IWA 33-3:2021
(Main)Technical guidelines for the development of small hydropower plants — Part 3: Design principles and requirements
Technical guidelines for the development of small hydropower plants — Part 3: Design principles and requirements
This document specifies the general principles and basic requirements of design for small hydropower (SHP) projects up to 30 MWe, mainly including hydrology, geology, energy calculations, project layout, hydraulics, electromechanical equipment selection, construction planning, project cost estimates, economic appraisal, social and environmental assessments. Application of this document is intended to be site specific, with the principles and requirements of design applied in accordance with the needs of proposed hydropower plant.
Lignes directrices techniques pour le développement de la petite hydraulique — Partie 3: Titre manque
General Information
Buy Standard
Standards Content (Sample)
INTERNATIONAL IWA
WORKSHOP 33-3
AGREEMENT
First edition
2021-03
Technical guidelines for the
development of small hydropower
plants —
Part 3:
Design principles and requirements
Reference number
IWA 33-3:2021(E)
©
ISO 2021
---------------------- Page: 1 ----------------------
IWA 33-3:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 2 ----------------------
IWA 33-3:2021(E)
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Hydrology . 1
4.1 Basic data . 1
4.2 Runoff (discharge) . 2
4.3 Flood . 3
4.4 Stage-discharge relation curve . 4
4.5 Sediment, evaporation, ice regime and others . 5
4.6 Rationality check of the outcomes . 5
5 Engineering geology . 6
5.1 General provisions . 6
5.2 Regional geology. 7
5.3 Engineering geology of the reservoir area . 7
5.4 Engineering geology of hydraulic structures . 8
5.5 Natural construction material .10
6 Hydraulic engineering and energy calculation .11
6.1 General provisions .11
6.2 Computation of runoff regulation . .11
6.3 Hydraulic energy calculation .12
6.4 Load forecast and electric power and energy balance .13
6.5 Selection of flood regulation and characteristic flood-control level .13
6.6 Selection of normal water level and dead storage water level .13
6.7 Selection of installed capacity and type of unit .14
6.8 Selection of dimensions of headrace and volume of daily regulation pool .14
6.9 Analysis of the reservoir sediment deposition and calculation of the backwater .14
6.10 Reservoir operation mode and operational characteristics .15
7 Engineering layout and hydraulic structure .15
7.1 General provisions .15
7.2 General engineering layout .16
7.3 Water retaining structure .18
7.4 Water release structure .20
7.5 Water diversion structure .23
7.6 Powerhouse structure .26
7.7 Engineering safety monitoring .31
7.8 Concrete strength and durability .32
8 Hydraulic machinery, fire protection, heating and ventilation .33
8.1 General requirements for selection of turbine and generator .33
8.2 Selection of turbine rated head.34
8.3 Selection of turbine type .35
8.4 Selection of basic parameters of the reaction turbine .36
8.5 Selection of basic parameters of the impulse turbine .38
8.6 Unit transient performance analysis .39
8.7 Turbine governing system .40
8.8 Turbine main inlet valve .40
8.9 Cooling water and drainage system .41
8.10 Oil system .42
8.11 Compressed air system .42
8.12 Hydraulic monitoring system .43
© ISO 2021 – All rights reserved iii
---------------------- Page: 3 ----------------------
IWA 33-3:2021(E)
8.13 Selection of lifting equipment .43
8.14 Fire protection .44
8.15 Heating and ventilation .44
8.16 Repair and maintenance equipment .45
8.17 Arrangement of hydraulic machinery equipment .45
9 Electrical system .46
9.1 Connection of the hydropower plant to the power system .46
9.2 Main electrical connection wiring .46
9.3 Selection of the main transformer .48
9.4 Selection of high-voltage electrical equipment .49
9.5 Overvoltage protection and earthing system .54
9.6 Lighting system.55
9.7 Layout of main electrical equipment inside and outside the power plant .55
9.8 Relaying protection and security automatic equipment .55
9.9 Excitation system .57
9.10 Automatic monitoring system .57
9.11 Plant service power supply and dam area power supply .58
9.12 DC operating power supply.58
9.13 Video monitoring system .58
9.14 Communication .58
10 Hydro mechanical structure .59
10.1 General provisions .59
10.2 Arrangement of hydro mechanical structure .59
10.3 Hoist selection for gates .61
10.4 Gate structure design .61
10.5 Anti-corrosion of hydro mechanical structures .61
11 Guidelines for construction planning .62
11.1 Construction diversion .62
11.2 Selection, planning and exploitation of the borrow area .64
11.3 Construction of the main works .64
11.4 Construction planning of roads and transportation .65
11.5 Construction plant facilities .65
11.6 Construction general layout .66
11.7 Overall construction programme .67
11.8 Construction safety .67
12 Social and environmental impact assessment .67
12.1 General provisions .67
12.2 Environmental impact assessment .68
12.3 Land acquisition and resettlement .69
12.4 Soil and water conservation .70
12.5 Social impact assessment .70
12.6 Conclusion of assessment and advice .71
13 Project cost estimates .71
13.1 General provisions .71
13.2 Project division .72
13.3 Costs and unit price .73
13.4 Engineering budget preparation .74
13.5 Composition of cost estimate documents .75
14 Economic appraisal.76
14.1 General provisions .76
14.2 Cost calculation.76
14.3 Benefits calculation .76
14.4 Economic cost benefit evaluation .77
14.5 Financial evaluation.77
14.6 Uncertainty analysis .78
iv © ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
IWA 33-3:2021(E)
14.7 Methods of scheme comparison .78
Annex A (informative) Workshop contributors .79
© ISO 2021 – All rights reserved v
---------------------- Page: 5 ----------------------
IWA 33-3:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
International Workshop Agreement IWA 33 was approved at a workshop hosted by the Standardization
Administration of China (SAC) and Austrian Standards International (ASI), in association with the
th rd
International Center on Small Hydro Power (ICSHP), held virtually from 19 to 23 October, 2020.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
A list of all parts in the IWA 33 series can be found on the ISO website.
vi © ISO 2021 – All rights reserved
---------------------- Page: 6 ----------------------
IWA 33-3:2021(E)
Introduction
Small hydropower (SHP) is well recognized as an important renewable energy solution to the challenge
of increasing access to electricity in remote rural areas. However, while most countries in Europe,
North and South America, China and India have high degrees of installed capacity, the potential of SHP
in many developing countries remains untapped and is hindered by a number of factors, including the
lack of best practices or standards for SHP development.
The technical guidelines for the development of small hydropower plants contained in this document
address the current limitations of the regulations applied to technical guidelines for SHP plants by
applying the expertise and best practices that exist across the globe. It is intended for countries to
utilize this document to support their current policy, technology and legislation. Countries that have
limited institutional and technical capacities will be able to enhance their knowledge base in developing
SHP plants on rivers/streams and existing water resource structures outlets such as dams, barrages,
navigation lock, canal falls, outfalls and flowing water (kinetic flow), including renovating/upgrading
the old SHP plants, thereby attracting more investment in SHP projects, encouraging favourable policies
and subsequently assisting in economic development at a national level. This document will be valuable
for all countries, but also allow for the sharing of experience and best practices between countries.
This document is the result of a collaborative effort between the United Nations Industrial Development
Organization (UNIDO) and the International Network on Small Hydro Power (INSHP). About 80
international experts and 40 international agencies were involved in this document’s preparation
and peer review. This document can be used as the principles and basis for the planning, design,
construction and management of SHP plants up to 30 MWe.
© ISO 2021 – All rights reserved vii
---------------------- Page: 7 ----------------------
International Workshop Agreement IWA 33-3:2021(E)
Technical guidelines for the development of small
hydropower plants —
Part 3:
Design principles and requirements
1 Scope
This document specifies the general principles and basic requirements of design for small hydropower
(SHP) projects up to 30 MWe, mainly including hydrology, geology, energy calculations, project layout,
hydraulics, electromechanical equipment selection, construction planning, project cost estimates,
economic appraisal, social and environmental assessments.
Application of this document is intended to be site specific, with the principles and requirements of
design applied in accordance with the needs of proposed hydropower plant.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
IWA 33-1, Technical guidelines for the development of small hydropower plants — Part 1: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IWA 33-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Hydrology
4.1 Basic data
4.1.1 The basic data include hydrometeorological data, river basin physiographic characteristics data,
information about the human activities impact, hydrological computation results of the basin and nearby
areas and the other relevant data. The changes in water resources management that occur upstream of a
hydropower plant during its long lifespan will alter the runoff regime. Thus, the present and foreseeable
needs of the population living on both sides of the river shall be taken into account for water supply,
irrigation, industrial, ecology and recreation purposes.
4.1.2 The data series upon which hydrological computation is based shall be checked for reliability,
consistency and representativeness.
4.1.3 The investigation of historical floods and dry seasons shall be carried out for the regions with
insufficient or no data; if the conditions permit, observation and survey of water level, flow and sediment
© ISO 2021 – All rights reserved 1
---------------------- Page: 8 ----------------------
IWA 33-3:2021(E)
shall be carried out, and a long-term water regime monitoring and reporting system may be set up if
necessary.
4.1.4 Considering the impacts of climate change on the evolution of river flows is necessary as the SHP
plants normally are on smaller catchment not having much channel storage becoming more vulnerable
for changes in flows in terms of discharge, intensity, spatial and temporal distribution variation. These
shall be studied for the basin from the simulation with hydrological models. The entire hydrograph set
shall be considered in planning and in fixing the capacity. Results of these specialized study should be
used for finalising the runoff data.
4.2 Runoff (discharge)
4.2.1 According to the design requirement and data availability, all or part of the following design
runoff results shall be provided:
a) historic daily runoff series measured or simulated at the site of the proposed hydropower plant;
b) annual mean runoff as well as the annual runoff, runoff in flood season, runoff during dry season
with the designated frequency (return period) or the design representative years;
c) the annual distribution of the runoff in the design representative years.
4.2.2 According to data availabilities, the design runoff should be calculated by the following method.
a) When sufficient measured runoff data are available on the project site, the frequency analysis shall
be used.
b) When there is a runoff gauging station in the downstream/upstream of the project site, in the river
basin, adjacent basin or nearby basin with similar homogeneous meteorological and hydrological
conditions, the hydrologic analogy method should be adopted.
c) If measured runoff data are not available, the rainfall-runoff relationship or model method may be
adopted according to the precipitation data and physiographic characteristics of the watershed.
d) When the runoff dat
...
INTERNATIONAL IWA
WORKSHOP 33-3
AGREEMENT
First edition
Technical guidelines for the
development of small hydropower
plants —
Part 3:
Design principles and requirements
PROOF/ÉPREUVE
Reference number
IWA 33-3:2021(E)
©
ISO 2021
---------------------- Page: 1 ----------------------
IWA 33-3:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii PROOF/ÉPREUVE © ISO 2021 – All rights reserved
---------------------- Page: 2 ----------------------
IWA 33-3:2021(E)
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Hydrology . 1
4.1 Basic data . 1
4.2 Runoff (discharge) . 2
4.3 Flood . 3
4.4 Stage-discharge relation curve . 4
4.5 Sediment, evaporation, ice regime and others . 5
4.6 Rationality check of the outcomes . 5
5 Engineering geology . 6
5.1 General provisions . 6
5.2 Regional geology. 7
5.3 Engineering geology of the reservoir area . 7
5.4 Engineering geology of hydraulic structures . 8
5.5 Natural construction material .10
6 Hydraulic engineering and energy calculation .11
6.1 General provisions .11
6.2 Computation of runoff regulation . .11
6.3 Hydraulic energy calculation .12
6.4 Load forecast and electric power and energy balance .13
6.5 Selection of flood regulation and characteristic flood-control level .13
6.6 Selection of normal water level and dead storage water level .13
6.7 Selection of installed capacity and type of unit .14
6.8 Selection of dimensions of headrace and volume of daily regulation pool .14
6.9 Analysis of the reservoir sediment deposition and calculation of the backwater .14
6.10 Reservoir operation mode and operational characteristics .15
7 Engineering layout and hydraulic structure .15
7.1 General provisions .15
7.2 General engineering layout .16
7.3 Water retaining structure .18
7.4 Water release structure .20
7.5 Water diversion structure .23
7.6 Powerhouse structure .26
7.7 Engineering safety monitoring .31
7.8 Concrete strength and durability .32
8 Hydraulic machinery, fire protection, heating and ventilation .33
8.1 General requirements for selection of turbine and generator .33
8.2 Selection of turbine rated head.34
8.3 Selection of turbine type .35
8.4 Selection of basic parameters of the reaction turbine .36
8.5 Selection of basic parameters of the impulse turbine .38
8.6 Unit transient performance analysis .39
8.7 Turbine governing system .40
8.8 Turbine main inlet valve .40
8.9 Cooling water and drainage system .41
8.10 Oil system .42
8.11 Compressed air system .42
8.12 Hydraulic monitoring system .43
© ISO 2021 – All rights reserved PROOF/ÉPREUVE iii
---------------------- Page: 3 ----------------------
IWA 33-3:2021(E)
8.13 Selection of lifting equipment .43
8.14 Fire protection .44
8.15 Heating and ventilation .44
8.16 Repair and maintenance equipment .45
8.17 Arrangement of hydraulic machinery equipment .45
9 Electrical system .46
9.1 Connection of the hydropower plant to the power system .46
9.2 Main electrical connection wiring .46
9.3 Selection of the main transformer .48
9.4 Selection of high-voltage electrical equipment .49
9.5 Overvoltage protection and earthing system .54
9.6 Lighting system.55
9.7 Layout of main electrical equipment inside and outside the power plant .55
9.8 Relaying protection and security automatic equipment .55
9.9 Excitation system .57
9.10 Automatic monitoring system .57
9.11 Plant service power supply and dam area power supply .58
9.12 DC operating power supply.58
9.13 Video monitoring system .58
9.14 Communication .58
10 Hydro mechanical structure .59
10.1 General provisions .59
10.2 Arrangement of hydro mechanical structure .59
10.3 Hoist selection for gates .61
10.4 Gate structure design .61
10.5 Anti-corrosion of hydro mechanical structures .61
11 Guidelines for construction planning .62
11.1 Construction diversion .62
11.2 Selection, planning and exploitation of the borrow area .64
11.3 Construction of the main works .64
11.4 Construction planning of roads and transportation .65
11.5 Construction plant facilities .65
11.6 Construction general layout .66
11.7 Overall construction programme .67
11.8 Construction safety .67
12 Social and environmental impact assessment .67
12.1 General provisions .67
12.2 Environmental impact assessment .68
12.3 Land acquisition and resettlement .69
12.4 Soil and water conservation .70
12.5 Social impact assessment .70
12.6 Conclusion of assessment and advice .71
13 Project cost estimates .71
13.1 General provisions .71
13.2 Project division .72
13.3 Costs and unit price .73
13.4 Engineering budget preparation .74
13.5 Composition of cost estimate documents .75
14 Economic appraisal.76
14.1 General provisions .76
14.2 Cost calculation.76
14.3 Benefits calculation .76
14.4 Economic cost benefit evaluation .77
14.5 Financial evaluation.77
14.6 Uncertainty analysis .78
iv PROOF/ÉPREUVE © ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
IWA 33-3:2021(E)
14.7 Methods of scheme comparison .78
Annex A (informative) Workshop contributors .79
© ISO 2021 – All rights reserved PROOF/ÉPREUVE v
---------------------- Page: 5 ----------------------
IWA 33-3:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
International Workshop Agreement IWA 33 was approved at a workshop hosted by the Standardization
Administration of China (SAC) and Austrian Standards International (ASI), in association with the
th rd
International Center on Small Hydro Power (ICSHP), held virtually from 19 to 23 October, 2020.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
A list of all parts in the IWA 33 series can be found on the ISO website.
vi PROOF/ÉPREUVE © ISO 2021 – All rights reserved
---------------------- Page: 6 ----------------------
IWA 33-3:2021(E)
Introduction
Small hydropower (SHP) is well recognized as an important renewable energy solution to the challenge
of increasing access to electricity in remote rural areas. However, while most countries in Europe,
North and South America, China and India have high degrees of installed capacity, the potential of SHP
in many developing countries remains untapped and is hindered by a number of factors, including the
lack of best practices or standards for SHP development.
The technical guidelines for the development of small hydropower plants contained in this document
address the current limitations of the regulations applied to technical guidelines for SHP plants by
applying the expertise and best practices that exist across the globe. It is intended for countries to
utilize this document to support their current policy, technology and legislation. Countries that have
limited institutional and technical capacities will be able to enhance their knowledge base in developing
SHP plants on rivers/streams and existing water resource structures outlets such as dams, barrages,
navigation lock, canal falls, outfalls and flowing water (kinetic flow), including renovating/upgrading
the old SHP plants, thereby attracting more investment in SHP projects, encouraging favourable policies
and subsequently assisting in economic development at a national level. This document will be valuable
for all countries, but also allow for the sharing of experience and best practices between countries.
This document is the result of a collaborative effort between the United Nations Industrial Development
Organization (UNIDO) and the International Network on Small Hydro Power (INSHP). About 80
international experts and 40 international agencies were involved in this document’s preparation
and peer review. This document can be used as the principles and basis for the planning, design,
construction and management of SHP plants up to 30 MWe.
© ISO 2021 – All rights reserved PROOF/ÉPREUVE vii
---------------------- Page: 7 ----------------------
International Workshop Agreement IWA 33-3:2021(E)
Technical guidelines for the development of small
hydropower plants —
Part 3:
Design principles and requirements
1 Scope
This document specifies the general principles and basic requirements of design for small hydropower
(SHP) projects up to 30 MWe, mainly including hydrology, geology, energy calculations, project layout,
hydraulics, electromechanical equipment selection, construction planning, project cost estimates,
economic appraisal, social and environmental assessments.
Application of this document is intended to be site specific, with the principles and requirements of
design applied in accordance with the needs of proposed hydropower plant.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
IWA 33-1, Technical guidelines for the development of small hydropower plants — Part 1: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IWA 33-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Hydrology
4.1 Basic data
4.1.1 The basic data include hydrometeorological data, river basin physiographic characteristics data,
information about the human activities impact, hydrological computation results of the basin and nearby
areas and the other relevant data. The changes in water resources management that occur upstream of a
hydropower plant during its long lifespan will alter the runoff regime. Thus, the present and foreseeable
needs of the population living on both sides of the river shall be taken into account for water supply,
irrigation, industrial, ecology and recreation purposes.
4.1.2 The data series upon which hydrological computation is based shall be checked for reliability,
consistency and representativeness.
4.1.3 The investigation of historical floods and dry seasons shall be carried out for the regions with
insufficient or no data; if the conditions permit, observation and survey of water level, flow and sediment
© ISO 2021 – All rights reserved PROOF/ÉPREUVE 1
---------------------- Page: 8 ----------------------
IWA 33-3:2021(E)
shall be carried out, and a long-term water regime monitoring and reporting system may be set up if
necessary.
4.1.4 Considering the impacts of climate change on the evolution of river flows is necessary as the SHP
plants normally are on smaller catchment not having much channel storage becoming more vulnerable
for changes in flows in terms of discharge, intensity, spatial and temporal distribution variation. These
shall be studied for the basin from the simulation with hydrological models. The entire hydrograph set
shall be considered in planning and in fixing the capacity. Results of these specialized study should be
used for finalising the runoff data.
4.2 Runoff (discharge)
4.2.1 According to the design requirement and data availability, all or part of the following design
runoff results shall be provided:
a) historic daily runoff series measured or simulated at the site of the proposed hydropower plant;
b) annual mean runoff as well as the annual runoff, runoff in flood season, runoff during dry season
with the designated frequency (return period) or the design representative years;
c) the annual distribution of the runoff in the design representative years.
4.2.2 According to data availabilities, the design runoff should be calculated by the following method.
a) When sufficient measured runoff data are available on the project site, the frequency analysis shall
be used.
b) When there is a runoff gauging station in the downstream/upstream of the project site, in the river
basin, adjacent basin or nearby basin with similar homogeneous meteorological and hydrological
conditions, the hydrologic analogy method should be adopted.
c) If measured runoff data are not available, the rainfall-runoff relationship or model method may be
adopted according to
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.