Where does the Macau water come from

11 August 2017

In end-2016, Macau’s total population was 644,900 and annual water consumption hit 86.70 million cubic meters. The number had been steadily rising.

“Over the past decade, Macau’s population has increased by nearly 26 percent and water consumption has increased by 44 percent, with the [Taipa and Coloane] islands seeing the most significant growth in water consumption,” says Oscar Chu, Deputy General Manager of the Macao Water Supply Company (Macao Water) to Macaunews.

To understand the journey of Macau’s water supplies, we have to go right back to the beginning.

Prior to 1924, when the first public reservoir – Crocodile Reservoir – was built in Guia Hill in the Macau peninsula, access to water supplies were limited to wells and rain water.

In 1935, Macao Water Supply Company was set up and the company signed a 60-year concession contract with the then Portuguese-Macau government. In 2009, the Macau SAR government granted Macao Water an extended concession to provide the water supply service for the city.

The contract remains valid for 20 years until 2030. It has undergone several restructures, but today Macao Water is still the only water supply company in Macau, responsible for the treatment and delivery of drinking water for the city.

Macau’s water system continued to develop from there. In 1936, the Ilha Verde Water Treatment Plant was built, using new treatment technologies and chlorine for disinfection.

The Main Storage Reservoir on Rua dos Pescadores was established in 1938. At the time, this reservoir was sufficient for water consumption of the entire city for three months.

In 1959 Macau suffered from a freshwater shortage. Following months of water rationing, the Guangdong Province government responded to requests from Macau’s communities to construct reservoirs in Zhuhai to help satisfy needs. This led to the construction of the Lapa Reservoirs and the Yinkeng Reservoirs, which were completed in 1960 and supplied water to Macau for free.

In 1966, Macau began buying raw water supplies from Zhuhai due to the increasing population and water demand. And in 1985, as a solution to the issue of lack of raw water supplies, Macau and Zhuhai began to use the Modaomen waterway in the West River as a source.

Water supply projects with the Guangdong government, such as the Zhuyin Reservoir, Datengxia Hydro Project, etc have ensured the long-term stability and safety of water supply in Macau and Zhuhai. Macau’s practice of buying water from Zhuhai continues to the present day.

“Because of Macau’s lack of raw water supplies and watersheds, as well as due to its inability to build large reservoirs, the mainland is a major water supplier for Macau,” Chu explains. “At present, more than 95 percent of raw water needs to be brought in from Zhuhai.”

Around 97,000 cubic metres of water were purchased in Zhuhai last year, according to data from Macao Water’s 2016 annual report. “We purchase raw water based on the water demand in Macau,” Chu adds.

Raw water supplies that serve Macau today mainly come from Xi Jiang or West River, with over 90 percent coming from the Modaomen Channel. The raw water is pumped from the Hong Wan Pumping Station to the Lapa Storage Reservoir, then delivered to treatment plants in Macau through three raw water pipes.

Zhuhai has a comprehensive raw water supplies system. Lapa Reservoir was completed in 1960 with a capacity of 2.4 million cubic metres, it has been the major water source of Macau since.

Zhuyin Reservoir was completed in 2011 and Macau is entitled to a 40 percent usage of the water from Zhuyin, which amounts to 16.05 million cubic metres of water. Zhuyin Reservoir is very important during salinity seasons since it is treated as the transfer system which is capable of ensuring the water supply safety in both Macau and the eastern part of Zhuhai.

From here, raw water is fed into the IIha Verde and the Main Storage Reservoir Water Treatment Plants. They’re then stored in the Main Storage Reservoir.

Around 95% of the water consumed in Macau comes through pipelines from mainland China.

After this the water is treated in three separate plants in Macau.

The plant at Ilha Verde is capable of producing 180,000 cubic metres daily.

The Main Water Reservoir Water Treatment Plant, which consists of three parts, produces 180,000 cubic metres a day.

The Coloane Water Treatment Plant, which came into operation in 2007, produces 30,000 cubic metres a day.

The total daily production capacity has been increased from 85,000 cubic metres in 1985 to 390,000 cubic metres at present.

“Once raw water enters water treatment plants, it goes through the water treatment process with advanced techniques,” explains Chu. These include coagulation and flocculation, a technique that enhances the removal of particles during the water treatment process; followed by sedimentation, plus filtration and disinfection. “Finally, the treated water is pumped into the water supply network for distribution.”

Final destination

After the treatment processes, water is pumped into the water supply network in Macau for distribution.

Water is supplied to buildings in Macau either directly, or indirectly. Direct water supply refers to an internal water supply pipeline inside a building being connected to the public water supply network; meaning water goes directly to the consumer through taps. This is typically found in buildings with a low floor count.

On the other hand, an indirect water supply usually indicates that building has a system in which water is stored and pressurised before being supplied to consumers within – and this is often found in high-rise buildings.

Some water systems in buildings in Macau feature storage tanks either placed underground or on the rooftop, as well as pipes, valves, and equipment for the water pressurising process.

The future

Macau has huge demands for water – and consumption levels are expected to rise still.

“We expect that the overall water demand would continue to increase gradually in the next two to three years at 2 to 4 percent annually,” Chu says. “With the upcoming development of the new reclamation areas, the Hong Kong–Zhuhai–Macau Bridge and various large-scale public and entertainment facilities in the [Taipa and Coloane] islands, the demand for water in that area will inevitably surge.”

Macao Water is actively preparing for rising demand, ensuring water infrastructures are readily available.

A fourth water treatment plant is in the works in Seac Pai Van, whereas the raw water source for the new water treatment plant will mainly come from the fourth raw water pipeline which will be built jointly by the Macau government and the Guangdong Province.

The construction work is expected to be completed and commissioned by the end of 2019. Upon completion, the new water treatment facilities will be able to provide a daily production capacity of 130,000 cubic meters of water.

Macau’s total daily water supply will increase to 520,000 cubic meters meeting the city’s development and water demand for the next ten years. (Macauhub)