Abstract: Based on the state of siltation in front of the lock of the Caotanzhuang Water Diversity Project on the Heihe River, analysis was carried out of effects of local scour, siltation and unbalanced silt transportation between the upper and down reaches on its eco environment. For its improvement,some practical engineering measures were brought forward, which are believed to be of great significance in maintaining normal operation of the project and bringing up its economic benefit. 

Key words: eco environment, inland river, siltation, water diversion project