Guest Columnist
John Richard Schrock
Hong Kong’s Answer to California's Droughts and Floods
This year began with much of California suffering massive rainfall. “Atmospheric rivers” drove intense storms. With 71 percent of California having experienced prolonged severe drought, three desperately dry years and the driest period in the last 1,200 years, disastrous flooding now washed from Western mountain slopes across housing and into the ocean. Levees burst. Hillsides collapsed.
A significant number of California’s coastal population derive from early immigrants from Hong Kong. So I would have expected that some of the discussion of how to plan for California’s future would have reflected Hong Kong’s long history in water management—probably the most successful on earth. Having lived in then-British Hong Kong in 1975-78, I witnessed it first hand.
Hong Kong has a crowded population. It grew from 1.7 million in 1945 to over 7.4 million today. But it is smaller than many U.S. counties. It is made up of a short mountain range peninsula and an array of islands including the main Hong Kong Island. A hard granite base pretty much excludes drilling for water. The China mainland has maintained a pipeline that provides freshwater. But it is nowhere enough for the population stacked in Hong Kong’s high rise buildings.
Halfway down the mountains are water catchments that catch the runoff from rain. During the seasonal monsoon, this channels runoff along the mountainside and then into catchment lakes. It also washes many snakes down the mountain and into the catchments where they enjoyed eating the frogs. So as a biology teacher, I would take my students there to go snake hunting at night.
Hong Kong is constantly building. Early on, they began delivering freshwater through one pipe system, and saltwater to flush toilets through a separate system. Because there was never a hard freeze in Hong Kong, the pipes could run along the outside of buildings.
During my time in Hong Kong, they built and ran a large desalination plant in Lok On Pai. But the cost of energy was too great and it ceased operating in 1981. It was cheaper to expand a pipeline to freshwater reservoirs upriver off the Pearl River.
One strategy that I have not yet heard mentioned for California is the building of freshwater reservoirs out into the ocean by joining together offshore islands. This allows the massive runoff that can occur in a short time to be captured and held before it would otherwise flow into and mix with the seawater.
In 1957, Hong Kong began building a dam out to outlying islands to form a freshwater bay. This was the Shek Pik Reservoir and it was completed in 1963. A second Plover Cove Reservoir was built and completed in 1968. This proved adequate for Hong Kong needs until the monsoon rains failed in 1977, a time I remember quite well. Yet, water rationing was fair. Their final major project was the High Island Reservoir completed in 1978.
In mainland China, when there is a shortage of electricity due to sustained hot summer weather and everyone is running air conditioners, the governmental policy is to increase industrial charges for electricity in order to reduce demand. However, in Hong Kong, when there were shortages in water, it was the citizens who had limited hours to draw water. In Hong Kong, the industrial base always took its full supply of water and was never rationed.
Generally, in China you do not drink water from the tap. It has been difficult for China to establish sewage treatment or large scale drinking water purification, although modern cities such as Dalian are working toward that goal. Drinking water is usually bottled or otherwise distributed. But while at a hotel in Hohhot, Inner Mongolia, there was a second gold-colored tap for drinking water from-the-tap. It remains a goal, a benefit that Americans rarely think about.
So, California has a growing dilemma on its hands: how to secure enough fresh water for its population when over time, the supply is continuing to shrink? Got any offshore islands that could be joined together? It will take time. And the expertise is just across the ocean in Hong Kong.