Creek networks: natural evolution and design choices for intertidal habitat recreation

With the current rise in sea level jeopardising coastal biodiversity and the efficiency of traditional flood defence solutions, more sustainable coastal management options are being considered. The use of artificially restored intertidal habitats (mudflats and saltmarshes) as buffer zones for tidal and wave energy has been tested at numerous sites in the UK and around the world. Since the 1970s, the design of these habitats has significantly evolved along with our understanding of the natural processes involved. This paper reviews the state of the art in intertidal habitat recreation, focusing mainly on creek networks, for which no global systematic design method exists. The main parameters that control their initiation and development are investigated through the observation of natural creek networks and through the reproduction of this development in laboratory and numerical models. In areas like San Francisco Bay, such parameters have already been used in geometric relationships to provide guidelines for creek network implementation, but these empirical relationships are likely to be very site dependent. A series of steps is proposed to extend this implementation technique to other sites, thus making the design strategy more systematic and globally applicable. The sustainability of existing habitat recreation schemes remains a debated point, making the need for quantitatively defined objectives and better implementation guidelines all the more pressing.