Keeping a promise: mitigation in action

Adam Boyden describes how Nicholas Pearson Associates is ensuring that mitigation actions are a success at the Coopers Edge development at the foot of the Cotswolds

Environmental impact assessment (EIA) requires that environmental statements describe the measures envisaged to mitigate the significant adverse effects of a development on the environment. These often include actions that are influential in the decision to approve the project.

However, in the UK, EIA legislation includes no specific requirement to monitor the implementation or effectiveness of mitigation measures. Instead, reliance is placed upon local councils securing mitigation measures in planning conditions and Section 106 agreements. Ensuring mitigation is implemented is important for the credibility of the EIA process, particularly for those affected by development.

EIAs for large urban developments (residential areas, business parks and industrial estates, for example) are usually for outline planning applications which have details missing that are submitted after outline permission as reserved matters applications, largely to avoid potentially abortive work. The environmental statement still needs to define significant effects and mitigation measures however, and reserved matters applications cannot stray from the terms of the original EIA without requiring an update to the environmental statement.

In 1999, Nicholas Pearson Associates was appointed to assess the environmental effects and coordinate the EIA for an outline planning application for a new neighbourhood of 1,900 homes, a mixed use centre, open spaces and infrastructure, on a 70 hectare former airfield site next to Gloucester and the Cotswold hills.

The EIA assessed a range of key impacts, including:

  • potential harm from increased recreational use of the adjacent species-rich meadows, a site of special scientific interest (SSSI);
  • the impacts on barn owls breeding and foraging on site;
  • landscape and visual impacts on an adjacent area of outstanding natural beauty;
  • impacts on veteran oak trees and their rare dead wood invertebrates;
  • enhancements from restoration of a culvert to an open watercourse;
  • potential increases in traffic and the need to encourage sustainable travel;
  • impacts of the adjacent M5 motorway on noise and air quality for new residents; and
  • impacts on archaeology – surveys revealed a Roman farmstead site.

Planning to mitigate

Through the EIA we were able to define means of mitigating these impacts through masterplanning and a range of management measures and report them in the environmental statement, including in a schedule of environmental commitments.

Further work was undertaken in consultation with the local authorities and Natural England to define mitigation strategies in more detail. A protection plan for the SSSI defined monitoring, management and community liaison actions to address potential increased use by new residents and improve the SSSI’s condition.

An action plan for barn owls proposed to create and monitor replacement habitats off-site. The veteran trees management plan proposed their protection and monitoring in open spaces. The developers also purchased part of the SSSI and an off-site mitigation area to secure these measures.

An open spaces strategy provided outline designs for play areas and green spaces. A strategy for the restored Wotton Brook watercourse and flood retention ponds set out environmental enhancements for these drainage features.

An archaeological strategy included for protection of the Roman farmstead and a watching brief (revealing a Roman burial). A construction environmental management plan also set out site rules for contractors, including to protect ground-nesting skylarks.

Being able to demonstrate that mitigation measures were deliverable was key to the approval of both the outline planning application, and the local plan allocations, in response to challenges by rival developers.

The mitigation strategies were secured by Tewkesbury Borough and Stroud District Councils in planning conditions and the Section 106 agreement. Construction started in 2006 and continues, with more than 500 houses currently built and occupied.

Keeping promises

The implementation of environmental mitigation measures, first identified in the environmental statement and taken through design and implementation, is an ongoing success.

The SSSI is in good condition and being managed properly, with local people kept aware and involved through annual surveys and a friends group. Barn owls have started to breed in the off-site habitats created nearby. The veteran oak trees, other trees and hedgerows are protected, new trees have been grown from acorns from the site, and new wetland areas provide new wildlife habitats, with Otters seen last year. Outside the protected areas, habitat clearance is only undertaken after ecological inspections. Leaflets and displays have kept residents and prospective buyers informed.

Ongoing challenges include the management of construction sites adjacent to open spaces, and the health of one of the trees, which are being monitored.

Implementation of children’s play facilities has also been delayed, which generated negative feedback from residents, but the developers are responding. The playground, in a central, green open space which we designed, has just been opened, and more facilities will follow in line with the open spaces strategy.

Overall, EIA has been important in identifying the actions developers needed to make to demonstrate their development is an environmental success. And EIA practitioners play a continued and important role in ensuring a good level of EIA follow-up practice at Coopers Edge and ensuring those promises are kept.


This article was written as a contribution to the EIA Quality Mark’s commitment to improving EIA practice.

Adam Boyden, MIEMA CEnv, is an associate at Nicholas Pearson Associates ([email protected])

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