The Geotechnical Engineering Office (GEO) is responsible for carrying out an initial investigation of both Government and private man-made slopes and retaining walls which were formed before the GEO was established and could pose a risk to life or property. The GEO also carries out some major slope upgrading works on behalf of other Government departments.

Since 1976, about $13.3 billion (as of 1 February 2010) has been spent on studies and upgrading works in respect of old (i.e. pre-GEO) substandard slopes under a long-term programme, i.e. the Landslip Preventive Measures (LPM) Programme. This Programme is managed by the Landslip Preventive Measures Branch of the GEO. The LPM Programme provides for the investigation, in a risk-based priority order, of man-made slopes in existence when the Geotechnical Control Office (renamed GEO in 1991) was set up in 1977.

As part of the implementation of the recommendations of the Slope Safety Review undertaken by the then Works Bureau, which were endorsed by the Executive Council in February 1995, the GEO received increased resources to accelerate the LPM Programme. The target is to complete the investigation and the necessary upgrading works on 800 high-priority substandard Government man-made slopes registered in the 1977/78 Catalogue of Slopes over a five-year period commencing on 1 April 1995 through an increase in the number of in-house staff and engagement of more consultants. Slopes identified in the New Catalogue of Slopes as posing an immediate and obvious danger are also investigated and upgraded under the LPM Programme.

As a result of the acceleration of the LPM Programme since 1 April 1995, the output of detailed slope stability studies and slope upgrading works by the GEO has increased significantly. The acceleration of the LPM Programme was originally arranged as a 5-year project. As part of Government's commitment to improving slope safety and its long-term strategy for upgrading and maintaining slope features in the New Catalogue of Slopes, the Project has been extended for another 10 years. This 10-year (2000-2010) Extended LPM Project will deal with high-priority substandard man-made slopes in the New Catalogue of Slopes. The target pledged to ExCo and LegCo in 1998 is to complete the upgrading works for another 2,500 high-priority substandard Government man-made slopes and undertake safety-screening studies for another 3,000 high-priority private man-made slopes by the year 2010. As before, consultants will be engaged in addition to deployment of in-house staff resources to implement the 10-year Extended LPM Project.

It is Government policy to make man-made slopes look as natural as possible to reduce their visual impact and improve the environment. Hence, apart from maintaining the highest standard of slope safety, the GEO is committed to enhancing the appearance of man-made slopes by including this objective as one of the key result areas of the slope safety management system. To pursue this objective, all slopes upgraded under the LPM Programme are provided with landscape treatments and, wherever possible, vegetation is used as slope surface cover and existing vegetation is preserved. A hard surface cover is used only as a last resort on slope safety grounds and as emergency repairs to landslide scars. Where the use of a hard surface cover is unavoidable, landscape measures are implemented to minimize its visual impact as far as practicable. A number of technical guidelines on good practice in slope landscaping works have been published by the GEO. The most comprehensive guidance document is GEO Publication No. 1/2000 - Technical Guidelines on Landscape Treatment and Bioengineering for Man-made Slopes and Retaining Walls. To improve the technology in greening slopes, the GEO has been researching into the use of vegetation in slope works and experimenting with new techniques of providing erosion control measures and vegetation covers to steep slopes. The results of the research provide useful knowledge for establishing robust, cost-effective and eco-friendly vegetation covers for man-made slopes.