Press release February 2003

Fenland Hydrotech designs and project-manages new bat house for Daubentons Bats at Ormesby water treatment works

Consulting engineers Fenland Hydrotech has designed and project-managed the installation of a new and unique bat house for Daubentons Bats at Essex & Suffolk Water's Ormesby water treatment works. Fenland Hydrotech liaised closely with Greena Environmental Consultancy at the outset of the project, and acted as Planning Supervisor under CDM regulations during construction.

Essex & Suffolk Water will be refurbishing different parts of the Ormsby treatment works in the future. A rare colony of Daubentons Bats is located in a cellar under one of the buildings. Bats and their roosts are protected by the Wildlife and Countryside Act 1981 and the Conservation (Natural Habitats and Conditions) Regulations 1994. To ensure no disturbance will be made to the bat colony during this time, a specially designed new home has been constructed. Working with Greena, Fenland Hydrotech designed and project-managed the building of the new bat house that replicates the conditions existing in the bats' present cellar environment. The new house is strategically situated alongside the bats' flight path between their current habitat and the Ormesby Broad, and it is hoped that the bats will be enticed to relocate the colony into the new house.

Over 100 bats are known to use the Ormesby site regularly every summer as a nursery roost. Miranda Davis, environmental co-ordinator for Essex & Suffolk Water, said: "Daubentons Bats are a relatively rare species and, like all the species and habitats on our sites, we wanted to make sure that they were well protected. Therefore, when the refurbishment of the treatment works building takes place, it will happen without any negative impact on the bats' hibernation area."

The bat house design comprises a single storey, two-room building with the rear room covered with an earth mound to maintain a stable temperature. Floors are bare earth to encourage a damp, humid atmosphere, and raised areas are built into the two roofs to trap hot air and create purpose-built 'hot spots' for roosting bats. Several temperature and humidity data loggers have been installed to allow licensed bat workers to monitor conditions within the roost.

There are several internal walls to act as wind breaks, and to create a selection of areas for the bats to inhabit. To eliminate draughts there is only one opening in the building, and this is fitted with a grille to allow the bats to fly in and out while preventing anything else from getting into the roost. Six Schwegler bat boxes have also been installed to give the bats an added incentive to accept their new home.

Fenland Hydrotech, based in Thrapston, Northamptonshire, is an independent firm of consulting engineers providing professional services to public and private sector clients in the UK and overseas. The company has particular expertise in the area of water engineering, including pipelines, sewerage, storm drainage, tunnelling, water treatment and distribution, and effluent treatment.

Fenland Hydrotech is a member of the Association of Consulting Engineers, and its Quality Assurance system is accredited to ISO 9001/BS5750 part 1. It provides a complete project management service from initial appraisal, through detailed design and documentation to contract administration, site supervision and cost control.