The Government announced today that it will launch the Pilot Scheme on Wading Line System at five low-lying road sections with a higher flooding risk to tackle flooding as early as possible and alert drivers on the road ahead, thereby reducing the possibility of vehicles stalling due to water damage.

The system is being introduced in view of the increasing likelihood of flooding at low-lying road sections caused by heavy rain under extreme weather. Five pilot road sections have been selected as they experienced serious flooding in September 2023, causing damage to vehicles and rendering them inoperable.

The road sections are at Chai Wan Road, Lung Cheung Road, Tsui Ping Road, Chatham Road North and Nam Wan Road in Tai Po Market.

Traffic arrangements will be implemented in phases from later this month at the relevant road sections to facilitate the installation of the system's warning signs. The installation is expected to be completed in mid-May.

Under the system, warning signs will be placed at low-lying road sections, including a red wavy line and the words "Wading Line" painted on the road surface, with a water meter gauge placed next to it and a sign erected next to the carriageway.

When the water level has reached or submerged the wading line, it indicates the depth of the water at the lowest point of the road ahead has reached 0.3m or above.

The Drainage Services Department (DSD) will install water level sensors called Flood Monitoring Devices at the lowest point of the road sections to collect real-time water level data.

When the devices detect the water level on the road has reached the warning level, the monitoring system will immediately alert relevant government departments. The DSD and the Highways Department will promptly deploy emergency response teams to inspect and clear blocked drains to reduce the risk of flooding.

When the depth of the water has reached 0.3m, there will be temporary traffic guidance on-site to prevent vehicles from entering the flooded road sections. The Transport Department will disseminate information on traffic arrangements accordingly and Police will give assistance as necessary.

If vehicles have entered low-lying road sections before the temporary traffic guidance is in place, drivers should stop their vehicles before reaching the wading line and avoid entering the flooded area. They should also turn on their hazard warning lights and follow the on-site directions to leave the temporarily closed road sections.