南水北调中线一期工程天津干线输水线路长、引水流量大、流量变化幅度大，且具有一定的天然水头。现根据天津干线的特点，以技术可行、安全可靠、经济合理、运行控制简单、保证水质、减少水量损失、减少永久占地以及对当地社会环境的影响最小为原则，对天津干线输水方案进行了论证。

Tianjin section of the first phase of the Middle Route of South-to-North Water Diversion Project has a long water transfer route, large water diversion flow quantity, huge variation of flow quantity, along with a certain natural head. In this paper, based on the characteristics of Tianjin section, and according to following rules, including technically feasible, safe and reliable, economically reasonable, simple operation, aimed to guarantee the water quality, reduction of water loss, minimizing the permanent land occupation, as well as decreasing the impacts on the local social environment, the process and thoughts of water delivery scheme in Tianjin section were demonstrated.