A notorious slope in the foothills of Castle Peak, scene of Hong Kong's largest landslide, has been made safe 12 years after the incident. The slope, covering 18 hectares near Butterfly Estate in Tuen Mun, has troubled government engineers for the past 20 years because of its loose soil and rock structure. In 1990 more than 20,000 cubic metres of debris and mud fell away from the slope in the biggest landslide in the SAR. Nobody was killed. Chief engineer of the Territory Development Department, Chu Kin-hong, said the site was first targeted for development in 1978. But when a survey was carried out engineers realised the hazard the slope posed and banned development there. Zonings for the area previously included residential and stadium developments. The slope now has been stabilised and cut flatter, with 17km of trench drains laid underneath to channel away underground water. A build-up of underground water usually leads to landslides, as in the case of the Shekkipmei landslip in August, 1999, which forced the evacuation of 700 residents from a public estate. In a visit to the site, Mr Chu also highlighted a bypass road built to divert heavy vehicles from Lung Mun Road. The new 2.6km dual two-lane Lung Fu Road, which opened last month, connects Wong Chu Road with the river trade terminal in Tuen Mun west. Heavy vehicles had jammed Lung Mun Road, causing a nuisance to residents in Tuen Mun West. The department also had built a barrier in Wong Chu Road to minimise noise pollution to residents, Mr Chu said. The three projects combined cost taxpayers $900 million.