Skip navigation

IAM clears and maintains sewers continuously before typhoon and rainy season to reduce the risk of flooding

IAM clears and maintains sewers continuously before typhoon and rainy season to reduce the risk of flooding

As the typhoon and rainy season is approaching, the Municipal Affairs Bureau (IAM) clears and maintains sewers continuously in various districts with a focus on stepping up inspections in areas susceptible to floods. The silt clearing work in multiple low-lying areas has been completed, and a total of over 200 tonnes of waste has been removed from public drains. IAM also continues to step up inspections of construction sites and food establishments and initiates prosecutions against violations of regulations. IAM appeals to the society to jointly protect the drainage networks to safeguard the normal operation of the drains.

IAM handles the areas susceptible to floods with priority. From January to March this year, IAM cleared 61,000 metres of sewers and unclogged catch basins for about 7,600 times, in addition to completion of records and analysis of CCTV footage of about 3,700 metres of sewers. During regular inspections and clearance of sewerage networks, solidified grease and cement grout are often found to obstruct the operation of sewers. This mainly involves food establishments which have not installed proper grease interceptors or have not cleared them regularly, causing the solidified grease to block the sewers, and illegal discharge of waste of construction sites, discharging untreated wastewater or construction waste to the public sewerage networks. IAM carries out operations continuously with relevant departments and has inspected the grease interceptors of food and beverage establishments for 243 times and 15 written records were issued to food establishments due to violations of the regulations. Meanwhile, inspections of the construction sites in various districts have been carried out for 202 times and 11 written records were issued.

Before the approach of typhoon and rainy season, IAM carries out inspections in low-lying areas and clears sewers, municipal pumping stations, rainwater catch pits, open channels and other facilities in various districts in advance. In addition, IAM follows up continuously the locations where flooding occurred previously, and increases the frequency of clearance work at the locations concerned. Upon the approach of a typhoon or rainstorm to Macao, the priority is given to inspections and clearance in low-lying areas susceptible to floods. If the Yellow Rainstorm Warning Signal or above is issued by the Macao Meteorological and Geophysical Bureau, IAM will activate the rainstorm emergency response team mechanism. Pumps will be turned on remotely for drainage of rainwater according to the real-time height of sea tides; staff will be sent to inspect the operation of rainwater pumping stations; pumps will be adjusted and controlled for speedy flood relief depending on the situations. When Tropical Cyclone Signal no. 8 or a rainstorm warning signal is issued, IAM will send staff to be stationed at all times at major drainage pumping stations. The outsourced emergency drain clearance personnel will assist in the inspection and emergency clearance work in various districts throughout Macao. After the typhoon, IAM will pool human and outsourced resources to focus on clearance of flooding sewers.

In view of the growing increase in the maintenance and management work of the sewerage networks, along with the issue of aging of the frontline drain clearance personnel, IAM has strengthened outsourced services and introduced technology, such as drain clearance robots for clearing box culvert drains, and utilisation of surveillance cameras (CCTV) in drains, to actively monitor the conditions of drains and increase the efficiency in management and control of the sewerage networks. IAM continuously improves the inspections, silt clearing, tracing and recording of drains, and strengthens random inspections and regulatory mechanism. IAM also continuously optimises and looks for suitable locations to build additional rainwater pumping stations so as to construct flood barriers along the shore to effectively reduce the risk of flooding.

IAM appeals to the public or businesses to refrain from pouring waste, grease and other substances to public drains in the streets. The sectors are required to step up clearing of grease interceptors and wastewater filtration equipment in construction sites. Cement grout and other construction waste or grease must not be discharged to the public sewers. The drainage networks should be protected with joint efforts, so as to avoid affecting the normal operation of catch basins and drains.

View gallery


All information on this site is based on the official language of the Macao Special Administrative Region. The English version is the translation from the Chinese originals and is provided for reference only. If you find that some of the contents do not have an English version, please refer to the Traditional Chinese or Portuguese versions.