Wicken Sedge Fen is a wetland reserve that has suffered a lowered water table in recent years, and this has been cited as responsible for a subsequent loss of typical plant species, the contraction of typical plant communities, and an influx of some new species assemblages. The drainage regime has, however, been extremely variable in the past as a result of drainage activity involving the piecemeal draining of nearby land, and cycles of failure, reinstatement, and occasional improvement of drainage structures. Efficient modern drainage destroyed these cycles and permanently lowered the water table. While the lowered water table can be implicated in some ecological changes at Wicken Fen, other factors, notably the mowing regime, have also been important. It is suggested that all desirable plant communities could be maintained or created at Wicken by partitioning the site, manipulating the water table locally, and maintaining traditional management where appropriate.