National Network of Regional Coastal Monitoring Programmes

WireWall is an innovative and cost-effective system to help optimise sea defence design and early warning processes, reducing construction costs and ultimately protecting coastal communities.

Reports are available and the full list of references and links is available at the bottom of the page.

Many countries with a sea border need man-made defences to protect them from coastal hazards such as flooding. In the UK 3,200 kilometres of coastline are defended, particularly in seaside towns and cities. Sea walls are designed to protect people, property and infrastructure from the harm caused by large waves that can occur when a severe storm happens at the same time as a high tide (Figure 1).

Figure 1. Coastal flooding at Crosby, December 2013.

When planning sea defences a lot of data are needed to understand the potential hazards that might occur in decades to come. Numerical tools (e.g. EurOtop) use this data to test suitable sea wall designs. The tools do this by estimating the "overtopping hazard" for each design i.e. what volume of water might come over the wall during storm conditions. Accuracy of the tools is assessed by checking outputs against measurements of overtopping volumes during storms. Field experiments have previously used large tanks placed behind the sea wall to catch the water that comes over. Such experiments are very costly and can be difficult to do, so only a few have been made. They also only provide a limited amount of data and none at all on the speed of the water that overtops: an important factor for public safety. This lack of measurements means there is large uncertainty in the numerical estimates of the hazards, so sea defences are overdesigned to have large safety margins and may therefore cost much more than they need to.

This project aims to take a low-cost instrument that has previously been used to measure waves in the open ocean, and convert it into a system ("WireWall") that will measure coastal overtopping hazard. The system will employ a 3-dimensional grid of capacitance wires that sense contact with saltwater. This signal will be used to measure the volume and speed of overtopping at vulnerable locations on the 900-metre-long sea wall at Crosby in the North West of England. This sea wall is reaching the end of its design life and intense monitoring of the local conditions has begun to aid the design of a new wall (Figure 2).

Figure 2. Crosby sea wall .

The WireWall interest group met at the NOC in Liverpool on 26th June 2018. The meeting saw colleagues from the NOC and HR Wallingford join forces with our partners, coastal authorities, consultants and researchers to discuss the progress so far and what's next for the innovative project. Lots of lively discussion was had with new challenges identified. Over lunch there was also the opportunity to get some hands on experience with a demonstration rig that showcased the technology that will be used.

Who's involved?

Wave Overtopping Clips collected in Cell Eleven of the regional monitoring programme

WireWalk: Changing shores - The Crosby Sequence

Through the coming together of science and the arts we have created a narrated coastal walk along Crosby's shoreline. This has been developed to raise awareness of shoreline change and coastal hazards. The poems capture changes in land use, coastal processes, shoreline management and observational techniques. By becoming more aware of changing coastal conditions we hope people will contribute to the consultation on the Vision for Crosby's Coastal Park 2030 and beyond.

Join us and download the GPS waypoints and MP3s from: We hope you enjoy Blitz Beach with its tower high waves, that's our WireWall study site.

Funded by AGU Celebrate 100 grants @Wirewall_NOC @SarahHymas @GreenSefton_

Coastal Walk - Changing Shores - The Crosby Sequence


Brown, J., Yelland, M., Pullen, T., Silva, E., Martin, A., Gold, I., Whittle, L., Wisse, P. 2021. Novel use of social media to assess and improve coastal flood forecasts and hazard alerts. Scientific Reports, 11(1).

Lashley, C., Brown, J., Yelland, M., van der Meer, J., Pullen, T. 2022. Comparison of deep-water-parameter-based wave overtopping with wirewall field measurements and social media reports at Crosby (UK). Coastal Engineering, 179, 104241,

Yelland, M, Brown, J., Cardwell, C., Jones, D., Pascal, R., Pinnell, R., Pullen, T., Silva, E. 2023. A system for in-situ, wave-by-wave measurements of the speed and volume of coastal overtopping. Communications Engineering, 2(1),

Project report:

Brown, J; Yelland, M; Pascal, R; Pullen, T.; Cardwell, C; Jones, D; Pinnell, R; Silva, E.; Balfour, C; Hargreaves, G; Martin, B; Bell, P; Prime, T; Burgess, J; Eastwood, L; Martin, A ; Gold, I.; Bird, C; Thompson, C; Farrington, B.. 2020 WireWall – a new approach to measuring coastal wave hazard. Southampton, National Oceanography Centre, 115pp. (National Oceanography Centre Research and Consultancy Report, 66).

Project datasets that accompany the report:

1. Brown J.; Pullen T.; Silva E.; Prime T.; Yelland M.J. (2020). WireWall project numerical wave overtopping volume estimates at Crosby Hall Road Carpark (north of Liverpool UK) using a beach profile in 1996 and three in 2017, estimates are for coastal conditions when there is photographic evidence of overtopping occurring between 2013 - 2017. British Oceanographic Data Centre, National Oceanography Centre, NERC, UK. doi:10/d898.

2. Brown J.; Pullen T.; Silva E.; Prime T.; Yelland M.J.(2020). WireWall project numerical wave overtopping volume estimates, for profiles in 1996 and 2017. Estimates are calculated at Crosby Hall Road Carpark (north of Liverpool UK) for joint wave and water level conditions that represent the return period curves in Liverpool Bay developed in 2011. British Oceanographic Data Centre, National Oceanography Centre, NERC, UK. doi:10/d9s9.

3. Yelland M.J.; Pascal R.W.; Pinnell R.; Cardwell C.L.; Jones D.S.; Brown J.(2020). WireWall project data, August 2018, generated during the dockside experiments performed at the National Oceanography Centre Southampton British Oceanographic Data Centre, National Oceanography Centre, NERC, UK. doi:10/d9qh

4. Yelland M.J.; Pullen T.; Silva E.; Pascal R.W.; Jones D.S.; Pinnell R.; Cardwell C.L.; Brown J.(2020). WireWall project data generated during the flume experiments performed at HR Wallingford during July to September 2018. British Oceanographic Data Centre, National Oceanography Centre, NERC, UK. doi:10/d9n9

5. Brown J.; Yelland M.J.; Pascal R.W.; Jones D.S.; Balfour C.A.; Hargreaves G.; Martin B.; Cardwell C.L.; Pinnell R.; Bell P.S.; Pullen T.; Silva E.; Prime T.(2020). Key WireWall project data generated during the field deployment at Hall Road Crosby (North of Liverpool UK), between October 2018 and March 2019 British Oceanographic Data Centre, National Oceanography Centre, NERC, UK. doi:10/d9pz

Data collected through later projects:

1. Yelland M.J.; Brown J.; Pascal R.W.; Jones D.S.; Cardwell C.L.; Walk J.A.; Martin B.; Darroch L.; Gardner T.(2024). Wave overtopping field data collected at the sea walls in Dawlish and Penzance (southwest UK) between March 2021 and March 2022. NERC EDS British Oceanographic Data Centre NOC. doi:10.5285/12ed58d6-7bb8-3eae-e063-6c86abc0689c