Boulders at Tal-Veccja cave to avert collapse

The Public Works Department is proposing boulders in front of the Tal-Veċċja cave, in St Paul’s Bay to prevent the collapse of the existing road.

The proposal forms part of new plans intended to prevent waves from crashing into the cave and threatening its stability.

The project is intended to safeguard the existing road and neighbouring properties from collapse.

The Tal-Veċċja area has seen extensive building development over the past decade.

In 2022, the Environment and Resources Authority had objected to plans submitted by the Public Works Department for the erection of a sea wall which would have covered the cave. The cave is situated in a cove.

The environment watchdog had warned that the proposed revetment would have an “irreversible impact on the integrity of the cove.”

ERA is still assessing the latest plans, which according to the Public Works Department will serve to protect the cave without covering it.

The Tal-Veċċja sea cave is recognised as a natural geomorphological feature and is protected as an Area of Ecological Importance.

Road may collapse, PDS warns

The intervention is being justified as a way of protecting the existing coastline from erosion.

A Project Description Statement warns that wave action during North East storms are damaging the existing infrastructure along this stretch of coastline.

“The combination of friable rock formation and wave action are posing a significant threat on buildings built near the coast, which now find themselves on the edge of the cliff face and in danger of toppling over due to the scour at the toe of the cliff”, a Project Description Statement states.

According to the same document the cave is composed of very friable Upper Coralline Limestone.

The attenuation of wave action by erecting the boulders would  decrease the rate of erosion on the cave during severe storms and would thus increase the safety of the third-party properties and the road sitting directly on top of the cave, “which are at risk of collapsing if the cave erodes further into the sea”.

The proposed works

The proposed works entail the extension of the existing rock armour revetment along the Xemxija Bay breakwater by circa 65m, and the laying of a boulder scree in front of Għar il-Veċċja, a semi-submerged cave present under Triq Stella Maris.

The boulder scree is being proposed to protect but not to cover the cave and coastal area from further erosion by aiding the waves to break before reaching land, a crucial feature seeing as the most dominant winds in the area are Gregale winds.

The current stairs leading to the sea will be demolished, and the concrete retaining walls will be covered by the proposed revetment.

The project would require the dredging of  material such as sand, pebbles and small rocks from the area which will be covered by boulders. The dredged-up material would then be used within the same project. A crane would then lay down each rock strategically, to ensure that the rock structure remains stable even during severe storms.

The PDS claims that from a visual perspective, the project will  enhance the coastal area and provide a safer space for pedestrians on Trejqet il- Veċċa, bathers and residents overall.

Impact on protected sea grass

A marine survey of the area confirms that an assemblage of protected Posidonia oceanica meadows lies within the footprint of the project.  Moreover, grass meadows located outside of the footprint of the proposed works may be impacted by changes to the water quality due to the potential release of contaminants like dust into the marine environment during construction.

But the study concludes that most of these impacts can be mitigated through good workmanship. Moreover, the  impact of the works on the integrity and conservation status of the two marine protected areas are deemed negligible due to the small-scale nature of the works.

More construction despite safety concerns

The plans come in the wake of an onslaught of construction activity in the area, which included a permit issued in 2019 for the development of 24 dwelling units and two offices with underlying garages constructed on seven levels above the street level and three levels below.

Reports related to this development, whose garages encroach on a protected green area, made no reference to the impact of excavations on the caves. But an application for a nine-storey hotel on an existing terrace overlooking the bay was withdrawn in February after a case officer called for a refusal of the permit.

The Environment and Resources Authority had expressed concern on the proposed excavation works in close proximity to the coastal cliffs and cave.