Sun Moon Lake—The Heart of Taiwan

Encircled by mountains, Sun Moon Lake is located in the geographic center of Taiwan, in the Nan­tou County township of Yu­chi. In the middle sits an island, named “Lalu Island” by the local Thao Aboriginal tribe. The lake gets its name from its shape—the north side is shaped like the sun, while to the south, it forms a crescent shape.

Orogenesis, the process of mountain formation, doesn’t lift all of the land uniformly, though—it also causes some areas to be lowered. As the land in the area that would become home to Sun Moon Lake was elevated, it was also pulled apart, and part of it sank to create an enclosed basin, surrounded by soaring mountains, where rainwater gathered to form the lake.

Sun Moon Lake sits at an altitude of 748 meters above sea level and covers some 8.2 square kilometers. It is Taiwan’s largest lake, and the only remaining orogenetically formed high-altitude lake of its type in Taiwan.

Sun Moon Lake’s pairing of brilliant waters and spectacular mountains has helped give it a lasting reputation for beauty.

The name “Sun Moon Lake” first appears in the 1821 Chinese travelogue Diary of Travels to Shuilishe: “Waters springing I know not whence collected to form this lake. It is several dozen li long and a third as wide. Its waters are colored cinnabar and turquoise, and it is named ‘Sun Moon Lake.’” Both for its fanciful name and its brilliant waters, Sun Moon Lake has been lauded as Taiwan’s most beautiful alpine lake.

Since ancient times, Sun Moon Lake has been home to the Thao tribe. Legend tells of a far-off time when the Thao ancestors saw a large white deer and pursued it along a river to the edge of the lake; astonished by the beauty of the lake that they had happened upon, they decided to settle in this seemingly god-given land. Long years afterward in the Qing Dynasty, when the Chinese arrived in Taiwan and set to developing the land, the Thao settlement was gradually overcome by the newcomers moving in, with the Aboriginal inhabitants pushed off to scattered villages along the lakefront.

Even bigger changes hit the area with the late-19th century Japanese occupation of Taiwan.

According to local history buff Deng Xiang­yang’s book The Heart of Taiwan, in 1919 Taiwan Den­ryoku Ka­bu­shiki Kai­sha (the predecessor to the modern Taiwan Power Company) chose Sun Moon Lake to be home to a hydroelectric power dam. Technician Na­ga­shige Ku­ni­hiro spent nine months in Europe and America studying similar dams, announcing on his return to Taiwan that the US’s largest dam at the time generated some 220 megawatts, and that if Taiwan could “use Sun Moon Lake to create a dam with a generating power of 180,000 horsepower,” the resulting 100 MW dam would leave the hydroelectric power industry in awe of how an island so small could generate so much power.

High-class hotels and restaurants have sprung up around the banks of Sun Moon Lake, and the recently completed cable car system has made it even easier to enjoy the spectacular scenery.

The Zhuo­shui River, which cuts its way through the Central Mountain Range, is Taiwan’s longest river, and also receives an average of 2,442 millimeters of rainwater a year. Hoping to make use of this wealth of water, Taiwan Den­ryoku constructed sluices to feed water from the upper reaches of the Zhuo­shui into Sun Moon Lake, preparing for construction of their hydro dam.

However, due to the vast scale of the project and the difficulty of rerouting the water, accidents were frequent. This was further compounded by the poor post-World-War-I economy, which put the expensive project in dire straits. Progress slowed to a crawl, and the work eventually ended up taking some 15 years, employing thousands of laborers, and being overseen by ten different governors-general. Over the course of construction, hundreds of technicians and engineers were dispatched from Japan to observe the work, all of whom were impressed by the magnitude of this project.

As a result, Sun Moon Lake grew in surface area from 4.5 square kilometers to 7.7 square kilometers, with the water level rising 18 meters. Most of Lalu Island was submerged and the face of the lake was forever changed, with even the “Sun” and “Moon” forms that gave rise to the name no longer as obvious as they once were.

As demand for electricity grew, steps were taken to harness Sun Moon Lake further, with Taiwan Power Company setting about constructing two pumped-storage hydroelectric plants on the western bank of the lake in the 1980s.

These plants use Sun Moon Lake as their upper reservoir­, with a dam across the Shuili River creating the lower reservoir, and the height difference between the two is used to drive water through the turbines that generate the electricity. The Ming­tan Pumped Storage Plant was completed in 1995, generating over 1600 MW of electricity thanks to the 380 m drop; not only does this plant generate more power than the Jin­shan Nuclear Power Plant, it is also the largest pumped-storage plant in Southeast Asia.

The cycle track that rings Sun Moon Lake was named one of ten “cycling routes that’ll take your breath away” by CNN, and is the very picture of mankind and nature living in harmony.

“With the completion of the pumped-storage plants, Sun Moon Lake actually became even more beautiful,” says Deng. In the past, whenever there was a drought the water levels would plummet and visitors would leave disappointed. Now the water level is much more stable, and you can actually sail through the picturesque scenery.

However, while the power plants have made the lake more beautiful, they have also done significant damage to the historic lands of the Thao.

“With their sacrifice, the Thao people helped change the path of Taiwan’s economic development completely,” says Deng. The hydroelectric engineering projects that took place at Sun Moon Lake facilitated the resource-intensive industries that created Taiwan’s miraculous economic growth, like aluminum smelting, steelmaking, and cement manufacturing. However, the risen lakewaters submerged the Thao’s legendary settlement and lands. The Japanese moved them to ­Tokka Village (later De­hua Village, now Ri­yue Village), giving each person just 0.2 hectares of land, after which the Thao population entered a gradual decline.

Since the 19th century Sun Moon Lake has been an inspiration to the literati. During the Japanese occupation, it was even honored as “the East’s number one” reservoir and became a world-renowned tourist destination.

In 1916, one Japanese resident constructed a spectacular mansion on the lakefront, which even remained standing unscathed after a massive earthquake razed many other buildings in the area the following year. With the completion of the reservoir, the mansion was submerged, but the Japanese authorities set to reconstructing it on its current site to play host to VIPs.

As Deng explains, ­Chiang Kai-shek converted the building to a temporary residence after his arrival in Taiwan, frequently hosting important guests there. The round-the-lake highway, Ci En Pagoda and other such facilities in the area were considered testaments to ­Chiang’s leadership, as well as further reinforcing Sun Moon Lake’s popularity.

A few years ago word spread that Sun Moon Lake was suffering serious silting problems. Many were worried that this could lead to the effective destruction of their beloved lake.

In fact, the Japanese were aware of the inevitability of this problem as far back as 1934, when after construction work was complete, experts estimated that with the rate of silting happening then, Sun Moon Lake would likely only have another century left. In other words, by their estimates, in just 20 years from today Sun Moon Lake’s silting problem may have become so severe that the lake can no longer store water.

“Time might be running out even faster for Sun Moon Lake, though,” says Deng. With large-scale agriculture going on upstream along the Zhuo­shui River leading to faster than expected soil erosion, the area around the outflow from Sun Moon Lake is becoming heavily silted, even creating sandbars. Boats are now forbidden to approach it, for fear of their getting beached.

According to Taiwan Power Company estimates, silt is now accumulating at the bottom of Sun Moon Lake at a rate of four centimeters per year. In order to prolong the lake’s life, efforts are already underway to create settling ponds along the sluices, in hopes of reducing the amount of silt that makes it into the lake. At the same time, plans are being developed to create a bypass tunnel that can channel the silt from the lake into the Zhuo­shui River. However, this would be a difficult project, and one that requires further investigation.

Regardless what is done, something must be done to save Sun Moon Lake.

Of the sites named among Taiwan’s Top Ten Landscapes, only Sun Moon Lake has been man-modified through civil engineering, and this only makes it more intriguing. However, the recognition of the lake’s spectacle is not the worship of man’s power over nature, but rather an encouragement for us to understand the lake better and find a way for mankind and Sun Moon Lake to coexist.