For basin-wide planning document a chapter on environmental impacts assessment is necessary while for feasibility study of projects the environmental impact statement should be prepared.

• 水利水电工程在流域规划和可行性研究阶段必须进行环境影响评价，在流域规划阶段编制环境影响评价篇章，在可行性研究阶段编制环境影响报告书。