The council and Jacobs UK considered a number of options to address beach lowering.
1. Do nothing
Doing nothing is not a viable option. Beach levels are lowering. If this continues, the beach will provide less protection from storms. This would increase the risk of damage to the sea defences, leading to coastal erosion and tidal flooding, putting people, properties and critical infrastructure at greater risk.
The loss of beach sand would eventually expose the underlying clay, reducing the quality of the beach for residents and visitors.
2. Do the minimum
Maintaining and repairing the existing sea defences would help extend their lifespan, but it would not address the ongoing loss of beach sand or the exposure of the underlying clay. As a result, the risk of storm damage, coastal erosion and tidal flooding would continue to increase.
3. Toe protection
This option would involve installing rock armour or concrete units at the base of the existing sea defences to help protect them as beach levels fall. While this could reduce the risk of damage to the defences, it would do little to prevent the ongoing loss of beach sand.
The beach would continue to lower, meaning further work may be needed in the future. For this reason, toe protection would not provide a sustainable long-term solution.
4. Beach recharge
This option would involve adding sand to the beach to restore it to levels similar to those seen before 2005. A higher beach would help protect the sea defences and improve the beach for residents and visitors.
However, without structures such as rock groynes to hold the sand in place, much of it would gradually wash away. This would mean that regular replenishment of the beach is needed, making beach recharge alone a less effective and sustainable long-term solution.
Although beach recharge was not selected as a standalone solution, it will be used occasionally following severe storms to replace sand that has been lost and help maintain beach levels.
5. Rock groynes
This option involves constructing 17 rock groynes along the beach to help trap and retain sand. Similar structures have already been installed successfully as part of the Rossall scheme in Wyre, where they have been shown to help retain sand on the beach.
The groynes would help create a higher and more stable beach, which would provide greater protection to the sea defences and reduce the risk of beach lowering. They would also help improve the beach for residents and visitors by retaining more sand on the beach. For these reasons, this option was chosen in combination with occasional beach recharge.
6. Timber groynes
Timber groynes have previously been used in Blackpool but were unsuccessful in retaining beach sand. While timber groynes can help hold sand on some coastlines, they are unlikely to be effective in Blackpool. This is because most of Blackpool’s sand moves on and off the shore, rather than along it (via longshore drift). This means they would not retain enough sand to maintain beach levels.
Past experience in both Blackpool and neighbouring Wyre has shown that timber groynes have not effectively retained sand. In contrast, the larger rock groynes installed in Rossall and Cleveleys are already proving effective at holding sand in place. Timber groynes can also cause localised erosion around the structure, reducing their effectiveness over time.
Timber groynes would require regular inspection, repair and eventual replacement because of the harsh wave conditions along our coastline. This would lead to ongoing maintenance, additional disruption for beach users and repeated environmental impacts. For these reasons, timber groynes were not shortlisted, as they would not provide an effective or sustainable long-term solution.
7. Offshore breakwaters
This option would involve constructing rock breakwaters offshore, parallel to the coastline. These structures can reduce wave energy and help retain beach material in some locations.
However, along Blackpool's coastline they would block the natural movement of sand from offshore onto the beach. This natural supply helps maintain beach levels, so preventing it could make beach lowering worse over time. For this reason, offshore breakwaters were not considered a viable option.
8. Sand engine
A sand engine involves placing a very large volume of sand on the beach and allowing natural coastal processes to gradually spread it along the coastline.
This option was investigated but was not considered viable for Blackpool. The coastline already receives a significant natural supply of sand from offshore. The main challenge is retaining that sand on the beach rather than adding more. A sand engine would not solve this problem because, without structures such as rock groynes to hold the sand in place, much of it would wash away.
A sand engine would also be costly to deliver and could have significant environmental impacts.
9. Beach drainage
Beach drainage involves lowering the water level beneath the beach to help reduce erosion and keep the sand more stable.
This option was investigated but was not shortlisted because it has not yet been proven to be effective in the UK. It would provide limited benefits during storms, when beach erosion is most severe, and would require ongoing maintenance.
After careful consideration, rock groynes combined with occasional beach recharge were considered the most effective, viable and environmentally sustainable solution.