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'Warping' using dredged material to raise the height of
the land surface
| Guidance: Using dredged material is a promising technique for increasing
saltmarsh colonisation rates within realigned sites is to raise the surface
elevation (and possibly create a system of artificial creeks) prior to breaching.
Sediments at suitable elevations which will drain and dewater between tides
are likely to develop saltmarsh vegetation at a more rapid rate than has
been observed at Tollesbury.
However, the typical surface elevation differences between coastal reclaimed
land and nearby saltmarsh in SE Britain, which may be 1.0 - 1.5m (Pethick
& Burd 1995) indicate that large-scale engineering, probably
using dredged materials, is likely to be required if this method is adopted."
(Gray 2002). |
Comment: This is a technique used extensively in the USA
where material is regularly dredged from offshore and deposited in potential
saltmarsh regeneration areas.
References
Gray, A.J.
2002.
Coastal Realignment - an Overview of Tollesbury.
CHaMPs.
Pethick, J.S. & Burd, F.
1995.
Sedimentary processes under managed retreat, NRA Research Seminar. Project 480/1/SW.
Restoring biodiversity to soft cliffs, 14-25.
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