Superintendence calls for survey of Harq Hammiem cave

The Superintendence for Cultural Heritage is calling for a full survey of the Ħarq Ħammiem cave, close to St George’s Bay, in view of the db Group’s proposed City Centre project on the site formerly occupied by the Institute for Tourism Studies.

The City Centre multi-use development includes a 464-room 5-star hotel, 162 residences, commercial office space, a shopping mall, a casino, restaurants and a basement car park.

The survey of the underlying cave has to include the full extent and depth of the cave; and the surveyed features of the cave have to be presented independently “as an overlay of the plans and sections of the proposed development”.

The Superintendence has also called for a geophysical report on the cave, which should “include statements on the stability of the cave and surrounding bedrock.”

The Ħarq Ħammiem cave complex was designated as an area of Ecological Importance and Site of Scientific Importance in 2008. The cave complex is the largest mean sea level cave complex containing freshwater in Malta. 

Nature Trust Malta has already expressed concern that excavation works in close proximity could lead to a possible collapse of the cave structure, in view of the geological formation of the area, which is composed of Lower Coralline Limestone. Moreover Nature Trust warns that the cave water could end up being contaminated by the sewerage systems, fuel storage and desalination and Reverse Osmosis plants. 

In its memo the Superintendence also called for the surveying of the historic military buildings.

The proposed development will also be subjected to a Heritage Impact Assessment (HIA) for which the Superintendence of Cultural Heritage will draw up terms of reference.

A report by the Environment and Resources Authority drafted in April has warned that the risk of subsidence in the large subterranean cavern at Ħarq Ħammiem, just off St George’s Bay, posed by high-rise development remains unclear, and further studies are needed to establish the impact of vibrations on the geology of the area.

“The project may lead to subsidence of the roof on the large subterranean cavern at Ħarq Ħammiem,” a screening report by the ERA on the proposed development on the former Institute of Tourism Studies site said, adding that “the risk of subsidence on the large subterranean cavern at Ħarq Ħammiem is currently unclear”.

According to a project development statement presented by the developers, plans have already been modified to protect the caves by pushing the hotel more to the east, with the western wing of the original proposal completely removed, in order to avoid “imposing excessive loading in the area of Għar Ħarq Ħammiem”, which is located on the western part of the site.

The original draft of the North Harbour Local Plan, published in 1999, had identified the Moynihan House area in St George’s Bay as a site for a car park. This was to be incorporated in commercial and residential facilities.

But the project was abandoned following a detailed study of the nearby cave, which was commissioned by the Planning Authority and revealed that it was far larger than originally thought.

The cave was found to open up and the water in it reached a depth of 52 metres below sea level. The surface of the water was found to be at a depth of 16 metres below sea level.