Lymington Harbour habitat replenishment scheme: Summary of works

As part of its Stewardship role and in fulfilment of its public body duty with regard to biodiversity, The Crown Estate has grant-aided the recent saltmarsh habitat replenishment scheme carried out by Black & Veatch for the Lymington Harbour Commissioners. The summary report on the implementation of the scheme and the initial results are included in a report to The Crown Estate by its client representative, Stuart Lowe of MarineSpace Ltd, which has now been published.

The relevant area of saltmarsh is believed to have been declining since the 1920’s and the scheme was designed to pump sediment dredged from the Yacht Haven during maintenance activities, up onto the existing saltmarsh, in an attempt to raise the mud levels. To ensure that sediment was retained on the site, drainage channels were blocked using semi-permeable structures made of willow and straw.  The structures were built across the main drainage channel and six subsidiary drainage channels.  To prevent erosion of the saltmarsh during sediment discharge, and to slow the flow of sediment and water away from the discharge point, a discharge pen was constructed. The pen consisted of an inner pen, with willow and straw walls and an outer pen with straw walls.  The dimensions of inner pen were approximately 10m x 10m.  The base of the inner pen was lined with coir matting and willow to prevent erosion of the saltmarsh. Habitat replenishment was successful insofar as there has been a marked increase in sediment levels across the site.

The report citation is:

Lowe, S. (2012).
‘Lymington Harbour habitat replenishment scheme: Summary of works’.
The Crown Estate, 18 pages. ISBN: 978-1-906410-35-3.

The report may be downloaded from The Crown Estate website at:
http://www.thecrownestate.co.uk/media/287939/lymington_harbour_habitat_replenishment_scheme_summary_of_works.pdf