Hong Kong’s beach authorities today vowed to investigate storm drainage systems after raging waters triggered by recent thunderstorms carved off large slices of beach in Shek O and Lamma Island.

Sand was washed away in the western part of Shek O beach and the northeast part of Hung Shing Yeh beach on Lamma. Trees’ roots were exposed and picnic tables were overturned by the heavy currents at Hung Shing Yeh as rains lashed the city for days.

“[We] will level the affected area with sand from within the beaches as far as possible,” the LCSD said, adding that much of the lost sand would be naturally and gradually replenished by tides and currents.