圖書典藏及影音數位平台

峨眉溪為中央管河川中港溪支流，上游屬新竹縣，下游屬苗栗縣。本溪發源於雪山山脈，南以鵝公髻山、獅頭山為分水嶺，與南庄溪流域相鄰，東以五指山為界，北隔寶山丘陵與客雅溪流域相鄰。自發源地由南向北流，於北埔西折至富興後再南迴，在苗栗縣三灣鄉之銅鑼圈與南庄溪匯合為中港溪，為一迂迴曲折之山地河川。流域面積116.6平方公里，河長33公里，全河道平均坡降為1/760，本溪治理範圍自大埔水庫洩洪道出口起至中港溪匯流處止，長度計約5.5公里。 本溪自民國94年6月由本局完成治理基本計畫並公告，迄今已歷時12年，期間歷經數十次颱洪，河道地形及周邊環境均有變化，為配合河道地形環境變化及社會發展需求，故辦理本計畫。

The Emei River is a tributary of Chunggang River. The length of management is about 6 km, from the confluence with the Chunggang River to the spillway of Dapu reservoir. The Second River Management Office completed a planning project in 2005, with the considertaiton of the peak discharge with 50 year recurrence period with 1.2m freeboard for Emei River. In the past 12 years from then, Taiwan experienced many typhoon events, which change the channel geomerty and surrounding environment of the Emei River. For the purpose of reflecting current environmental situation and social development need, this study examines the flood conveyance capacity and provides the management stratagies in the Emei River. The Emei River is a valley-type river, remaining its original look. Thus, the management measures should respect to the characters of river. Based on this principle, the river management approaches of channel improvement suggested revetment heightening and improving consolidation to protect the capacity of conveyance at upstream of Emei bridge. For the rest part of Emei River, the study suggests non-engineering measures to maintain the natural environment, such as land management and flood alarm system. The main flood of Emei River is from Dapu reservoir, and thus the system of disaster prevention should correspond with flood alarm system of Dapu reservoir. According to the guideline of Dapu reservoir, for the resident safety and reduce property losses, the alarm shoud be broadcast an hour before discharge.

本研究檢討中港溪支流峨眉溪的通洪能力，並研擬治理對策。研究發現，峨眉溪部分河段通洪能力不足，尤其在舊峨眉橋附近，且十寮坑大橋梁底高程未能滿足防洪標準。 為此，建議採取「管理取代治理」的原則，優先進行舊峨眉橋固床工調整、河道疏濬及護岸加強，以提升通洪能力。同時，應強化大埔水庫洩洪警報系統，並鼓勵採用生態工法，以維持河川自然風貌並兼顧生態保育。長期而言，建議拆除改建梁底高程不足的十寮坑大橋。