Justification

Areas at risk from flooding in the Bangor area (NRW, 2020).

Flood risk management plan

The West of Wales SMP2 and Western Wales Flood Risk Management Plan have identified that in the Hirael area “there would be significant increases in flood risk and sea level rise” and recommends that long term planning should look at “realignment and redevelopment… to provide a more secure future for development of this waterfront area”. 

Properties at risk of tidal flooding for a 1/100 year event at 2020 and 2055 sea levels

The case for change

The main benefit of the project is the reduction of the risk of tidal and surface water flooding to people and property in Hirael. The proposed scheme(s) will reduce this risk for 79 properties from a 1/100 year tidal flooding event up until 2050 (after which time, further consideration of the management solutions will be required). This will help to ensure a healthy, resilient and sustainanble community in future.

The 50-year period has been recommended for the following reasons:

  • Modelling has shown that beyond 2050, there will be large-scale changes to the local flood regime, meaning defending Hirael will become increasingly challenging.

  • To ensure the scheme fits in with the wider West of Wales SMP2.

  • Another review may be needed.

Economic Case

A broad array of options have been considered in the assessments so far. Through this initial assessment, all offshore options have been rejected because of their impact on the environment, high associated costs, and because land-based options would be needed on top to mitigate against non-wave (tidal) flooding. The sample opposite shows a simplified breakdown of the costs involved with each option, and demonstrates that option 4 is the most economically sensible.

Strategic Outline Case report findings

Weakening and inadequate defences

The coastal frontage of Beach Road is comprised of a mixture of defences which are beginning to show their age, and modelling has revealed they would only protect Hirael from a 1 in 3 year flood event (33% chance of such a flood happening in one year). If you want to know more about flood events, click below…

Hirael flood prevention scheme

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