Nature Trust (Malta) has questioned whether dredging works in Wied tal-Grazzja, Marsalforn, are covered by the right permit and whether they are being monitored by the planning authority.

It must be ensured that any protected species will not be affected, the NGO said, adding that the use of heavy machinery could cause irreversible damage to the valley’s ecosystem.

A study had revealed a number of rare species in Wied tal-Grazzja and this alone, Nature Trust said, showed heavy machinery should not be used to clean the valley. While encouraging the harvesting of rainwater, any such measures had to ensure biodiversity was safeguarded.