Development of Options

Option development is about gathering information and then identifying potential coastal defence management options. These options (longlist and shortlist, see below) are then appraised in a consistent way to identify the leading options that will deliver the greatest benefits for the community in the most cost-effective way.

Appraisal of Langstone defence measures and selection of the leading options has been undertaken within the framework of the Environment Agency Flood and Coastal Erosion Risk Management (FCERM) appraisal guidance (FCERM-AG). To access the guidance click here.

Longlist Options

Developing a longlist of options is the first part of the option development process, this is described in the Langstone Longlist Report 

In developing the longlist, all potential defence measures to implement various management options are considered. These include:

Do Nothing:

• Stop maintenance and repair existing defences, no works would be carried out.

Do Something:

• Do minimum. Small scale reactive repairs or maintenance of existing repairs to manage health and safety risks.
• Maintain. Proactive repair and larger scale maintenance or refurbishment of existing defences. 
• Improve. Raising the height and lengthening of the existing defences or constructing new higher, longer defences to improve the standard of protection provided. 

Improve options considered for the longlist included frontage wide measures such as tidal barriers, lagoons, relocation and community resilience; as well as discrete measures ranging from seawalls, revetments, embankments and groynes to property level protection, self-raising flood walls, beach nourishment and demountable defences.

From this longlist, those options not technically suitable were screened out in each area.

Shortlist Options

The second stage of the option development process is the appraisal of the longlist against a number of questions using multi-variate analysis.  Doing this helped to identify a shortlist of options, as described in the Langstone Short List Report

We posed the following questions to the longlist options:

• Support the strategy preferred options?
• Reduce residual flood risk?
• Manage erosion risk?
• Impact on ecology?
• Impact on heritage?
• Impact on landscapes?
• Impact on processes?
• Support broader outcomes, aspirations and contributions?
• Have stakeholder support?
• Require low, medium or high levels of maintenance?
• Have short, medium or long design of life?

Is the longlist option....

• Technically feasible?
• High, average or low cost compared to other options?

Leading Options

The final stage of the option development process is the appraisal of the shortlist to identify the leading options for the Langstone frontage, this is described in the Langstone Preferred Option Report

The shortlisted options were appraised, scored and ranked against environmental and social impacts, technical feasibility and cost to identify Leading Options.