Innovation

• To ensure a stable agricultural water supply, we adjusted three water intake weirs and eleven ground sills using eco-friendly construction methods. This adjustment removed barriers to the longitudinal movement of aquatic organisms in the stream and improved the longitudinal slope of the riverbed, balancing agricultural water intake, river safety, and ecological sustainability.
• Utilization of Subsurface Water: By removing existing weir structures and using coiled stainless steel collection pipes to extract subsurface water beneath the riverbed, we minimized ecological impact and ensured water availability during both high and low water periods.
• Weir-less Water Intake: By removing existing weir structures and constructing riverbed frameworks using stone ground sills, we utilized upstream natural pools for water intake, maintaining stable water depths even during low water periods.
• Full-Section Fishway: By partially removing existing weir structures and creating a series of stepped deep pool units with dry stone masonry, the weir structures can also serve as habitats for aquatic organisms in addition to their water intake function.
• Ecological Water Canal: By improving existing concrete canals using dry stone masonry pitching, and creating a seepage barrier with clay and non-woven fabric at the canal bottom, we developed a porous ecological environment. Additionally, we installed gently sloped biological corridors, enabling the canal to function for water conveyance, microhabitat, and as a biological passage.
• Use of Local Materials: Utilizing concrete debris and local stones removed during construction for riverbed filling and masonry materials reduced the need for external materials and achieved an earthwork balance in the overall project.

Challenges

• The entire project utilized dry stone masonry methods without the use of concrete or cement mortar. During construction, we conducted educational training and hands-on sessions on construction methods to ensure that the construction companies understood the design intentions and key construction points. This ensured that the machinery, processes, and materials met the actual construction needs.
• The project included the removal of ground sills in the river channel, adjustment of revetment openings, and construction above water supply pipelines. Throughout the project, we needed to communicate and coordinate with various governing units, such as the Water Resources Department of the City Government, District Office, Taiwan Water Company, and Forestry and Nature Conservation Agency, fully demonstrating the effectiveness of horizontal communication among public departments.

Thoroughness

• Intake Protection and Sediment Trapping Measures: At the intake, we installed spur dikes to deflect flow and used stone barriers to trap sediment, preventing floodwaters from directly hitting the intake and blocking large amounts of sediment carried by the floodwaters, thereby facilitating subsequent maintenance and management.
• Sediment Discharge Measures: We installed backwash maintenance pipes and sediment discharge valves at the end of the collection pipes and water conveyance pipes to remove sediment from the collection pipes, extending the system’s lifespan.
• Ecological Conservation Measures During Construction: Within the project area, the ecological team identified several natural rock formations and plant specimens as conservation targets. During the design phase, careful planning of construction routes and protective barriers along these paths were implemented. This approach aimed to minimize disturbance to the riverbed substrate and vegetation caused by construction machinery.

Outstanding Achievements of the Project

• During the construction period, this project was supervised by the Irrigation Agency of the Council of Agriculture, Executive Yuan, and received an excellent grade.
• We implemented occupational safety and health education training, along with safe construction practices, ensuring that no work-related accidents occurred during the construction period.
• We maintained good relations with the local community, effectively communicated the construction process, and ensured that no public complaints or reports were filed regarding the construction work.
• As the construction was located in a hillside area with narrow access roads, the construction team demonstrated great dedication and diligence, maintaining excellent project control despite the challenging work environment. As a result, no environmental penalties were incurred during construction.

Significant Benefits of the Project

• Improved Water Intake Efficiency: The intake weirs of the three canals at Tianliaoyang had suffered from upstream siltation, causing partial stream bed drying during low water periods, which made it difficult for downstream farmlands to access water. After the project's completion, the drying phenomenon was significantly improved, providing ample water supply for Canal No. 3 and ensuring the ecological base flow downstream.
• Restoration of Stream Biological Corridors: Yuanwankeng Creek, a tributary with the highest number of migratory species in the Shuangxi River system, boasts 42 native fish species, 7 shrimp species, 3 crab species, and 2 snail species. An impressive 76% of these species migrate between the river and the sea. This improvement project restores the longitudinal corridor for biological migration, serving as a model for river restoration projects in Taiwan.
• Restoration of Biological Corridors Between Canals and Rice Fields: The diverse mosaic landscape of the Tianliaoyang area attracts various bird species and terrestrial wildlife. After improving the irrigation canals, the project connected the stream, canals, and rice fields into an ecological water system network, making this area a benchmark for Taiwan's Satoyama ecological restoration efforts.

1. Destination Coordinates: 25.0112866, 121.9253952
2. Exit National Highway 1 at Badu Interchange (Exit to Provincial Highway 2D). Head towards Ruifang/Provincial Highway 62/Nuannuan.
3. Turn right onto Jifu Road (Provincial Highway 2B).
4. Drive approximately 26 kilometers.
5. Turn right onto Caoling Historic Trail/Yuanwankeng Street.
6. Your destination will be along this route.