Dike Renovation, Taijang National Park, Tainan, Taiwan

Taijang National Park was established in 1999 in Tainan, Taiwan. It is the eighth national park in Taiwan with special aims to protect the local wetlands biodiversity, preserve the history of immigrant settlement, and promote the cultural features of the salt and fishing industries. To complete such missions, many existing dikes needed to be repaired or renovated. The project described herein was for the renovation of an abandoned fishpond so that it could be reinstated as a water park for visitor recreation and fishing.

Tainan City government required the renovation to be a sustainable solution to meet the needs of aesthetic appearance, eco-friendliness and a water-accessible environment. The dikes should be erosion free so that it stands safely without being damaged by the water.

The conventional solution to renovate the dikes is to rebuild a concrete-faced earth dikes. Such construction method is relatively straightforward; however, the concrete surfaces will be vulnerable to cracks over time. It is neither cost effective, eco-friendly, nor aesthetic. The better solution is to reshape existed earth dikes and protect their surface with sandbags provided by ACE Geosynthetics. To protect the levee below the water level from erosion and scour, a pedestal of about 50cm in square was used along the toe of the levee and cemented bricks were used for as facings of dikes. Then, the sandbags in-filled with in situ soils were stacked for the levee surface above the water level. Besides, one new levee was added to connect original dikes. It was formed by a wrap-around mechanically stabilized earth (MSE) containing ACEGrid^® GG geogrid, sandbags, and soils.

These dikes nowadays function well with greenery appearance. Such design is really beneficial for local ecological development, made for an enhanced epiphytic plant environment in this area and promoted more biodiversity in Taijang National Park.