APEM were commissioned by Dŵr Cymru Welsh Water (DCWW) to support the development and management of the site at Llanishen & Lisvane reservoirs.
The future of Llanishen and Lisvane reservoirs has been subject to a decade-long planning saga. In 2013, the site’s previous owner, Western Power Distribution (WPD) lost its appeal to build 324 houses at Llanishen reservoir. Following this, WPD sold both reservoirs to steel company, CELSA UK, who wanted a secure water supply for their steel plant in Tremorfa (CELSA is supplied water from Lisvane Reservoir).
In 2016, after years of uncertainty, Dŵr Cymru Cyfyngedig – trading as Dŵr Cymru Welsh Water (DCWW) – secured the 999-year lease for Llanishen and Lisvane reservoirs and the surrounding land from CELSA UK. The aim of the acquisition was to safeguard and enhance the reservoirs for future generations.
Essential maintenance and safety works started in June 2016 to bring the reservoirs up to modern operating standards. In the meantime, an extensive community consultation has been undertaken by DCWW to enable local people to share their views on the kinds of leisure and recreational activities that could be offered there once remediation works are completed.
The development requires careful balancing of the needs of visitors with those of an operational reservoir. DCWW has a duty to protect, maintain and, where possible, enhance the biodiversity of the site. Much of the site is designated as SSSI or SINC due to the presence of unique flora and fauna so requires a specialist approach.
APEM have supported DCWW since 2016 to bring the reservoirs up to DCWW’s high operating standards, including essential ongoing maintenance and safety works. This work was a necessary step to enable the continued supply of non-potable water to CELSA UK.
The maintenance work involved vegetation clearance, dam wall repairs, replacement of and repairs to valves and pipes, perimeter fencing installation, and a new management regime for the vegetation on the reservoir embankments under the SSSI designation. In 2017, Llanishen reservoir was fully drained enabling a full inspection and replacement of critical supply pipelines and valving. APEM’s niche specialist teams supported DCWW throughout this process, with our fish rescue team assisting during dewatering and the ornithology team employing nesting water bird watching briefs.
Since 2016, APEM, on behalf of DCWW, have surveyed and recorded all the ecological constraints and opportunities on site in preparation for the proposed construction and ongoing management of the proposed development.
The site encompasses two Sites of Special Scientific Interest (SSSI) which are of national ecological value:
• Lisvane Reservoir SSSI is designated for its overwintering wildfowl
• Llanishen and Lisvane Reservoir Embankments SSSI is of special interest for its diverse assemblage of grassland fungi including up to 25 species of waxcap
The site also encompasses nine non-statutory Sites of Importance for Nature Conservation (SINC) covering species and habitats such as glow worm, grass snake, common toad, lichen, marshy grassland, wet woodlands and locally rare water plants.
DCWW aims for the site to become a resource for the local community, offering recreational activities for health and wellbeing in addition to supporting the existing biodiversity. The development proposal includes access improvements, landscaping and parking on site. Formal paths around both reservoirs have been carefully designed to guide visitors around the site and protect the areas of highest ecological value. There will be a new visitor hub with a water sports centre, café, a venue for functions and a boat workshop for undertaking maintenance and repairs.
Bird hides and floating islands will be constructed on Lisvane reservoir. This area will become a winter conservation zone for visiting waterfowl (underpinning and supporting the SSSI designation). A further conservation zone will be created in woodland, featuring a learning zone with a Welsh roundhouse to support education and training development.
Since the site was acquired, APEM have delivered a comprehensive suite of surveys and reporting to support DCWW’s ambitious aims for Llanishen and Lisvane reservoirs. These have included:
The delivery of these services ensured that DCWW have a detailed understanding of the conditions and flora and fauna present at this important site. This will inform future management as well as planning applications for the visitor hub development. We continue to work closely with DCWW and always be on hand with our locally-based field teams to support the delivery of this ambitious and exciting project.
