Articles & Case Studies

CPV gives a raft of support for wildlife islands

Posted: Tuesday 2nd April 2013

Floating islands have been constructed by the pipework engineering company CPV Ltd for bio-engineering and erosion consultants Water-Lines Solutions Ltd. The floating islands, using a buoyancy subframe, were recently installed as part of a new nature reserve, now being created at a former quarry and landfill in Rugby.

Prefabricated at CPVs Romsey production site, a total of 106 frames were used to construct three floating islands, with a total area of just under 1,000m2, for the nature reserve at Parkfield Road quarry. The site was originally used in lime and clay quarrying and was later operated, during the 1980s and 1990s, as a waste depository for the adjacent Rugby Cement Works.

The islands at Parkfield Road offer a refuge for birds, amphibians and small mammals, such as water voles. They are anchored by concrete blocks and synthetic ropes, which will be adjusted as the quarry gradually fills to 70m depth of water above ordnance datum. The detailed planning process identified that the site could be a suitable habitat for White Clawed Crayfish, a species that is under threat from the invasive Signal Crayfish introduced from America in the 1960s. Records suggest that the White Clawed crayfish may have been present although none were recorded during recent surveys nevertheless, CEMEX has provided a suitable habitat should they be present.

CPV produced airtight, welded frames in black 110mm polypropylene pipe, with a rectangular polypropylene grid fitted across each frame. Inside each of these floating trays, Water-Lines Solutions installed eight 1m2 coir (coconut fibre) pallets, planted with nursery-grown reeds and grasses. The company chose CPV following their successful cooperation on other floating island and reed bed projects. These have included design variations, such as the addition of submerged gabion baskets to provide an effective fish refuge and spawning ground.

Once a pastime of the young and the shipwrecked, building a raft is now a more serious business, with growing numbers of floating reed beds and island wildlife havens featuring in water treatment schemes and landscape remediation. Construction uses a combination of natural and synthetic materials to produce a fertile yet durable platform for flora and fauna.

The current owners of the site and operators of the cement plant, CEMEX UK, initiated this ambitious and imaginative restoration project in 2010 and commissioned civil engineering and earthworks contractors, Fox (Owmby)Ltd, to undertake the remediation programme which commenced in June 2011.. This initially required dewatering and removal of 178,000 cubic metres (267,000 tonnes) of cement kiln dust from the eastern end of the quarry, before reshaping areas of the landform. The new lake is now filling naturally with rainwater, as grasses and shrubs are becoming established and transforming the wildlife attraction and visual appeal of the surrounding slopes.

Read the magazine online

August 2021

About the magazine »
Magazine archive »


Information for advertisers »

British Water buttonwood marketing Water Aid Huber Pulsar Button June 13 Cranfield University Harvey Communications wateractive
Pulsar New Banner