The lack of maintenance of slopes and retaining walls is a major contributory factor to many landslides in Hong Kong. Standards for the maintenance of slopes were given in the Geotechnical Manual for Slopes (2nd Edition, 1984) and in the Geoguide 5: Guide to Slope Maintenance (3rd Edition, 2003). This Geoguide, which is a consensus document, presents the recommended standards of good practice for the maintenance of man-made slopes and retaining walls in both the private and public sectors.

    
Routine Maintenance Inspection

The prime purpose of Routine Maintenance Inspections is to establish the need for basic maintenance works. Such inspections can be carried out by a layman, including property management or maintenance staff.

Routine Maintenance Inspections should be carried out at least once every year. Any required maintenance works should be completed before the onset of the wet season in April. In addition, owners should arrange to inspect the drainage channels and clear any blockage before and after a heavy rainstorm or a typhoon. 

Routine slope maintenance works can be carried out by a building contractor. A list of contractors is available for inspection at District Offices and the Buildings Department.

 
   
Engineer Inspection for Maintenance

Although proper routine maintenance of a slope can greatly reduce the probability of landslip, the slope may still not be sufficiently safe because of various reasons such as inherent design or construction deficiencies, inadequate maintenance or changes that have taken place in the vicinity.

Owners should engage a qualified Geotechnical Engineer to look for these slope safety problems. The Engineer will advise the owners on how to maintain the slope and on the need for a stability assessment and any required improvement works. The recommended maintenance works and any required stability assessment and improvement works should be carried out as soon as possible. Engineer Inspection should be carried out at least once every five years.

A list of Registered Professional Engineers (Geotechnical) can be obtained from this website. You may also call our Slope Safety Hotline to obtain a fax copy of the "List of Registered Professional Engineers (Geotechnical)".

  
  
Regular Monitoring of Special Measures

Regular Monitoring of Special Measures are only necessary in fairly rare circumstances. Such requirements are normally established by the designer. Regular Monitoring of Special Measures need to be carried out by specialist firms. These should be conducted at the recommended frequency, or more frequently as required. Any works identified by the inspections should be carried out as soon as possible.