Halcrow's Liza Hollinghurst describes the approach taken to ecology and environmental impact assessment (EIA) on the Cotswold Canals Regeneration Project
Led by the Cotswold Canals Partnership (CCP), the Cotswold Canals Regeneration Project (CCRP) aims to restore two of Gloucestershire’s canals to navigation: the Stroudwater Navigation and the Thames and Severn Canal; collectively known as the “Cotswold Canals” and extending over 58km.
Opened in 1779, the Stroudwater Navigation extended inland from the village of Framilode, on the banks of the River Severn, to Wallbridge in Stroud. This was followed by the Thames and Severn Canal in 1789, which continued the canal network from Wallbridge to the River Thames at Lechlade.
The development of the railway network ultimately contributed towards the demise of the canals, with the closure of the Thames and Severn Canal in 1933 and the Stroudwater Navigation in 1954.
This abandonment led to the disintegration of the canals, with them becoming either in-filled and incorporated into the expansion of the local built environment, or gradually recolonised by aquatic and terrestrial flora.
The project
The CCRP project team comprises Stroud District Council and their partners, including Halcrow Group. A phased approach is being implemented. Phase 1a commenced in 2009 and focused on the restoration of a 6km corridor, comprising bridges, locks, bunds and in-filled sections.
The corridor was divided up into 17 application sites and an EIA undertaken for each. Planning permission was granted, with specific conditions stipulated as required for individual reaches. The construction environmental management plan (CEMP) for each application site made use of the information gained through the EIA process.
Due to the complexity of Phase 1a and the EIA process, Halcrow’s EIA coordinator and ecologist employed an integrated and collaborative approach to assessing the ecological receptors for each site.
The EIA coordinator and ecologist first undertook an ecological scoping visit along the entire Phase 1a corridor. They were able to discuss the known, and potential, biodiversity and conservation value of the corridor in relation to the proposed design. This was a valuable exercise as it provided the EIA coordinator with an initial appraisal of:
- the ecological receptors present or likely to be present;
- the type of species surveys likely to be required and their timing; and
- the potential ecological impacts associated with the proposed construction phase that would require tailored mitigation measures.
While a joint site visit by the EIA coordinator and the project ecologist is not usually conducted, in this case it was deemed useful owing to the significant ecological impacts likely during construction.
This collaborative approach continued throughout the ecological appraisal and subsequent species surveys, which identified the potential for protected species to inhabit the canals and their riparian habitats and other sensitive receptors in close proximity.
The ecologist also ensured the EIA coordinator was aware of which species surveys were to be undertaken, their optimal survey season and the survey findings.
The following ecological issues were identified:
- active badger outlier setts were recorded at two separate sites;
- bat surveys at one site recorded eight bat species; four of which are species of principal importance under section 41 of the Natural Environment and Rural Communities Act 2006; and
- evidence of otter activity at three separate sites.
The ecologists undertaking the species surveys also prepared detailed mitigation measures which were incorporated into the CEMPs.
Regular liaison between the EIA coordinator and designated ecological clerk of works (ECoW) for Phase 1a is also being undertaken. The ECoW has been conducting weekly visits of six construction sites since 2011. After each visit, the ECoW prepares a report which is circulated to external stakeholders and the project team, including the EIA coordinator.
This communication has ensured that the EIA coordinator is aware that the ecological conditions in the individual CEMPs are being followed and monitored, and that all sensitive receptors are adequately protected.
Ecological impact assessments
The collaborative and integrated approach during Phase 1a has delivered ecological impact assessments (EcIAs) that have supported each application site throughout the planning process.
These EcIAs have assessed the biodiversity and conservation value at each site, recommending where necessary mitigation measures and ecological enhancements that are appropriate to the locality, habitats, and species present.
These measures have included:
- the permanent closure of two outlier setts, under licence by Natural England;
- a landscaped planting scheme to enhance existing habitats for badgers;
- the creation of a wildlife pond;
- monitoring known areas of otter activity during the interim and construction phase;
- not undertaking any night-time work to mitigate for potential otter presence;
- monitoring breeding waterfowl prior to any in-channel works;
- installing 60 bird and bats boxes through grant funding from the Big Lottery Fund's “Awards for all” scheme; and
- installing a range of species-specific bat boxes at a site with significant bat presence.
The EIA coordinator and ecologist/ECoW roles have been occupied by the same people since 2010, which has helped maintain continuity for the project team and the contractors appointed to different Phase 1a sites.
This continuity also benefits the client with the EIA coordinator and ecologist/ECoW having a comprehensive knowledge of the project, and being able to pool their respective skill sets to resolve any issues. This successful approach has also provided the client with an example of best practice that can be used as a model throughout the remaining phases of the CCRP.
This article was written as a contribution to the EIA Quality Mark’s commitment to improving EIA practice.
Liza Hollinghurst, MIEEM MEECW, is an environmental engineer at Halcrow Group (a CH2M Hill company)
