Mode 3 is a efficient water supply mode because of rainwater usage and combined water supply between Longzi Lake and colleges,and plan 3 is considered best due to its least drawdown.

• 工况3既考虑了雨水利用,又考虑了龙子湖工程与高校杂用水供水系统联合运行,为一个高效供水方案,其中方案3水位下降最小为推荐方案。