1.0.1 This Code is formulated with a view to adapting the construction and development needs of small hydropower stations (hereinafter referred to as "power station"), reflecting the technical advance and new experiences in small hydropower stations, unifying the design specifications and improving design quality.
1.0.2 This standard is applicable to designs of new, extended and rebuilt power stations with an installed capacity of 50MW~5MW, an outlet voltage class of under 110kV, and a unit capacity not exceeding 15MW. This Code may apply to power station with an installed capacity of less than 5MW by reference.
1.0.3 The power station design shall be carried out on the base of river, reach and local water conservancy and hydropower planning as well as local power planning. The opinions from the adjacent areas shall be solicited for the development of power stations with possible effect on the upstream and/or downstream.
1.0.4 The power station design must comply with the current technical and economic policies of the country; be given an overall consideration in as aspects of electric power market demands and the requirements in local water conservancy, hydropower, navigation, water and soil conservation, environmental protection, etc.; be taken with the measures in the light of the realities of specific regions; and utilize water resource in reason.
1.0.5 The power station design must carry out the investigation, exploration, and test; and acquire the basic material and data on hydrology, meteorology, topography, geology, building material, reservoir inundation, migration resettlement, environment, national economy comprehensive utilization, etc.
1.0.6 The power station design shall meet the requirements of the current relevant standards of the country besides this Code.
2 Hydrology
2.1 General Requirements
2.1.1 In the hydrological analysis and computation, the following data and materials shall be collected and acquired: hydrometeorology and natural geographic features of this watershed and adjacent watersheds; human activities effect like water conservancy and hydropower engineering development, soil conservation and so on in this watershed; historical flood investigation data of this area; returns of comprehensive analysis and research of hydrometeorology in this area, etc.
2.1.2 Analysis and check shall be carried out for the basic data, parameters and analytical computation results referenced by the hydrological computation, so as to demonstrate their rationality and feasibility.
2.2 Runoff
2.2.1 The runoff computation shall provide all or part of the following runoff data of the dam location:
1 Annual, monthly and ten-day runoff series and long term average annual runoff;
2 Annual and season runoff and annual distribution in design typical year;
3 Daily average flow duration curve, etc.
2.2.2 Based on different material/data conditions, the design runoff computation shall be carried out according to the following methods:
1 The design annual runoff may be directly computed with frequency computation method where there are continuous runoff series data of over 20 years (including interpolation) available for the dam location;
2 The design runoff data (results) of the reference station may be corrected according to the catchment area and the precipitation and diverted to the use for the dam location where the dam location has the run-off data of less than 20 years but the upstream and/or downstream or adjacent watershed has the run-off data of over 20 years (including interpolation);
3 The design runoff computation may be carried out with the area synthesis method where the data above is unavailable.
