Most of Macao's water comes from the West River's Modaomen Channel in the Zhuhai City.
Raw water, i.e. water before it is treated, is pumped from the Hong Wan Pumping Station to the Lapa Storage Reservoir in Zhuhai. Surplus water is stored in Shedikeng, Yinkeng and Nanping reservoirs for emergency and regulation of the salinity of water during the dry seasons.
Flowing from the Lapa Reservoir, at a high topographic level, water is carried by gravity through two one-meter-diameter pipes (capable of supplying up to 180,000 m3 per day) to Ilha Verde's and the Main Storage Reservoir's Treatment Plants in Macao, and stored in the Main Storage Reservoir.
To learn more: Modaomen raw water supply to Macao
General information
The Modaomen Raw Water Supply System is located in the Zhuhai City at the eastern side of West River. Its intake gate is located at Guadingjiao.
The whole system, which has a total length of 20 km from the Intake Gate at Guadingjiao to Ilha Verde Treatment Plant in Macao, originates at Hongwan West and stretches horizontally through Nanping and Wanzai districts to Lapa Reservoir, and then divided into two branches supplying water to Gongbei in Zhuhai and Ilha Verde Treatment Plant in Macao.
A system to prevent high salinity and breakdown...
During the dry season in winter and spring, the salinity of the water source occasionally exceeds the standard for drinking water. The water supply system is reliable, but guarantees against a hypothetical breakdown of the pumping station, the channels or the pipeline must be taken.
To face these eventualities, we have built storage reservoirs and used two water resources for salinity regulation as well as for enhanced safety and reserve in water supply.
This new system, with the two water resources, is comprised of four major parts:
Implementation of the new system
The new system, excluding the Nanping Reservoir Extension Project, involved excavating 700,000 m3 of soil and 150,000 m3 of gravel, using 25,000 m3 of concrete and laying 30,000 m3 of stone lining. The total investment was about RMB$30 million.
This project started at the beginning of January 1986. The raw water intake gate at Hongwan, which was the first part of the system, was put into operation in May 1988 and the second part at Guadingjiao was subsequently put into operation in early 1989.
It can now provide 220,000 m3 of raw water per day to Macao while during the rainy season, it can also supply 200,000 m3 of raw water to Gongbei.
Recent improvements
In the recent years, through the joint effort of Macao and Zhuhai, huge investment was made and many large projects were done, such as:
In 1991, investment was made jointly by both Macao and Zhuhai companies to shift the intake to another site situated 500 m upstream besides the main navigation route.
In 1993, investment was made by our company to lay a 2.6 km long pipeline of 1.2m diameter from Baishichong to Ilha Verde Treatment Plant for salinity dilution purposes in emergency cases. The daily supply capacity of this pipeline is 140,000 m3/d. The principal role of this pipeline is the linkage of raw water resources at Dajingshan Reservoir and Nanshawan Pumping Station of the north supply system with the south supply system of Modaomen. The realization of the linkage of these two systems of raw water supply considerably reinforced the security of water supply to Macao.
In 1994, investment was made through loan from Macao on extension works of Nanping Reservoir. The storage capacity of this reservoir is 5 millions m3. It is linked up with Lapa Reservoir through a 2.2-km long tunnel with a diameter of 2.2m.
By the end of 1998, a 2.681-km long pipeline of diameter 1.6-m from Nanshawan Pumping Station to Nanping Reservoir was completed. The pipeline connects the southern and the northern raw water supply systems, significantly increasing the opportunity to fill water in Nanping Reservoir during the salinity period in winter and spring so as to maintain satisfactory salinity level in the southern raw water system.
In May 2001, the Guangchang Pumping Station was built in Zhuhai to replace the Nanshawan Pumping Station in which the water quality is deteriorating in the recent years. High salinity period in Guangchang is shorter than that in Guadingjiao where is located at downstream 2.5 km away from Guangchang. Therefore the Guangchang Pumping Station can improve the anti-satinity capability of Zhuhai and Macau in the dry season every year.
From March 2002 till March 2003, the Dam of the Lapa Reservoir was consolidated and enlarged; the capacity of the Lapa Reservoir was enlarged to 2.45 million cubic meters.
Form April to August 2004, Zhuhai started the project of enlargement of the Shedikeng Reservoir. There is totally 200,000 cubic meters increase in the capacity.
From August to September 2004, a project of removal of sludge from Tanzhou Inner River was commenced. The process was to remove 15,500 tons of sludge in the river channel, so as to increase the flow rate to the Hongwan pumping station.
