圖書典藏及影音數位平台

依據南水局104年「白河水庫更新改善規劃檢討及聯合運用規劃」，為持續推動白河水庫後續更新計畫，同時提高整體水力排砂效率，建議增加繞庫防淤設施，並經行政院納入「前瞻基礎建設?水環境建設」項下之『白河水庫後續更新改善工程』推動。為達成白河水庫延壽目標，同時降低清淤土方暫置與去化處理之機會成本，爰辦理本繞庫防淤工程設計委託案，希期早日付諸執行，以促進白河水庫之永續利用與經營。

A. Background Baihe Reservoir was completed in June, 1965. The initial storage capacity of the reservoir was 2,509.3×104 m3. Due to severe siltation, the storage capacity in 2017 diminished to 1,018×104 m3 (about 41% of the initial storage capacity). In order to restore the storage capacity, reduce water shortage risks, improve flood control functions, and implement the sustainable operation of Baihe Reservoir, the Southern Region Water Resources Office, WRA, MOEA initiated “Baihe Reservoir Water Conservancy Improvement Project” in October, 2012. In accordance with the Southern Region Water Resources Office report of “Planning of Rehabilitation and Joint-use of Baihe Reservoir” published in 2015, to continue a subsequent restoration plan of Baihe reservoir and also to improve the efficiency of hydraulic desilting, a construction of bypass desilting facilities was recommended. This Sediment Bypass Engineering Project, executed under the “Subsequent Restoration and Improvement Project of Baihe Reservoir” of “Future Infrastructure Development Program”, had been approved by the Executive Yuan and is aimed to extend the operational life of Baihe Reservoir. B. Design concept The design of the sediment bypass engineering should lead to a efficient condition of water and sand intake. Furthermore, the design should also avoid affecting the safety of the existing facilities (e.g. the left abutment of the auxiliary dam). In addition, for this project area, public lands and planned roads of urban planning should be prioritized. For the location of outlet, the current condition of the existing facilities and the flooding capacity should be considered to avoid affecting the safety of the existing drainage structures. C. Project design The design flow rate is 200cms, and this engineering project consists of guiding structure, inlet, sediment bypass channel, hydraulic machinery, etc. The sediment bypass channel is divided into open channel transition section, sluice gate section, culvert section I, tunnel section, culvert section II and outlet. The dimensions of each section are briefly described as follows: a. Guiding structure (L=140m) b. Inlet (L=45.01m) c. Sediment bypass channel (L=1,515.54m) Sediment bypass channel includes open channel transition section (L=15m), sluice gate section (L=20m), culvert section I (L=391.88m), tunnel section (L=301.67m), maintenance opening section (L=10m), culvert section II (L=561.59m), and outlet (L=215.4m). d. Radial gate (5m(W)×5.5m(H)) D. Project duration and cost The estimated period of this project is about 33 months (1,000 calendar days). Furthermore, the estimated project cost is about 588 million NTD (design fee included) or about 581 million NTD (design fee excluded). The construction contract of this project is estimated around 571 million NTD.