir.

The defences will include walls, banks, demountable weirs, gates and glass panels with extensive landscaping and habitat creation also taking place.

As part of our works scope, we were contracted to carry out the following:

  • Mechanical clearance of 7 hectares of Himalayan balsam along the River Exe using a combination of brushcutters and an excavator-mounted flail. Care was taken to ensure that the Himalayan balsam was cut below the lowest growing node.
  • Application for Environment Agency herbicide spraying permissions
  • Spraying 7 hectares of re-growth along the banks with herbicide
  • Providing advice and input into fortnightly environmental progress meetings

We used our bespoke interactive mapping service –TIM, so that the client and the project team could track progress and see the areas where Himalayan balsam was or had been present. This is important because it means that any future works involving interfaces with contaminated areas can be properly planned.

“Thomson Habitats have assisted us from the early pre-tender stages of this project. We asked them to carry out the initial Himalayan Balsam clearance works due to their prior knowledge of the site, and their extensive experience in carrying out invasive species works. From the outset, they have worked pragmatically and effectively, and have become part of the wider project team. The site team worked hard to ensure that the Himalayan Balsam clearance works were undertaken on time and in accordance with best practice. Their TIM software in particular, has proved to be of huge assistance – particularly in our monthly environmental progress update meetings. We look forward to continuing our working relationship with Thomson Habitats on site.” Marcus Hargreaves, BAM Nuttall.

Soft landscaping works, Gatwick Airport flood alleviation scheme

The brief

We assisted our client with the delivery of a 19ha online flood storage area to the Gatwick Stream tributary.

This scheme will allow for a one in 100 year level of protection and will help to prevent the flooding of Gatwick Airport and the A23. We were commissioned to undertake the soft landscaping, invasive species management and ecology elements of the works.

What Thomson Habitats did for the client

  • Mechanically cut and hand pulled up to 0.82ha of Himalayan balsam along the existing Gatwick Stream, and implemented a subsequent spraying regime
  • Ripped 12.5ha of compacted soil to shatter the clay pan and facilitate seeding
  • Hydro-seeded the same area with a wildflower meadow grass mix suitable for clay
  • Planted 10,700 native bare-root transplants
  • Planted 680 12-14cm native bare-root specimen trees
  • Supplied and planted native riparian plants along parts of the newly constructed scheme
  • Undertook an electric fishing exercise in two phases to assist with in-channel works

Vegetation clearance, Congresbury Yeo

The brief

We worked with our client Team Van Oord, to facilitate the construction of flood defences at Congresbury Yeo.

The project will involve a £5m contract to design and build 140m of new embankment, raising over 1100m of existing embankment on the North Bank and raising over 1200m of existing embankment on the South Bank.

Due to the location of the scheme, and its proximity to a SSSI (Site of Special Scientific Interest) and the wider SAC (Special Areas of Conservation) of the Severn Estuary, sensitive working methodologies needed to be utilised prior to construction.

What Thomson did for the client

To facilitate these works we:

  • Cleared over 3km of existing hedgerow using excavator mounted mulchers and tree-shears
  • Cleared out ditches to facilitate drainage and prevent flooding
  • Sensitively cleared vegetation by hand on areas of archaeological interest to prevent damage and disturbance
  • Grubbed out stumps and arisings on the North and South Banks
  • Mechanically mulched arisings using a tracked mulcher
  • Installed over 1km of great crested new (GCN) exclusion fencing to prevent amphibians from entering the site.

The outcome

Working within a fast-paced environment, all works were delivered to a tight deadline and to the clients’ satisfaction.

“Thomson Habitats provided an excellent service. Their works were completed ahead of programme and in accordance with the specification. They are always quick to respond, flexible and accommodating to our demands. I would not hesitate to use them again” Giles Lord, project manager, Kier.

Water vole mitigation, Wallasea Island

The brief

During 2013, we worked with Thomson Ecology to assist their client, a multi-disciplinary civil engineering and building contractor, with water vole mitigation works on a 670ha wetland habitat creation scheme. The scheme will be Europe’s largest man-made nature reserve, using five million tonnes of excess spoil from Crossrail.

The works involved a combination of displacement methodology and traditional trapping methods. The water vole displacement exercise, undertaken across 3km length of ditches, is one of the largest ever undertaken within the UK.

What Thomson Habitats did for the client

  • Supplied and installed 250m of water vole fencing
  • Installed 24 earth coffer dams to block off ditches and facilitate the drain down
  • Drained down 8,990m of ditches for water vole displacement and trapping
  • Cleared 125,800m2 of vegetation within ditches and on the banks to facilitate the trapping and displacement
  • Destructively searched 8,990m of water vole ditches — and over 1000 burrows - through a combination of mechanical excavation and hand digging
  • Supplied and installed 30 custom water vole release pens within the receptor area.

Highways

Badger and otter fencing and soft landscaping, Aylesbury

The brief

We worked with our client, Kier Infrastructure & Overseas, to facilitate the construction of a new road in Aylesbury as part of the Berryfields Major Development Area Works. Berryfields Major Development Area (MDA) is situated off the A41 to the North West of Aylesbury. It includes 3,000 new homes, a district centre, and schools.

What Thomson Habitats did for the client

We were commissioned to undertake extensive fencing and soft landscaping works. As part of these works we:

  • Installed 400m of post-and-rail otter fencing
  • Installed 4000m of post-and-rail badger fencing
  • Installed wildlife gates including associated concrete shuttering work
  • Hydro-seeded 32,734m2 with a rye-grass highways mix
  • Planted an attenuation pond with native marginal and emergent plant species

The outcome

Despite difficult ground conditions and tight deadlines, these works were completed in time to facilitate the opening of the new highway.

Great crested newt (GCN) mitigation works, M1

The brief

Thomson Habitats worked with our client, a Costain-Galliford Try Joint Venture, on the M1 J19 to J16 Smart Motorway in Northamptonshire. The smart motorway programme is a £65m scheme and is part of Highways England’s Collaborative Delivery Framework. The works focussed on increasing capacity on the M1 between J16 and 19 and will allow traffic to use the hard shoulder.

What Thomson Habitats did for the client

Thomson Habitats worked closely with sister company, Thomson Ecology, and Costain-Galliford Try to deliver the great crested newt (GCN) mitigation works. As part of our works we:

  • Cleared 4.5km of trees, scrub and shrubs to facilitate the installation of GCN fencing
  • Supplied and installed 4.5km temporary GCN fencing
  • Installed approximately 400 pitfall traps and 450 carpet tiles
  • Provided ecological watching briefs for the above
  • Carried out a 25 day GCN trapping and translocation exercise
  • Constructed 30 log piles and eight brick hibernacula
  • Provided client access to our award-winning bespoke GIS project management software – TIM (Thomson Interactive Mapping).

The outcome

Despite numerous logistical difficulties, challenging terrain and working adjacent to an active motorway, we were able to complete the works to programme and to a high quality.

“Thomson have proven to be highly valuable on this scheme. Despite the difficulties of the ground, tight programme and access issues, Thomson have completed the works to a high standard and have maintained the highest levels of professionalism. Their TIM software has proven to be of huge assistance and clearly sets them apart from their competitors. I would not hesitate to use them again.”

Senior Agent, Costain.

Rail

Badger sett exclusions, multiple locations

As part of Thomson Ecology’s framework agreement with Network Rail, and working in partnership with them, we carried out badger sett closures and exclusions on multiple sites across Network Rail infrastructure.

One of the sites, Rowlands Hall in Hampshire, required an emergency badger sett closure, as the sett was undermining a main rail line. There was a significant risk of the line becoming damaged, due to subsidence or the collapse of the sett structure. Following extensive consultation with Natural England, we were granted an emergency licence for the closure of the sett, and were permitted to close the sett outside of the normal season.

As part of our works we

  • Surveyed and mapped out four separate badger setts
  • Cleared over 1400m2 of dense vegetation and trees to facilitate mitigation works
  • Supplied and installed over 70 metal one-way badger gates
  • Supplied and installed over 1400m2 of heavy-duty PVC chain-link mesh
  • Provided Safe Systems of Work packs for all work sites
  • Provided safety critical staff for all work sites including COSS and Lookouts where required

“As part of our national ecology framework, we approached Thomson Ecology to carry out various badger sett surveys and associated sett closures across our rail infrastructure. Time was of the essence for these works, as several of the setts were undermining active rail links, and without immediate action could have caused serious damage. Thomson Ecology & Thomson Habitats worked closely together to provide a turnkey approach, ensuring that all of the required sett closures were undertaken in line with our programme and to a high standard of quality and safety. I would not hesitate to use them on other projects."

Craig Marshall, Network Rail.

Ecological mitigation works, Intercity Express Programme, Doncaster

The brief

As part of their Intercity Express Programme (IEP) depot contract, we worked with our client VolkerFitzpatrick to facilitate the construction of a £70m railway depot. The project involves the construction of a new maintenance, servicing and stabling facility that will be constructed for the maintenance of Hitachi Super Express (IEP) trains at Doncaster Carr Intercity Express Depot.

What Thomson Habitats did for the client

In partnership with Thomson Ecology, we were responsible for the delivery of all the ecological aspects of the scheme. To support these works we:

  • Undertook extended Phase 1 and desk top surveys
  • Compiled an invasive species remediation strategy to deal with Himalayan balsam, Japanese knotweed and cotoneaster that were present on site
  • Undertook dusk/dawn emergence and return-to-roost surveys for bats and associated reporting
  • Completed trackside vegetation clearance works to facilitate topographical surveys and construction works
  • Provided ecological watching briefs to supervise the vegetation clearance works during the breeding bird season

The outcome

Working collaboratively with Thomson Ecology, we were able to provide our client with a complete service including ecology surveys and reports as well as the practical vegetation management and invasive species remediation works.

Ecology support services, Stockley Junction

The brief

Following an initial request to undertake an ecological watching brief, we have been involved on this site for four years. We have been called in to advise on a range of different ecology issues.

What Thomson did for the client

  • Call-outs at short notice for surveys and watching briefs to allow the works programme to continue without delay
  • Advice on reptiles, newts, breeding birds, and bats to allow scrub and tree removal
  • Advice on closing a badger sett
  • Population monitoring of previously translocated newts and reptiles to satisfy licence requirements
  • Fish rescue before ponds could be infilled
  • Identification and specification of approach to dealing with Japanese knotweed
  • Arranged for archaeological input on several occasions.

The outcome

All works were delivered to tight deadlines and to the client’s satisfaction. Environment Manager, Elwen Tasker, said: ‘Thomson’s ability to provide a wide range of professional environmental services at short notice has been invaluable to our project programme.’

GCN mitigation, rail improvement project, Hampshire

The brief

Following ecological survey reports identifying habitat potential for great crested newts, Thomson Habitats were brought in to undertake the appropriate mitigation works for Osborne’s proposed rail improvement project.

These mitigation works involved installing temporary amphibian fencing across difficult boggy terrain with sharp variations in gradient. Installation of pitfall traps and carpet tiles was also required. The fencing would surround the contractors’ haulage route, compound location, and the works area on both sides of the railway embankment.

What Thomson Habitats did for the client

  • Clearance of woody vegetation and scrub in preparation for the great crested newt fence line
  • Supply and installation of temporary amphibian fencing, pitfall traps and refugia
  • Supply and installation of a Thomson TEC (temporary exclusion channel) newt grid at the entrance to the site, allowing contractors to drive through freely, whilst still excluding the newts

The outcome

The project was completed to a high standard with positive client feedback, in spite of the harsh weather conditions and difficult terrain.

We were able to install all mitigation features by the programme deadline, which allowed the great crested newt trapping period to commence as planned.

Soft landscaping, Stoke Gifford, Great Western Rail Line

The brief

Working for our client VolkerFitzpatrick, we delivered the soft landscaping works at their Stoke Gifford Depot site, as part of the Intercity Express Programme (IEP) on the new Great Western Rail Line.

The depot is part of a major infrastructure and transport programme worth £5.8 billion.

Following our earlier involvement on the scheme, we were asked to carry out grassland seeding works, planting of specimen trees, native shrub planting, and the installation of log piles for wildlife habitat.

What Thomson did for the client

  • Hydroseeded 59,000m2 of bank areas with grass seed
  • Planted 76 specimen trees
  • Planted over 2,700 shrub and 2,800 scrub plants, installing a biodegradable mulch mat for each plant
  • Created 10 log piles across the site to provide habitats for reptiles and other species

Added value

We provided our client with added value by:

  • Providing advice on scope feasibility and costings during the tender process
  • Suggesting hydroseeding on steep banks to remove the need for soil cultivation works.
  • Notch planting of shrubs , to eliminate the need to excavate pits, and therefore reducing planting time
  • Using Thomson Interactive Mapping (TIM) software to enable site progress to be easily accessed by the whole project team, and the client, in real time

The outcome

Working on steep gradients and coordinating our work with other site activities, we were able to complete the works safely and avoid delays. The landscaping works were completed within our client’s time frame and to specification, resulting in a very satisfied client.

Vegetation clearance works, mothballed rail, East West Rail

The brief

We worked with our client to assist with a major rail project, to connect East Anglia with central, southern and western England. As part of this project, 17km of mothballed railway is being converted back into a live high speed rail line.

What Thomson Habitats did for the client

Thomson Habitats, in conjunction with Thomson Ecology, were asked to undertake the cess-to-cess clearance, and further clearance of strips along the route in its entirety to facilitate topographical surveys and detailed design work at the GRIP 2 stage.

Large sections of the works involved working in highly sensitive habitats with ecological constraints for dormice, badgers, reptiles, breeding birds and great crested newts. Thomson Habitats proposed a novel approach utilizing RRV vehicles along the existing line to minimise habitat disturbance and to optimise working efficiencies.

  • Using RRV Unimogs we cleared a trackbed width, 10m approx, of vegetation along the 17km section
  • Installed a temporary haul road to facilitate plant access and egress
  • Undertook the clearance of 85 strips on the northern and southern sides of the cess, to facilitate topographical surveys

Major projects

Great crested newt (GCN) mitigation works, Steart Peninsula

The brief

Due to predicted changes in the West Somerset coastline caused by the rising of the sea level, wetland has been created to support local wildlife as well as helping manage the flood risk to the local community.

What Thomson Habitats did for the client

  • We installed 5km of temporary newt fencing in order to trap amphibians including great crested newts. Some of the newt fencing was installed around water-bodies
  • We undertook translocation of suitable pond material to a nearby great crested newt receptor site
  • We drained and in-filled six ponds
  • We installed log hibernacula to provide habitat for the great crested newts within the receptor site
  • We translocated over 2000 great crested newts
  • We completed chytridiomycosis swabbing and analysis

Habitat creation for newts and reptiles, Thames Gateway

The brief

Thomson Habitats were required to turn a 30 hectare area of open land into a receptor site for newts and reptiles. This extensive project formed part of our mitigation programme on the largest ecological project in Europe.

What Thomson Habitats did for the client

  • As the area was known to have been bombed extensively in the past, we undertook desk studies and a field survey to determine the likelihood of coming across unexploded ordnance, and had a UXO banksman on site for the duration of the works.
  • We constructed 24 ponds of varying designs with an average surface area of 250m2. We used a bentonite clay liner with a top soil cover. After the ponds had been filled, seven species of native aquatic plants were added. They were soon populated with a variety of invertebrates.
  • Over 12,500 trees of varying species were hand planted, log piles and hibernacula were created and existing vegetation is now re-colonising the disturbed soil.
  • Stock fencing was erected to keep nearby cattle out of the site.

The outcome

Thomson Ecology conducted a monitoring survey in April 2010. Adult great crested newts were found in 22 of 24 ponds, and eggs in 23. This shows breeding activity in over 95% of the ponds and witnesses to the success of the translocation and habitat creation. Reptile monitoring continued; the initial signs being positive. The monitoring will continue for ten years for great crested newts (GCNs) and five years for reptiles.

MG5 grassland, Birmingham Airport

The brief

On a SSSI just south of Birmingham, we have worked with our client on a meadow restoration project, to enhance MG5 meadow grassland. The area consists of 21 fields, incorporating meadows, hedges, marshes, open water, woodland and scrub.

Meadows contain some of the UK's richest grassland flora; however, some of the grassland types have declined severely during the 20th century nationwide, and are now rarely found. Due to the extension of Birmingham Airport, some of the area is being lost in the development, so the MG5 grassland must be reinstated elsewhere.

What Thomson Habitats did for the client

  • Flailed and mulched vegetation
  • Cut hay on areas of the site
  • Rotovated the soil
  • Treated areas of Japanese knotweed by spraying
  • Brush-harvested seeds from areas of the site, which were sown at a later date to recreate the species-rich grassland

Water vole mitigation, Wallasea Island

The brief

During 2013, we worked with Thomson Ecology to assist their client, a multi-disciplinary civil engineering and building contractor, with water vole mitigation works on a 670ha wetland habitat creation scheme. The scheme will be Europe’s largest man-made nature reserve, using five million tonnes of excess spoil from Crossrail.

The works involved a combination of displacement methodology and traditional trapping methods. The water vole displacement exercise, undertaken across 3km length of ditches, is one of the largest ever undertaken within the UK.

What Thomson Habitats did for the client

  • Supplied and installed 250m of water vole fencing
  • Installed 24 earth coffer dams to block off ditches and facilitate the drain down
  • Drained down 8,990m of ditches for water vole displacement and trapping
  • Cleared 125,800m2 of vegetation within ditches and on the banks to facilitate the trapping and displacement
  • Destructively searched 8,990m of water vole ditches — and over 1000 burrows - through a combination of mechanical excavation and hand digging
  • Supplied and installed 30 custom water vole release pens within the receptor area.

Wetland creation, Crossness STW, London

The brief

We worked with a large utilities company to carry out extensive enhancement of an existing nature reserve in East London. As the region's last remaining areas of grazing marsh and the largest reed bed in Bexley, this important site supports water voles, wintering and breeding birds and rare invertebrates.

What Thomson Habitats did for the client

  • Cleared 20 hectares of vegetation including the felling of trees
  • Excavated wader scrapes
  • Excavated and lining a reed bed, covering a 1.5ha area
  • Planted over 70,000 reeds
  • Enhanced four water vole ditches and creating two new ditches
  • Built pathways and a viewing area
  • Installed a wind pump
  • Installed barn owl boxes
  • Erected over 2km of stock fencing and temporary wildlife fencing
  • Planted shrubs and trees, and treating invasive weeds on site

Renewables

Badger mitigation works, Dudgeon cable route

The brief

We worked with our client, Carillion Utilities, to facilitate the construction of an onshore cable route for the offshore Dudgeon Wind Farm.

There were numerous badger setts that were within 100m of the cable route. One, an annex sett, which unlike the others was within the footprint of the cable route, needed to be closed and then destructively searched under licence. Usually, the closure and destructive search of an annex sett requires the construction of an artificial badger sett. Due to time constraints and landowner permissions this was not an option. So, following close liaison between Thomson Habitats, Carillion and Natural England, a novel approach was proposed.

The annex sett was temporarily closed under licence, and monitored for a period of 21 days. Once this 21-day period was over, Carillion carried out horizontal directional drilling under the active sett. under an ecological watching brief.

Upon completion of the drilling, the badger exclusion measures were removed, and the sett was re-opened.

What Thomson Habitats did for the client

  • We carried out initial badger surveys
  • We liaised with Natural England and Carillion Utilities in proposing the novel solution to carry out horizontal direction drilling and temporary sett closure, under licence.
  • We closed a nine-entrance annexe badger sett.
  • We closed a single-entrance outlier sett.
  • We monitored gated entrances over a three week period.
  • We supervised the horizontal directional drill to ensure that no damage was done to the badger sett.
  • We provided dedicated mapping services including our award-winning interactive mapping platform TIM to collate ecological project data.

The outcome

To our knowledge, this is the first time that Natural England have licensed a horizontal directional drill under an active badger sett within the UK.

Our novel approach helped to save Carillion and their client over £500k. This was due to not having to pay land access fees, and cost savings achieved through a reduction in the works programme.

“Thomson Habitats were an integral part of the project delivery team, and have played a key role in helping us to discharge the ecological mitigation works. Despite conflicting demands, they have provided a pragmatic, professional service and have been quick to respond and assist where needed.”

Scott Marsden, Carillion Utilities Project Manager.

Ecological mitigation works, Dudgeon off-shore wind farm cable route

The brief

We worked with our client Carillion Utilities, to facilitate the construction of an onshore cable route for the offshore Dudgeon Wind Farm. The project will involve a £30m contract to design and build a 47km onshore twin 132kv cable route. This route is the longest in the UK.

What Thomson Habitats did for the client

  • Walkover surveys and ecological gap analysis for bats, trees and watervoles
  • Dedicated mapping services and the use of our bespoke interactive mapping service, TIM, to collate and share ecological project data
  • Ecological assistance and advice throughout the project duration
  • Clearance of hedgerows down to ground level along the entirety of the cable route, over a five week period
  • Water vole mitigation works on ten ditches across the cable route, using the displacement methodology
  • Extensive great crested newt (GCN) trapping and translocation for 19 metapopulations across 55km of GCN fencing
  • Provision of watching briefs for ditch fluming and field access works over an eight week period

The outcome

Working within a fast-paced and dynamic environment, all works were delivered to a tight deadline and to the clients satisfaction.

“Thomson Habitats were an integral part of the project delivery team, and have played a key role in helping us to discharge the ecological mitigation works. Despite conflicting demands, they have provided a pragmatic, professional service and have been quick to respond and assist where needed. We would not hesitate in using them on other projects.”

Scott Marsden, Carillion Utilities Project Manager

Utilities

Japanese knotweed remediation, Kingston-upon-Thames

The brief

Our brief was to advise on and implement a strategy to deal with a stand of Japanese knotweed (JKW) which was within the construction footprint of a new treatment facility at Hogsmill Sewage Treatment works.

What Thomson did for the client

Using a 14 tonne excavator and two articulated dumpers, we excavated the JKW stand and moved it and associated contaminated soil to a designated area on the site. We stockpiled it onto root barrier membrane which prevented it contaminating the ground underneath and also shaped it to blend in with the existing landscape. This was away from the construction area so that any re-growth of JKW could be treated with herbicide over a two year programme.

Added value

We provided an in-house JKW clerk of works, who ensured that the excavation continued until rhizome fragments were no longer visible. He also monitored the dumpers to ensure that they were kept at a safe load to avoid contaminated material spilling during transportation.

We put in place bio-security measures to stop the spread of contaminated material. This included the installation of Heras fencing and signage in order to exclude unauthorised contractors and personnel from the works area. In addition, washing stations were used to clean boots and plant prior to leaving the site.

The outcome

The JKW stand was successfully moved and stockpiled. The work was completed ahead of schedule, enabling our client to get a head start on their construction programme. In addition, we were pleased that our site supervisor was praised by our client on his management of the works.

Wetland creation, Crossness STW, London

The brief

We worked with a large utilities company to carry out extensive enhancement of an existing nature reserve in East London. As the region's last remaining areas of grazing marsh and the largest reed bed in Bexley, this important site supports water voles, wintering and breeding birds and rare invertebrates.

What Thomson Habitats did for the client

  • Cleared 20 hectares of vegetation including the felling of trees
  • Excavated wader scrapes
  • Excavated and lining a reed bed, covering a 1.5ha area
  • Planted over 70,000 reeds
  • Enhanced four water vole ditches and creating two new ditches
  • Built pathways and a viewing area
  • Installed a wind pump
  • Installed barn owl boxes
  • Erected over 2km of stock fencing and temporary wildlife fencing
  • Planted shrubs and trees, and treating invasive weeds on site