The dispersed location of project sites could make implementation management and supervision difficult. The sites of this project were spread in the north, east, and southwest of Chongqing, mostly in mountainous terrain, making management and supervision difficult for both the project management office and ADB.
Inadequate consideration of the project sites' topography and geological conditions in project feasibility studies and detailed engineering designs could lead to unexpected cost increases during implementation. There was a significant cost increase in land acquisition and resettlement due to changes in the project scope and additional land acquisition that needed to be undertaken because of the complex geological conditions in some sites resulting in increased civil works costs in some packages.
Inadequate consideration of climatic constraints,working seasons in the project sites, difficult terrain, and availability of experienced local labor and construction materials can cause construction delays with implications on project implementation periods and costs .
The selection of subprojects and project timeliness need to consider the Implementation complexity (such as topography, adverse weather conditions at the construction site, and the need for specialized experts), experience of the executing agency, availability of specialist contractors, and available working seasons.