5.2　General Layout of Project

5.2.1　Dam site（or dam axis）and powerhouse site shall be selected after techno-economic comparison on the basis of topographic and geological conditions，layout of project，operating conditions，construction conditions，land requisition，inundation loss，environmental impact，construction quantities，investment，and rational utilization of water energy，etc.

5.2.2　The general layout of project shall meet the requirements for multi-purpose utilization，while the layout of structures for water retaining，releasing，diversion，power generation，navigation and ecological water releasing shall be arranged properly after techno-economic comparison.

5.2.3　If the water retaining structure of a dam-type hydropower station is a concrete dam or a stone masonry dam，the powerhouse may be designed as at-dam-toe or water retaining type，and it may also be a river-side powerhouse if the riverbed is narrow.If the water retaining structure is an earth-rock fill dam，the river-side powerhouse may be adopted.

If impacted by sedimentation，the sediment prevention and releasing facilities shall be installed at the intake.

5.2.4　The powerhouse of a hydropower station in river channel should be located on a river reach where the riverbed is stable and the flow is smooth，and it is favorable for water drawing，sediment releasing，flood discharging，navigation，external access and construction diversion of the hydropower station.

5.2.5　For the headwork of a diversion type hydropower station，the dam-less or low-dam（including bottom grating dam）diversion may be adopted.On a curved river reach，the intake should be placed on a stable riverbank downstream of the pointed end of the concaved bank on a curved course，and sediment prevention and releasing measures shall be taken.

5.2.6　If the water retaining structure of a composite-type hydropower station is a concrete dam or a stone masonry dam，the intake may be located in the dam or on the bank，and shall be close to the sediment releasing facility of the project if impacted by sedimentation.If the water retaining structure is an earth-rock dam，the intake should be placed on the bank.

5.2.7　For a hydropower station on an irrigation channel，its setup should be incorporated with drop or chute structures.

If the hydropower station and the drop structures are built separately，the connection part of diversion channel and tailrace channel with the irrigation channel shall keep the flow stable.

5.2.8　For projects with navigation structures，the powerhouse and navigation structures should be arranged on either side of the riverbed separately；if they have to be on the same side，necessary engineering measures should be taken to meet requirements for navigation flow and access.

5.2.9　If there are many floats or ices on the river where the hydropower station is located，necessary measures shall be taken near the intake area of diversion structures to intercept and remove them.

5.2.10　Structures of a hydropower station should be arranged away from high or steep slopes；if this cannot be avoided，the stability of slopes shall be analyzed.Engineering measures shall be taken for any unstable slopes and dangerous rock mass.