Restoring eco-hydrological regime
Our construction methodology ensured minimum impact of the Wicken Fen works on the delicate fenland ecology, and recieved a commendation from the National Trust.
We designed and supervised a scheme comprising part of an improvement plan to restore the eco-hydrological regime needs of the target fen vegetation communities. The scheme consists of pumping water from Monks Lode from a 4.5 metre deep sump chamber and through a pipe 2 metres below Wicken Lode, to a second sump using power from a wind pump tower.
The water from Monks Lode is low nutrient calcareous water, used to inundate and saturate the Fen and improve its chemistry and degree of saturation. The site is one of the few remaining fragments of fenland wilderness in East Anglia and as one of the most important wetlands in Europe, its biodiversity is exceptional.
Initially, working closely with the EA and NT, we did a vegetation assessment of the site together with water vole and otter surveys and found that the scheme would have no negative effects –and should have positive benefits.
We carried out detailed geotechnical and structural scheme design and produced construction drawings including the pump chambers, to be constructed using caisson rings and the pumping main under Wicken Fen.
Our team’s contribution to the project included:
- Early contractor involvement (the ECI partner was Birse)
- Design of temporary works
- Preparation of specification and tender documentation
- Tendering of the works (Birse were awarded the contract by the EA)
- Full time engineering supervision of the construction works
- Close-out and validation reports
Our construction methodology ensured minimum impact of the temporary works on the delicate fenland ecology. The excavation plant and wind pump components were transported to the site along protective track-way and the fen was left virtually unaltered after the wind pump was erected and removal of the track-way.
The works have had only positive environmental effects. We received a specific commendation from the National Trust for our management and supervision of the scheme and in particular the efforts made to ensure the site’s ecology was safeguarded throughout and that the impact of the work on visitors and local users was kept to a minimum.