秦岭输水隧洞出口端邻近黑河金盆水库，为缩短洞线长度，减小工程投资，在勘察设计阶段对下穿黑河金盆水库区的地质条件进行认真研究。在对地面大量调查基础上，采用钻探、物探、取样试验等综合勘察手段，运用定性分析与定量计算相结合的评价研究方法，详细分析秦岭输水隧洞通过区的工程地质、水文地质特征及隧洞施工对水库渗漏的影响程度。根据影响分析结果，研究提出相应的防止库水渗漏的隧洞施工建议。经施工实践证明，秦岭输水隧洞洞线方案选择经济合理、对库区及地下水环境的影响小，达到了预期的效果。

The exit of Qinling Water Diversion Tunnel is located nearby Jinpen Dam at Heihe Valley in Xi’an, China. In order to shorten the length of the tunnel line and reduce the engineering investment, the geological condtions of the tunnel section crossing underneath Jinpen Dam are studied. The influences of engineering geological conditions, hydrogeological conditions and the construction of the tunnel section of Qinling Water Diversion Tunnel on seepage of Jinpen Dam are analyzed in detail by means of comprehensive investigation method and qualitative analysis and quantitative calculation method. Finally, some suggestions are given. The construction practice shows that the tunnel construction scheme is rational and effective,and just has a liltle impact on the environment of Jinpen Dam and grouandwater.