Optimizing power facilities in low-lying areas

Customers’ Flood Control Measures

To enhance the reliability and stability of the power transmission and distribution system, CEM regularly maintains and repairs the power supply system, including substations, medium-voltage network, low-voltage network, and the parts that connect to the handover points at customer premises or offices/factories, such as the public power distribution networks and associated power supply facilities. CEM also examines the customers’ building communal electrical installations at any time when necessary.


Customer substation

Power transmission and distribution network

Meter and circuit breaker (no higher than 34.5kVA)


Customer substation

Power transmission and distribution network

Meter and circuit breaker (no higher than 34.5kVA)


The Revision of “Technical specifications for new building’s electrical installations in low-lying area”


In order to enhance the disaster prevention and resilience of new buildings in low-lying areas, CEM completed the revision of “Technical specifications for new building’s electrical installations in low-lying area” in September 2018 after communicating and coordinating with relevant departments. Electrical installations in new buildings, including transformers, main switchboards and meter boxes, etc., must be installed above the flood protection level set by Macau SAR Government in order to minimize the impact of flooding on such installations. In addition, CEM plans to relocate some of the customer substations at Porto Interior to higher locations. Apart from solving the flooding issues in the long run, it can also improve power capacity for the old districts.

Customers’ Responsibility

Regarding the existing buildings, customers’ communal electrical installations (as shown below) in buildings are jointly owned by the property owners and are generally installed on the ground floor at the building entrance. If customers do not raise such electrical installations accordingly, the power supply will still be affected by floods.

To reduce the impact of flooding in the long run and achieve the best flood control effect, apart from enhancing and raising CEM’s power facilities, property owners can also hire experienced electrical contractors to raise up the communal electrical installations in buildings in accordance with the above-mentioned “Technical specifications for new building’s electrical installations in low-lying area”. This will improve the overall disaster prevention capability and resilience.

Main Low Voltage Switchboard

Distribution Circuit Breaker

Collective Line Distribution Board

Building Main LV Circuit Breaker

Meter Board



How to raise electrical installations in your building?


Citizens or building owners who intend to raise their building’s power supply equipment, such as raising electrical installations at the ground floor to a higher position, will be determined according to the actual situation. Customers can hire an experienced electrical contractor and submit the related project application to CEM. We will assess and provide technical support for the design and installation of the related projects.

Customers can submit the application by sending email to customer.centre@cem-macau.com.

For inquiries about disaster prevention related to electricity, please call: 2833 9911

If you need to find an electrical contractor, please contact the electrical technician in the “Electrical Contractor List” to consult and learn about project details and related services provided by them.


Generally speaking, the scope of work regarding raising meters and communal electrical installations above the flood protection level includes the following:

  1. Ensure the flood protection level is above +4.21msl
  2. Raise the installation level through checking site conditions, while taking existing building limitations into account but without affecting operational and safety requirements
  3. Provide individual design for approval, and indicate:
    i) The location of main collective panel;
    ii) Power cables between pothead and main collective panel or main collective panel and CCL (including necessary civil works) that may need to be reinstalled
  4. During the upgrade period of main collective panel, CEM can provide temporary power supply under customers’ request
  5. Ensure that the power cable connected to inlet is waterproof, which can further enhance waterproof performance




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