On 3 October 2018, RSBP Scotland completed a new realignment project at their Skinflats nature reserve on the Firth of Forth. The final stage of this work involved excavating a 25m-wide breach in the seawall.

The final stage of this work involved excavating a 25m-wide breach in the seawall and the story of the day (with photographs) can be found at the RSPB Community website. We have also added details of this project to our completed coastal adaptation schemes database, OMReg.

The Skinflats reserve forms a key part of RSPB Scotland’s wider vision for the Inner Forth landscape. The aims for the Inner Forth include finding ways to offset past habitat losses from land claim; create a more sustainable shoreline and provide a safe high tide roost areas for birds.

Bothkennar Field, where the new realignment was completed, had already been a managed saline wetland. A Regulated Tidal Exchange (RTE) structure was installed here in 2009 to allow controlled amounts of tidal water onto the site. This RTE project included construction of a new landward defence line and the installation of a pipe and sluice.

The RTE was successful in establishing coastal habitats on the site and it quickly became a high tide roost for several bird species. However, the infrastructure used to bring seawater onto the site was not really functioning as planned. This prompted the RSPB to examine more sustainable methods of delivering high quality intertidal habitat. Managed realignment was the best option.

For the realignment, a single small breach was excavated in an old embankment to allow water to flow into the site on the larger tides. The existing embankments became the new coastal defence line and these banks were improved.

We are delighted to have been able to support this work. We carried out the feasibility study, hydrodynamic modelling, conceptual design, impact assessment and planning application work and provided support and advice during the valuable public exhibitions.

The realignment has been performing as anticipated. In advance of the project, some members of the public had understandable concerns about the flood risk associated with it and the risk of erosion of the saltmarsh. However, we have learned so much about managed realignment design over the last 25 years, that there was a very good understanding about how it would function and the low risk of erosion. The design allows for very slow and benign flows through the breach. Therefore, the excavated breach in the sea wall has been very stable indeed. 

The project was funded by the Heritage Lottery Fund through the Inner Forth Landscape Initiative and EcoCo Life.

Learn more about ABPmer's habitat creation services.

^{References:
ABPmer, OMReg, RSPB Community (1) (2)}

^{Images courtesy of RSPB}