final report1111 - UNDP

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Content

Chapter 1 General Information .................................................................................. 1

1.1 Overview .............................................................................................................. 1

1.2 Hydrology ............................................................................................................. 1 1.2.1 Climate ........................................................................................................... 1 1.2.2 Hydrology ...................................................................................................... 2

1.3 Engineering Geology ............................................................................................ 2 1.3.1 Landform........................................................................................................ 2 1.3.2 Strata lithology ............................................................................................... 3 1.3.3 Natural building materials .............................................................................. 3

1.4 Engineering Tasks and Scale ................................................................................ 3 1.4.1 Necessity and advantage ................................................................................ 3 1.4.2 Project scale ................................................................................................... 4

1.5 Project Layout and Main Buildings ...................................................................... 4 1.5.1 Engineering scale and building level ............................................................. 4 1.5.2 General project layout .................................................................................... 5 1.5.3 Main buildings ............................................................................................... 5

1.6 Electromechanical and Metallic Structure ........................................................... 6 1.6.1 Hydraulic machinery ...................................................................................... 6 1.6.2 Electrical connecting system method ............................................................. 6 1.6.3 Main equipment selection .............................................................................. 6 1.6.4 Metal structure ............................................................................................... 7

1.7 Project Management ............................................................................................. 7

1.8 Construction Management Plan ........................................................................... 7

1.9 Labor Safety and Industrial Sanitation ................................................................. 8

1.10 Submerge and Land Requisition ........................................................................ 8

1.11 Water and Soil Conservation .............................................................................. 9

1.12 Environmental Impact Assessment .................................................................. 10

1.13 Project Cost Estimates ...................................................................................... 10 1.13.1 Compilation basis....................................................................................... 10 1.13.2 Unit price ................................................................................................... 11 1.13.3 Total project investment ............................................................................. 11

1.14 Economic Evaluation ....................................................................................... 11

1.15 Conclusions and Suggestions for Future Work ................................................ 11 1.15.1 Conclusions ................................................................................................ 11 1.15.2 Suggestions for future ................................................................................ 12

Chapter 2 Hydrology ................................................................................................. 16

2.1 Overview of the Drainage Basin ........................................................................ 16

2.2 Climate ............................................................................................................... 16

2.3 Basic Hydrological Data .................................................................................... 17 2.3.1 Hydrological station network and information ............................................ 17 2.3.2 Application of the data ................................................................................. 18

2.4 Runoff ................................................................................................................. 19

2.5 Flood ................................................................................................................... 19

2.6 Water-level Discharge Relation Curve at the Dam and Plant Site ..................... 19

2.7 Sediment ............................................................................................................. 21

2.8 Attached Figures ................................................................................................. 22

Chapter 3 Engineering Geology ............................................................................... 25

3.1 Overview ............................................................................................................ 25

3.2 Regional Geology ............................................................................................... 25 3.2.1 Landform...................................................................................................... 25 3.2.2 Strata lithology ............................................................................................. 25 3.2.3 Geological structure ..................................................................................... 26 3.2.4 Hydrological geology................................................................................... 26

3.3 Natural Building Materials ................................................................................. 26

3.4 Conclusions and Suggestions ............................................................................. 26

Chapter 4 Engineering Tasks and Scale ................................................................... 28

4.1 General Situation ................................................................................................ 28 4.1.1 Physical geography ...................................................................................... 28 4.1.2 Social and economic situation ..................................................................... 28 4.1.3 Hydropower resources and the development and utilization situation ........ 29 4.1.4 Necessity of the project ................................................................................ 29

4.2 Scale of Power Generation Projects ................................................................... 30 4.2.1 Power supply range and load forecast ......................................................... 30 4.2.2 Drafting of the scheme ................................................................................. 30 4.2.3 Calculation of hydropower and installed capacity selection ........................ 31

Chapter 5 Project layout and main buildings ......................................................... 35

5.1 Design basis ........................................................................................................ 35 5.1.1 Main technical specifications and references .............................................. 35 5.1.2 Basic design information ............................................................................. 35 5.1.3 Project grade and standards ......................................................................... 36

5.2 Project location and general layout .................................................................... 36

5.2.1 Location of the dam ..................................................................................... 36 5.2.2 Location of the power house ........................................................................ 38 5.2.3 Selection of water diversion method ............................................................ 40 5.2.4 General layout of the project ........................................................................ 41

5.3 Water retaining structures ................................................................................... 41 5.3.1 Layout of the dam ........................................................................................ 41 5.3.2 Stability calculation ..................................................................................... 42 5.3.3 Flood discharge and energy dissipation facilities ........................................ 43

5.4 Open canal diversion method (comparative plan) .............................................. 43 5.4.1 Open canal ................................................................................................... 43 5.4.2 Pressure forebay ........................................................................................... 44

5.5 Penstock (recommended plan) ........................................................................... 45

5.6 Power house and booster station ........................................................................ 46 5.6.1 Selection of the power house location ......................................................... 46 5.6.2 Power house structure .................................................................................. 46 5.6.3 Booster station ............................................................................................. 46 5.6.4 Housing for the use of administration .......................................................... 47 5.6.5 Entrance road ............................................................................................... 47

Chapter 6 Electromechanical and metal structures ............................................... 48

6.1 Units ................................................................................................................... 48

6.2 Access mode to power system and main electrical connection .......................... 50 6.2.1 Access mode to power system ..................................................................... 50 6.2.2 Main connection........................................................................................... 50

6.3 Selection of main electromechanical equipment ................................................ 52 6.3.1 Short circuit current ..................................................................................... 52 6.3.2 Selection of the main electrical equipment .................................................. 52

6.4 Layout of the electromechanical equipment ...................................................... 54 6.4.1 Inner-plant electrical equipment layout ....................................................... 54 6.4.2 Layout of the booster station ........................................................................ 54

6.5 Metallic structure ................................................................................................ 55 6.5.1 Dam and metallic structures at the water intake .......................................... 55 6.5.2 Metallic structure for tailwater ..................................................................... 56 6.5.3 Penstocks...................................................................................................... 56 6.5.4 Main quantities of metallic structures and equipment ................................. 56

6.6 Heating ventilation and fire protection ............................................................... 56 6.6.1 Heating ventilation ....................................................................................... 56 6.6.2 Fire protection .............................................................................................. 57

6.7 Lightning protection and earthing ...................................................................... 60

Chapter7 Project Management ................................................................................ 61

7.1 Introduction ........................................................................................................ 61

7.2 Operation management ....................................................................................... 62 7.2.1 Project dispatching operation ....................................................................... 62 7.2.2 Management and maintenance of the structures .......................................... 62 7.2.3Management and maintenance of metallic structures ................................... 62

7.3 Scope of project management and protection .................................................... 63 7.3.1 Project management scope ........................................................................... 63 7.3.2 Protection scope ........................................................................................... 63

7.4 Project management facilities and maintenance of the equipment .................... 64 7.4.1 Project management facilities ...................................................................... 64 7.4.2 Maintenance of the equipment ..................................................................... 64

Chapter 8 Construction organization planning ...................................................... 66

8.1 Project profile ..................................................................................................... 66

8.2 Construction diversion ....................................................................................... 67 8.2.1 Diversion standards ...................................................................................... 67 8.2.2 Diversion method ......................................................................................... 68

8.3 Selection of the material site and the excavation ............................................... 68 8.3.1 Selection of the material site ........................................................................ 68

8.4 Construction of the project’s main works ........................................................... 68

8.5 Construction of the diversion system ................................................................. 69

8.6 Construction of the power house ........................................................................ 70

8.7 Transportation for construction .......................................................................... 71 8.7.1 Selection of transportation means ................................................................ 71 8.7.2 Outbound transportation .............................................................................. 71 8.7.3 Internal transportation .................................................................................. 71

8.8 General layout of the construction ..................................................................... 72 8.8.1 The planning and layout principle of the construction ................................ 72 8.8.2 Construction zoning and layout planning .................................................... 72 8.8.3 Waste slags site ............................................................................................ 73

8.9 General construction progress ............................................................................ 74 8.9.1 Implementation basis and principle ............................................................. 74 8.9.2 General construction progress...................................................................... 74

8.10 Main construction machinery ........................................................................... 74

Chapter 9 Labor Safety and Industrial Sanitation ................................................. 76

9.1 Design Basis ....................................................................................................... 76 9.1.1 Provisions of the national and local administration ..................................... 76 9.1.2 Technical specifications, procedures and standards ..................................... 76

9.2 Project Overview ................................................................................................ 76 9.2.1 Project location ............................................................................................ 76 9.2.2 Project layout ............................................................................................... 76 9.2.3 Characteristics of natural conditions ............................................................ 77 9.2.4 Project benefit and major hazards ................................................................ 77

9.3 General Layout of the Project ............................................................................ 77

9.4 Labor Safety ....................................................................................................... 79 9.4.1 Prevention of Fire and Explosion ................................................................ 79 9.4.2 Electrical damage prevention ....................................................................... 79 9.4.3 Mechanical damage prevention and crash damage prevention .................... 80 9.4.4 Flood prevention and drowning prevention ................................................. 80

9.5 Industrial Sanitation ........................................................................................... 80 9.5.1 Noise proof and vibration proof ................................................................... 81 9.5.2 Temperature and humidity control ............................................................... 81 9.5.3 Lighting and illumination ............................................................................ 82 9.5.4 Dust proof, antifouling, anti-corrosion and antitoxin .................................. 82 9.5.5 Anti electromagnetic radiation ..................................................................... 82

9.6 Safety and Health Facilities ................................................................................ 82

9.7 Safety Precautions .............................................................................................. 83 9.7.1 Labor safety precautions .............................................................................. 83 9.7.2 Emergency measures ................................................................................... 83

Chapter 10 Inundation Treatment and Land Requisition ..................................... 85

10.1 Overview .......................................................................................................... 85

10.2 Design Basis ..................................................................................................... 85 10.2.1 Laws and Regulations, Specifications and Codes ...................................... 85 10.2.2 Design data................................................................................................. 86

10.3 Inundation Treatment ....................................................................................... 86

10.4 Land Requisition of the Project ........................................................................ 86

Chapter 11 Water and Soil Conservation ................................................................ 87

11.1 Principles and Standards ................................................................................... 87

11.2 Project and Overview of Project Area .............................................................. 87 11.2.1 Overview .................................................................................................... 87 11.2.2 Status and Prevention of soil erosion ......................................................... 88

11.3 Forecast of Water and Soil Erosion .................................................................. 88 11.3.1 Forecasting Basis ....................................................................................... 88 11.3.2 Forecasting Time Period ............................................................................ 88 11.3.3 Content and Method of Forecast ................................................................ 89 11.3.4 Forecast results and comprehensive analysis ............................................. 89

Feasibility report of Chipota falls hydropower station

1

Chapter 1 General Information

1.1 Overview

The China - Zambia Renewable Energy Technology Transfer Project carried out

jointly through cooperation by UNDP, Zambia Ministry of Mine Energy and Water

Resources and Ministry of Science and Technology of the People’s Republic of China,

is focusing on the rural electrification in Zambia. By way of capacity building and

demonstration projects, this project will absorb and utilize the Chinese experience to

promote social and economic development in Africa. The project term is 4 years.

CHIPOTA FALLS hydropower station (hereinafter referred to as CHIPOTA

hydropower station) is located on the MULEMBO River, CHELA TAMBULE village,

SERENJE region of the Central Province of Zambia, 400 km away from Lusaka, the

capital. The geographical location of the site is latitude 13°13' 4.8" S, and longitude

30°25' 52.24" E. The river is the third-order tributary of Zambezi River (first-order

tributary is the Luangwa River, and the second-order tributary is Lukasashi River).

The river originates from the Muchinga Mountains, and the source is at an elevation

of 1615m. Above the dam site, the length of the river is about 25.8km, the average

gradient ratio is about 6‰, and the catchment area is about 140km2.

The installed capacity of the project is 2 x 100kW, with a design head of 45.38m,

and a design flow of 0.68m3/s. The average annual power generation capacity is

1.3553 million kWh, with annual installed utilization hours of 6777 hours. The main

works consist of the dam, penstock, power house, tailrace and booster station.

Through the site survey, data collection and sorting in June 2016, a Feasibility

Study Report of CHIPOTA FALLS Hydropower Station was completed in late August

of 2016.

1.2 Hydrology

1.2.1 Climate The Central Province of Zambia has a mild tropical savanna climate, abundant

rainfall, and an average annual temperature of 21℃. It has three seasons throughout


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the year: from May to August, it is the dry, cool season, with the temperature between

15 ~ 27℃, a harvest season for most crops; from September to November, it is the dry,

hot season, with the temperature between 26 ~ 36℃; from December to the next April,

it is the warm, wet season, with the temperature slightly lower than the dry cool

season, and the annual rainfall concentrated in this season. According to the

meteorological data of the Hong Kong Observatory (1961~1991 year), the average

annual rainfall is 1133.6mm.

1.2.2 Hydrology There are no rain-gauge and hydrological stations near the site and rivers

surrounding the site. Thus, it lacks hydrological data.

Runoff

The CHIPOTA hydropower station has a catchment area of 140km2. Since there

is no measured hydrological data at the dam site, the runoff is calculated by

combining the field measurement with the distribution regularities of the average

monthly discharge at Shiwang’andu gauging station, which is located in Northern

Province; thus, the average monthly flow at this site will be determined using the

same process. The results obtained will be re-measured and the imputed results will

correspond to the fact. After calculation, the average annual flow at the dam site of

CHIPOTA hydropower station is 0.68m3/s, for P=25%, P=50%, P=75%. The three

design average monthly flows are respectively 1.14m3/s, 0.68m3/s and 0.4m3/s.

Flood

Since there is no measured flood data at the dam site, it is proposed to adopt the

reverse estimation of the historical flood line to work out the flood discharge, which is

figured out to be 110m3/s.

1.3 Engineering Geology

1.3.1 Landform The site is located in a platform fracture zone. Through long-term erosion of the

river, the platform broke into sections lengthwise along the river and formed

multiple-cascade waterfalls. On the left bank of the river is a dense forest and steep

mountains, and on the left of the ridge is another small tributary. On the right side of

the river are relatively flat mountains. At the elevation position where the

final-cascade waterfall is visible is a relatively flat and open sloping field, where the


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trees are flourishing but relatively sparse. A traffic road is located on the right side of

the river. Above the visible first-cascade waterfall is flat grassland, which is not

eligible for storage capacity.

1.3.2 Strata lithology The site selection is conducted without carrying out a geological survey, but

with only the general field visit. Above the dam site no adverse geological structure is

found. Portions of rocks in the section of riverbed are exposed. On the left and right

bank is flat grassland where the covering layer is not thick; thus, the excavation of

dam foundation works is relatively simple.

Below the dam site, the riverbed ladders are fault scarps, forming cascade

waterfalls. The fault scarps have no signs of further development towards the

upstream. The rock is dark red, and should be karst-rock, a kind of basalt. It is hard.

The area for the plant is a gentle sloping field with exposed rock. The rock

property is same as that of the riverbed.

1.3.3 Natural building materials The adjacent area of the site is the basalt area, the stone of which is suitable for

water conservancy engineering. In the valley near the site, there is silver sand,

however, which is of high silt content and is only suitable to be used as mortar, but

not structural parts. The timber is mainly weed trees, which can be used as auxiliary

material of scaffolding, while the building materials need to be purchased.

1.4 Engineering Tasks and Scale

1.4.1 Necessity and advantage The area is rich in mineral resources, forests and water resources, but the

development level is not high. The local people mainly live on crop farming. The

social and economic conditions in the region are still at a moderate level in Zambia.

The population near the site is about 15,000. It is where the headman

KABAMBA resides, where there are communities, a primary school, junior high

school (high school to be built), hospital and local court. It is understood that the

residents here basically have no access to electricity for lighting and other living

conveniences; and only a few residents get lighting electricity through household

solar energy devices. It is very necessary to build a power station to supply electricity

for lighting and the processing of agricultural products.


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Additionally, the development of CHIPOTA hydropower station can enhance

the development of mineral and tourism resources, to promote local economic

development rapidly and stably. At the same time, the project will improve the

electrification, while reducing the consumption of biological fuel and improving the

ecological environment. Therefore, the construction of CHIPOTA hydropower station

is critical.

1.4.2 Project scale The proposal of installed capacity is based on the requirements of recent

household and production use and a 5~10 year projection to ensure that the waterfall

landscape does not change greatly. According to calculations, the recent maximum

household electricity load is 120kW, the guaranteed output power of the site is

154.72kW (P=75%), and the average output power is 246.87kW. Therefore, it is

relatively reasonable to choose the installed capacity of 2×100kW. The index of the

hydropower station is in Table 1-1.

Table 1-1 Calculation Results of Hydropower Index

Item Index

CHIPOTA Hydropower Station：

Design head（m） 45.38

Guaranteed discharge（m³/s） 0.40

Guaranteed output（kW） 154.72

Installed capacity（kW） 2×100

Average annual generation(kWh） 1355,300

Annual utilization hours（h） 6777

1.5 Project Layout and Main Buildings

1.5.1 Engineering scale and building level CHIPOTA hydropower station is a hydropower project mainly for power

generation, with a maximum dam height of 3.5m and an installed capacity of

2×100kW. According to the Design Code for Small Hydropower Station

(GB50071-2002) in China, this project is categorized as level V, whose main


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buildings, i.e., the dams, powerhouses and penstocks and other temporary buildings,

are categorized as level V. Each building level and the corresponding flood standards

are listed in Table 1-2:

Table 1-2 Building Level and Flood Standards

Building Level Flood Standards（Return Period）

Design Calibrated

Dams 5 10 20

Powerhouses 5 20 50

Penstocks 5 10 20

Other temporary buildings 5 5 Note: Due to the lack of flood data, the actual calibrated flood is estimated to be

110m3/s (Chapter Hydrology).

1.5.2 General project layout The power station project consists of a dam, penstock, powerhouse, tailrace and

booster station. The dam is arranged in an appropriate position in the upper reaches of

the first-cascade waterfall. The penstocks are laid along the right bank of the river.

The powerhouse is arranged on the gentle slope on the right bank, where the bottom

of the fourth-cascade waterfall is. The booster station is arranged by the upstream side

close to the powerhouse.

1.5.3 Main buildings The dam type is a rubble concrete gravity dam. The crest elevation is 1421.50m,

0.73m below the deck elevation of the upstream bridge. The minimum foundation

plane elevation is 1418 m. The maximum dam height is 3.5m. The length of the dam

axis is 30m. The crest width is 1.50m, and the maximum dam bottom width is 4.00m.

The upstream face is vertical, and the downstream dam slope is 1:0.7. The overflow

face uses WES curve and underflow energy dissipation is adopted.

The power generation water diversion system is arranged on the right bank of

the dam, including the water inlet and penstocks. The design flow is 0.68m3/s. The

water diversion pipelines use a steel pipe structure.

Powerhouse: The power station is the ground powerhouse and adopts a masonry

structure type and a light roof, with a length of 12m, width of 6.8m, height of 4.5m,

and powerhouse ground elevation of 1371.50m. Two sets of stand-alone 100kW


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Turgo turbine generator units are installed in the powerhouse, with a total installed

capacity of 200kW. The turbine model is XJA-W-46/1×11, and the spacing between

units is 5m.

The booster station is arranged on the upstream side of the powerhouse. The

plane size is 5×5m (length×width), and the ground elevation is 1371.5m. The main

transformer is arranged in the booster station by the side upstream from the

powerhouse.

1.6 Electromechanical and Metallic Structure

1.6.1 Hydraulic machinery After a comparison and selection of installed capacity, the power station is

installed with 2 sets of Turgo turbine generator units with a stand-alone capacity of

100kW and a total installed capacity of 200kW.

The design head of the power station is 45.38m. Through comprehensive

economical comparison, the model of the selected water turbine is XJA-W-46/1×11.

Its rated head is 46m, rated speed is 600r/min, and rated flow is 0.34m3/s.

The model of the generator is SFW100-10/740, with a rated capacity of 100kW,

and a rated voltage of 0.4kV.

Main auxiliary equipment: The model of the speed governor is CJWT-1.

1.6.2 Electrical connecting system method Residents in the vicinity of the power station basically have no access to

electricity for lighting and other living conveniences. It is understood that very few

residents get electricity for lighting through household solar energy devices. This

power station will solve the electricity utilization of 15,000 people in the vicinity.

There is no power grid nearby, thus, the station will operate off the grid. The total

installed capacity of the power station is 2×100kW, and the annual power generation

capacity is 1.3553 million kWh. It is 10km from the power station to the power

supply area, and the power is delivered to the community via 11kV lines and then

stepped down to 400V/200V to the users.

1.6.3 Main equipment selection The triad NDK-2001 low voltage unit intelligent control panels have been

selected as the generator voltage side controller and power distribution unit. Each is

inbuilt with a ME-630A type air circuit breaker. A ZR-VV22-95mm2 type flame


7

retardant PVC insulated cable has been selected as the generator terminal lead,

running with one line per phase.

The 11kV line side switch equipment is of outdoor type. A ZW8-12/630 type

vacuum circuit breaker and isolation switch GW9-12/630 is adopted.

In order to support the generator capacity, the main transformer has adopted a

three-phase oil immersed natural cooling copper core double winding transformer,

which is designed according to the main wiring. The model number is S11-250, 11 ±

5%/0.4kV, and the capacity is 250kVA.

1.6.4 Metal structure The power station is a diversion type hydropower station mainly for power

generation. The metal structured equipment includes one metallic gate (including the

supporting hoist), one φ300 flushing gate valve, one trash rack, a 69t penstock with

accessories, and 6 expansion joints. The distance between the dam and the

powerhouse is short, and the gate hoisting equipment is small in size and of low

operating frequency. If adopting an electric device to control the hoist, the cost will be

high and the maintenance difficult, so we chose to adopt a manual device for it.

The length of the main pipe of the penstock is 530m with a diameter of 650mm,

and wall thickness of 6 ~ 8mm.

1.7 Project Management

CHIPOTA hydro power station is located on the MULEMBO River where

headman KABAMBA lived, in CHELA TAMBULE village, SERENJE area, Central

Province, Zambia. This is a hydropower station mainly for hydropower generation

with an installed capacity of 200kW. During the construction period, a construction

project department shall be established to perform the function of administration; after

the project is built, it will be transferred to the owner who will perform the permanent

operation and administration functions of the project.

1.8 Construction Management Plan

The whole project is arranged on the right bank, where the slope along the river

bank is gentle, and there is more available construction space. Therefore, it is

considered to make use of the existing terrain conditions for production and living


8

during the construction period. The general construction planning principles are: take

construction needs of the main works as the center; make an overall plan; make a

compact layout; fall fewer trees; and make it easy for management. The layout of all

of the construction facilities should: meet the needs of the construction process and be

consistent with the relevant local safety, fire prevention, health and environmental

regulations, etc.

1.9 Labor Safety and Industrial Sanitation

Labor safety includes fire prevention, explosion-proofing, electrical damage

prevention, mechanical vibration hazards prevention and noise dampening. In

addition to making fire protection engineering facilities in the powerhouse, it also

needs to strengthen the fire prevention education. Open flame is strictly prohibited in

the powerhouse. Pressure vessels are all equipped with pressure relief devices, so all

personnel need to take strict precautions against explosion. It is required to regularly

check all of the electrical equipment and the electrician-used safety tools. In the initial

power generation scheme, the electrical part of the power distribution unit, which may

come in contact by the operating personnel, shall be installed with protective railings

and safety signs.

In terms of the structures like the working platform, pedestrian channel, the

various holes, pits and gate slots, water collection wells, hanging hole, shaft and so on,

the fall height of which is more than 2.0m, a 1.2m high fixed protective railing needs

to be installed. A check valve shall be installed on the water pump drainage pipeline

of the mechanical drainage system to prevent water intrusion.

Noise reduction should be made by reasonably arranging the noise sources.

Arrange the main noise sources, such as the main transformer station and switch

station, in the location of the duty room which is far away from the power house. The

partition wall shall be arranged between the duty rooms to reduce the chance of

hearing loss to the operator on duty.

1.10 Submerge and Land Requisition

The dam of the CHIPOTA hydropower station is very low. Below the normal

water level is the natural river course where there is no farmland or submerged houses;


9

thus, there is no submerge loss. According to the geological survey results at the dam

site, both sides of the dam have good stability, and no bank landslide will be caused

after the dam is completed.

According to the junction layout and construction organization design of the

power station, the permanent project land occupied by the CHIPOTA hydropower

station is about 4500m2, which is mainly used for the powerhouse, booster station,

water diversion and power generation system. Temporarily occupied land for the

project construction use is 2000m2, which will be mainly temporarily occupied by a

slag disposal pit and construction enterprises.

1.11 Water and Soil Conservation

The possible newly increased water and soil loss area due to this project mainly

includes the excavation surface area in the main works area, living quarters,

permanent road excavation surface area, material field excavation and stripping area,

slag disposal pit surface area, and temporarily occupied land area, equaling a total of

6500m2.

Prevention and control measures: the prevention and control of the newly

increased water and soil loss area in the project construction area should be led by

engineering measures, such as building flood control and slag blocking structures in

the slag disposal pit; building a slag ridge and drainage around the material field and

construction working face; building drainage ditches on both sides of the construction

road; making use of the control and fast-acting property of the engineering measures

to ensure the recent construction waste slag and solid waste is not out of the ditch and

will not be dumped into the river.

Investment budget estimate: the water and soil conservation project of the

CHIPOTA hydropower station is a supporting project of the main works. The project

mainly includes the soil and stone material field, the abandoned material field, the

temporary construction land and the water and soil conservation design and control.

The remediation content is slag blocking, sod revetment, drainage and greening. The

total investment of the water and soil conservation is 10,600 USD.

Feasibility�report�of�Chipota�falls�hydropower�station�

10

1.12 Environmental Impact Assessment

The CHIPOTA hydropower station does not produce waste water, waste gas or

waste residue. The beneficial effects come forth after the implementation of the

construction, and it will be great and lasing for a long period. While the negative

effects may come forth mainly in the implementation process of the construction, it

will be small and lasting only a short period. The requisition of the land is irreversible,

but the other negative effects can all be reduced by adopting certain measures, and

there will be no limiting factors restricting the launch of the project.

The waste water in the construction will be discharged into the river after

treatment in the primary treatment pool, which will be set near the aggregate flushing

field and construction area of the gate and dam project. The waste oil produced by

mechanical maintenance will be treated by building a horizontal-flow type oil-water

separation tank. The sanitary sewage will be treated by a septic tank. Transport

vehicles must be installed with an exhaust buffer to ensure standard vehicle exhaust

emissions requirements. At the same time, the control of construction mechanical

noise will be managed. Supervision and management will set up a specialized

environmental protection management institution to monitor sanitary conditions,

water quality and noise.

The increased investment for the project environmental protection is 8,800

USD.

1.13 Project Cost Estimates

1.13.1 Compilation basis 1) The construction shall be implemented on the basis of the Budget Estimate

Quota of Water Conservancy Construction Project issued by the Ministry of Water

Resources, the People’s Republic of China in 2002

2) The installation project shall implement the Budget Estimate Quota of Water

Conservancy and Hydropower Equipment Installation Project issued by MWR of the

People’s Republic of China in 2002

3) The construction machinery time and cost shall be implemented on the basis

of the Time Cost Quota of Water Conservancy and Hydropower Project Construction

Machinery issued by the Ministry of Water Resources of the People’s Republic of


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3) Comprehensive assessment of the investigation and study: there are no

environmental factors limiting the construction of the project. From the perspective of

environmental protection, the project is feasible.

The project has a superior geographical location and significant social benefit. It

is technically feasible with good conditions for the construction. It will play a positive

role in promoting sustainable and stable economic development in the region.

1.15.2 Suggestions for future 1) To investigate the hydrogeological information of the project site, providing

reliable basis for hydrological calculation.

2) To optimize the design of various hydraulic structures.


13

Table 1-3 Engineering Characteristic Table

S. No. Name of index Unit Parameter Remark

I Hydrology MULEMBO

River

1 Catchment area km2 140

2 Average annual rainfall mm 1133.6

3 Average discharge m3/s 0.68

II Characteristic water level

（I） Powerhouse

1 Submerged water level m 1369.50

III Water diversion system

（I） Dam

1 Dam axis length m 30

2 Dam height m 3.5

3 Crest elevation m 1421.50

4 Crest width m 1.5

5 Bottom width m 4.0

（II） Penstock Outdoor steel tube

1 Main pipe length m 530

2 Main pipe inner diameter mm 650

3 Fork tube diameter mm 400

4 Wall thickness mm 6-8

5 Design total discharge m3/s 0.68

（III） Powerhouse

1 Ground elevation m 1371.50

2 size (L * W* H) m 12×6.8×4.0

3 Mounting elevation of turbine m

1372.08


16

Chapter 2 Hydrology

2.1 Overview of the Drainage Basin

The CHIPOTA hydropower station is located on the MULEMBO River (where

the headman KABAMBA is located), CHELA TAMBULE village, SERENJE region

of the Central Province of Zambia. The river is the third-order tributary of Zambezi

River (first-order tributary is the Luangwa River, and the second-order tributary is

Lukasashi River). The river originates from the Muchinga Mountains, and the source

is at an elevation of 1615m. The length of the river above the dam site is about

25.8km and the average gradient ratio is about 6‰. The catchment area is about

140km2.

2.2 Climate

The central province of Zambia has a mild tropical savanna climate with

abundant rainfall, and an average annual temperature of 21℃. It has three seasons

throughout the year: from May to August, it is the dry cool season, with the

temperature between 15 ~ 27℃, a harvest season for most crops; from September to

November, it is the dry, hot season, with the temperature between 26 ~ 36℃; from

December to April, it is the warm, wet season, which has a relatively lower

temperature than the dry cool season and the annual rainfall concentrated in this

season. According to the meteorological data of the Hong Kong Observatory

(1961~1991 year), the average annual rainfall is 1133.6mm. The rainfall data is in

Table 2-1 below.

Table 2-1 SERENJE Rainfall Records

Climate data Year January February March April May June Total

Rainfall (mm) 1961-1991 279.4 251.6 155.8 42.6 5.3 10.3

Climate data Year July August Septem Octobe Novemb Decembe 1133.6


17

ber r er r

Rainfall (mm) 1961-1991 0.3 0.3 0.6 15 110.9 261.5

Note: The geological coordinates of the weather station: latitude 13.2°S,

longitude 30.2°E, cited from the Hong Kong Observatory

2.3 Basic Hydrological Data

2.3.1 Hydrological station network and information There are no rain-gauge stations or hydrological stations near the site and rivers

surrounding the site. Thus, it lacks hydrological data.

According to the Site Selection Report of Chipota Falls, Chilambwe Falls and

Nyinaluzi Sites prepared by the International Center on Small Hydro Power, in order

to identify the data of the section runoff, the engineers concluded the value to be 1.3

m3/s through field measurement and identified this value as the monthly average in

April. They used the distribution regularities of the average monthly flow at

Shiwang’andu gauging station located in the northern province to work out the

average monthly flow of the whole year. Based on the average monthly flow series,

they were able to calculate the average monthly flow duration curve of the CHIPOTA

FALLS hydropower station site.

Table 2-2 Annual Flow Conversion Table of Average Monthly flow at CHIPOTA

FALLS SITE

Month 1 2 3 4 5 6 7 8 9 10 11 12

Shiwang’andu

average monthly

flow

12.9 15.5 18.4 15.4 10.9 8.4 7.1 5.5 4.2 3.2 3.2 7.5

Convert coefficient

1.3/15.4≈0.0844

CFS average monthly discharge

1.08 1.30 1.55 1.30 0.92 0.71 0.60 0.46 0.35 0.27 0.27 0.63

F

2.3.

the

mea

whi

that

mea

feas

freq

Figu

Figure 2-1 A

2 ApplicatiAfter acq

site, in ord

asurement s

ich is very

t the averag

asurement v

sibility study

They ra

quency and

ure 2-2 Ave

Feas

Average mo

on of the daquiring the

der to veri

survey of th

close to the

ge monthly

value in A

y will adop

anked the "G

draw the fre

erage month

sibility report of

onthly flow

ata above men

fy the relia

he flow in J

e converted

flow durat

April is con

t the above

GFS averag

equency cur

hly flow freq

of Chipota falls

18

duration cu

ntioned ave

ability of t

June 2016.

d average v

tion curve a

nsistent wit

results for r

ge monthly

rve.

quency curv

hydropower st

urve of the C

erage month

he data, th

The averag

value, which

acquired thr

th the actu

relevant cal

flow" in Ta

ve of the CH

tation

CHIPOTA F

hly flow du

he team con

ge flow in J

h is 0.71m3

rough conv

ual results.

lculation.

able 2-2 to

HIPOTA FA

FALLS SITE

uration curv

nducted a

June is 0.7m

3/s. This sh

verting the

Therefore,

make empi

ALLS SITE

E

ve at

field

m3/s,

hows

field

the

rical


19

2.4 Runoff

The hydrological data is limited and the project is very unique. The power

station only needs to meet the community households’ demand for electricity;

therefore, there will be no damage to the waterfall landscape. Considering that the

only power supplier requires a high guarantee rate, the design guarantee rate is 75%.

Please check the frequency curve and Q75%=0.4m3/s which supports this claim.

Table 2-3 CHIPOTA Station Site Design Monthly Runoff Table

Item Design monthly runoff (m3/s)

25％ 50％ 75％

CHIPOTA

hydropower station 1.14 0.68 0.40

2.5 Flood

According to the introduction of headman KABAMBA at the location of the

MULEMBO River, floodwaters will submerg the road bridge upstream the dam site.

The bridge is 1422.23m high and 12m wide, and the riverbed elevation at the bottom

of the bridge is about 1419.50m. Assuming the depth of water at the bridge site is 3m

and the flow rate is 3m3/s, then the flood is estimated to be 110 m3/s of which the dam

will be able to accommodate.

2.6 Water-level Discharge Relation Curve at the Dam and Plant Site

Based on the measurement on the topographic maps of the CHIPOTA power

station in June 2016, we will intercept the river section at the dam site and plant, and

calculate the section flow by using the following formula:

Q ——cross-sectional flow 　

n ——River reach roughness

R ——Section hydraulic radius

AIRn

Q ×= 21

321

natu

of 5

sele

disc

tabl

Tab

Wat

d

Dis

Watpl

Dis

Accordin

ural river co

5‰, and the

ecting the tu

charge, and

le 2-4.

ble 2-4 Wat

ter level at th

dam site (m)

scharge (m3/s)

ter level at thlant site (m)

scharge (m3/s)

Figu

Feas

I

A

ng to the fie

ourse. The s

e roughness

urning poin

correcting t

ter-Level D

e 1419.5

) 2.2

e 1366

) 3.82

ure 2-3 Wate

sibility report of

——slope

——flow a

eld survey,

slope of the

s adopts 0.0

nt of section

the contrary

ischarge Re

Dam

1420

10.58

1366.5

11.23

er-level Dis

of Chipota falls

20

of the hydra

area, m2

the river w

e water surf

04. We calcu

n, checking

y inflection

elation of th

m and Plant

1421

39.18

1367

19.93

scharge Rela

hydropower st

aulic grade

where the po

face approxi

ulated the f

the relation

amount. Th

he Natural R

Site

1422

68.41 1

1368

46.57

ation Curve

tation

line

ower station

imately ado

flow at each

n between w

he calculatio

River Course

1423 1

100.38 17

1369 1

86.73 13

e at the Dam

n is located

opts the ave

h water leve

water level

on results ar

e at CHIPO

1424 14

73.21 235

1370 13

38.20 200

m Site

d is a

erage

el by

and

re in

OTA

425

5.02

371

0.35

2.7

with

sedi

水位

（）

Figu

Sediment

The catch

h less hum

iment quant

1365

1366

1367

1368

1369

1370

1371

1372

0

水位

（m）

Feas

ure 2-4 Wate

hment above

man activity

tity in the ri

50

sibility report of

er-level Dis

e the CHIP

y effect and

iver is small

100

流

厂址水

of Chipota falls

21

charge Rela

POTA powe

d very low

l.

0 150

流量（m3/s）

位流量关系

hydropower st

ation Curve

er station ha

w water an

0 20

系曲线

tation

at the Plant

as thick gro

nd soil eros

00 25

t Site

ound vegeta

sion. Thus,

50

系列1

ation

the


22

2.8 Attached Figures

Figure 2-5 Schematic Diagram of CHIPOTA Site Upstream Basin

Fi

igure 2-6 Sc

Feas

chematic D

sibility report of

iagram of G

of Chipota falls

23

General Lay

hydropower st

yout of the C

tation

CHIPOTA PPower Station


24

Figure 2-7 Topography and Geomorphology in CHIPOTA Power Station Area


25

Chapter 3 Engineering Geology

3.1 Overview

The MULEMBO River is located in CHELA TAMBULE village (where the

headman KABAMBA resides), SERENJE region of the Central Province of Zambia.

It originates from the Muchinga Mountains. There is little geological data for this

project. After an on-site survey, the ground covering layer in the area is not thick and

rocks are exposed. Base on the preliminary judgment, the rocks at the location are

estimated to be basalts, with the rock mass being quite hard. The place is in a good

geological condition.

3.2 Regional Geology

3.2.1 Landform The site is located in a platform fracture zone. Through long-term erosion of


multiple-cascade waterfalls. On the left bank of the river there is dense forest and

steep mountains. There is another small tributary on the left of the ridge. The

mountain body on the right is relatively flat. A relatively flat and open sloping field at

the same elevation position of the last-cascade waterfall can be found. The forest there

is flourishing, but relatively sparse. Traffic passage is on the right side of the river.

The area above the visible first-cascade waterfall is flat grassland, which is not

eligible for storage.

3.2.2 Strata lithology The site selection was conducted without carrying out a geological survey but

with only a general field visit. No bad geological structure was found at the dam site

and above, and some of rocks at the riverbed are exposed and are estimated to be

basalts. The grassland on both banks of the river are flat. Thus, the excavation of the

dam foundation will be relatively simple.

The riverbed ladders below the dam site are fault scarps, forming cascade

waterfalls. The rock is dark red, and estimated to be karst-rock, a kind of basalt. The


26

rock is hard and has high compressive strength.

The area where the plant will be built is a gentle sloping field, where the rock is

exposed and the rock property is the same as the riverbed.

3.2.3 Geological structure Zambia is a typical inland country, and its territory is on a plateau with little

undulation. The landscape is hilly by appearance, with the average elevation being

above 1000m. The topography of the land slopes from the northeast to the southwest.

The Zambia River and its tributaries, the Kafue River and the Luangwa River, flow

from north to south, while the Zambezi River flows from east to west into the Luapula

River.

3.2.4 Hydrological geology The layer is generally 2-3m in thickness, not very thick where underground

water is not found. But, abundant quaternary phreatic water is distributed in the

quaternary unconsolidated formation at the small valley

3.3 Natural Building Materials

The place around the site is the basalt area, and the rock is available for water

conservancy engineering. In the valley near the site, there is silver sand; however, it is

of high silt content and only suitable to be used as mortar, but not for any of the

structural sections. The timber is mainly weed trees which can be used as auxiliary

material for scaffolding, while the building materials will need to be purchased..

3.4 Conclusions and Suggestions

1. The penstock anchorage block (pier) foundation is made of gravel soil or

gravel containing low liquid limit clay as the bearing layer. The characteristic values

of the bearing force are 260kPa and 220kPa respectively.

2. The soil covering where the plant foundation will be built is very thin; thus, a

masonry foundation should be used.


27

Figure 3-1 Regional Geological Structure


28

Chapter 4 Engineering Tasks and Scale

4.1 General Situation

4.1.1 Physical geography

Zambia is located in the inland plateau in the middle, southern part of the African

continent. The elevation ranges between 1000m to 1500m for most of the region,

sloping from northeast to southwest.

Zambia has a mild and cool tropical savanna climate, with an average annual

temperature between 18～20℃. It has three seasons: from May to August, it is the dry,

cool season, with the temperature between 14 ~ 32℃, a harvest season for most crops;

from September to October, it is the dry, hot season, with the temperature between 26

~ 32℃; from November to April, it is the warm, wet season, with the temperature

lower than the dry and cool season. Most of the rainfall in a year occurs during this

season. Annual rainfall is about 1400mm in the northern part, gradually reduces

toward the southern part to 700mm.

CHIPOTA hydropower station is located on the MULEMBO River (where the

headman KABAMBA resides), CHELA TAMBULE village, SERENJE region of the

Central Province of Zambia. The river is the third-order tributary of Zambezi River

(first-order tributary is the Luangwa River, and the second-order tributary is

Lukasashi River). The site is 400 km away from Lusaka, the capital. The geographical

location is latitude 13°13' 4.8" S, longitude 30°25' 52.24" E.

4.1.2 Social and economic situation

The main economic pillars in Zambia include agriculture, mining and services.

The economy is heavily reliant on the copper mining industry. Therefore, its economy

often fluctuates with the changes of mineral industry. In order to change this situation

and promote sustainable development, the government has decided to implement

economic diversification and market oriented economic policies, focusing on the

development of agriculture, tourism, gem development, hydropower and other


29

competitive industries. At present, the economy has achieved continuous growth in

successive years. According to the statistics in 2014 made by the World Bank,

Zambia's GDP and GDP per capita were 27.07 billion USD and 1802 USD

respectively. The actual growth rate and inflation rate in 2014 were estimated to be

5.6% and 7.9%. Therefore, Zambia has a lower middle-income economy.

4.1.3 Hydropower resources and the development and utilization situation Africa has 40% of the world's hydropower resources, but suffering a power

shortage. But, only 8% of the hydropower resources of the entire African continent

have been developed. At present, there are still more than 500 million people without

access to electricity services, and electrification is particularly important in rural areas.

Most small hydropower stations are located in remote rural areas, and they play an

important role for the electrification, promotion of local production, improvement on

living standards and employment in these areas.

Zambia is located in the middle southern part of Africa with abundant water

resources, accounting for 45% of Southern Africa’s water resources. The hydropower

potential is preliminarily estimated to be 6765MW, in which 1715MW has been

developed. Therefore, Zambia has paid much attention on the investment of

hydropower projects.

4.1.4 Necessity of the project This region is endowed with a large potential of mineral resources, forest and

rich water resources, but the development level is not high. Most of the people there

rely on agriculture to make a living. The social and economic conditions in the region

are still at a moderate level in Zambia.

In the area near the site the population is about 15000. There are many

communities in the area, as well as a primary school, junior high school (high school

to be built), hospital and local court. As per investigation, the residents here have

neither electric lighting nor other electrical means of consumption. Only a few

residents achieve lighting electricity through household solar energy devices. This

project will supply electricity for household use, as well as for the processing of

agricultural products. Tt will increase the electrification and reduce the consumption

of biological fuel and improve the ecological environment. Therefore, the

construction of CHIPOTA hydropower station is critical.


30

4.2 Scale of Power Generation Projects

4.2.1 Power supply range and load forecast After consulting the Zambian side, the supply range of this project is identified

to only include the 15,000 consumers within the area of the site. Taking 10W/person

as the electricity consumption per capita, 80% as the simultaneity rate for electricity

consumption, the current maximum electricity load is 120KW. Taking the estimated

electrical consumption in the next 5~10 years and the protection of the waterfall

landscape into consideration, the installed capacity of the power station is

preliminarily identified to be 200kW, which can meet the present demands, as well

future demands.

4.2.2 Drafting of the scheme As per the topographic and geologic conditions, two schemes are drafted in the

feasibility study and compare different selections of the dam site, plant site and water

diversion method as follows:

Scheme I: The dam is about 25m upstream the existing bridge and the

powerhouse is on the flat land at the bottom of the gentle slope on the right bank of

the 4th cascade waterfall. Water is diverted to the pressure forebay through an open

canal and then diverted to the power house by penstocks.

Scheme II: The dam is located at about 25m downstream the existing bridge and

the powerhouse on the hillside half-way up the gentle slope on the right bank of the

4th cascade waterfall. Water is diverted directly from the dam to the power house by

penstocks.

The advantages and disadvantages of the two schemes are shown in table 4-1.

Table 4-1 Comparison of the two schemes

Item Advantages and disadvantages

Advantages Disadvantages


31

Scheme I

1. The dam will be upstream of the little bridge, with a shorter dam axis andsmaller amount of labor. 2. With a crest elevation of 1422m, the head loss of the open canal is small. 3. The power house is close to the riverbed, on flat ground, with small excavation quantity and short tailrace.

1. Because the dam is located upstream the little bridge, the diversion structure shall be lengthened which will go across the road, leading to an increase of labor time, and a more difficult construction and construction diversion. 2. An open canal occupies a larger area. A greater amount of excavation and abandoned slags are liable to cause soil erosion and damage the ecological environment. The construction of an open canal needs a large quantity of aggregates and a pressure forebay at the end needs to be built, so the construction period will be longer. 3. The ground elevation of the power house is low which does not meet the flood prevention requirement and will influence the safety.

Scheme II

1. The dam is located downstream the little bridge. The broad downstream riverbed supports construction diversion. 2. Penstock has little effect on the ecological environment, needs small earth-rock project quantity and short construction period and is convenient for the management and maintenance in the following operation. 3. The layout of the plant area is rational, which is in favor of the delivery and installation of the equipment. It avoids the impact of a flood, favoring the safety of the power station.

1. With longer dam axis, the project quantity is increased. 2. With a crest elevation of 1421.5m, the penstock head loss is increased.

Taking all factors into consideration, Scheme II is more suitable and is

recommended by this feasibility study.

4.2.3 Calculation of hydropower and installed capacity selection Based on the actually measured CHIPOTA topographic map and taking the

influence of backup water level and mounting elevation of the units into consideration,

the gross water head of the power station will be 50.0m. As per the preliminary layout

plan, the penstock will be about 530m long. According to the hydrological calculation,

the design average monthly flow at the site will be Q50%=0.68m3/s, which is identified

as the design reference flow. As an only power supply, the station needs a high

guarantee rate. The design guarantee rate of the power station is identified to be 75%

and the guarantee flow is Q75%=0.4m3/s.

(1) Calculation of pipe diameter

The pipe diameter is calculated as per the following formula:


32

732.5

HQD =

In the formula: D=pipe diameter（m）；

Q=Reference flow (m3/s)，Q50%=0.68 m3/s；

H=Calculated head (m)，H=50.00m；

The pipe diameter of the penstock at the CHIPOTA hydropower station is

D=0.65m;

(2) Calculation of head loss

The penstock of CHIPOTA hydropower station is 530m long, and the frictional

head loss is calculated as per the following formula:

In the formula: L=Pipe length（m），L=530m；

D=Pipe diameter（m），D=0.65m；

V=Flow rate in pipe (m/s)，V=2.05m/s；

Partial head loss is calculated as per the following formula:

∑h 局＝g

V

2

2

⋅ζ

Table 4-2 Statistical Table of the Partial Head Loss Coefficient

Loss position ζvalue Quantity Total Horn mouth 0.2 1 0.2

Bottom valve 0.7 1 0.7 Gate valve 0.1 1 0.1

Elbow and bend 0.3 3 0.9 Gate slot 0.2 1 0.2

Total 2.1 The total head loss is h△ frictional＋∑hlocal＝4.17＋0.45＝4.62m

So the net head of power station is: hnet＝50.00－4.62＝45.38m。

(3) Calculation of hydroenergy

1) Calculation of guarantee output

When the design guarantee output P=75%，the guarantee flow Q75%=0.4m3/s,

the corresponding head loss will be 1.65m and the net head is 48.35m.

When the average output coefficient is proposed to be 8.0, then the guarantee


33

output is:

Nguarantee=A×Qguarantee×Hguarantee=8.0×0.4×48.35=154.72kW

2) Calculation of average output

When the design guarantee output P=50%，the average flow Q50%=0.68m3/s,

the corresponding head loss will be 4.62m and the net head is 45.38m.

Ndesign= A×Qdesign×Hdesign=8.0×0.68×45.38=246.87kW

(4) Installed capacity selection

1) Select the installed capacity based on the guarantee output. Considering the

requirement for power supply reliability, taking 1.5 as the installation coefficient, the

installed capacity of the power station is 232.08kW.

2) When selecting the installed capacity based on the average output and the

installed capacity of the power station is 246.87kW.

When ensuring the electricity supply and the waterfall landscape, installed

capacity of the power station is preliminarily identified to be 2×100kW.


34

The index of the hydropower station is shown in Table 4-3.

Table 4-3: Table of Calculation Results of Hydroenergy Index

Item Index

CHIPOTA hydropower station:

Design head（m） 45.38

Guarantee flow（m³/s） 0.40

Guarantee output（kW） 154.72

Installed capacity（kW） 2×100

Average annual power generation capacity

（104 kW.h） 135.53

Annual utilization hours（h） 6777


35

Chapter 5 Project layout and main buildings

5.1 Design basis

5.1.1 Main technical specifications and references (1) Standard for Classification and Flood Control of Water Resources and

Hydroelectric Project SL252-2000; (2) Design Specification for Stonemasonry Dam SL25-2006; (3) Specifications for Seismic Sesign of Hydraulic Structures SL203-97; (4) Design Code for Hydropower House SL266-2014; (5) Design Specification for Intake of Hydraulic and Hydroelectric Engineering

SL285—2003; (6)Code for Fire Protection Design of Hydraulic and Hydroelectric Engineering

SL329—2005; (7) Design Criterion ofReservoir Management SL106—96; (8) Hydraulic Design Handbook.

5.1.2 Basic design information (1) Task for engineering development

With an installed capacity of 2×100kW and a design annual power generation of

1.3553 million kWh, the engineering task of CHIPOTA hydropower station is mainly

for power generation.

(2) Rock physical and mechanical indexes

Dam foundation physical and mechanical indexes adopted in the stability

analysis and calculation are as follows:

(3)Weak weathered basalt:

Bulk density:2.69-2.73g/cm³;porosity: 0.73%-1.10%;

Saturated compressive strength: 700—800kg/cm2.

Friction coefficient f rock/rock=0.55-0.65

f concrete/rock=0.60-0.65

(4) Dam body anti-slide stability safety coefficient

Basic combination (normal operation condition): Kc≥1.05

Special combination (check condition): Kc≥1.00

(5) Seismic intensity


36

With seismic intensity being less than VI degree, seismic defense will not be

considered.

5.1.3 Project grade and standards CHIPOTA hydro power station is a hydro power project aiming at power

generation, with a maximum dam height of 3.5m and an installed capacity of 2×

100kW. According to Design Code for Small Hydropower Station (GB50071-2002),

this project is a V grade project, with the dam, power house and penstock of its main

construction being in the category of 5thgrade and other temporary constructions of

the 5thgrade. See table 5-1 for the construction grade and the corresponding flood

standards.

Table 5-1 Construction grade and flood standards

Construction Grade Flood standard

（recurrence interval） Design Check

Dam 5 10 20 Power house 5 20 50 Penstock 5 10 20 Other temporary construction 5 5 Note: Due to lack of flood data, the actual check flood is estimated to be 110m3

/s.

5.2 Project location and general layout

5.2.1 Location of the dam Dam site plans

The site of the dam shall be located at a suitable place upstream from the 1st

stage waterfall. There will be a traffic bridge and road about 50m upstream from the

waterfall. With exposed rock and a shallow coverage layer, the geological conditions

are good. Both banks of the dam site are flat grasslands, without requisite conditions

for a reservoir. Through field reconnaissance, two feasible options of dam sites for

CHIPOTA hydropower station are decided: the upper site is 25m upstream from the

traffic bridge and the lower site is 25m downstream from the traffic bridge, which are

50m apart. Comparison shall be made based on the aspects of topography, geology,

flood impact, construction, water head utilization, etc., and the optimum shall be

adopted.


37

Comparison of the plans

From the view of topography: 1. Mountains on either bank of the upper dam site

are basically symmetrical. The water flow is straight and unhindered with a riverbed

elevation of 1419.70m;

2. Mountains on the banks of the lower dam site are asymmetrical with left bank

steep and right bank flat. The riverbed changes from narrow to wide with an elevation

of 1419.30m and the long dam axis is favorable for the flood discharge and energy

dissipation.

From the view of geology: the two dam sites are not far apart, with similar

lithology of the bedrock at the under-part of the riverbed and basically the same

hydrogeological condition. Both upper and lower dam sites are of granite geology

with hard and intact rock. There is no large fault passing by near the dam site that will

cause instability and leakage.

From the view of flood impact: 1. The upper dam site locates upstream from the

traffic bridge, when discharging flood, no farmland, buildings, etc., will be submerged,

so the dam height has only to meet the requirement for water diversion.

2. The lower dam site locates downstream from the traffic bridge and the

normal pool level of the dam will be restricted by the traffic bridge. When discharging

flood, the submergence depth of the traffic bridge increases (according to on-site

survey, the traffic bridge was always submerged during the flood season over the

years); however, due to less utilization of the bridge, short-term submergence will not

bring about any big effect.

From the view of construction: 1. With a shorter dam axis, the upper dam site

needs correspondingly smaller work quantities; however, its thicker covering layer

will lead to bigger excavation quantity. The diversion structure shall be lengthened

which will go across the road, leading to an increase of work quantities, harder

construction, longer construction period and harder construction diversion.

2. With a longer dam axis, the lower dam site needs larger work quantities for

the dam body; however, the work quantity for the diversion structure will be reduced,

crossing with the road will be avoided and it will be much easier for construction

diversion.

From the view of water head utilization: the normal pool level of the upper dam

site is 1422.00m, while the lower dam site is 1421.50m. With a difference of 0.5m,

the advantage in water head utilization is not obvious.


38

Through comparison, the two dam sites are near to each other, with basically the

same topographic and geologic conditions. Both have no submergence loss and little

impact from flood. They have little difference in water head. However, the upper dam

site has larger diversion structure quantities and the diversion structure spreads across

the road causing more difficult construction and diversion, as well as a longer

construction period. For the lower dam site, though its dam body quantities will be

slightly larger than the upper dam site, the length of the diversion structure will be

shortened, crossing with the road will be avoided and it will be much easier for

construction diversion at the same time.

Taking all factors into consideration, the lower dam site, which is more rational,

will be the suggested plan of this feasibility study.

Figure 5-1 Bridge near dam site

5.2.2 Location of the power house Power house site plan

The power house will be located on the gentle slope of the right bank at the same

elevation with the last stage seeable waterfall (riprap bridge). According to field

reconnaissance and topographic maps and taking the factors of water head utilization,

geological conditions, layout of the penstock, tailwater connection, basic excavation

quantity, etc., into consideration, the optimum plan shall be decided.

Plan I: The power house shall be located at the bottom of the gentle slope, in the

open area on the right bank close to the riverbed. The ground elevation is

1367.00m~1368.00m and the design elevation of the power house shall be 1367.50m.

Plan II: The power house shall be located on the slope half-way up the gentle


39

slope, with the ground elevation of 1371.0m~1373.0m and power house design

elevation of 1371.50m.


From the view of water head utilization: the ground elevation of Plan I is 4.00m

lower than Plan II, so the utilizable water head of Plan I is higher.

From the view of plant area layout: for Plan I, the plant site is flat with the gate

of the power house facing southwest and the booster station being placed behind the

power house. For Plan II, the ground elevation is higher than Plan I and there is open

ground in front of the southwestward gate which connects the access road naturally.

The booster station locates at the upstream side of the power house, which facilitates

the transport and installation of the equipment.

From the view of tailwater connection: according to the units installation

drawing, now that the bottom plate elevation of the tailwater pit is 1.55m lower than

the ground elevation of the power house and the design water depth is 0.2m, the

tailwater level of Plan I is 1366.15m, while that of Plan II is 1370.15m. Through field

survey and consultation with local residents, the submergence water level over the

years was about 1369.50m, so Plan I fails to meet the flood prevention requirement.

When a flood comes, there is a risk of tailwater reverse flow, which affects the normal

operation of the power station.

From the view of foundation excavation quantity: Plan I has an open and flat

ground, needing smaller foundation excavation quantity while Plan II needs a slightly

larger foundation excavation quantity than Plan I.

Take all factors into consideration, Plan II is more rational and will be the

recommended plan of this feasibility study.

Figure 5-2 riprap bridge and sloping land near the plant site


40

5.2.3 Selection of water diversion method Water diversion plan

Based on the comparison in chapter 4, the two diversion methods of open canal

diversion and penstock diversion are proposed. Take the aspects of water head

utilization, construction condition, environment impact, project management, project

investment, etc. into consideration and choose the best the plan.

Plan I applies an open canal to divert water. The open canal is laid along the

contour on the right bank of the river course, connecting to a pressure forebay at the

end. After the forebay, there is pipeline laid along the hillside to the power house.

Plan II applies a penstock to divert water. The penstock goes out directly from

the dam to the power house along the hillside on the right bank of the river course

according to landform.


From the view of water head utilization, open canal diversion for small

hydropower station normally adopts 1/1000 canal slope with smaller water head loss

than penstocks, therefore, the gross water head in Plan I is higher than Plan II.

From the view of construction condition, the construction of open canal in Plan I

needs a large quantity of aggregates. A pressure forebay at the end needs to be built. A

lack of local labor and field mining of stone materials will lead to a slow construction

progress and long construction period. Plan II applies penstocks to divert water for

power generation directly from the dam, which requires fewer materials and a simpler

construction process, and the construction progress can be guaranteed under the

condition of less labor force.

From the view of environmental impact, an open canal in Plan I occupies a larger

area. A greater amount of excavation and abandoned slags are liable to cause soil

erosion and damage the ecological environment. While in Plan II, the laying of

penstocks needs smaller earth-rock quantities and a shorter construction period, which

causes little impact on ecological environment.

From the view of project administration, the open canal in Plan I crosses the

forest land. Litters like leaves are likely to accumulate. Regular cleaning is needed,

which increases the administrative cost. While in Plan II, the penstock is laid directly

from the dam to the power house. When water overflows the dam, litters like leaves

are not easy to accumulate, so it is convenient to maintain.


41

From the view of project investment, Plan II adopts a penstock, which will

obviously cost more than Plan I.

In sum, Plan I features a higher utilizable water head and a smaller investment.

While its disadvantages in the aspects of ecology, construction period and

administration are prominent, the loss outweighs the gain. Though the investment of

Plan II is higher, the construction progress is faster. Being environment-friendly and

convenient in maintenance, Plan II is generally more rational. Therefore, Plan II will

be the recommended plan of this feasibility study.

Figure 5-3 Slope on the right bank

5.2.4 General layout of the project According to the comparison of the plans, the power station project in Plan I

(comparative plan) consists of a dam, an open canal, a pressure forebay, a penstock, a

power house, a tailrace, booster station etc. Plan II (recommended plan) consists of a

dam, penstock, power house, tailrace, booster station, etc. The dam will be located at

a suitable place upstream from the 1st stage waterfall. The open canal or penstock will

be laid on the right bank along the river. The power house will be on the right bank

gentle slope under the 4th stage waterfall. The booster station will be placed on the

opposite side of the power house.

5.3 Water retaining structures

5.3.1 Layout of the dam The dam will be a rubble concrete gravity dam, which will be designed based on

the requirements of Design Specification for Concrete Gravity Dams DL5018-1999

and relevant laws, rules and regulations, referring to dams of the same type. It will

also take into consideration the comprehensive factors of the natural geological


42

conditions, natural building materials, the overall arrangement requirements of the

project, etc.

Plan I (comparative plan): according to the layout of the open canal, the dam

crest elevation is determined to be 1422.00m, 0.23m lower than the bridge deck. The

lowest foundation plane elevation is 1418.50m. The maximum dam height is 3.50m.

The dam axis length is 24.00m. The dam crest width is 1.50m, and the maximum dam

bottom width is 4.00m. The upstream face will be vertical and the downstream will

have a slope of 1:0.7. The overflow face uses a WES curve and underflow

energy dissipation is adopted.

Plan II (recommended plan): On the premise that the dam height meets the water

intake arrangement and hydraulic conditions, the elevation of the dam crest is set to

be 1421.50m, 0.73m lower than the elevation of the small bridge deck. The lowest

foundation plane elevation is 1418.00m. The maximum dam height is 3.50m. The

dam axis length is 30.00m. The dam crest width is 1.50m, and the maximum dam

bottom width is 4.00m. The upstream face will be vertical and the downstream will

have a slope of 1:0.7. The overflow face uses a WES curve and underflow

energy dissipation is adopted.

5.3.2 Stability calculation Since the cross sections of the two plans are basically the same, stability

calculations are the same as well. Choose one of the plans for calculation, taking Plan

II as an example:

(1) The gravity dam calculation shall be performed as per the requirements of

Design Specification for Concrete Gravity Dams DL5018-1999, shear resistance

strength formula shall be used for sliding resistance stability calculation and the

material mechanics method shall be applied in the stress calculation.

(2) Calculation conditions

Normal pool water level is 1421.50m and there is no water downstream.

Design flood level: (none).

Check flood level is 1423.00m and the corresponding downstream water level is

1422.30m.

Riverbed elevation is 1419.30m.

Shear resistance friction coefficient in riverbed stability calculation f=0.55.

(3) Load combination


43

The following three combinations of load are the control condition of gravity

dam stability calculation.

a. Basic combination: reservoir normal water level without downstream water,

self-weight of the dam and uplift pressure, etc.

b. Special combination: check flood level and corresponding downstream water

level, self-weight of the dam, uplift pressure, etc.

(4) Stress calculation results

The material mechanics method is applied in the stress calculation, see table 5-2

for the results. We can know from the table that the stress value should meet the

requirements of design specification.

Table 5-2 Stress Calculation Results unit: Kpa

Calculation condition Dam

σ1(Upstream side) σ2(Downstream side)

Basic combination 218.33 331.23

Special combination 182.98 366.58

(5) Sliding resistance stability calculation results

Shear resistance strength formula is applied for sliding resistance stability

calculation, see table 5-3 for the results. The calculation results meet the requirements

of the specification.

Table 5-3 Foundation Plane Sliding Resistance Stability Calculation Results

Calculation condition Basic combination Special combination

Dam 1.59 1.36

5.3.3 Flood discharge and energy dissipation facilities According to the design, a WES practical weir is adopted as an overflow weir.

Since the overflow weir is not high and the downstream riverbed foundation is good,

underflow energy dissipation is applied and no other dissipation engineering is

needed.

5.4 Open canal diversion method (comparative plan)

5.4.1 Open canal Plan I adopts an open canal to divert water, with a design discharge velocityof

0.68 m3/s and a canal length about 380m. The longitudinal slope adopts 1/1000. After


44

calculation, a 1.2m×1.4m canal cross section can meet the requirement and the

design water depth is 0.75m. The canal uses M7.5 stone masonry lining with M10

mortar finishing on the inner side and 100mm thick C20 concrete for the bottom plate.

5.4.2 Pressure forebay In Plan I, the water diverted from the open canal shall be regulated by a pressure

forebay before entering the penstock.

According to the layout of the project diversion system, the forebay shall be laid

on the hillside of the right bank. The design dimension of the cross section is 6.0m

long, 5.0m wide and 4.0m deep. A stone masonry side wall and 200mm thick C20

concrete inner lining are adopted for seepage prevention, and the bottom plate shall be

poured with 250mm C20 concrete.

(1) Normal water level

Normal water level of canal end, i.e., the normal water level of pressure forebay

is 1422.0m.

(2) Lowest water level

The minimum water depth to prevent pressure the forebay from producing

cyclones is calculated as per the following formula:

of which,

C=coefficient, 0.5~0.7, symmetric water intake applies the smaller value

V=water velocity inside the pipe, in full capacity operation V=2.05m/s

A=diameter of the pipe

It is calculated that the power station △h=1.22 m and the lowest water level is

1420.78.

(3) Highest water level

Considering the actual landform of the forebay, the spillway will not be set in the

forebay. Instead, it will be located close to the riverbed upstream the canal. The

overflow weir of the spillway adopts a WES practical weir, with a water depth of

0.3m, therefore, the highest water level of the forebay is:

∇H highest=1422.00+0.3+304*1/1000=1422.60m

(4) Forebay roof elevation

The highest water level of the forebay plus 0.3m safety freeboard is the roof

elevation of CHIPOTA power station

21

aVCh =Δ


45

forebay∇H=1422.60+0.3=1422.90m.

(5) Forebay width

According to the actual landform and the requirement of the forebay regulation

volume, the design net width of the forebay in CHIPOTA hydropower station is 6m.

(6) Forebay length

According to the landform and the regulation volume, the forebay length of

CHIPOTA hydropower station is 5m, the total forebay volume is 120 m3 and the

regulation volume is 75m3.

5.5 Penstock (recommended plan)

(1) Selection of the pipeline

In order to guarantee the safe operation of the penstock, the pipeline is laid

mostly along the stable ridge with the total length of the penstock’s main pipe being

530m.

(2) Configuration of the pipeline

According to the specification, an exposed penstock structural analysis method is

applied to calculate the penstock. The main pipe axis is 530m long, with 6 anchorage

blocks and 6 expansion joints along the line. The diameter of the main pipe is 650mm,

the pipe wall thickness is 6-8mm calculated as per the initial estimate formulaδ≥

[PD]/[2φ〔σ〕](the allowed stress 〔σ〕is 160Mpa) and the space between

supporting piers is 5-8m. The total weight of metal works is about 69t.

(5) Anchorage blocks and supporting piers

The anchorage block balances the axial unbalanced force caused by the turning

of the penstock by its self-weight. The anchorage blocks will be built on a rock

foundation with greater base dimensions; thus, the foundation stress will meet the

requirement and recheck will not be performed. The weights of the anchorage block

need shall be calculated as per formula ∑∑ − Yf

XKG＝

, with the safety coefficient

K=1.5, and the friction coefficient between anchorage block and rock foundation

f=0.5. The weight of each anchorage block is calculated and listed in the following

table. Anchorage block 6#, with a larger size and buried underground, will be used in

the bifurcation of the main pipe and needs no calculation.

Anchorage Block center Block center Weight for Volume for Actual


46

block No. elevation (m) design water

head (m)

block

calculation (t)

block

calculation (m3)

volume of the

block (m3)

1# 1420.00 1.50 86.08 35.87 36.75

2# 1417.00 4.50 77.75 32.40 32.40

3# 1411.75 9.75 22.22 9.26 18.00

4# 1406.05 15.45 25.66 10.69 18.00

5# 1388.30 33.20 25.64 10.68 18.00

The supporting pier balances the normal component forces from the weights of

the penstock, the water inside the pipe, the friction force between the steel pipe

support and the pier by its self-weight. With greater actual volume and most of it

being buried underground, the supporting pier bears smaller horizontal force; thus, the

requirements can be met.

5.6 Power house and booster station

5.6.1 Selection of the power house location The power house is of the diversion type ground power house. It will be placed

on the right bank gentle slope under the 4th waterfall, taking factors of topographical,

geological and traffic conditions into consideration. According to the comparison of

the power house site plans, Plan II is more rational than Plan I. The power house shall

be located halfway up the gentle slope, with a ground elevation of 1371.00m~

1373.00m, and a power house design ground elevation of 1371.50m. The design

tailwater level is 1370.15m, 0.65m higher than the submergence water level.

5.6.2 Power house structure The power house applies a masonry structure. According to the layout and the

mounting requirements of the generators, the space between generators shall be 5.0m.

The dimension of the power house is 12×6.8×4.5m and the roof applies a light, steel

roof truss.

5.6.3 Booster station The booster station is placed on the opposite side of the power house, with a

plane dimension of 5×5m and the ground elevation of 1371.50m. The main

transformer is located at the side close to the power house.


47

5.6.4 Housing for the use of administration The housing for the use of administration applies a masonry structure, which is a

1-story, 2-bay building very near to the entrance road, with an area of 20m2.

After the completion of the main works in the plant area, treatment shall be taken

to the disturbed slope and the revetment. Afforestation and beautification of the

environment shall be carried out as well to make the plant area look tidy.

5.6.5 Entrance road The traffic is convenient in the plant area. There is only a need to select a route

from near the dam to build a road with sand-gravel pavement 3.5m wide and about

650m long.


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Chapter 6 Electromechanical and metal structures

CHIPOTA hydropower station has an installed capacity of 200kW, with 2×

100kW units installed. The model of the turbine is XJA-W-46/1×11. The model of

the two generators is SFW100-10/740. There are two speed governors, and two sets of

φ400 intake valves as well. A plane metal gate shall be installed at the intake of the

dam equipped with a 2t manual screw hoist. The dimension of the gate is（width×

height）0.9m×0.9m. There shall be a φ300 gate valve at the sand flushing orifice.

6.1 Units

(1) Power station original data

Normal water level: 1421.50m

Ground elevation of the power house: 1371.50m

Design tailwater level: 1370.15m

Installed capacity: 200kW

Installed sets: 2

Guaranteed output: 154.72kW

Annual power generation: 1.3553 million kWh

Annual utilization hours: 6777h

Design water head: 45.38m

(2) Selection of turbine type

Based on hydropower calculation, with design water head being 45.38m and a

monthly average discharge being 0.4m3/s when the design guaranteed ratio is 75%

(the guaranteed output is 154.72kW), 2 sets of units with 100kW unit capacity are

selected.

Since the water head of the power station is 45.38m, the following types of units

can be suitable: Francis turbine, Turgo turbine and cross-flow turbine. Below is a

comparison of the representative units that suit the water head of the power station.

The Francis turbine gives higher efficiency at rated point and higher utilization

of water head; however, it’s more complicated than the other two, and with a smaller


49

runner it is more difficult to manufacture. The efficiency of Turgo turbine is relatively

lower, but with a simple structure it is convenient to maintain and it has a wider

working condition range at rated point. The cross-flow turbine has higher efficiency

than the Turgo turbine, a simple structure and smaller unit power output; however,

there are fewer factories producing this type at the present. After comprehensive

comparison, model XJA-W-46/1×11 units are selected.

Turbine model： XJA-W-46/1×11.5

Rated water head： 46m

Rated discharge: 0.34m/s

Rated output: 111kW

Rated rotation speed: 600r/min

Generator model: SFW100—10/740

Rate capacity: 100kW

Rated voltage: 0.4kV

Power factor: 0.8

Speed governor model： CJWT-1

Excitation: generator matched static silicon controlled excitation

Intake valve model：Z941H—10φ400

(4) Selection of the auxiliary equipment

a. Inner plant hoisting machine

In the installation of the units, the maximum hoisted parts in the plant are 2.5t.

Mobile profiled-steel-made supporting frame is adopted, equipped with a manual

hoist with a lifting capacity of 5t.

b. Technical water supply system of the units

Technical water supply shall be determined by the manufacturer of the units.

c. Drainage system

The cooling water and other seepage water shall be drained directly to the

downstream riverbed.

d. Oil system

The quantity of turbine oil and insulation oil in this power station is small, so two

0.2m3 gasoline barrels shall be equipped.

e. Maintenance tools

In order to meet the requirements for maintenance and exchange of operating


50

units and the auxiliary equipment, this power station shall be equipped with one set of

tools for routine maintenance.

Table 6-1 Hydraulic mechanical equipment table

No. Name Equipment specification & model

Quantity

1 Turbine XJA-W-46/1×11 2 sets

2 Generator SFW100-10/740 2 sets

3 Speed governor CJWT-1 2 sets

4 Excitation Static silicon controlled excitation

2 sets

5 Intake valve Z941H-10φ400 2 sets

6.2 Access mode to power system and main electrical connection

6.2.1 Access mode to power system The residents in the nearby areas of the power station mostly have no access to

illumination and other household electricity. It is known that very few residents have

solved the problem of illumination through household solar devices. This power

station will power a population of 15,000 in the nearby areas. There is no power grid

nearby, thus, the station will operate off the grid. The total installed capacity of this

power station will be 2×100kW and annual power generation will be 1.3553 million

kW.h. The distance from the power station to the supply area is 10km. A 11kV line

will be adopted to deliver electricity to the community. After the voltage is reduced to

400V, the electricity will be supplied to the users.

6.2.2 Main connection (1) Connection of the generator voltage side and increased voltage side

There are 2 sets of units in this power station. The rated voltage of the generator

is 0.4kV. There is one single circuit of outgoing line from the high voltage side,

without nearby loads. According to the combination of generator and transformer, the

two types of main connection schemes are analyzed, see figure 6-1 for details.


51

Scheme 1 Scheme 2

Figure 6-1 Scheme 1: Enlarging unit connection is adopted at the generator voltage side and

the two units share one main transformer; transformer-line group connection is

adopted at the increased voltage side. Connection of this scheme is simple and clear

and is convenient to maintain. It simplifies the connection at the high voltage side,

occupies less land and needs smaller excavation and less investment. Its disadvantage

is that when the main transformer is under failure or overhaul, the electricity from the

two generators can’t be transmitted. However, the failure rate of the main transformer

is low, requiring longer overhaul cycle and shorter outage time.

Scheme 2: Unit connection is adopted at the generator voltage side, with one unit

connecting to one transformer; Single bus connection is adopted at the increased

voltage side. This scheme operates flexibly. With small failure influence range and

simple relay protection, it features higher reliability. However, there will be more high

voltage electrical equipment, leading to increases of space for equipment layout and

investment on the whole electrical connection. Based on the above analysis and considering the actual operation experience of

small-sized hydropower station, scheme 1 is recommended.

(2) Plant electricity, power supply to the plant area and dam area

The rated voltage of the generator is 0.4kV, so the plant electricity and the power

supply to the plant area will come directly from the 0.4/0.23kV voltage bus of the

generator.

One set of DC220/50Ah DC system shall be equipped.

Please refer to enclosed Main Electrical Connection Diagram.


52

6.3 Selection of main electromechanical equipment

6.3.1 Short circuit current Because it operates as an independent system (take 0.8 as the power factor of the

system and 25kVA as the contralateral breaking capacity), the short circuit current of

the recommended electromechanical connection scheme is calculated. See Figure 6-2

for the system connection and equipment parameters and table 6-2 for the calculation

results of short circuit current.

10KVLG-3510Km

Figure 6-2

Table 6-2 The calculation of short circuit current

Short circuit point

T＝0s Short circuit

current（KA）

T＝0.6s Short circuit current

（KA）

T＝1s Short circuit

current（KA）

Short circuit current peak value（KA）

d1 1.52 1.48 3.82

d2 6.94 3.87 18.01

6.3.2 Selection of the main electrical equipment The selection of electrical equipment form bases on the principle that it should

be advanced in technology, rational in economy and simple and convenient in

maintenance. It should also meet the requirements of latest regulations and

specifications.

Technical parameters of the electrical equipment are selected under normal

working conditions and the performances of the electrical equipment are examined as

per different short circuit circumstances. Both of the above two should be met at the

same time.

Preliminary selection

The control and distribution devices at the generator voltage side will apply a


53

triad NDK-2001 low voltage generator unit with intelligent control panels, inside of

each installed with a ME-630A air circuit breaker, which is safe and reliable in

operation and convenient in maintenance. The outgoing lines of the generator will

adopt a ZR-VV22-120mm2 flame retardant PVC insulated cable, with one single line

per phase.

The switching device at the 11kV line side is of outdoor type, using a

ZW8-12/630 vacuum circuit breaker as its circuit breaker and GW1-10/630 as its

disconnector.

To match with the capacity of the generator, the main transformer will apply a

three-phase oil-immersed two copper core winding transformer with natural cooling.

According to the main connection design, its model is S11-250, 12.1±5%/0.4kV,

with a capacity of 250kVA.

Key parameters of the main electrical equipment with voltages of each level are

shown in enclosed diagram.

Check the equipment with short circuit current To simplify the calculation, take the total current of the corresponding short

points as the short circuit current to check the equipment. The full opening time of the

circuit breaker is 0.1s. Back-up protection action time at the 11kV side is 0.5s and the

thermal stability calculation time is tjs=0.6s; protection action time at the 0.4kV side

is 1s and the thermal stability calculation time is tjs=1s.

All the equipment selected has been checked to be acceptable.

Generator excitation

The generators in this power station adopt static silicon controlled excitation

system, which is powered directly by the generator. The excitation system shall be

supplied by the manufacturer of the generators.

Plant-service power supply and DC system

Plant-service power supply adopts a GGD distribution panel.

DC system of this power station adopts non-maintaining lead-acid battery, with

complete sets of DC equipment with a rated voltage of 220V and a capacity of 50 AH.

As the DC power source of the station, it shall meet the requirement for DC loads in

the operation of automatic devices for plant control, protection and safety, the

operation of circuit breakers, emergency lighting, etc.


54

6.4 Layout of the electromechanical equipment

This power station applies a diversion-type ground power house located at the

right bank of the riverbed. The mounting site is at one side of the entrance gate of the

power house.

6.4.1 Inner-plant electrical equipment layout According to the layout characteristics of the main electrical connection and low

voltage horizontal hydro-generator, the two triad panels of the generator, two

excitation panels, one plant service panel and one DC panel shall all be placed at the

downstream side of the units.

6.4.2 Layout of the booster station According to the key project layout, topography and geomorphology near the

power station and the direction of the incoming and outgoing lines, the booster station

is located close to the power house opposite to the entrance gate of the power house.

This arrangement is simple and clear, featuring unhindered incoming and outgoing

lines, compact arrangement and less occupation of area.

Table 6-3 Electrical equipment material No. Name Specification Unit Qty A Generator & equipment nearby 1 Units control panel NDK-2001 pc 2 2 Excitation panel NWLC pc 2

3 Shared panel for wiring and main transformer

GGD-02 pc 1

4 Battery and charging feedback panel

pc 1

5 Plant electricity distribution box pc 2

B Main transformer and booster station equipment

1 Transformer S11-250/11 12.1/0.4kV set 2 2 11kV circuit breaker ZW8-12/630，630A set 1 3 11kV disconnector GW1-10/630A set 1 4 Voltage transformer JDZXW-11 set 1 5 11kV arrester YH5WS-12.7/50 set 1 C Conductor and cable 1 Cable ZR-VV 22-120，1kV m 200 2 Cable ZR-VV 22-70，1kV m 180 3 Cable ZR-VV-3×10+1×6, 0.6/1kV m 20 4 Cable kVVP7*1.5 m 300 D Lighting luminaire Indoor and outdoor set 1


55

E Auxiliary equipment 1 Electricity pole Steel structure set 2

2 Pin insulator pc 3

3 Suspension insulating strip pc 6

4 Ball-end hoist pc 3

6.5 Metallic structure

This is a diversion-type power station mainly for power generation. Metallic

equipment includes two metallic sluice gates (including the hoisting machine), one

φ300 sand flushing gate valve, one trash rack, 69t penstocks and accessories and 6

expansion joints. The dam is very near to the power house, so the hoisting equipment

is small scaled and seldom used, therefore, manual actuator shall be adopted.

The details of the metallic structure is shown in table 6-4.

6.5.1 Dam and metallic structures at the water intake a. Working gate and the hoisting equipment at the intake

There shall be a plane metallic sluice gate at the intake of the dam with a 2t

manual screw hoist.

Technical properties of the working gate and its hoisting equipment are as

follows:

Dimension of the orifice（width×height）: 0.9m×0.9m

Design water head: 2～4m

Orifice type: open

Sluice gate type: metallic gate

Sluice gate dead weight: 0.85t

Orifice number: 1 orifice

Sluice gate number: 1

Hoisting machine: 2t manual screw hoist

b. The trash rack at the intake is arranged with an angle of 70°, as per hydraulic

requirement and shall be cleaned manually.

Main technical properties of the trash rack are as follows:

Dimension of the orifice（width×height）: 1.2m×1.8m

Design water head: 2.0m


56

Dead weight: 0.4t

Orifice number: 1 orifice

Rack number: 1

Clean method： trash be cleaned by manpower

c. Gate valve at the sand flushing orifice

There shall be one Φ300mm sand flushing orifice in the dam equipped with a

Z541H-100I DN300 gate valve.

6.5.2 Metallic structure for tailwater The overhaul of the power station will not be influenced by normal water level,

so there won’t be a tailwater sluice gate.

6.5.3 Penstocks The penstocks are in total 530m long, with a diameter of 650mm and tube wall

thickness of 6~8mm. Q345C spiral pipes are adopted as steel material and the

penstocks and the supporting structures have a total weight of 69t. (see chapter 5

Design for the details).

6.5.4 Main quantities of metallic structures and equipment Table 6-4 Main quantities table of metallic structures and equipment

No. Item Specification Unit Qty. Remarks

1 Sand flushing gate valve of the dam Z541H-100I DN300 1

2 Embedded parts t 0.12

3 Intake sluice gate 0.9×0.9 m t 0.85

4 Embedded parts t 0.12

5 2t manual hoist set 1

6 Trash rack of the dam 1.2×1.8 m t 0.4

7 Penstocks φ650，δ=6--8mm t 60

8 Expansion joints φ650 pc/t 6/4.5

6.6 Heating ventilation and fire protection

6.6.1 Heating ventilation The power house of this station is of ground type. The main power house is a

one-story building with good ventilation, so the natural ventilation method shall be

adopted. Smoke exhaust measures shall combine with the ventilation system.


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6.6.2 Fire protection 1. General conditions and characteristics of the project

This is a runoff diversion-type power station, focusing on power generation, with

an installed capacity of 200kW. The main power house of the station is a single story

ground building, 12m long, 6.8m wide and 4.5m high. There are 2 turbine generators

with a space of 5.0m. Each unit is equipped with 6 panels beside it at the downstream

side.

The booster station is located opposite to the entrance gate of the power house,

5m long and 5m wide, equipped with one main transformer and a 11kV outgoing line.

2. Design basis of fire protection

(1) Specification on Compiling Preliminary Design Report of Small Hydropower Stations SL179—2011;

(2) Electrical-mechanical Design Code of Hydropower Plant DL/T5186; (3) Code for Fire Protection Design of Hydraulic and Hydroelectric Engineering

SDJ278; (4) Design Code for Heating Ventilation and Air Conditioning of Power House of

Hydropower Station DL/T5165; (5) Fire Protection Specification in Building Design GBJ16; (6)Code of Design for Water Spray Extinguishing Systems GB50219-95; (7)Code for Design of Extinguisher Distribution in Buildings GBJ50140; (8) Code for Design of Automatic Fire Alarm System GB50116; (9) Typical Extinguishing and Protection Regulation of Electrical Equipment

DL5027; (10) Code of Design for Sprinkler Systems GB50084. 3. Design principle

(1) Carry out the principle that “Fire Prevention First, Prevention and Control

Combined” and abide to the specification and relevant policies.

(2) Adopt fire retardant materials for construction and decoration materials, etc.

(3) The design should guarantee that the fire driveway, fireproof space,

emergency exit, emergency smoke exhaust, illumination, etc. meet the requirement of

relevant specification.

(4) Take full advantage of the sufficiency of water source of hydraulic and

hydroelectric project.

(5) Choose qualified products tested by relevant product quality supervision and

inspection departments for firefighting equipment, which should be safe and reliable,

convenient in use, advanced in technology and rational in budget as well.


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(6) Meet the requirement that “relying mainly on self-rescue while seeking for

aid from outside”.

4. Fire protection design

Based on the equipment installed in the buildings of the project and its purpose,

according to the regulations in Code for Fire Protection Design of Hydraulic and

Hydroelectric Engineering SDJ278-90 and Fire Protection Specification in

Building Design GBJ16-87 (2001 version), the fire risk classification and fire

resistance rating of the buildings in the project are listed in table 6-5.

Table 6-5 Main production building fire risk classification and fire resistance rating

table

No. Building/structure name Fire risk classification Fire resistance rating

Remark

1 Main & auxiliary powerhouse and mounting room

4th 2

2 Central control room 3rd 2

3 Main transformer site 3rd 2

4 Distribution device structure 4th 2

Fire protection of buildings

This power station is of diversion-type with buildings located dispersedly, which

mainly consists of the dam, steel pipeline, power house and booster station. With

electromechanical equipment densely placed inside the power house and operation

and management staff concentrated, the plant area shall be the key area for fire

protection in this project.

The permanent buildings of the power station adopt a masonry structure frame,

which caters to the specified fire resistance rating. There are driveways straight to

each building as well.

The space between buildings conforms to the requirement of fire protection

distance and there are evacuation routes inside each building which meet the

requirement of fire safety. The fire protection of the buildings and the

electromechanical equipment shall be arranged under integrated consideration.

Firefighting pipelines shall be buried, with one hydrant set inside the power house.

The fire water shall be fetched from the penstock and the fire protection area shall


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cover the whole building. A suitable number of fire extinguishers shall be equipped as

well. The fire hydrant shall be hung on the wall, 1.2m above ground, equipped with

one 20m long hose and one fire nozzle of 13mm diameter.

Fire protection of electromechanical equipment

1) Fire protection of power house electromechanical equipment

Besides 1 fire hydrant, there shall be 3 portable powder extinguishers, and 3

portable foam extinguishers as well. Openings and holes of switching box,

distribution panel and automatic device panel shall be plugged with fire retardant

materials.

2) Fire protection of booster station and outside of the plant

The booster station is small in area, so the focus of fire protection is the main

transformer loaded with a large quantity of oil. One sand box shall be equipped near

the inlet of the booster station as well.

Fire water supply

The fire water shall be connected to the fire hydrant in the power house after

decompression before the gate valve of the penstock.

Fire electricity

According to the regulations in Code for Fire Protection Design of

Hydraulic and Hydroelectric Engineering (SDJ278-90), emergency illumination

power source shall be connected to the DC system of the power station.

Emergency illumination shall be set in the main power house.

Main firefighting equipment Table 6-6 Main firefighting equipment table

No. Equipment name Main specification & model Unit Qty. Mounting

place 1 Indoor fire hydrant DN50 pc 1 Power house

2 Portable powder extinguisher MF8 pc 3 Power house

3 Portable foam extinguisher MP8 pc 3 Power house

4 Sand box pc 1 Booster station

5 Gas mask pc 2 Power house


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6.7 Lightning protection and earthing

The overvoltage protection of all level voltage distribution equipment shall be

arranged as per the requirements of specifications and regulations, see electric main

wiring diagram for details. A group of zinc oxide arrester is set at the 11kv side to

guarantee that lightning incoming surge will not jeopardize the main transformer,

generators and main electrical equipment under any operation mode.

Install lightning band for direct lightning strike protection of the power house.

The lightning band shall be connected with the column steel structure of the power

house by welding, with earthing bodies arranged along the wall. The earthing

resistance is required not to exceed 10Ω.

The earthing networks in the switching station and power house are formed

jointly by the horizontal earthing trunk and vertical earthing electrodes. Apply -50mm

×5mm galvanized flat steel for earthing trunks, -50mm×5mm galvanized flat steel

for earthing wire and 2.5m long φ50mm×4mm steel pipe for earthing electrodes.

The burial depth of the earthing bodies shall be 0.8m. The earthing resistance of the

main earthing network is required to be smaller than 4Ω, otherwise, remedial

measures, using two earthing bands to connect with the main earthing network of

switching station and power house, shall be taken so as to meet the requirement.

The main earthing network of the power house shall be welded to be like a mesh

with foundation reinforcing steels of 3 meter’s spacing before pouring the turbine

piers. It shall be welded with the tailwater pipe, diversion pipe and the shell of the

turbine. There should be at least two connection points with the two earthing bands in

the cable duct as well. The earthing resistance shall not exceed 4Ω. All of the outside

casing of the electrical equipment and the neutral line of the generator in the power

house shall be connected to the main earthing network.

The outside casing and frame of the electrical equipment in the switching station

should be connected to the earthing network in the switching station.

The equipment earthing and lightning earthing all over the power station should

be mutually independent.


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Chapter7 Project Management

7.1 Introduction

CHIPOTA hydro power station is located on the MULEMBO River where


Province, Zambia. This is a hydropower station mainly for hydropower generation

with an installed capacity of 200kW. During the construction period, a construction

project department shall be established to perform the function of administration; after

the project is built, it will be transferred to the owner who will perform the permanent

operation and administration functions of the project.

The establishment of CHIPOTA hydro power station’s administrative

organization abides by the following principles:

1. On the premise of ensuring safety in production and operation, constantly

enhance the enterprise’s economic benefits and perfect its management function,

optimize labor combination and use labor scientifically, rationally and economically;

2. The management organization should be simplified, with clear functions and

flexible operation;

3. With a small installed capacity and small number of workers, build only

necessary places for production, office work and resting;

This project is a small (II type) project with a total installed capacity of 200 kW.

According to Rural Hydroelectric Power Plant Manpower and Budget Standards and

the actual condition that the power station adopts automatic operation with less staff

on duty, the personnel quota of this project is 6, of which, 5 for production and 1 for

administration.


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Table 7-1 Departments and personnel quota list

No. Departments Quota (person) Remark

A Management staff 1

B Production staff 5

1 Hydraulic and electromechanical operation 4

2 Overhaul 1

Total 6

7.2 Operation management

7.2.1 Project dispatching operation

This project is of pressure diversion type and the discharge is adjusted

automatically by the speed governor of the turbine. The water overflows the weir crest

during shutdown.

7.2.2 Management and maintenance of the structures

(1) Dam

Since the inlet gate and the flushing gate valve are seldom used, and the flow

velocity is high, the erosion and cavitation of the valve, switching facility, gate valve,

etc. shall be inspected timely each year during the low-water season. If necessary,

overhaul must be arranged.

(2)Water diversion system for power generation and the power house

Apart from the regular maintenance and inspection, inspection and maintenance

at the same time of the overhaul of the units should be arranged on the wetted parts of

penstocks, main power house, etc. Maintenance and regular overhaul and test should

be carried out on all of the electromechanical devices as per relevant regulations and

specifications.

7.2.3Management and maintenance of metallic structures

There are 530m of penstock totaling 69t, 1 sluice gate, 1φ300 sand flushing gate

valve, 1 trash rack and 1 set of gate slots in this power station, bearing the tasks of


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water level control, flood discharge, sediment ejection, water conveyance, protecting

the safe operation of the units, etc. Regular maintenance, rust and corrosion

prevention should be carried out according to the requirements of regulations,

specifications and the design. The corrosion prevention of the penstocks adopts

coating materials of longer protection period and stricter construction technology to

prolong the service life of the penstock. No matter which anti-corrosion measure is

taken, the surface of the steel plate shall be pretreated to remove the rust to meet the

specified cleanliness and roughness before anti-corrosion coating. Trial operation

shall be performed on the discharge equipment before the flood season, so as to

guarantee flexible and reliable operation and timely input.

7.3 Scope of project management and protection

7.3.1 Project management scope

The management scope of this project should include: the key project area and

the production and living area.

The key project area includes: surrounding areas of diversion dam, penstock,

power house, tailrace, booster station, fire water supply facilities, communication

facilities, entrance traffic facilities, etc., 20m away from the outer contour of the

structures.

The production and living area include: permanent buildings in production and

living area.

The land and project occupied land within the management scope are under

unified management of the Management Department, and destruction of grasses and

trees, burial of tombs, erecting of electric poles, stacking of sundries, building of

houses, etc. are forbidden inside.

In case there is any conflict, the local regulations in Zambia shall prevail.

7.3.2 Protection scope

Project protection scope: 200m away from the boundary of the project

management scope.


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Attention should be paid to the water and soil conservation and environment

protection in the above mentioned protection area.

In case there is any conflict, the local regulations in Zambia shall prevail.

7.4 Project management facilities and maintenance of the equipment

7.4.1 Project management facilities

Management facilities in the management area of this project include: diversion

system, power house, communication facilities for electricity dispatching, permanent

buildings in production and living area and traffic roads.

Permanent buildings

Permanent buildings are divided into 2 parts: (1) the production plant and its

auxiliary part and (2) the building for living and welfare. The construction areas of

each part are: 81.6m2for production plant and 20m2for living.

Permanent traffic roads

There are already roads around the project area to link with the outbound traffic.

A simple sand-gravel road needs to be paved into the power house.

Management facilities

Because the installed capacity of this project is very small, there will not be any

special hydrological observation facilities, transportation means will not be purchased

and SPC telephones from the telecom department shall be used for communication.

7.4.2 Maintenance of the equipment

(1) Engineering inspection

The aim of engineering inspection is to avoid accidents, therefore, signs of

abnormality must be caught in time, causes must be analyzed and preventive

measures against accidents must be taken.

Patrol-inspection on hydraulic structures like the dam, penstocks, power house,

etc. should be carried out from the construction period to the operation period,

including daily patrol-inspections, regular patrol-inspections and patrol-inspections

under special circumstances.


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(2) Engineering inspection

Since the project scale is small, only the dam water level will be observed at the

site with a fixed water gauge.


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Chapter 8 Construction organization planning

8.1 Project profile

CHIPOTA hydropower station is located on the MULEMBO River where


Province, Zambia, with an installed capacity of 200kW.

The main structures of this project include the dam, penstocks, power house,

tailrace, booster station and living area.

(1) Hydrometeorological conditions

Central Province of Zambia has a Savannah climate, featuring a mild climate,

plentiful rainfall and an annual average temperature of 21℃. There are three seasons

all the year round: a dry and cool season from May to August with a temperature of

15～27℃, which is the harvest season for most of the crops; a dry and hot season

from September to November with a temperature of 26～36℃; and a warm and

humid rainy season from December to April, with a lower temperature than the dry

and cool season, which concentrates the precipitation of the whole year. According to

the meteorological data from Hong KongObservatory (1961~1991), the multi-year

average precipitation is 1133.6mm.

(2) Topographic and geologic conditions

The station site is locatedin a platform breaking zone. Under long-term scouring

of the river, the platformbrakes longitudinally along the river course, forming

multi-level waterfalls. The left bank of the river is covered with deep forest on a steep

slope, with a small branch river lying on the left side of the ridge. The right bank of

the river is relatively smooth. There is a flat and vast sloping land with the same

elevation with the last level visible waterfall. The trees grow well but relatively sparse.

The traffic road is on the right side of the river. Above the visible first-cascade

waterfall is flat grassland, which is not eligible for storage capacity.

No defective geological structure is found above the dam site. Part of the


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riverbed rock of this river reach is exposed with a flat grassland on both banks. The

covering is not thick, so the excavation of the dam foundation will be relatively

simple.

Below the dam site, the riverbed ladders are fault scarps, forming cascade

waterfalls. The fault scarps have no signs of further development towards the

upstream. The rock is dark red, and should be karst-rock, a kind of basalt. It is hard.A

plant area lies on the gentle sloping land, with exposed rock. The rock properties are

the same with the riverbed.

(3) External and internal traffic and the supply condition of wind and water

It is 400km from the Capital Lusaka to SERENJE area of Central Province, with

a trunk road equivalent to a secondary asphalt road. It is 20km from the trunk road to

the power station, connected with a flat earth road. Vehicles may be transported after

some slight repair of the earth road. It is 10km from the local community to the

station, linked with a forestry path.

The construction water will be pumped directly from MULEMBO River, while

living water is connected to the community. The dam site and plant site shall be

equipped with two 50kW diesel generators, respectively, to supply construction

electricity.

8.2 Construction diversion

8.2.1 Diversion standards

According to Standard for Classification and Flood Control of Water

Resources and Hydroelectric Project (SL252-2000), this project is a V grade project,

with the dam, power house and diversion structure being in the category of 5th grade.

The flood recurrence interval is 10 years for the earth-rock cofferdam. According to

the project quantities and the construction plan, taking foundation ditch submergence

loss and the impact to the construction into consideration, the diversion adopts a

three-year frequency flood standards of low-water season in May ~August.


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8.2.2 Diversion method

(1) Dam diversion

Diversion method: the construction diversion of the dam adopts a one-step

diversion. It will consist of building an earth cofferdam downstream the little bridge

and diverting water downstream the dam by way of the excavated diversion canal on

the left bank. The cofferdam shall be about 22m long and the diversion canal about

45m long. The height of the cofferdam and the excavation depth of the diversion canal

can be adjusted according to the earthwork equalization of the diversion canal and the

dam.Material for the cofferdam: a combination of bags of clay and earth-stone

material.

(2) Plant area diversion

The plant area is on the right bank of the river. Tailwater from power generation

will be drained to the river through tailrace. The ground of the plant area is relatively

flat, several meters higher than the river course which normally has a low water level.

The construction of the plant is very convenient and there will not be any need for a

cofferdam or construction diversion.

8.3 Selection of the material site and the excavation

8.3.1 Selection of the material site

The layout of the project construction is relatively scattered and there are not

many sand and aggregate materials used in this project. Besides stones, the sand and

aggregate materials needed by the project shall use local materials from site.

8.4 Construction of the project’s main works

The header project consists of structures like the dam, intake sluice gate,etc.

Excavation of the foundation

Drain the waterlogging, seepage water and surface water in the foundation ditch

timely to ensure that the excavation will not be disturbed by water.

Earthwork excavation: drill holes manually, load explosives manually


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usingpneumatic drills, , perform presplitting blasting and stage excavation from top to

bottom and from the bank slope to the riverbed and adopt a millisecond short delay

extrusion step blasting.

Slag discharge: Collect and load the slag manually, discharge the slag with

trolley to the slag stacking site downstream from the dam.

Casting of the rubble concrete

The rubble concrete strength grade is C20. A trolley will be the main method for

the placement of concreteinto the tank and manpower will be applied for embedding

stones. Compact the concrete with aninsertion vibrator and sprinkle water manually

for maintenance. After the casting of rubble concrete coverage, the clearance of the

tank shall follow.

8.5 Construction of the diversion system

The diversion system includes water intake and penstocks.

Engineering of the intake

Earthwork excavation: adopt step excavation from top to the bottom. Drill holes

with pneumatic drills, apply surrounding presplitting blasting.

Masonry: Stones are carried manually. The mortar shall be carried to each

masonry site by manpower. Mortar base slurry method shall be applied in the

constructionand the masonry rises evenly layer by layer.

Concrete construction: concrete shall be delivered by manpower. After placement

of concrete, scrape manually and compact the concrete with insertion vibrator. When

the strength of the lower layer concrete reaches 25kg/c ㎡, prepare for the casting of

the upper layer; meanwhile, chiseling of the concrete surface shall be done before

casting of the concrete.

Reinforcing bar and formengineering: implement according to

Technical Code for Construction of Small Hydropower Station (SL172—96).

Construction of the penstocks

The pipeline is 530m long. Drill holes with pneumatic drills step by step, load


70

explosives manually and adopt presplitting blasting. The slags shall be delivered out

by manpower.Those can be utilized shall be used as masonry aggregates for the

anchorage blocks and supporting piers, while the abandoned slags shall be stacked

nearby and used for planting grasses and trees as per water conservancy requirements

after completion of the project.

Processing and mounting of the steel pipe: the steel pipe shall be molded and

processed as per design dimension in the factory, transported to the plant area by a 15t

truck and lifted and welded on site by applying a hoisting machine.

Concrete casting of the anchorage locks and supporting piers: the concrete shall

be mixed in a mixer, delivered to the construction site by trolleys, scraped and

vibrated by manpower.

8.6 Construction of the power house

The power house is a masonry structure frame power house, with 2 horizontal

hydro-generators installed inside.

Foundation excavation

The excavation of the power house foundation takes the elevation of 1371.50m

as the datum plane, above which open excavation shall be applied and below which

trench excavation is used. The excavation of the side slope should abide by the

procedure from top to bottom.

The earthwork excavation adopts step excavation from top to the bottom. Drill

holes with pneumatic drills, load explosives manually and adopt presplitting blasting.

The slags shall be collected by a bulldozer, loaded to a 5t dump truck by a backhoe

excavator and delivered to the area 30m’s range on the right, downstream from the

power house.

Foundation masonry

The power house adopts stone masonry strip foundation. The mortar is mixed in

the mixer and the stones are laid manually, with C20 concrete ground ring-beam on

top.


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Power house

The power house adopts masonry structure. According to the layout of the

generator units and the installation requirement, the space between units shall be 5.0m,

so the dimension of the power house shall be 12×6.8×4.5mand the roof applies light

steel roof truss.

Mounting of the units

In the installation of the units, the maximum hoisted parts in the plant are 2.5t.

Mobile profiled-steel-made supporting frame is adopted, equipped with a manual

hoist with a lifting capacity of 5t.

8.7 Transportation for construction

8.7.1 Selection of transportation means

Based on the actual condition of this project and external traffic, the

electromechanical equipment shall be delivered by sea and road jointly and all of the

construction materials shall be deliveredmainly by road transport.

8.7.2 Outbound transportation

It is 400km from the Capital Lusaka to SERENJE area of Central Province, with

a trunk road equivalent to a secondary asphalt road. It is 20km from the trunk road to

the power station, connected with a flat earth road. Vehicles may be transported after

some slight repair of the earth road. It is 10km from the local community to the

station, linked with a forestry path. In this design, a 650m long 3.5m wide

sand-gravelroad to the power house will be enough to meet the requirement.

8.7.3 Internal transportation

Internal transportation connects the work areas, warehouse and slag stacking site

inside the construction site and all of the production and living areas, which must be

linked to the outbound transportation. The internal transportation of this project is in

good condition and the materials will be delivered by simple road transport.


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8.8 General layout of the construction

8.8.1 The planning and layout principle of the construction

The whole project is located on the right bank, where the bank slope is gentle,

providing many available construction sites. Therefore, the production and living area

during the construction shall make best use of the existing topographic conditions and

be placed on the gentle slopes near the engineering area. The general layout and

planning of the construction shall follow the principles of

construction-need-orientation, overall consideration and planning, compact layout,

less deforestation and convenience for management, living and production. The layout

of each construction facility should make its best to meet the construction requirement

of the main work, avoiding interference and repetitioustransport of the materials. It

will make rational utilization of thetopographic condition and try to realize compact

arrangement so as to reduce preparation work. The division and layout of the sites

should conform to the regulations of the country relating to safety, fire protection,

public health, environment protection, etc.

8.8.2 Construction zoning and layout planning

Sincethe layout of the project is scattered, the construction of the project shall be

carried out by blocks and by zones based on the characteristics of the project,

topographic and traffic conditions and the organization form of construction

management. The whole project can be divided into three parts of construction zones:

dam, penstocks and power house.

Dam construction zone

The dam construction zone mainly focuses on the construction of the diversion

and sand flushing facilities of the dam and the upper part of the penstock. The planned

area of temporary buildings in this construction zone is 100m2, occupying a floor area

of 130m2, which is located near the project zone.

Penstock construction zone

The penstock construction zone contains the construction of penstocks. The

living and production facilities are located on the gentle slope near the curve of the


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penstock. The area ofall of the temporary buildings in this construction zone is

planned to be 300m2, occupying afloor area of 450m2, which is located on the right

sides of the penstock.

Power house construction zone

The construction of the power house includes the construction of power house,

tailrace, booster station and the lower part of the penstock. The total area of various

temporary buildings is planned to be 400m2, occupying a floor area of 500m2, which

is located around the plant area. See table 8-1 for the areas of permanent and

temporary housing in each construction zone.

Housing for living and officeswill be built on the open land near the power house.

Six integrated board houses with a dimension of 6m×2.4m will be adopted.

Table 8-1 Area list for living and administration camps and temporary warehouses

8.8.3 Waste slags site

The site will make best use of the rock slags produced in the excavation of the

buildings’ foundations. Those that cannot be utilized shall be delivered to the waste

slags site. Part of the slags excavated from the plant area will be used as engineering

material, while the residue backfills the low-lying part by leveling the ground. No

extra slag site shall be arranged.

No. Items Building area（m2

）Floor area（m2

） Remark

1 Dam construction zone Temporary building 100 130 Temporary

land use

2 Penstock construction zone

Temporary building 300 450

Temporary land use

3 Power house construction zone

Temporary building 400 500

Temporary land use

4 Housing for living and offices 86.4 120 Temporary land use

Temporary land use in total 886.4 1200


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8.9 General construction progress

8.9.1 Implementation basis and principle

The construction progress of this project shall be controlled as per the average

level of the power stations of the same type in China. According to Code for

Construction Organization Plan of Building Engineering GBT50502-2009,as based

on the actual situation of the project, the construction progress shall be divided into

four stages: project starting period, project preparation period, main works

construction period and project completion period.

8.9.2 General construction progress

(1) Project starting period

The proprietor shall take charge to start the work of external traffic, construction

electricity, communication, landexpropriation, public bidding, etc. with a planned

time table of 2 months.

(2) Project preparation

Main jobs that should be done during this period are: ground leveling, internal

traffic, diversion engineering, building of temporary housing and construction plant,

etc., with a planned time table of 1 month.

(3) Main works construction period

This period starts from the beginning of the project to the time when all of the

units generate power, with a planned construction period of 11 months.

(4) Project completion period

This period starts from the time when all of the units generate power to the time

when the project is completed and accepted, with a planned time table of 1 month.

8.10 Main construction machinery

See table 8-2 for the main mechanical equipment needed in this project.


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Table 8-2 Main mechanical construction equipment table

No. Equipment name Specification Unit Qty. Remark

1 Pneumatic drill YT-24 set 5

2 Down-the-hole drill YQ150A set 2

3 Air compressor 4L-20/8 set 2

4 Water pump 3B33 set 2

2B31A set 2

5 Backhoe WY40-HZ set 1

6 Crawler bulldozer TS-140 set 1

7 Truck crane QC20 set 1

8 Excavator 200 set 2

9 Concrete mixer 0.4 m³ set 3

10 Diesel generator 50kW set 2

11 Lithotripter set 1

12 Sand producing system set 1

13 Transport hopper set 10


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Chapter 9 Labor Safety and Industrial Sanitation

9.1 Design Basis

9.1.1 Provisions of the national and local administration Document of the Ministry of Power Industry, China Renewable Energy

Engineering Institute---Notice on Adding the ‘Labour Safety and Industrial

Sanitation’ in the Compilation of a Feasibility Report (S.D.G.S [1997] No.0014).

9.1.2 Technical specifications, procedures and standards

1) Code for design of occupational safety and health of hydropower projects

(NB35074-2015)

2) Code of safety operation in power engineering construction(Part of

substation)(DL5009.3-2013)

3) Code for fire projection design of hydropower projects (GB50872-2014)

4)Technical code of construction and installation for hydroelectric and hydraulic

engineering(SD267-88)

9.2 Project Overview

9.2.1 Project location


tribe chief KABAMBA resides), CHELA TAMBULE village, SERENJE region of the

central province of Zambia. It is 400 km away from the Capital Lusaka, located at

latitude 13°13' 4.8" S and longitude 30°25' 52.24" E.

9.2.2 Project layout

The powerhouse is a diversion-type ground plant. The powerhouse and booster

station are located at the gentle slope on the right bank at the bottom of the

fourth-cascade waterfall. The newly built 650m permanent road makes outgoing

traffic relatively convenient. The management room is located close to the hillside

beside the incoming road. Layout of the whole powerhouse area is relatively simple.


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9.2.3 Characteristics of natural conditions

The central province of Zambia has a mild tropical savanna climate, abundant


the year: from May to August, it is the dry cool season, with the temperature between

15 ~ 27℃, a harvest season for most crops; from September to November it is the dry

hot season, with the temperature between 26 ~ 36℃; and from December to April, it is

the warm wet season, with the temperature slightly lower than the dry cool season,

with the annual rainfall concentrated in this season. According to the meteorological

data of the Hong Kong Observatory (1961~1991 year), the average annual rainfall is

1133.6mm.

9.2.4 Project benefit and major hazards

The installed capacity of the hydropower station is 200kW, and the long term

average annual power output is 1,355,300kWh.

After the project is completed, major hazards consist of the following:

1) Combustible substances in the powerhouse may cause fire;

2) A large number of high and low voltage electrical equipment in the

powerhouse may cause personnel injury in the case faulty handling or accident;

3) The hydro- turbine generator, air compressor and other equipment in the

powerhouse will generate excessive noise during operation, which may cause hearing

loss, as well as affect the health of the managing personnel;

4) The wires and cables in the powerhouse will produce poisonous gas if caught

fire, which will affect the personnel’s health and cause poisoning.

9.3 General Layout of the Project

This project is a diversion-type ground powerhouse, with the main powerhouse

being only one story and 12m long by 6.8m wide. It is parallel to the riverbed, with

the mounting site and the entrance gate on the right. The main powerhouse will be

equipped with two sets of 100kW inclined type turbine-generator units, with a spacing

of 5m between them.


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The power station has a set fire extinguishing system with a water supply coming

from the pipe of the circulating pump inside the powerhouse. A fire hydrant and other

fire extinguishing equipment should be installed in the main powerhouse and booster

station to meet the fire extinguishing requirements.

The engineering area should have a reliable solution of electrical storm

protection. A lightning belt should be installed on the roof, connected to the column of

the steel structure of the power house by welding, with a grounding device arranged

along the wall.

The CHIPOTA hydropower station is located in a mild climate, and the main

powerhouse will adopt a natural ventilation system.

The booster station is located at the opposite side of the powerhouse entrance

gate, adjacent to the powerhouse and is facilitated for electrical connection. The main

transformer is arranged inside the booster station, which is facilitated for operation

and maintenance of the main transformer. 1.7m high fences should be installed around

the perimeter of booster station in order to guarantee the safety of all personnel and

prevent any risk of electric shock. A clear path of at least2m wide between any high

voltage electrical equipment and the fence should be maintained in order to guarantee

the safety of all personnel.

The simple design of the powerhouse allows for natural light to enter the

structure during the day. It is also fitted with artificial lighting to light the facility

during the night. The main powerhouse has been equipped with emergency

illumination to ensure lighting is provided during any electricity outages.

Regularl inspections are required for all electrical equipment and tools in order to

prevent any electrical damage and ensure personnel safety,

Mechanical equipment inside the powerhouse must meet the requirements and

specifications of any proper safety distance. The safety requirements of the protective

enclosure and the protective shield of mechanical equipment should be in accordance

within the provisions of the relevant standards. All mechanical equipment shall meet

the qualifications and standards in regards to reliability and safety performance.

When the inlet and–outlet lines of the booster station are put into operation, any


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and all safety requirements of construction should be met.

9.4 Labor Safety

Labor safety is the guarantee of normal operation of the hydropower station,

which includes fire prevention, prevention of explosion, electrical damage prevention,

mechanical damage prevention, dropping damage prevention, flood prevention and

drowning prevention in the main powerhouse and booster station.

Due to the presence of a large number of electrical equipment inside the plant,

the inspection personnel and maintenance personnel are at risk of electrical injury or

accidental electric shock caused by improper handling. The main high-voltage

equipment is located in the booster station, where improper handling or carelessness

may cause personal injury. Qil tanks, cables and other flammable material in the plant

increase the risk of fire and damage to the electrical equipment andthe plant.

Malfunction of the pressure relief devices, such as the compressed air tank, oil

pressure device in the speed regulator, main transformer and other pressure vessels

increase the risk explosion.

9.4.1 Prevention of Fire and Explosion

Heating using open fire is strictly prohibited in all workplaces of the hydropower

station. A reliable electrical storm protection and grounding system should be installed

in the plant, booster station and other structures.

Besides 1 fire hydrant, there shall also be 3 portable dry powder extinguishers

and 3 portable foam extinguishers. 1 sand box shall also be equipped near the entry of

the booster station. A water supply shall be connected to the fire hydrant in the plant

after decompression, in front of the gate valve of the penstock.

9.4.2 Electrical damage prevention

The main transformer of this project shall be installed outside. 1.7m high fences

should be installed around the perimeter of the booster station in order to guarantee

the safety of all personnel and prevent any risk of electric shock. The fence door shall

be installed with a lock, as well as a yellow warning sign: "Beware of Electric Shock".


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A clear path of at least 2m wide between any high voltage electrical equipment and

the fence should be maintained.It is strictly prohibited to set up a communication wire

line, broadcasting line and low voltage line on the high-voltage equipment framework.

There is also a large number of low-voltage equipment in the plant that may increase

the risk of injury and should be operated with caution in order to decrease the risk of

injury. In the transition periodfrom the initial stage of operation to the normal stage of

operation, protective railings and safety signs should be installed around the

distribution devices using electricty. Operating safety distance of operating personnel:

a distance of at least 0.6m wide should be maintained between live distribution units

with a voltage below 35kV and the railing. The voltage of working lights used by the staff are required to meet provisions of

the GB/T3805-93 Extra-low Voltage (LEV) Limit Value. Lighting fixtures must be

installed at least 2.4m above the floor., If the voltage of the fixture exceeds provision

of the Extra-low Voltage (LEV) Limit Value, effective measures should be taken in

order to prevent electric shock.

9.4.3 Mechanical damage prevention and crash damage prevention

Set slots to fix the temporary protective railings at the holes and pits that may

form a falling height of more than 2m during maintenance.

9.4.4 Flood prevention and drowning prevention

Set reliable drainage facilities on the ground floor of the main powerhouse and

the booster station. The outlet elevation of all drains, pipes and channels going to the

outside of the building should be higher than the downstream flood level of the

powerhouse. The water pump drainage pipeline of the machinery drainage system

should be set with a check valve.

9.5 Industrial Sanitation

Industrial sanitation includes noise and vibration proofing, temperature and

humidity control, lighting and illumination, dust proofing, antifouling, anti-corrosion,

anti-toxicity and anti electromagnetic radiation, etc.

Water turbines, generators and other equipment may produce noise which may


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greatly harm the hearing function of the staff and may cause hearing loss. For

long-term staff that are working in the powerhouse, the high humidity inside may

cause arthritis.

When the water turbine generator, transformer, circuit breaker and other

equipment are in operation, they will produce excessive noise. When the circuit

breaker trips, the noise may exceed 115dB, which can seriously impact one’s physical

and mental health: hearing loss, and a variety of diseases, such as heart disease,

hypertension, neurosis, etc. In high temperature and humidity work environments,

especially where the relative humidity is higher than 75% and the temperature is

higher than 35℃ , it is easy to develop symptoms of rheumatism arthritis.

Flammable and explosive materials in the powerhouse will produce low fluorine

compounds, noxious smoke and other harmful substances in the course of operation.

There is an increased risk of health issues if there is poor ventilation. Personnel

exposed to microwave radiation may develop the following health issues:

dysfunction of the nervous system, blood circulation system, reproductive system,

blood micro elements, physiological metabolism, etc. All safety precautions should be

considered and necessary protective health gear should be worn.

9.5.1 Noise proof and vibration proof

Reasonably arrange the noise sources to reduce the harm of noise to human ears.

Arrange any loud equipment in the duty rooms far away from the powerhouse. Set

partitions between each duty room and use an indoor air conditioner with silence

design in the control room and main offices. The personnel on duty should enter the

powerhouse with ear protection to reduce the harm of industrial noise.

When choosing a water turbine generator type, the manufacturer is required to

choose and install equipment with a noise level not exceeding 85dB (A), so as to

reduce the noise level of the working environment.

9.5.2 Temperature and humidity control

This plant has a one-story powerhouse with good ventilation. But, it is also

necessary to open the windows from time to time for ventilation to ensure proper

temperature and humidity and health of the staff in the workplace. In the general duty


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places and unattended places, do a good job of mechanical ventilation to promote the

lifespan of the equipment and health of the inspecting personnel.

9.5.3 Lighting and illumination

The project has been designed to make full use of natural light in the day, and at

night with artificial lighting. All of the workplaces should be installed with

illuminators according to the requirements. The main powerhouse has been equipped

with emergency illumination to ensure the lighting needs in case of accidents.

9.5.4 Dust proof, antifouling, anti-corrosion and antitoxin

When the mechanical braking device is put into operation, it will produce dust,

and part of the braking devices that contain asbestos products may decompose and

produce harmful substances during the braking process. Therefore, the brake material

is preferred to use mechanical brake parts with good wear resistance and less dust.

Any industrial waste oil shall not be discharged into the watercourse and shall be

delivered to the designated location after treatment.

The storage battery in the DC system is a fixed lead-acid maintenance free

battery, which will emit a small amount of gas during operation. As long as the

ventilation is strengthened, there will be no need for special treatment.

9.5.5 Anti electromagnetic radiation

For staff exposed to microwave radiation, they should reduce the harm of

electromagnetic radiation to the human body mainly through the control of operating

time. When the electric field intensity is 111KV/m, 15KV/m and 20KV/m, the

operation time should be respectively limited to 3h, 1.5h and 10min.

9.6 Safety and Health Facilities

In regards to the safety and health agency, the safety engineers shall be

responsible for carrying out safety and health publicity and education, engineering

monitoring, safety equipment repair and maintenance to ensure the normal operation

of electrical equipment. Safety engineers are required to have a rich experience of

project management and work safety; be familiar with laws and regulations,


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specifications and standards relevant to safety and health aspects; be familiar with the

performance and usage of various monitoring equipment; can timely discover and

deal with security risks; and can take emergency rescue measures when an accident

happens.

A safety and health agency needs to be equipped with anacoustimeter,

thermometer, hygrometer, multimeter and necessary safety publicizing equipment.

9.7 Safety Precautions

9.7.1 Labor safety precautions

In accordance with the requirements of GB2894 Safety Signs, safety signs

should be made and hung up in a conspicuous location. Safety signs include No

Crossing, No fire, Electric Shock, Beware of mechanical injury, Watch your step,

and Ear defenders.The location of firefighting equipment and safe evacuation exit

signs shall also be clearly marked.

The safety engineers should do a good job of safety publicity, standardize the

safety operation of the staff and regularly maintain the safety facilities to ensure the

safety of the staff. Emergency measures should be taken once a safety accident

occurs.

9.7.2 Emergency measures

When any equipment breaks down, the main equipment will be under protection

of automatic protection device. Parts of equipment without automatic protection

device will require emergency repair or be replaced by spare equipment to ensure the

safety of system operation.

In case of personal electrical injury, poisoning, mechanical or dropping damages

or other personal injuries, emergency measures should be taken to treat the wounded.

If the personnel experiences electrical injury, we should first switch off the electricity

and then treat the injured. In case of poisoning, the poisoned should be immediately

carried out of the room and receive treatment from the medical staff. For patients who

go into shock, they should immediately receive artificial respiration and be helped to


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recover respiratory function with the greatest efforts. In case of fire, firefighters and

security personnel should immediately organize an emergency evacuation from the

emergency exit and immediately organize fire fighting. For all of the wounded

personnel, paramedics should organize a timely rescue, and if necessary, contact the

hospital for additional help.

In case of over-level flood, the management and the relevant local departments

will organize flood-fighting and emergency rescues to ensure the safety of the

facilities.


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Chapter 10 Inundation Treatment and Land Requisition

10.1 Overview

The CHIPOTA hydropower station is a diversion-type hydropower station with

an installed capacity of 2×100kW. The main project consists of the dam, penstocks,

plant, tailrace and booster station, etc. The hydropower station is primarily aimed for

power generation. The maximum height of its water-retaining dam is 3.5m and the

normal water level is 1421.50m.

10.2 Design Basis

10.2.1 Laws and Regulations, Specifications and Codes (1) The Law of Land Administration of the People's Republic of China

(1999.1.1);

(2) Forest Law of the People's Republic of China (1998.7.1);

(3) Notice on the Relevant Issues Concerning Construction Land of Water

Conservancy and Hydropower Projects (G.T.Z.F [2001] No. 355);

(4) Interim Measures on collection and usage of the Fees for Forest Vegetation

Regeneration（C.Z [2002] No. 73）;

(5) Specifications on land requisition and resettlement design for Construction of

Water Resources and Hydropower Projects (SL290-2009);

(6) Compilation and Calculation Standard of Design Budget Estimation for

Hydropower Project (2002 Edition);

(7) Design Code for Small Hydropower Station (GB50071 - 2014);

(8) Other relevant laws, regulations, policies and professional technical

specifications.

This design shall be temporarily implemented in accordance with the existing

laws and provisions established by China, the inundation and land requisition

operations shall be undertaken by the owner in accordance with the provisions

established in Zambia.


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10.2.2 Design data

(1) The measured topographic map (1:1000);

(2) Construction layout of CHIPOTA hydropower station;

(3) Other relevant data.

10.3 Inundation Treatment

The diversion dam of the CHIPOTA hydropower station is very low, and below

the normal water level is the natural river course. There is no loss without farmland

and houses inundated.

According to the geological survey of the dam site, both sides of the dam show

high level of stability. Therefore, it will not cause bank landslide once completed.

10.4 Land Requisition of the Project

Land requisition includes both permanent as well as temporary requisitions in

accordance with the project area, construction area, living area and plant. The

construction area comprises construction campsites, construction sites, and the

abandoned slags field.

1) Permanent land requisition

According to the project layout and construction design, the permanent land

requisition of the CHIPOTA hydropower station is about 4,500m2, which principally

comprises the plant, booster station, diversion power system and entrance road.

2) Temporarily land requisition

The temporarily land requisition of the hydropower station is about 2,000m2,

mainly comprising the abandoned slags field and constructor area.


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Chapter 11 Water and Soil Conservation

11.1 Principles and Standards

The water and soil conservation measures should be a part of the overall design

of the project, and should be designed, constructed and operated observing the same

standards as the main project.

The standards observed for water and soil conservation measures are the

following: (1) Technical Regulation on Water and Soil Conservation of Development and

Construction Projects (GB50433 - 2008);

(2) Standards for Classification and Gradation of Soil Erosion (SL190 - 2007);

(3) Comprehensive control of Water and Soil Conservation—General rule of

planning (GB/T15772 - 2008);

(4) Comprehensive control of Water and Soil conservation—Regulation of

acceptance (GB/T15773 - 2008);

(5) Comprehensive control of Water and Soil Conservation—Method of benefit

calculation (GB/T15774 - 2008);

(6) Technical specification for Comprehensive control of Soil and Water

Conservation - Technique for erosion control of gullies (GB/T16453 - 2008);

(7) Cost constituents and Calculation standards for Design Budget Estimate of

Water Conservancy and Hydropower Project.

This design shall temporarily be implemented in accordance with the existing

laws and provisions of China; the owner shall complete procedures pursuant to

provisions established by Zambia.

11.2 Project and Overview of Project Area

11.2.1 Overview

CHIPOTA hydropower station is mainly aimed for power generation. It presents


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a rubble concrete gravity dam, with a maximum height of 3.5m, a design installed

capacity of 2×100kW and an average annual output of 1,355,300 kWh. The project

consists of the dam, penstocks, plant, tailrace and booster station. The pipelines are

arranged on the right bank of the river course and laid along the hillside. The booster

station is arranged on the upstream side of the plant. The total project duration is 13

months, with its main part requiring 10 months out of the overall duration.

11.2.2 Status and Prevention of soil erosion


tribe chief KABAMBA resides), CHELA TAMBULE village, in the SERENJE region

of the central province of Zambia. The site is located in a platform fracture zone.

Based on the soil erosion module diagram of similar areas, we have analyzed the

water and soil erosion conditions combined with spot-surveying. We conclude that the

main status is surface erosion, with a loss intensity varying from slight degree to

moderate degree.

11.3 Forecast of Water and Soil Erosion

11.3.1 Forecasting Basis

The erosion of this construction project includes any and all excavation exposed

surface, abandoned slags surface and side slope, resulting from the lack of observance

of protective measures. We will analyze and forecast the possible water and soil

erosion and associated hazards.

11.3.2 Forecasting Time Period

The forecast is divided into two periods: the construction period and the

operation period. The operation period is mainly to generate electricity without

erosion. Therefore, the erosion mainly occurs in the construction period and the initial

operation period. The forecast period of water and soil erosion will be determined

according to the project construction period (12 months) and the natural enclosure

restoration time. For the purposes of this project, the period will be 1 (one) year.


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11.3.3 Content and Method of Forecast

The content for water and soil erosion forecast mainly includes:

(1) Forecast of original landform and vegetation damage;

(2) Forecast of amount of abandoned slags;

(3) Forecast of the possibly caused water and soil erosion area and the total

amount of newly increased erosion;

(4) Forecast of damage from water and soil erosion.

There are many methods applied for the purpose of water and soil erosion

forecasts. Based on the actual condition of the project and the maneuverability of each

method, the following forecast methods may be applied in different areas: the natural

slope ratio accumulation method for the abandoned slags filed and the analogue

method for each prevention and control subarea.

11.3.4 Forecast results and comprehensive analysis

(1) Disturbance of the original landform, damaged land and vegetation

conditions

Disturbance ground area of the CHIPOTA hydropower station mainly refers to

the construction requisition area and directly affected area, including the main project

area, stone materials field, abandoned materials field, temporary construction facilities

(construction warehouse, temporary stockyards, construction road etc.). Details are

shown in table 11-1：

Table 11-1 Disturbance area, damaged land and vegetation area (unit: m2)

Category No. Project name Total

Project

construction

area

1 Main project area 1863

2 Living area 140

3 Permanent road 3750

4 Soil and stone materials

f ield 150

5 Abandoned slags f ield 100

6 Temporary construction land 300


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Total 6303

(2) Forecast of total amount of newly increased water and soil erosion

Possible newly increased erosion area of the project mainly includes the

excavation surface area, living area, area of the permanent road, the exploiting

stripping area of the material field, abandoned slags filed and temporarily land area,

which account for a total area of 6500m2.

Based on the field survey, the project adopted a natural slope ratio accumulation

method and an analogue method to forecast the amount of water and soil erosion in

the construction period and the affecting period. The total amount of newly increased

erosion of the project is expected to be 60t.

(3) Forecast of damage from water and soil erosion

The project has disturbed the ground area in the construction process and caused

the formation of an amount of abandoned slags. Provided proper prevention and

control measures are not taken, an area of 6500m2 will face soil erosion of up to 60t.

Therefore, we must pay attention to the water and soil conservation requirements of

the project, keep the erosion under effective control and reduce its levels to the

minimum extent.

11.4 Prevention and Control Scheme for Water and Soil Erosion

11.4.1 Prevention and control principle and objective

The purpose is to restore or rebuild the damaged forest land and other water and

soil conservation facilities as soon as possible, protect the ecological environment,

reduce erosion to allow for the restoration rate of disturbed land up above 98%.

In the case of land that has observed a reduction or loss in its water and soil

conservation function as a result of the effect of excavation, filling and other activities

in the construction process, we should timely take engineering and vegetation

measures to restore or improve its water conservation functions, allowing for the

erosion control treatment to reach a level higher than 91%. We should also control the

newly increased erosion and insure the control rate is above 98.6%.


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The abandoned slags should be located centrally and both engineering and

vegetation measures should be taken to allow for the protection rate of abandoned

slags to reach 95%, thus allowing for a reduction and control of the sediment entering

the river.

For permanently and temporarily requisition land, measures such as recultivation,

planting, as well as other afforesting measures should be taken in order to increase the

vegetation restoration rate up to 86%, and the vegetation coverage rate up to 71%.

11.4.2 Prevention and control responsibility

The water and soil erosion prevention and control scheme include the following

two aspects: (1) The key administration area of the construction refers to the main water

and soil conservation damage area which includes the dam, penstocks,

plant and the construction road as well as the renting land during the

construction period. Additionally, it should also include land aimed at

temporarily construction work.

(2) The area damaged by water and soil erosion as a result of construction

activities is a directly affected zone, and responsibility is to be assumed

by the constructor.

11.5 Measures of Water and Soil Conservation

11.5.1 Overall layout of water and soil conservation measures

Taking the abandoned soil (stone) field and the main project prevention area as

the key flood control area, take systematic prevention and control measures and form

a feasible erosion prevention and control system. The water and soil conservation

scheme of the project area should be mainly based on the biological measures and

should be supported by the engineering measures. Biological measures are mainly the

afforestation of the main project area and the affected area, foresting of the abandoned

slags field and material field. There are only a few areas in need of engineering

measures, mainly in the form of supplementation.


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11.5.2 Layout of prevention and control engineering measures

The construction technique of CHIPOTA hydropower station is not complicated

and there will not be many types of disturbance. Although quantity of abandoned soil

and stones and slags is small, the construction will cause new water and soil erosion.

Therefore, the water and soil conservation facilities must be implemented

simultaneously with the main project to provide a timely control of the erosion. The

residue blocking facilities must be completed prior to the main project so as to avoid

erosion.

(1) Key project area (penstocks, plant)

Key buildings of the CHIPOTA hydropower station include the dam, penstocks,

plant, among others.

For the excavation area, we can reclaim the forestry land, create water

conservation forest and plant grass, conduct a rational allocation of trees, shrubs and

grass; restore vegetation as soon as possible to conserve water and soil. For the plant

area, we can make an overall garden landscape design and improve traffic.

(2) Abandoned soil (stone) field

We should combine engineering measures and vegetation measures. Make the

abandoned soil (stone) site a retaining engineering, so as to play a important role of

the retaining wall in water and soil conservation.

11.5.3 Water and soil erosion monitoring

Newly increased water and soil erosion of the project is mainly caused by the

abandoned slags, so the focus of the water and soil monitoring is the abandoned slags

area. The key point is to monitor the quantity and damages of water and soil erosion,

as well as the engineering benefit of water and soil conservation.

11.5.4 Remedial measures for water and soil erosion

If water and soil erosion occurred, we should set debris dams in the downstream

river course to block the upstream erosion sediment and timely remove them to the

abandoned slags field on gentle land.


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11.6 Construction Organization Design and Budget Estimate

11.6.1 Construction organization design

(1) Organization and management measures

The owner will be responsible for the organization and implementation of the

water and soil conservation scheme, coordination with the main project and

delegation of supervision with qualified supervisory company. The water

administrative department will be in charge of the supervision and inspection of the

implementation of the water and soil conservation scheme and acceptance of relevant

facilities.

(2) Technical assurance measures

This scheme should be designed and taken as the basis for construction and

acceptance after validation by the water administrative department.

(3) Funding sources and arrangements

Required funds of the water and soil conservation project will be included in the

total project investment plan and be raised by the owner. The aforementioned funds

will be used for its specific purpose only.

11.6.2 Budget estimate for water and soil conservation

The water and soil conservation project of the CHIPOTA hydropower station is a

supporting project of the main project, which mainly includes the design for water and

soil conservation, the soil and stone materials field, the abandoned materials field and

the temporary construction land. The remediation content is slag blocking, sod

revetment, drainage and afforesting. The total investment of the water and soil

conservation is 10,600 US Dollars.


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Chapter 12 Environmental Impact Assessment

12.1 Regional Environmental Conditions of the Project

12.1.1 Engineering overview

CHIPOTA hydropower station consists of the dam, diversion pipelines,

powerhouse and booster station, etc. The power station has an installed capacity of

2×100KW, a design head of 45.38m, a design discharge of 0.68m3/s, an annual power

generation capacity of 1,355,300 kWh, and 6777 installed utilization hours.

12.1.2 Natural environmental conditions

Engineering geology

The site is located in a platform fracture zone. Through long-term erosion of the


multiple-cascade waterfalls. On the left bank of the river there are dense forest and

steep mountains, and on the left of the ridge there is another small tributary. On the

right side of the river there are relatively flat mountains; at the elevation position

where the final-cascade waterfall is visible there is a relatively flat and open sloping

field, where the trees are flourishing but remain relatively sparse. Traffic road is

located on the right side of the river. Above the visible first-cascade there is flat

grassland, which is not eligible for storage capacity.

Hydrology and weather

The central province of Zambia has a mild tropical savanna climate, abundant


the year: from May to August it is the dry cool season, with temperatures between 15

~ 27℃, a harvest season for most crops; September to November is the dry hot season,

with temperatures between 26 ~ 36℃. December to April is the warm wet season,

with temperatures slightly lower than those observed in the dry cool season; the

annual rainfall is concentrated in this season. According to the meteorological data of


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Hong Kong Observatory (1961~1991 year), the average annual rainfall is 1133.6mm.

12.2 Preliminary Environmental Impact Assessment

The construction of the power station has little influence on the natural

environment. The project is located in an area of no farmland submersion or cultural

relic protection, and the project covers an area of general forestland. Its adverse

effects are mainly observed in the requisition of the construction land in the social

environmental aspect. The owner of the project is responsible for the treatment of the

requisited construction land, and implements negotiable compensation for the project

land acquisition according to relevant provisions and the current reality. The problem

of project land occupation can be properly solved.

From an environmental perspective, there is no major environmental issue to

obstruct the project, making the development of the CHIPOTA hydropower station

project feasible.

12.3 Design Basis and Standards

Design basis (1) Environmental Quality Standard of Surface Water (GHZB1-1999);

(2) Ambient Air Quality Standard (GB3095-96);

(3) Noise Limit for Construction Field (GB12523-90);

(4) Technical Specification for Comprehensive Treatment of Water and Soil

Conservation.

Design Standards (1) GHZB1-1999 Environmental Quality Standard for Surface Water;

(2) GB5749-1992 Sanitary Standard for Drinking Water;

(3) GB5084-1992 Farm Irrigation Water Quality Standard;

(4) GB8978-1996 Comprehensive Sewage Discharge Standard;

(5) GB3095-1996 Atmospheric Environmental Quality Standard.

The information contained in this design shall abide by the existing laws and

provisions established by China. Provided any corresponding regulations from


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Zambia were applicable, the Owner shall complete procedures pursuant to the

provisions established in Zambia.

12.4 Design of Environmental Protection Measures

12.4.1 Ecological environmental protection measures

(1) To strengthen the work of protection and recovery of forest and grass

upstream.

(2) To strengthen the construction supervision and environmental protection

education. Legal and environmental protection education should be carried out for the

benefit of construction personnel as well as for the awareness promotion of relevant

laws and regulations of the state and the identification of the national protected wild

animals in the construction area. It is required to have the staff understand the

significance and effect of wild animal protection and understand that the protection of

wildlife is the duty of every citizen.

12.4.2 Treatment measures for the construction and production of wastewater and

domestic sewage

In order to protect the water quality of the river, engineering treatment measures

should be taken to manage the construction wastewater.

(1) Wastewater treatment scheme for the sand and stone material processing

system.

As the artificial sand and stone material processing system consumes large

amounts of water, it is suggested to set a wastewater treatment circulatory system to

reduce the discharge of wastewater. The wastewater pollutants produced by the sand

and stone material processing system are mainly sediment suspended solids. In a

wastewater treatment project, the process for reducing the suspended solids content is

relatively simple, reaching the discharge requirements simply through sand setting

and a sedimentation treatment. Add coagulant in the treatment process to accelerate

sedimentation.

(2) Waste water treatment scheme for concrete mixing system


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The concrete mixing system itself does not discharge production wastewater, but

produces wastewater in the flushing process. The concentration of suspended solids

and PH value of the wastewater is high, allowing for a centralized treatment.

According to the requirements of the comprehensive wastewater discharge standard

established by the national and local environmental protection department, the

concentration of suspended solids of the treated wastewater should be lower than

70mg/L, with a PH value between6-9. In a wastewater treatment project, the process

applied for the reduction of the suspended solids content and the PH value is

relatively simple, reaching the discharge requirements simply though sedimentation

and the addition of acidoid.

(3) Treatment measures for sporadic decentralized wastewater

In the construction process, when it is difficult to provide centralized treatment

to some flowing, decentralized wastewater sources, we should try to use the terrain

conditions to dig drainage ditches and set sumps to allow the wastewater to receive

natural sedimentation before entering the river to reduce sediment content.

(4) Treatment measures for the construction of domestic sewage

The construction of domestic sewage mainly contains suspended solids, BOD,

COD, nitrogen, phosphorus and other nutrients, which do not reach comprehensive

sewage discharge standards, and can be discharged after being treated through a

small-sized integrated wastewater treatment equipment. The medical sewage of the

construction medical station can be discharged following the disinfection treatment.

In the construction of the living area, public toilets with septic tank should be built.

12.4.3 Treatment measures in the construction of a waste residue

In order to effectively prevent rainwater erosion from causing water and soil loss

and the waste residue collapse, such waste residue field should provide a slope

reinforcement treatment and build a retaining wall. In addition, in order to restore the

vegetation landscape in the construction area, we should timely provide new soil on

the waste residue field after the completion of the construction work, and plant shrubs,

trees with a well-developed root system and a strong drought resistance capability.


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12.4.4 Protective measures against dust and noise

In the dry season, water the construction road to reduce the levels of dust; the

construction excavation process includes a wet dust removal operation; use a sealed

cement injection pump for loading and unloading cement in the transportation process;

concrete mixing equipment should be equipped with dust remover. The construction

personnel working near the noise source should wear protective anti-noise earplugs

and earmuffs.

12.4.5 Greening measures in the construction area

The permanent living area and office area should adopt point-line-surface

combined small garden type with green lawns, hedges, flowers, fruit trees and some

ornamental plants to create a beautiful work and living environment for the power

station workers.

We should fully carry on the site remediation and greening work for the

temporary construction land (including the slags field and each production area) after

the completion of the construction work. The original cultivated land should be

restored according to relevant provisions of the state, and the rest of the temporarily

occupied land should be greened to the furthest extent possible.

12.4.6 Health protection measures

In view of common infectious diseases and various infectious diseases that may

be caused by the project construction in the project area, from the three links, namely,

the source of infection, the transmission way and the susceptible population, the

following comprehensive protection measures should be taken:

(1) The construction unit shall provide necessary medical equipment and

prevention and treatment medicine against infectious diseases in the construction site,

establish and perfect the disinfection and isolation system, improve the disinfection

measures and prevent iatrogenic infection.

(2) We should spread prevention knowledge of infectious diseases among the

engineering staff, mobilize people to carry out regular mosquito, fly and rodent

eradication and other patriotic health campaign to improve environmental hygiene and

strengthen personal hygiene protection.


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(3) The construction area should adopt a centralized water supply system, and

the water quality and hygiene requirements should meet the national Sanitary

Standard for Drinking Water (GB5749-85). For decentralized water supply, sufficient

protection of the water sources should be provided to ensure drinking water safety.

12.5 Environmental Monitoring

The project is a small water conservancy and hydropower project, and will not

produce wastewater or gases in the operation process. The water quality will not get

worse after the power generation process, so the environmental monitoring program

will mainly be for the construction period.

12.5.1 Construction production of wastewater and domestic sewage monitoring

During the peak period of the construction production, the production of

wastewater discharged from the main construction subsidiary enterprises will be

uniformly monitored through sampling 1-2 times, and the monitored items will

mainly consist of the PH value, suspended solids and petroleum. In the dam area and

living and office area of the powerhouse, we will collect domestic sewage 1-2 times

for monitoring, and there will be 7 main monitoring items, namely, the PH value,

suspended solids, COD, BOD5, ammonia nitrogen, total phosphorus and coliform.

The purpose of this monitoring program is to understand the discharge of wastewater

and its influence over the river water quality.

12.5.2 Construction noise pollution and air pollution monitoring

The project is small, and the monitoring points are located in the main

construction and production sites, living areas and on both sides of the construction

and transportation main road. The items to be monitored are: levels of noise, SO2,

NO2, and total suspended particulates. It will be better to set the monitoring time in

the early and middle stage of the construction, in order to provide the basis for labor

hygiene protection of the construction personnel.

12.5.3 Population health condition monitoring in the construction area

To timely grasp the physical health of the construction personnel and effectively


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control the spreading of infectious diseases, we should monitor the health condition of

the construction personnel throughout the construction period, focusing on monitoring

the incidence rate change of insect borne infectious diseases like malaria, epidemic

encephalitis B and water-borne infectious diseases like bacillary dysentery, typhoid

fever, paratyphoid fever, viral hepatitis, etc. to provide the basis for construction

management. This work should concurrently be under the management the

construction medical station or the township health center.

12.6 Budget Estimation of Environmental Protection Design

Environmental protection investment refers to the environmental protection

investment projects of the power station project and the environmental protection

measures taken in order to reduce any adverse effects of the project. Environmental

protection investment of the project includes three sections including environmental

protection investment in the construction area, population health protection

investment, and environmental protection, monitoring and supervision during the

construction period. The total environmental protection investment in the construction

period is 8,800 US Dollars.


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Drawings of CHIPOTA FALLS Station

1. Hydraulic-Plane Layout of CHIPOTA FALLS Station (Compared Plan) 01

2. Hydraulic-Plane Layout of CHIPOTA FALLS Station (Recommended Plan) 02

3. Hydraulic-Plane Layout of Dam (Compared Plan) 03

4. Hydraulic-Plane Layout of Dam (Recommended Plan) 04

5. Hydraulic-Design Diagram of Dam (Compared Plan) 05

6. Hydraulic-Vertical Section of Dam (Compared Plan) 06

7. Hydraulic-Design Diagram of Dam (Recommended Plan) 07

8. Hydraulic-Vertical Section of Dam (Recommended Plan) 08

9. Hydraulic-Design Diagram of Diversion System (Compared Plan) 09

10. Hydraulic-Design Diagram of Diversion System (Recommended Plan) 10

11. Hydraulic-General Plane Layout of Plant Area (Compared Plan) 11

12. Hydraulic-General Plane Layout of Plant Area (Recommended Plan) 12

13. Hydraulic-Plane Layout of Powerhouse 13

14. Hydraulic-Layout of Turbine-generator Units 14

15. Construction Organization-Layout of Construction Diversion (Compared Plan) 01

16. Construction Organization-Layout of Construction Diversion (Recommended Plan) 02

17. Construction Organization-Plane Layout of General Construction (Recommended Plan) 03

18. Construction Organization-Layout of Dam Construction Area (Recommended Plan) 04

19. Construction Organization-Layout of Penstock Construction Area (Recommended Plan) 05

20. Construction Organization-Layout of Dam Construction Area (Recommended Plan) 06

21. Construction Organization-Construction Progress Chart 07

22. Electric-Plane Layout of Electromechanical Equipments 01

23. Electric-Plane and Section of Booster Station 02

24. Electric-Main Electrical Connection Diagram 03

final report1111 - UNDP

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