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Adaptation strategies for the bay of Cala Millor

Action alternatives to reduce coastal vulnerability to climate change
 

Introduction

The rise in mean sea level in Cala Millor will progressively reduce the width of the dry beach, increasing coastal vulnerability to flooding and extreme events. This evolution implies the loss of ecosystem services and economic activity linked to the beach.

The expected impacts and consequences are not uniform across the whole area, so it is necessary to differentiate and identify the specific needs of each zone. Key sections include the northern area, the central area where the former Estanyol was located, and the connection point with the natural area of Punta de n’Amer. To reduce the risk associated with these impacts, it is necessary to implement adaptation strategies that improve the resilience of the coastal front, articulating different strategies and measures according to the particularities of each identified section.

Within the framework of the project, different action alternatives have been analysed, of which two main strategies are considered: the setback of the urban front or the adaptation of the existing coastline. All strategies analysed in detail are included in this report.

The following sections present these strategies and the intervention variants developed for each of them.

Adaptation strategies analysed

Strategy Description Analysis result
No action Do not carry out significant interventions in the coastal system and maintain the current situation of Cala Millor beach, assuming that natural processes and coastal dynamics continue to evolve without specific adaptation actions. It was considered as a reference scenario, but it was discarded because it was understood not to respond adequately to the identified risks associated with climate change. The repair costs of the effects of flooding and storms are very high; by 2050 the width of the dry beach is considerably reduced and by 2100 it disappears in some areas.
Setback Planned retreat of the seafront promenade to reduce the exposure of the urban front to flooding, beach loss, infrastructure damage, and the degradation of ecosystem and socio-economic services. It makes it possible to maintain a dry beach width and a more resilient shoreline through planned sand nourishment and nature-based solutions. In the northern area it is complemented by a containment structure or breakwater.
Adaptation Gradual adaptation of the coastal front to new risk conditions, assuming the progressive loss of dry beach and prioritising the reduction of flood risk. It is based on hybrid solutions for flood protection and landscape management, with a coastal park-dike and terraced boundary.
Developed variants
Three main proposals were developed:
  • Setback with vegetated topography and containment structure
  • Setback with park berm and containment structure
  • Adaptation with park-dike and terraced boundary

Proposed strategies

VEGETATED TOPOGRAPHY: Setback with vegetated topography and northern containment structureSetback
This proposal sets out a retreat of the seafront promenade in the southern area that would make it possible to place a series of vegetated sand elevations capable of acting as a natural barrier against storms. The intervention maintains the width of the dry beach and places the seafront promenade in a more set-back position, which helps reduce the urban heat island effect and improve adaptation to extreme heat episodes.
In the northern area, the groyne makes it possible to increase the dry beach surface and maintain the protection service it provides, largely preventing impacts on the urban fabric and buildings that flooding under extreme conditions would cause. In addition, this strategy offers the opportunity to recover the former coastal lagoon of Estanyol, increasing the ecological and landscape value of the area.
COASTAL BERM PARK: Setback with berm park and northern containment structureSetback
This variant proposes transforming part of the current seafront promenade into a coastal park with berm, in continuity with the coastal pine grove of Punta de n’Amer. The new green space contributes to improving thermal comfort, increasing the albedo effect, and giving the coastal front a more natural character.
Unlike the previous option, it does not contemplate the recovery of Estanyol, but it creates a publicly accessible space integrated into the landscape that combines social use and coastal protection functions. In the northern area, the groyne makes it possible to increase the dry beach surface and maintain the protection service it provides, largely preventing impacts on the urban fabric and buildings that flooding under extreme conditions would cause.
PARK-DIKE: Adaptation with park-dike and terraced boundary Adaptation
This proposal assumes a progressive loss of the dry beach and sets out a gradual adaptation of the coastal front through hybrid solutions for flood protection and landscape management.
In the northern area, the raising of the existing wall is foreseen until it reaches approximately 0.55 m above the current level by the 2050 horizon, with the aim of reinforcing protection against flood events. In the southern area, the creation of a coastal park with terraces and direct access areas to the sea is proposed. The intervention protects against flooding and creates a new public space in a context of progressive reduction of the dry beach.

Strategy selection process. Final phase

The alternatives presented are part of the process developed in the LIFE AdaptCalaMillor project to define a climate change adaptation strategy for the bay of Cala Millor. The project promotes the active participation of stakeholders and society in defining these solutions, with the aim of reaching agreements based on scientific knowledge.

The project methodology has been structured in two phases. In the first, an analytical framework was defined to support decision-making for climate change adaptation. In the second, currently under development, a participatory methodology is being applied to select and prioritise adaptation strategies.

In this final phase, two proposals are being evaluated together with the different stakeholder groups in the territory: Setback with vegetated topography and Setback with park berm. The final solution will be selected on the basis of environmental, technical, and socio-economic criteria, with the aim of improving the resilience of the coastal system in the long term.

Compare alternatives
Setback options currently under evaluation: A1 (vegetated topography) and A2 (park berm).