The tunnel has been accused of preventing underground water reaching the nearby Feitsui Reservoir, and a report by Academia Sinica researcher Wu Chu-tsung states that continuous development in the upper reaches of the Peishi Creek, including major projects like the freeway, have seriously affected the reservoir's water quality.
而由於工程地點鄰近翡翠水庫，中研院研究員吳俊宗的調查報告就指出，水庫所在的北勢溪上游近年不斷開發，重大工程如北宜高速公路施工，已造成水庫水質明顯惡化。