Xiyaburi dam project poyry july_2012_v_03

1 Xayaburi HPP, Presentation 16 July 2012, Luang Prabang

Monday 16 July 2012, Luang Prabang

Xayaburi Run-of-River HPPPresentation to Government of Lao PDR

and other interested Stakeholders

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Content of Presentation 1. General2. Introduction of Pöyry3. State of the art for run-of-river power plants4. MRC Guidelines5. Xayaburi HPP and other hydro schemes in the Mekong6. Prior Consultation Process7. Roles of Pöyry8. MRC Guidelines9. Dam safety 10.Sediments 11.Water Volume in the River12.Fish Migration13.Trans-boundary Effects14.Main project changes recommended and implemented15.Ongoing investigation works for the detailed design16.Downstream effects of Run-of-river power plants similar to the Xayaburi Power Plant17.Video Presentation on Project18.Conclusions

Xayaburi HPP, Presentation 16 July 2012, Luang Prabang

General• The general intention of this presentation is to inform the audience on

– particularities of a run-of-river hydropower scheme– the compliance of the project with the MRC design guidelines– particular issues which were raised during the Prior Consultation Process– the concerns related to the issue of sediment transport in the lower reaches of the

Mekong River – the influence the project might have on the water flow quantities in the lower

reaches of the Mekong River• It will also be shown what changes the project developer intends to actively

introduce in the project to positively influence the sediment transport process and the other requirements stipulated in the MRC Design Guidelines.

• The Xayaburi project has been under development since 2007 and the following studies / reports have been completed by others and used as basis:

– Feasibility study– Environmental and social impact assessments– EPC tender documents– Various Studies on this project and general information available


Presenters of Pöyry

• Knut Sierotzki, Responsible Director for Hydropower Asia and Russia, 25 years experience in water management and hydropower globally, since 1991 also working in SE Asia

• René Schmidiger, Senior Project Manager and Dam Expert, 36 years experience in hydropower projects in all continents, since 1992 also working in SE Asia

• Dr. Robert Zwahlen, Senior Environmentalist and Biologist, 35 years experience in environmental impact assessments and management projects mainly in the tropics, since 1989 also working in SE Asia, independent expert of World Bank, ADB and other international organisations on environment


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• Engineering balanced sustainability™ is about improving resource efficiency. It involves finding solutions to improve energy, water, material and supply chain efficiencies while improving the overall return on investments.

7Xayaburi HPP, Presentation 16 July 2012, Luang Prabang

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...WITH 120 YEARS OF HYDRO EXPERIENCE

• 1895: Foundation of Elektrobank in Zurich, Switzerland

• 1911: Association of Finnish Steam Boiler Users established (later Fuel and Power Economy)

• 1946: Elektrobank’s engineering department becomes Elektro-Watt

• 1965: Elektro-Watt becomes Elektrowatt Engineering Services and later Electrowatt Engineering

• 1972: Ekono Oy was established by separating the Consulting business from the Finnish Association.

• 1993: Jaakko Pöyry Group acquired Ekono’s energy business and continued under name Ekono Energy

• 1997: Acquisition of Electrowatt Engineering by the Jaakko Pöyry Group

• 1998: Energy business group of Jaakko Pöyry Group operates under name Electrowatt-Ekono

• 2004: Acquisition of Verbundplan GmbH by the Jaakko Pöyry Group

• 2006: Electrowatt-Ekono and Verbundplan called Pöyry under the Pöyry Group’s rebranding strategy

• 2011: Acquisition of SwedPower AB by Pöyry Group


Major Hydropower projects of Pöyry under execution in 2012

Current Projects No. of MWLaja I, Chile 35Taschinas, Switzerland 11Thurfeld, Switzerland 2Deriner, Turkey 670Ermenek, Turkey 300Tuirial, India 60Macchu Piccu II, Peru, 100Quitaracsa, Peru 112Rucatayo, Chile, 56Limberg II PSP, Austria 480Reisseck II PSP, Austria 430Uma Oya, Sri Lanka 150Siah Bishe PSP, Iran 1,000Rheinfelden, Switzerland 116Tsankov Kamak, Bulgaria 80Rudbar-Lorestan, Iran 450Lehen HPP, Austria 20Xayaburi, Lao PDR 1,470Ashta, Albania 90Beyhani 1, Turkey 550Karlsdorf Gössendorf, Austria 20Total capacity under execution 6,202


Nam Ngum 2 Hydroelectric Project, Lao PDR

Client South East Asia Energy Ltd., BangkokThailand

Project DetailsDam height 181 mCrest length 510 mSpillway capacity 9,000 m3Power tunnel 1 x 675 m 3 x 210 mGross head 164 mRated discharge 422 m3/sPowerhouse (surface) 3 x 205 MW

Scope of ServicesIndependent owner’s engineer - feasibility, tender, detailed design and construction supervision

Execution Period2004 – 2011

181 m concrete faced rockfill dam and 615 MW hydropower plant (Francis units)


FREUDENAU HYDRO POWER PLANT, AUSTRIA

ClientÖsterreichische Donaukraftwerke AG

Scope of Services• Prefeasibility study• Feasibility study• Engineering design• Tendering and procurement services• Design of backwater area in cooperation with

Vienna Metropolitan Administration• Construction and erection supervision• Commissioning


Run-of-river power plant with 6 bulb turbines of 30 MW, rated capacity 172 MW


BIRECIK DAM AND HYDROPOWER PLANT, TURKEY

ClientMinistry of Energy and NaturalResources (DSI), Turkey

Scope of Services• Feasibility Study• Final Design• Construction design• Site Management• BOT development• Operation


62.5 m high concrete gravity dam/fill dam with concrete core, 672 MW, 6 Francis turbines


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Client:Nathpa Jhakri Power Corporation Ltd. (NJPC), Shimla, India

Scope of Services (1990-2003):• Preparation and review of technical specifications• Review of detailed designs and civil construction

drawings• Establishment of quality control procedures• Assistance in solving technical problems during

construction• Settlement of claims• Advice on construction methodology and

equipment• General project monitoring and management

1500 MW run-of-river power plant in the Himalayan foothills

NATHPA JHAKRI HYDROPOWER SCHEME, INDIA


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Client: Ceylon Electricity Board

Description:• Implementation of a 78 MW run-of-

river scheme

Scope of Services (1998-2003):• Tender documents and drawings• Assistance in pre-qualification and

tender evaluation• Civil engineering drawings• Review of E&M design and

documents• Supervision of construction, erection

and commissioning

Kukule Hydropower Plant, Sri Lanka


RHEINFELDEN POWER STATION, SWITZERLAND/GERMANY

ClientKraftübertragungswerke Rheinfelden AG

Project DetailsReplacement of power plant from 1895Owners engineer for design of a 116 MW run-of-river scheme to replace existing power planwith 4 bulb turbines a total discharge of 1500 m³/s.

Scope of Services• Final Design• Environmental impact assessment and

investigations• Assistance to client for receiving the

concession from the authorities• Construction Design and Supervision

Execution Period1984 – 1994 2004 – 2011


State of the Art in run-of-river power plants

The technology for run-of-river power plants is now about 120 years old. Some of the first schemes were built along the river Rhine between 1895 and 1905. During the last 120 years considerable developments have taken place in technical fields as well as in the sustainability of such schemes.


State of the Art in Run-of-river power plants

• The reservoir level has to be kept largely constant (head) and inflowing water is constantly released either through the turbines or the spillway

• The water is not stored (except impounding) and therefore the mean daily flow regime of the river is not affected

• This is in contrast to high head storage schemes where large volumes of water are stored by means of high dams

– storing excess water during the high flow season and releasing water during the low flow season and

– accumulating the river flow sediments in the reservoir



Today the following main principles are used in the design of the run-of-river power plant:

– to built the weir and power structure as flexible as possible allowing the routing of floods, sediments and nutrients directly through the system.

– to allow migration of fish and other aquatic animals through or around the dam structure

– to have the best available equipment to avoid pollution, to allow downstream fish migration and best use of the energy

– to allow for efficient navigation and to support recreation– to satisfy the highest safety standards according national and international norms– to support the general development of a region with the supply of safe, reliable

and clean energy



Various upstream and down stream fish migration systems e.g. fish lock, fish ladder, natural by-pass channel, fish lift etc.Protection of the area and ban of fishing and hunting in the vicinity of all structures.



Fish Friendly Turbine


Fish Friendly Turbines:

Turbine Type Length of Fish5-10 cm 30-50 cm

Francis >50% up to 100%Kaplan 5-10% 15-30%Fish-friendly turbines <5% 5-10%

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Mortality of fish passing through turbines



Release of Sediments– Most of the larger run-of-river schemes

with dams / weirs larger than about 20m height are equipped with larger bottom outlets for sediment release.

Examples: – India, CWC request from public and

private developers the use of large bottom outlets is required for the continuous release of sediments during the monsoon period.

– China, some large run-of-river dams have sediment outlets e.g Three Gorges

– Sudan, Merowe (Nile River), large Sediment outlets were provided

– France, CNR will explain in their presentation


MRC design guidelines

• The preliminary MRC design guidelines is one of the documents developed for the implementation of the 1995 Mekong Agreement to assure a sustainable development of the Mekong River Basin

• The guidelines deal with the following issues:– Navigation lock system– Fish passing facilities– Sediments– Water quality and aquatic ecology– Safety of dams

• For downstream countries the issue of sediments and nutrient is of particular interest for the long-term development of the lower Mekong Regions


Xayaburi scheme and other hydro schemes in the Mekong

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Upstream Hydropower developments:

1. Manwan HPP, 1550 MW, 132 m high dam with seasonal storage

2. Jinghong HPP, 1750 MW, 108 m high dam3. Nouzhadu HPP, 5850 MW, 261.5 m high dam, multi-

annual storage4. Xiaowan HPP, 4200 MW, 294.5 m dam, multi-annual

storage

The schemes under development (Xiaowan & Nouzhadu) are storage schemes and will also trap large amounts of sediments to secure the operation of the d/s power plants.

Reference: Department of Sedimentation, China Institute of Water Resources Hydropower Research

Downstream hydropowerDevelopments:

1. All d/s schemes are run-of-river schemes.

2. None of this schemes have any pond larger then a few hours of operation

3. Dam heights are below 30m


Xayaburi scheme, Overview


Xayaburi scheme, Main Features

Country: Lao PDRLocation: Xayaburi town, Approximate 80 km south of Luang PrabangCommercial operation: October 2019 (expected)Construction cost: $3.8 billionOwner(s): Xayaburi Power Company Limited (XPCL)Dam and SpillwaysHeight: 32.6 mLength: 820 mType of spillway: 7 x radial gates, 4 low level outletsSpillway capacity : 47’500 m3/sPond Capacity : 726 Mio m3, filling time with mean Mekong flow about 50 hoursCatchment area: 272,000 km2

Full supply level: 275 m a.s.l.Power stationHydraulic rated head: 18 mTurbines: 7 x 175 MW Kaplan-type, 1 x 60 MW Kaplan-typeMaximum capacity: 1,285 MWEnergy Production: 7’405 GWh, Export to Thailand 6’985 GWh supplies electricity for 3 Mio people or 750’000 familiesFor Lao PDR 420 GWh supplies electricity for 1 Mio people or 200’000 families


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Xayaburi scheme, Construction Sequences

River diversion phase 1: construction cofferdams at the right side of the Intermediate block

Cofferdam completion schedule

May 2013

Stage 1 Intermediate Block completion

scheduleJun 2014


May 2013

DOWNSTREAM


30303030


River diversion phase 1: construction Navigation log and spillway

Navigation Lock and Spillway completion

scheduleOct 2014

DOWNSTREAM


31313131


River diversion phase 2: construction coffer dam at the left side of the Intermediate block

Cofferdam removal schedule

Oct 2014


Oct 2014


Jun 2015DOWNSTREAM


Jun 2015


32323232


River diversion phase 2: construction coffer dam at the left side of the Intermediate block

Main structure of Powerhouse & Fish ladder completionscheduleMar 2018

DOWNSTREAM


33333333


River diversion phase 2: removal coffer dam at the left side of the Intermediate block


Mar 2018Powerhouse commissioningSep 2019

DOWNSTREAM


Mar 2018


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Role of Pöyry

• Contractual basis:– Consulting Services Agreement for Compliance Review– Between GOL and Pöyry Energy (5. May 2011)

• Scope of work: to report on whether – Xayaburi Power Company (Owner) has complied with and satisfied the

Mekong River Commission (MRC) Design Guidelines – GOL and the Owner have taken into consideration the comments

submitted by the MRC member countries during the Prior Consultation Process

– GOL and Owner have complied with the terms of “Prior Consultation Project Review Report on Xayaburi Project”, dated 24 March 2011

– Issues relating to development, construction and implementation of Xayaburi and any discrepancies, conflicts and needs for changes in connection with comments by the riparian countries


Role of Pöyry, Compliance StudyPöyry has performed in 2011 a Compliance Study based on the previous documentation on the following topics.

– Following the “Prior Consultation Process” according to the MRC guidelines, the MRC stakeholder countries issued comments on Xayaburi project

– Critical comments were raised by Vietnam, Cambodia and Thailand– Main items of concern and potential improvements are:

• Retention of sediment• Migration of fish

– Pöyry carried out a Compliance Report with the objective to:• Assess comments made by stakeholders and MRC on the current design• Evaluate these comments against the MRC guidelines• Identify points where the current design does not fully follow the MRC guidelines• Propose measures to make the Xayaburi project fully compliant with the MRC guidelines

– The Compliance Report was issued to the Government of Lao in August 2011.– Continuous assistance to the Government of Lao to address the technical queries

raised.


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Main issues raised in the Prior Consultation Process

• The main concerns of the riparian countries are:– Trans-boundary issues – Certain impacts not addressed in as great detail as one would like

• Sediment trapping• Nutrients• Fishery• Biodiversity• Socio-economic aspects

• These concerns can be remedied during the construction stage by:– Additional investigations recommended – Implementation of certain design changes

• Providing of flushing gates to allow release of sediments• Improvement of fish pass facilities


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• Findings MRC Expert Group Safety of Dams – Issues will be taken into account

• Findings MRC Expert Group Navigation Lock System – Suggested changes will be introduced

• Findings MRC Fishery Expert Group (fish ecology and fishery)– Gaps are identified and recommended actions will be implemented

• Findings MRC Fishery Expert Group (fish passage facilities)– Recommendations are reasonable and applicable recommendations will

be checked and taken into account


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• Findings MRC Fishery Expert Group (socio-economics and rural livelihood aspects)

– Baseline investigation– Monitoring– Compensation measures

• Findings MRC Sediment Expert Group on sediments – Sedimentation during construction – Adaptive management of flushing devices

• Uncertainties considering available data • Uncertainties considering future development• Mitigation of sediment concentration peaks


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Dam safety


• General design principles– State of the art design principles and design methods are being used

and which are in line with the size and importance of the project • Overall project safety concept

– The concept is being developed in which the different project parts (or elements) will be design according to different criteria, depending on their importance and damage potential. Applies to civil works and also all equipment.

• Flood design – Follows internationally accepted concepts

• Seismic design – ICOLD guidelines will be followed where project parts will be designed

for OBE (operation basis earthquake, 145 yr), DBE (design basis earthquake, 475 yr) and checked against the SEE (safety evaluation earthquake, 10’000 yr), depending on their hazard potential

• Design complies with MRC design guidelines

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Sediment measures proposed by Pöyry (1)

• Main concerns expressed – Reduction of sediment content in Mekong River downstream of Xayaburi– Can have detrimental effects up to Mekong delta in Vietnam – Leading there to costal erosion and intrusion of sea water – Reduction of nutrition content in Mekong River downstream of Xayaburi– Having detrimental effect on fish population – Leading to reduction of fishing yields in River downstream – Negatively affecting downstream population

• Current sediment transport regime – The main sediment transport in the river takes place during the high flow

season – In the present state the yearly sediment flow in the river is in a stable

state, although influenced by the construction of dams in China (see explanations of CNR)


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• Basic requirement for sediment transport– Xayaburi dam must be a transparent dam and mimic the natural

conditions (see MRC Guidelines) – This means the dam must be capable not to retain and store the

sediments, but to release them towards downstream in natural way• Introduction of low level outlets

– The original spillway outline design has been adapted by introducing 4 large capacity low level outlets equipped with radial gates

– Their dimensions are 12 m (width) and 16 m (height) – Their sill level is 14 m lower than the spillway sill level – The number of the original spillway openings has been reduced by 3

openings and the spillway sill level has been lowered by 2m • Purpose of the low level outlets

– The low level outlets will allow, in combination with the spillway, to • route sediment loaded flood flows through the available low level and spillway

openings and to• draw down the reservoir and to flush the sediments towards downstream


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• Cross section of low level outlet


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• Cross section of spillway outlets


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Sediments (5)

• Longitudinal section along spillway complex, showing both spillway opening and low level openings

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230238


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• Timing of sediment release– Flood routing will be done during high river flows in the flood flow season– Reservoir flushing will be done also during the flood season primarily

during the weekend – The operations will be done in each year in order to mimic close natural

conditions • Effect of these operations

– These repetitive operations will prevent the excessive accumulation of sediments in the reservoir and which would be lacking in the downstream

• Control of sediment concentration – Too high sediment concentrations in the water released through the low

level outlets would be detrimental to the river fauna – The sediment concentration will be controlled by combined release

operations through the low level outlets (high concentration) and the spillway openings (low concentration)


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• Control of effect of these operations – Potential sedimentation in the reservoir will need to be monitored by

repetitive bathymetric surveys– Based on these results the flood routing and reservoir flushing operations

can be adapted to the current needs – The installed release facilities offer full flexibility in this respect – Monitoring of sediment concentration downstream during flushing

operation• Coarse sediments

– Will need to be transported by mechanical means (see CNR note)• Conclusion

– With the planned sediment release facilities and the intended operation procedures it will be possible to achieve a project facility transparent to sediments

– The sediments entering the reservoir will be transferred towards downstream and potential negative effects of lack of sediment there can be reduced to a minimum.


Xayaburi HPP, Presentation 16 July 2012, Luang Prabang47

Flow Volume in Mekong River (1)

• Main concerns expressed – The current flow volume of the Mekong River would be affected by

Xayaburi– There would be less flow in the low flow season – There could be higher flood flows

• Principle of run-of-river plant – There will be no seasonal storage of water volumes – The daily inflow into the reservoir corresponds to the daily outflow (see

also CNR)• Effect of Xayaburi on downstream river flow conditions

– The current flow conditions in the river will therefore virtually not be changed

– Minor changes are possible caused by daily variations in the power production (causing reservoir fluctuations up to 30 cm)


Flow Volume in Mekong River (2)

– Equally minor changes are to be expected during the weekend, when power production will be reduced

– The effect of such changes in the water flow, which can cause water level variations limited to less than one meter, will reduce and finally equalize along the river the further away downstream one gets from the dam

– The speed of the downstream water level variations can be controlled by operational measures. There will thus be no sudden water level rises.

• Flushing operations – Such operations can affect the downstream water flow for a longer river

stretch– But flushing is only planned to be performed in the high flow season, when

changes in the river flow are less felt

Environmental and Social Impact Assessment (ESIA)

Carried out in 2007 - 2010– The studies carried out be by the EIA Consultant cover all the aspects which need

to be covered for such a project and to comply with GoL requirements– The local environmental law in Lao PDR follows Worldbank/IFC guidelines– The total environmental cost are adequate even some of the total cost are

accounted under other topics, e.g. cost for fishpass

The environmental studies were approved by GoL on 13 September 2010Main findings:

– Minor impact on local population, limited re-settlement required– Minor impact on fish fauna, Environmental Impact Assessment (EIA) survey only

identified limited amount of fish speciesImprovements recommended for the ESIA:

– Additional survey of actual physical conditions, especially on fish species– Additional study on sedimentation


Technical Paper No. 8 by MRCThe MRC published the main results of the main fish migration systems in the Lower Mekong Basin.There are three different migration systems:

– The Lower Mekong Migration System (LMS)This migration system covers the stretch from the KhoneFalls downstream to southern Cambodia, including the Tonle Sap system, and the Mekong Delta in Vietnam.

– The Middle Mekong Migration System (MMS)From just above the Khone Falls and upstream to the LoeiRiver, Thailand, the migration patterns are determined by the presence of large tributaries connecting to the Mekong mainstream.

– The Upper Mekong Migration System (UMS)The third migration system occurs in the upper section of the river, approximately from the mouth of the Loei River and upstream towards the border between Lao PDR and China (probably continuing into China).

Whereas the LMS and the MMS are inter-connected to a large degree, the UMS appears to be relatively isolated, with little “exchange” between the UMS and the other migration systems. These populations should be regarded as separate biological unit.


Technical Paper No. 8 by MRC

Main conclusions1. The LMS and MMS migratory system are

playing a crucial role in the fisheries of the Tonle Sap and Mekong delta.

2. The main spawning areas are in the LMS and its tributaries.

3. The UMS is not (or very limited) connected to the other migratory systems and has only significance for the local fisheries in this stretch of the river.

4. The highest biodiversity of the Mekong is in the area downstream the Khone falls in Cambodia.

5. The area between the mouth of the LoeiRiver and the Chinese Border: One of the remarkable species in the UMS is the Giant Mekong Catfish (Pangasianodon gigas). It seems genetically to be a local subspecies which might be separated from the downstream population.


Fish Migrations

Mainly two types:• anadromous: adults move upstream for reproduction, young move

downstream• catadromous: adults move downstream (for reproduction in the sea),

young move upstreamOther migrations, over longer or shorter distances, not necessarily related to reproduction.


General effects of HPPs

Main impacts of dams on fish migration:• Dams interrupt upstream fish migration• Downstream migrations go mainly through the turbines, with a high

risk of injury and mortality• Fish that do not migrate for reproduction can be influenced by

fragmentation of the populations (no genetic exchange between populations isolated by dams).


Main Measures Taken

Different measures have been developed for maintaining fish populations and migrations, as:• Fish ladders of different types• Fish lifts• Traps combined with transport• Fish hatcheries and artificial restocking of rivers (in cases where

migrations could not be maintained and/or other conditions led or contributed to the decrease in fish populations)

• Fish friendly turbines (turbines reducing risk of injuring or killing fish)


Fish Hatcheries

• Done in cases where barriers (dams) are too high to be passed with a fish ladder

• where other conditions (mainly water quality) threaten fish populations

• usually done only for economically important species


Limitations

• Experience gained so far mainly in North American and European rivers.

• Historic targets for measures were mostly Salmonids, i.e. fish which can cope with fast currents and rather high steps.

• Recently, fish passes were implemented which are acceptable for a wider range of fish species.

• Limited experience with fish passes in large tropical rivers but rapidly growing with the experiences in other countries e.g. Brazil



Fish passing facilities (1)

• The present layout of the fish passing facilities comprises the following main structures

– facility for upstream migration, – fish passage recording system for upstream migration and – facility for downstream migration

• The selected system is very comprehensive and employs a state-of-the-art technology and covers all operational conditions of the scheme

• However there are a few issues which need improvementto be in compliance with the MRC design guidelines.

Main Problems Identified

• Potentially very high amount of biomass, i.e. a very large number of migrating fish, during certain periods.

• High number of species with a very wide range of size.• Therefore different migration requirements, especially concerning

manageable flow speed and height of steps.• Limited knowledge of fish migrations (in terms of species, numbers

and seasonal distribution) at the project site.



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The following investigations are recommended:1. During the first stage of the construction:

– develop additional baseline data on biology, ecology and livelihood restoration

– improve the knowledge concerning the specific requirements of the aquatic fauna on the fish passage facilities

2. Investigations to be done independently from the start of the construction when sufficient data are available and under national or multinational responsibility:

– additional investigations on trans-boundary issues on hydrology and baseline investigations (fauna, flora, habitat and socio-economy)

– A cumulative impact assessment of the mainstream dams

Area influenced by Xayaburi dam

Area influenced by other dams



The following design adaptations are recommended:

• The fish passage facilities should be amended as follows:

– The planned facility should be adapted as follows:

• The downstream passage needs to be changed at the inlet and outlet structures

• The velocity of the channels needs to be adapted based on the proposed investigations

• The head difference between the pools needs to be adapted (too high); this will lead to a longer fish passing facility.

– There should be a system provided to allow fish passage during construction

– Flexibility allowing later improvements if required



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– The MRC design guidelines require several independent systems:

• The navigation lock should be adapted to serve as a fish lock (also during construction stage)

• Space for a fish lift should be prepared





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Furthermore the following additional measures are recommended:– Fish friendly turbines have been recommended in the feasibility study.

The degree of fish friendliness of the turbines should be verified with the envisaged supplier of such turbines.

– It is recommended to set-up and operate a fish breeding station for the augmentation of the existing fish population and re-introduction of locally endangered species for release in a suitable river stretch.


Additional Recommendations

Given the lack in baseline information, the following is recommended:

• Aquatic baseline investigation concerning important habitats, spawning areas, feeding areas, etc. within the future reservoir area.

• Fish survey: species inventory, migration patterns, abundance, total fish biomass and larval drift.

• Identification of target species which represent whole groups (concerning size and migration patterns, economic importance, etc.); swimming ability and behavioural studies.


Fish Migration and Biomass Study

• A study has started which aims at providing additional information on migrations and biomass.

• A suitable sampling site was chosen about 1 km d/s of the dam site.• Main method applied is detecting migrating fish by means of hydro

sonar; four stations are being used (one fix on each river bank, two mobile ones on boats).

• First field campaigns have been carried out end of March / April and • First reports were submitted.


First Results

Size of fish migrating upstream (April 2012):

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May 2012 (right)• about 50% 0-20 cm• about 10% > 1 m, up to 2.2m

April 2012 (left)• about 50% 0-20 cm• about 5% > 1 m


First Results (2)


Follow-up

Ongoing activities:• Follow-up on studies, monitoring results• Initiation and supervision of implementation of environmental

measures on site• Maintaining discussion and exchange of information with relevant

stakeholders• Integration of new findings into design of fishway



Main project changes recommended and to be implemented

• The following changes will be implemented in the project• A) Sediment transportation

– Provision of large capacity low level outlets– Allows passage of the sediments towards downstream during high flow

season – The aim is a transparent dam with respect to sediments

• B) Fish passage– Fish passing facility in navigation lock

• Allows fish passage also during construction period– Adaptation of fish ladder system (step height) depending on findings of

baseline studies – Provision of a fish lift (additional) if baseline studies indicate the need for it

• C) Navigation locks– Improvements in upstream lock approach area (avoidance of bends) – Changes in lock feeding system (making operation more smooth)

Recommended investigations

Investigations to be carried out specifically for Xayaburi (i.e. by the developer) during the construction stage:• Fish survey and related studies for optimising

fish pass facility• Additional socio-economic studies on the

effects of Xayaburi in the reservoir area and in the downstream proximity

• Continuous measurements of flow, water quality and other parameters

• Baseline study for sediment content and sediment composition of Mekong river in project area

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Framework studies to be carried under national or multinational responsibility, independent from the start of the construction:• CIA and trans-boundary assessment of effects of all HPP developments in the

Mekong basin (also taking into account effects of planned and operating dams in China).


Ongoing investigation works for the detailed design

The following main topics of investigations are on-going or have already been completed:

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Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q41 Seismic investigation

1.1 Geological investigations2 River quality measurements3 Hydrological measurements

3.1 River Sedimentation sampling4 Meteorology measurements5 Additional ecological studies

5.1 Fish survey6 Additional social studies

2010 2011Investigation TopicsS/N 2012



Conclusions by Pöyry

• The Compliance Study performed by Pöyry has established those areas where the project was not yet fully in compliance with the MRC preliminary design guidelines

• Proposals on actions to be taken to bring the project into full compliance were made

• The necessary actions have all been initiated by now and which consist of

– Actual changes to the project and its future operation – Additional studies and investigations in areas where knowledge deficits

were identified • With these actions taken it can be considered that the project will not

have unacceptable negative effects and restrictions on the population living downstream of the project, and therefore also not in the neighboring countries further south

• Following this carefully balanced approach the project fulfills the highest standards in accordance with the current State-of-the-Art

THANK YOU!


Technology

Xiyaburi dam project poyry july_2012_v_03