River of ruin
Highway 18 is lined with alternating trees and shrubs. The shrubs are stocky with bright red and yellow leaves at the top, and the trees are taller, deep green and punctuated with pink blossoms. It's a gaily outfitted parade that never moves, but looking at it through the window of a car moving 70kph, it's a five-alarm fire of blurry color.
Chances are that if you're driving this route you're heading for Alishan. It's the nation's highest-profile tourist attraction and those pink and red trees and shrubs were put there by the Taiwan Forestry Bureau to make it all the more high-profile. With so much color on the roadside and the excitement of a trip to a sacred mountain, you can be forgiven for not noticing the bureau's more formidable project: Naoliao Creek.
The creek is an eyesore. Most days it hasn't but a trickle of water in a bed banked by a chasm of boulders dozens of meters across. But a closer look at those boulders shows that Naoliao isn't always just a trickle. During typhoon season, the creek can quickly become a torrent of water rushing down the mountain -- often taking the mountain with it.
"Naoliao Creek is considered Chiayi County's priority-one landslide area," said Yeh Shang-liang (葉賢良), the director of the Forestry Bureau's Chiayi district office. He explained that, during the giant quake of September 1999, 53 hectares of forested mountain area in the Naoliao Creek watershed slid into the creek itself. That was followed by a series of typhoons -- Nari, Toraji, Aere, Mindulle and a dozen others -- that caused further landslides and compromised soil structure in the steeply graded area.
"The real hazard of soil erosion isn't the loss of land." Yeh said, "It' s the tainting of a water source used for drinking."
The problem predates the 1999 earthquake. Since 1984 the Naoliao Creek watershed has been the site of 72 projects designed to retain soil either by planting trees -- the roots of which reinforce the soil structure -- or restructuring riverbeds to prevent flooding. More than half those projects have been undertaken in the past five years.
All told, the projects have carried a price tag of NT$238 million, a small price to pay compared with the NT$700 million in damage to forests and agriculture caused by typhoon Toraji in 2001.
The lion's share of that sum went to taming Naoliao Creek. The creek drops more than 1,000m over 5.4km from an altitude of 1,380m above sea level to just 310m above sea level. The site of the most construction is in the creek's final stretches, where the terrain flattens out and flooding has previously caused the most damage. Here the banks of the creek have been lined with boulders stacked one by one to create 4m-high walls. At one particularly tight bend in the creek the walls reach more than twice that height.
The scale of the project is hard to fathom. Seeing it is believing and the Forestry Bureau has accommodated this by laying a path of flat stones on the highest bank to serve as a walkway. It leads to an area several hectares in size where the bureau has planted hundreds of saplings, now just knee-high, that will one day be a forest of ficus and a tourist attraction worthy of the route to Alishan.
Yunlin wood to Alishan doth come
Further back on Highway 18, about 15km from where it branches off of Highway 1, the trees come up much faster. The area, 2 hectares, is currently a field of dirt, but in a matter of months it will be a full-grown forest. No, they aren't "Frankentrees" or the product of biotechnology, but are from a different type of industry. This is Taiwan's first "Tree Bank" -- a kind of fiduciary forest -- and an investment the Forestry Bureau hopes to profit from in subtle ways.