'Water drainage may be behind Tai Tam landslide'
A former head of the government's Geotechnical Engineering Office (GEO) on Monday said water draining from a pipe next to homes at Tai Tam's Redhill Peninsula could be responsible for a serious landslide there last week. The Buildings Department said earlier that unauthorised work had taken place at a house left in "immediate danger" by the landslide, while officials were seeking a court warrant to enter another property after they were refused entry.  Two neighbours were also told to temporarily close off their gardens and outdoor swimming pools pending further checks. The authorities have not said whether they think unauthorised works could have led to the landslide.  Former GEO chief Raymond Chan told an RTHK programme that water draining from a pipe could have played a role. "If you look at the aerial photos, you can see water continuously draining from a pipe, and there were at least four signs of water leakage on the top of the slope. If this type of leakage persists, it can increase the water content in the lower layers of the slope and easily trigger landslides," he said. Chan said there are strict rules regarding slope maintenance, including leak prevention and repair work, but these may not have been followed.  "Whether it's lawful construction or not, our industry and the government are actually very concerned about any work done on the top of the slope, including excavation projects, water pipe projects, swimming pools and other water facilities," he said.