Overview
The works were commissioned by The Woodland Trust, at Fairfield Forest near Bromsgrove, Worcestershire, and required the replacement of the existing brook culvert along with the construction of a new access track and car park.
The existing watercourse crossed beneath a compacted stone access track with 4x 225 Ø mm clay pipes and 1x 300 Ø mm iron pipe acting as culverts, which were undersized and in a state of poor repair resulting in restricted flow capacity and the potential for increased flooding. The solution was to construct a new 1200 Ø mm culvert complete with 2x vegetated bag headwall system (RootLok system), to replace the existing culvert, whilst working within the existing watercourse without the aid of over pumping due to the ecological constraints imposed within the contract.
In addition, the Woodland Trust required the construction of a new stone vehicle access track approx. 450 m long to access various parts of the woodland together with a 90 m² stone car park.
Challenges
The scheme presented a significant number of challenges, given that the works were undertaken within a site designated as Ancient Woodland as follows:
- Development of a detailed traffic and pedestrian management plan to mitigate traffic congestion at the site access
- Maintenance of pedestrian access at key ‘rights of way’ which travers the site and are to remain open.
- Presence of high-pressure gas main which travers the site
- Protection of existing tree root systems which are within the proposed pavement and temporary haul route all construction
- Protection of Ancient Woodland tree roots within the area of access road construction
- Protection of woodland ecology
- Flood risk during periods of prolonged rainfall
- Pollution risk to sensitive woodland watercourses and fauna
- Unauthorised access
- Working within a live watercourse without over pumping
Outcomes
Through proactive planning, strong environmental controls and close coordination with key stakeholders, the access track, carpark and culvert replacement works were delivered safely, ahead of programme, on budget and with zero defects at the point of hand over. The upsized culvert provides long term flood resilience and supports The Woodland Trust’s commitment to sustainable woodland management,
Furthermore, no environmental or safety incidents were recorded (including zero RIDDOR’s ), allowing the continual access to both The Woodland Trust personnel and members of the public to the woodland amenity.
This project highlights effective planning within a environmentally sensitive ancient woodland demonstrating McPhillips ability to deliver complex works around critical infrastructure such as high-pressure gas mains.
Benefits & Added Value
Through the implementation of McPhillips quality management plan the following benefits and added value were incorporated into the project as follows:
- Through careful traffic coordination material deliveries were phased outside of peak traffic resulting in no local traffic disruption with local supply partners
- Localised ‘no dig’ construction techniques, together with strengthened passing points incorporated into the access road to protect / preserve tree root zones close to the surface
- Maintaining unauthorised access within the works through strict fencing erection and maintenance with controlled access and egress.
- Utilisation of tree friendly aggregates with no history of Ancient Woodland disputes
- Phased culvert construction utilising temporary open ditch diversion to mitigate silt disturbance whilst maintain existing fauna and flora
- Localised weather monitoring to allow for works scheduling within drier periods
- Detailed utility surveys and liaison with Cadent Gas with inclusion of plant exclusion zones and advance protection mat installations
- Provision of gate marshals at all rights of way crossing points together with the erection of clear pedestrian friendly signage.
Pollution control with downstream silt nets/bunds, off site designated refuelling zones utilising HVO fuel (not diesel) and strict environmental monitoring in accordance with our ISO 14001 accredited procedure’s.
Client Testimonial
“Thanks again to you and your team for all the work you have done on this and for the professional way you operate.”
John Virgo – Contracts manager (The Woodland Trust)