The Wading Line System will be set up at Chai Wan Road, Lung Cheung Road in Wong Tai Sin, Tsui Ping Road in Kwun Tong, Chatham Road North in Ho Man Tin and Nam Wan Road in Tai Po Market.
These five low-lying road sections were heavily flooded during what were described as “once-in-500-years” deluges in September 2023, officials said.
The system comes with red wavy lines painted on roads, water level markers and real-time monitoring equipment.
Drainage officials will also install flood-monitoring devices at the lowest points of the road sections to collect real-time water level data.
When the water level reaches 0.1 metres, staff from the Drainage Services and Highways departments will be deployed to clear blocked drains.
Traffic will be diverted on site when the water level reaches 0.3 metres.
If water rises above this level, it can seriously damage vehicles.
When officials get a flood warning, they will send teams to the site within 15 to 30 minutes.
With installation work starting in late April and expected to be completed by mid-May, the five pilot projects cost around HK$700,000, a government spokesperson said.
Officials will examine the scheme’s effectiveness before deciding on the next step.
