Cliffe Pools

Habitat creation details

The site had a long history of un-authorised access, fly-tipping and anti-social behaviour. Therefore, before restoration work could commence, considerable effort had to be put into site safety and removal of contaminants. With help from Medway Council, a grant was secured from the Office of the Deputy Prime Minister (now Department of Communities and Local Government) to clear up an area of substantial copper contamination.

The saline lagoon habitat originally developed as a by-product of the dredging activity, whereby the old clay pits had marine or estuary dredgings pumped into them in a solution of estuary water. This led to the formation of large, deep and often featureless saline lagoons. Because of the high conservation status of the habitat, specialist saline lagoon ecologists were consulted to improve these as part of the restoration planning process.

The restoration aims to create a complex of mixed depth saline lagoons and brackish pools where birds can feed. Within this, islands and shallow margins will be formed for nesting and roosting birds. This work will increase the value of the site for wintering, passage, and in particular breeding water birds, while maintaining and improving its value for the specialist saline lagoon invertebrate species. Installing mechanisms to control and manage water levels within the brackish pools and lagoons will enhance them further.

Restoration will be achieved primarily through:

• Targeted disposal of dredgings to infill existing saline lagoons; to reduce their depth to increase feeding habitat for waterfowl; and to create nesting islands.

• Creation of shallow margins through re-profiling of the edges of currently deep lagoons to provide open and vegetated margins.

• Creation of additional islands through isolation and re-profiling of existing causeways and, if practicable, excavation of areas in the northernmost brackish pools.

Deeper areas will be retained to help maintain more stable salinities within the shallower areas of these water bodies.

The rate of restoration largely depends on the quantity and type of dredging being deposited at the site and this will determine priority for the order of work. When only small to medium quantities of dredgings are available, priority will be to deposit them in areas with a lower capacity to create islands and shallows. Larger quantities will be deposited in the larger lagoons. In order to protect the lagoon invertebrates, an area has been set aside as a refuge for them.

This approach to the site’s restoration is a good example of a partnership between a conservation charity and a commercial dredging partner that will provide a sustainable use for dredging material.