houay mak hiew fishway design criteria and concept · o hydrology and water levels upstream and...

research for a sustainable future

Houay Mak Hiew Fishway Design criteria and concept

December 2020 -Design Draft

Garry ThorncraftLee Baumgartner

Martin Mallen-Cooper Peter Thew

Oudom Phonekhampheng Thonglom Phommavong

Wayne Robinson Phousone Vorsane

Houay Mak Hiew Fishway

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Charles Sturt University National University of Laos

Funding provided by Asian Development Bank, Department of Irrigation, Ministry of Agriculture and Forestry (GoL) and Australian Centre for International Agricultural Research

For further information contact: Principal Contacts Lee Baumgartner Oudom Phonekhampheng Professor Charles Sturt University Institute for Land Water and Society [email protected]

Vice President National University of Laos [email protected]

Disclaimer: Information contained in this report has been formulated with all due care, CSU and NUOL does not warrant or represent that the report is free from errors or omission, or that it is exhaustive. CSU and NUOL disclaims, to the extent permitted by law, all warranties, representations or endorsements, express or implied, with regard to the report including but not limited to, all implied warranties of merchantability, fitness for a particular purpose, or non-infringement. CSU and NUOL further does not warrant or accept any liability in relation to the quality, operability or accuracy of the report. The report is made available on the understanding that CSU and NUOL, its employees and agents shall have no liability (including but not limited to liability by reason of negligence) to the users of the report for any loss, damage, cost or expense whether direct, indirect, consequential or special, incurred by, or arising by reason of, any person using or relying on the report and whether caused by reason of any error, omission or misrepresentation in the report or otherwise. Users of the report will be responsible for making their own assessment of the information contained within and should verify all relevant representations, statements and information. Furthermore, whilst the report is considered to be true and correct at the date of publication, changes in circumstances after the time of publication may impact upon the accuracy of the presented information.

Garry Thorncraft, Lee Baumgartner, Martin Mallen-Cooper, Peter Thew, John

Conallin, Oudom Phonekhampheng, Thonglom Phommavong, Wayne

Robinson, and Phousone Vorsane

Cataloguing in Publication provided by the Institute for Land, Water and Society (ILWS) Charles Sturt University, Albury, NSW, 2640.

To be cited as :

Thorncraft et al. (2020). Houay Mak Hiew Fishway: Concept design report. Charles Sturt University and National University of Laos

mailto:[email protected]

[email protected]


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Contents

1. Executive Summary ............................................................................... 3

1. Introduction ............................................................................................ 4

2. Background on Fishway Design ............................................................. 5

2.1 Attraction ................................................................................................ 5

2.2 Passage ................................................................................................. 5

3. Operation of Houay Mak Hiew Regulator ............................................... 7

4. Biology and Hydrology ........................................................................... 7

4.2 Fish size ............................................................................................... 10

4.3 Migration and water levels .................................................................... 10

5. Fishway Design .................................................................................... 16

5.1 Passage - Fishway Options .................................................................. 16

5.2 Application of Preferred Fishway Design .............................................. 19

6. Fishway Layout .................................................................................... 20

6.1 Attraction (fishway entrance) ................................................................ 21

7. Potential Construction Techniques ....................................................... 22

8. Fishway Entrance and Gate Management Plan ................................... 23

9. Community Management Plan ............................................................. 23

10. Trash Racks and Site Security ............................................................. 24

11. Fish Monitoring ..................................................................................... 24

12. Conclusion ........................................................................................... 24

13. Acknowledgements .............................................................................. 25

14. References ........................................................................................... 25

15. Appendix .............................................................................................. 26


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1. Executive Summary

Background

• In Lao PDR freshwater fish are a major source of food security and livelihoods. • Most fish in Lao PDR migrate upstream and downstream to compete life cycles. • Flood and Regulator gates and dams block or restrict migrations so that fish cannot complete

life cycles and fish populations decline. • Fishways are a passage of water – usually a low-gradient channel – around a barrier, that

migratory fish can easily migrate upstream and downstream.

First Fishway Design Masterclass for Lao PDR

• A limited (by Covid) Fish Passage Masterclass was held at Dondok Campus in Vientiane by the National University of Lao (NuoL) and Charles Sturt University (CSU), Australia in Dec 2020; with participation by Department of Irrigation (DoI), Provincial Office of Agricultural and Forestry (PAFO), District Provincial Office of Agricultural and Forestry (DAFO), Department of Livestock and Fisheries officers (DLF), as well as representatives and experienced fishers (male and female) of the local community at the proposed site. The Masterclass provided an overview of all aspects of designing fishways with a focus on developing a concept design and cost estimate for a fishway at Houay Mak Hiew.

Development of Fishway Concept Design

• Engineers, biologists, river operators and fishers have worked together to produce a concept design that will: pass fish, be cost-effective, and be easy to operate and maintain.

• There are 2 key aspects to fishway design: i) attracting fish into the fishway and ii) passing fish through the fishway. The first requires a high discharge relative to the river and an entrance that is easy for fish to locate. The second aspect requires understanding the water depths, velocities and turbulence that suits the migrating fish at the site.

• To achieve these design objectives background data is needed on: o Hydrology and water levels upstream and downstream o Biology (e.g. fish size) and migration season

• Several fishway designs were assessed and the vertical slot fishway design was considered the most suitable for Houay Mak Hiew Regulator because it has highly variable upstream and downstream water levels.

• The fishway should made of cells measuring internally 3m long and 2m wide, with a channel and new gated road culvert a minimum of 4m deep.

Next Steps

• NUOL and CSU in cooperation with the masterclass team have developed a fishway concept design recommendations and preliminary costings.

• The next steps are for DoI/ADB to commission: 1. Further engineering work to examine bed materials, structure and construction

options. 2. Detailed design, tender and construction.

• An operation manual needs to be developed with the design. • On completion of the fishway a training during the first wet season with regulator operators

is needed to so that all staff are familiar with the fishway • Finally, there needs to be monitoring of the fishway to evaluate that is it passing fish and to

provide recommendations for any improvements.


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1. Introduction

Fish passage is a specific science which requires cross-cutting between engineering and fisheries disciplines. It has been stated than “whilst an engineer might learn much fisheries, and a fisheries manager a lot of engineering” in the end both are needed to build a suitable fish pass. Best practice

fish passage design must therefore include both fish biologists and irrigation engineers to gain the best outcomes. This ensures that engineers gain an appreciation for fisheries-specific issues, and fisheries staff gain an appreciation for engineering concerns. Both groups can learn invaluable information from local fishing people’s knowledge, both on fish species present and seasonal water

level changes that influence fish behaviour. When working together the teams are able to move forward with shared understanding.

In early 2020, the ADB, in collaboration with DOI, secured budget for a fishway at the outlet regulator at That Luang Marsh (TLM). The water levels in the TLM are controlled by flood regulating structures, situated along the bank of the Mekong River. The structure prevents back-flooding from the Mekong River in the wet season and stores water for irrigation in the dry season. These structures currently block all movement of fish from the Mekong River to the TLM.

Fish migrate on a regular basis, over distances ranging from a few meters to thousands of kilometres, to feed or to reproduce. The creation of any barrier across a watercourse will impact both upstream and downstream fish movements and opportunities for reproduction and growth. In Lao PDR, fish seeking access to floodplains and riverine habitats during the wet season and require subsequent return access to dry season refuge areas in rivers. To reconnect TLM with the Mekong, there are various fisheries and engineering challenges to overcome.

Best practice in the region, for groups new to fishway design and at challenging sites, has been to run a “Masterclass on Fishway Design”. These classes follow an established format and contain an

equal number of engineering and fisheries students who work collaboratively to co-design a fish pass. The class takes four days and the team essentially: (a) select a site, (b) discuss the fisheries aspects of the site; (c) visit the site and discuss logistics; (d) scope three priority fishway designs; (e) refine that into a single “favoured” design; (f) draft the technical specifications and a draft cost estimate. The outcome is a list of engineering specifications that can then be used to prepare detailed tender documents.

Owing to local capacity constraints, the Masterclasses are usually run by international experts with decades of experience in fish pass design. Together these experts guide the students through the design process. However, difficulties with Covid have made international travel difficult; and alternative option has been chosen:

• Reduced masterclass (2 days workshop, 1 day field survey). International instructors would develop a series of content. Local instructors would coordinate local participants and deliver the content, who would be limited to a smaller focus group of key staff from the project team (20 people).

This report documents the process undertaken in the master class, and subsequent discussions between DOI, PAFO NUOL, CSU and a design company engaged to do the concept designs and cost estimates, to produce a co-designed fishway which is ratified by both fisheries, engineering and structure management disciplines.


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2. Background on Fishway Design

As background to the project we summarise two fundamental components to fishway design:

i) Attraction: which concerns attracting fish to the fishway entrance, and

ii) Passage: which concerns passing fish through the fishway.

2.1 Attraction

Attraction involves: fishway discharge, entrance location and design. Providing sufficient discharge (flow) in the fishway to attract fish is a primary design consideration, and a starting point for fishway design. Using more than 10% of river flow in the fishway is a common target in design. At very low flows often all flow can pass through a fishway, while in high flows in the rainy season it would likely be less than 10%.

The entrance location needs to be designed so that fish can locate it easily and this involves two key design principles:

i) Locating the entrance at the upstream limit of migration, and

ii) Ensuring that the fishway flow is easily detectable by fish and not masked by turbulence and crossflows.

Achieving these conditions involves design and operation of the whole structure or sluice gate. If the structure is a new design, most aspects of the structure need to be considered (e.g. abutment, gates, stilling basin, dissipators) to meet these two criteria. For both new and existing structures, operation of sluice gates is important to provide attraction. The objective in design and operation is to provide flow patterns that guide fish to the fishway entrance, under the different streamflow conditions that fish are migrating.

2.2 Passage

Passage involves all aspects or fish passing through the fishway channel itself. It is essential to know, or provide the best estimate, of:

1) The minimum and maximum size of fish that are migrating.

2) Season and flows when fish are migrating

3) The water levels at the structure, to link with 1) and 2).

To develop these three aspects into fishway design criteria, a conceptual model of fish migration and flows for the site is used and was developed during a Masterclass held in Vientiane in 2020. This is a simple explanation (text, table or diagram) of what fish are migrating (species and sizes) at what flows. Often data is incomplete, so the model represents the best understanding of fish migration and is likely to include opinions of professionals and fishers, as well as scientific data. A simple conceptual model of migration, fish size, abundance, season and flow are shown in Figure 1; this example was developed through local fisher surveys and refined in the Masterclass.

The conceptual model of flows and fish migration determines: the flow patterns downstream of the structure to examine for entrance location and design (e.g. low flows and low turbulence, or high flows and high turbulence); and the optimum upstream and downstream water levels for the fishway.


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Knowing the size of fish, and the flows at which they are migrating, determines the hydraulics of the fishway channel (e.g. smaller fish have lesser swimming ability and larger fish require greater depth).

Figure 1. A simple conceptual model for fish passage design showing migration, fish size, abundance, season and flow at Houay Mak Hiew (Note abundance etc in this case refers to when they are likely present based on the participants perception, not necessarily overall relative numbers).


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3. Operation of Houay Mak Hiew Regulator

Understanding the operation of a structure is fundamental to fishway design. The regulators (2) were built to prevent Mekong River floodwater inundation upstream into the rice paddy fields and Vientiane urban areas, as well as provide storage of freshwater for dry season irrigation. When downstream water levels are higher than upstream water levels the regulator gates are closed to prevent water moving upstream. The regulators are completely closed in dry conditions, though leakages is high, even when gates ae closed.

Over a year, the regulator gates are generally closed from November to May; and depending on the onset and duration of the wet season, open from June to October. This overlaps with both the upstream and downstream fish migration season (Figure 1.). These operations will affect fish migrating up to the regulators and through any new fishway, so the management plan for the regulator will have to be updated to incorporate operating the fishway for maximum efficiency, whilst still maintaining the functioning of the regulator. Stakeholders in managing the gates agreed during the masterclass that adapting current gate operation was acceptable and a new plan could be developed.

The fishway should be left open for as long as possible and never partially open; that is, it must be either fully open or fully closed. At the start of the wet season the first water should be released down the fishway and entering the main downstream channel before opening any gates. As gates are sequentially opened and as the wet season develops, the fishway should remain fully open and gates operated in a sequence to maintain attraction flow to the fishway. This should be done as part of commissioning the new fishway.

4. Biology and Hydrology

4.1 Fish Community

The Houay Mak Hiew is located on the Vientiane floodplain, which drains into the Mekong River (Figure2.) and comprises 2 regulators (Figure 3). The wetland behind the regulator used to be accessed by migratory fish species of varying economic, livelihood and conservation importance. The hydrology of the system is influenced by monsoonal weather patterns. An estimated 104 freshwater native freshwater fish species have been identified through local fishers surveys, as being present below the regulator (Table 1.). As fish cannot pass easily through the gates when they are storing water for irrigation, and only for limited times later in the wet season when tailwaters rise, it is likely that fish migrating for breeding and grow phases are significantly impeded and subject to high mortality rates as they congregate under the regulators.


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Figure 2. Houay Mak Hiew is located on the Vientiane floodplain, which drains into the Mekong

River through two regulators at this site.

Figure 2. The two regulator structures that make up the Houay Mak Hiew Floodgate Regulator.


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Table 1. Fish species in the Houay Mak Hiew, their expected minimum and maximum sizes when migrating and their seasonal behaviour (NUOL Survey of local fishers in November 2020 as part of preparations for the masterclass).

N- not found, U- uncommon, C- common, A- abundan

U -upstream

M main reg,

S- secondary reg

Flow type most caught, F-fastwater, S-slow water

B- Bottom swimers, M, Mid water, T- surface

S- stong swimmer, N- normal, W- weak

D- Dry season only, E1- early

Typical months migrating upstream (example Jul-Aug)

Typical months migrating downstream (exampl Min Max

Most common size

No Lao Name Species Common1 Pa Tong Dao Chitala ornata U U S B S D Jun-Jul Oct-Nov 100 700 5002 Pa Tong Kaiy Chitala blanci U U S B S D Jun-Jul Oct-Nov 100 700 5003 Pa Tong Na Notopterus notopterus U U S B S D Jun-Jul Oct-Nov 100 250 2004 Pa Makphang Tenualosa thibaudeaui U U M S B S D Jun-Jul Oct-Nov 20 150 1005 Pa Tep Paralaubuca typus U U M F T N E Jun-Jul Oct-Nov 70 150 1006 Pa Sanark Raiamas guttatus C U M S F T N E1,E2 Jun-Jul Oct-Nov 70 150 1507 Pa Soudjum Hampala dispar U U M S T N E2 Jun-Jul Oct-Nov 80 200 2008 Pa Soudkarn Hampala macrolepidota U U M S T N E2 Jun-Jul Oct-Nov 80 200 200

9 Pa SoiHenicorhynchus

siamensis C U M S F T N E1 Jun-Jul Oct-Nov 50 150 10010 Pa Sa E Mekongina erythrospila U U M S F T N E1 Jun-Jul Oct-Nov 50 100 15011 Pa Pak Barbonymus gonionotus C U M S S M N E1 Jun-Jul Oct-Nov 70 200 20012 Pa Pak Nuat Hypsibarbus malcolmi C U M S S M N E1 Jun-Jul Oct-Nov 70 200 20013 Pa Phone Cirrhinus microlepis U U M S F T N E1 Jun-Jul Oct-Nov 100 150 20014 Pa Sakang Puntioplites falcifer U U M S F T N A Jun-Jul Oct-Nov 150 200 20015 Pa Vienfai Barbonymus altus U U M S F T N A Jun-Jul Oct-Nov 50 200 200

16 Pa Joke Cyclocheilichthys enoplos U U M F B S E2 Jun-Jul Oct-Nov 300 700 50017 Pa Ern Tadeng Probarbus jullieni U U M F B S E2 Jun-Jul Oct-Nov 500 700 50018 Pa Ern Khao Probarbus labeamajor U U M F B S E2 Jun-Jul Oct-Nov 500 700 50019 Pa Khamun Catlocarpio siamensis U U M F B S E2 Jun-Jul Oct-Nov 500 1000 70020 Pa Wa Nanor Bangana behri U U M S F B S E1 Jun-Jul Oct-Nov 250 300 25021 Pa Kaeng Cirrhinus molitorelle U U M S S T S E1,E2 Jun-Jul Oct-Nov 150 200 30022 Pa Ethai Osteochilus hasselti C U M S F T N E1,E2 Jun-Jul Oct-Nov 50 200 10023 Pa Phia Labeo chrysophekadion U U M S F B S E1,E2 Jun-Jul Oct-Nov 300 800 50024 Pa Kheng Anabas testudineus C U M S S T N E1 Jun-Jul Oct-Nov 40 70 5025 Pa Kar Pristolepis fasciata C U M S S T N A Jun-Jul Oct-Nov 50 90 8026 Pa Kadert Trichogaster trichopterus C U M S S T S A Jun-Jul Oct-Nov 30 60 5027 Pa Men Osphronemus exodon U U M S S T S E1 Jun-Jul Oct-Nov 30 60 5028 Pa Khor Channa Striata C U M S S T S A Jun-Jul Oct-Nov 50 500 50029 Pa Do Channa micropeltes U U M S S T N E1 Jun-Jul Oct-Nov 50 700 60030 Pa Larth Mastacembelus armatus C U M S S B N E1 Jun-Jul Oct-Nov 200 600 50031 Pa Moumun Botia modesta U U M S S M N E1 Jun-Jul Oct-Nov 50 100 7032 Pa Douk Ui Clarias macrocephalus C U M S S B N A Jun-Jul Oct-Nov 150 300 25033 Pa Douk Ent Clarias batrachus C U M S S B N A Jun-Jul Oct-Nov 150 300 20034 Pa Khere Bagarius yarrelli U U M S S B S M Jun-Jul Oct-Nov 400 1000 50035 Pa Kherng Hemibagrus wyckioides U U M S F B S E1,M Jun-Jul Oct-Nov 400 1000 50036 Pa Khao Wallago attu U U M S F S S E1,E2 Jun-Jul Oct-Nov 200 800 50037 Pa Lerm Pangasius siamensis U U M S F B S E1 Jun-Jul Oct-Nov 500 800 60038 Pa Ling Pangasius djambal U U M S F B S E2 Jun-Jul Oct-Nov 500 800 60039 Pa Nanoo Helicophagus waandersi U U M S F B S E1 Jun-Jul Oct-Nov 300 600 300

40 Pa XouaymakmaiPangasianodon

hypophthalmus U U M S F B S E1 Jun-Jul Oct-Nov 500 800 60041 Pa Phor Pangasius bocourti U U M S F B S E1 Jun-Jul Oct-Nov 500 800 60042 Pa Ort Pangasius conchophilus U U M S F B S E1 Jun-Jul Oct-Nov 400 800 50043 Pa Xouaysor Pangasius krempfi U U M S F B S E1,E2 Jun-Jul Oct-Nov 400 800 50044 Pa Nang Gnern Micronema bleekeri U U M S F B S E1,M Jun-Jul Oct-Nov 200 350 30045 Pa Ngorn Pangasius macronema U U M S F T N E1,M Jun-Jul Oct-Nov 100 350 25046 Pa Ngorn Pangasius siamensis U U M S F T N E1,M Jun-Jul Oct-Nov 100 350 25047 Pa Ngorn Pangasius pleurotaenia U U M S F T N E1,M Jun-Jul Oct-Nov 150 250 20048 Pa Khop Belodontichthys dinema U U M S F T N E1,E2 Jun-Jul Oct-Nov 200 400 35049 Pa Douk Phun Clarias gariepinus U U M S F B N E1 Jun-Jul Oct-Nov 400 800 50050 Pa Nin Oreochromis niloticus U U M S F T N E1 Jun-Jul Oct-Nov 150 200 20051 Pa Nai Cyprinus carpio U U M S F B S E1 Jun-Jul Oct-Nov 400 800 70052 Pa Kingnar Ctenopharyngodon idella U U M S F B S E1 Jun-Jul Oct-Nov 400 700 800

53 Pa Ket LepHypophthalmichthys

molitrix U U M S F B S E1 Jun-Jul Oct-Nov 400 800 70054 Pa Khao Xaiy Sikukia gudgeri C U M S S T N E1,E2 Jun-Jul Oct-Nov 50 100 10055 Pa Pok Puntius orphoides C U M S S T N E1,E2 Jun-Jul Oct-Nov 50 100 100

56 Pa Khao Systomus spA Thai Catch C U M S S T N E1,E2 Jun-Jul Oct-Nov 50 100 10057 Pa Khao Noi Puntius aurotaeniatus C U M S S T N E1,E2 Jun-Jul Oct-Nov 150 200 150

58 Pa Dork NgiewCyclocheilichthys

repasson C U M S S T N E1,E2 Jun-Jul Oct-Nov 150 200 10059 Pa Kheelarm Labiobarbus siamensis C U M S S T N E1,E2 Jun-Jul Oct-Nov 150 200 20060 Pa Kheelarm Labiobarbus leptocheilus C U M S S T N E1,E2 Jun-Jul Oct-Nov 150 200 200

61 Pa HuakhengHenicorhynchus

ornatipinnis C U M S S T N E1,E2 Jun-Jul Oct-Nov 150 200 20062 Pa Namoum Osteochilus lini C U M S S T N E1,E2 Jun-Jul Oct-Nov 150 200 20063 Pa Soi Henicorhynchus lobatus C U M S S T N E1,E2 Jun-Jul Oct-Nov 150 200 200

64 Pa SoiHenicorhynchus

siamensis C U M S S T N E1,E2 Jun-Jul Oct-Nov 150 200 20065 Pa Khanglaiy Crossocheilus atrilimes U U M S S T N E1,E2 Jun-Jul Oct-Nov 40 60 5066 Pa Khanglaiy Crossocheilus oblongus U U M S S T N E1,E2 Jun-Jul Oct-Nov 40 60 5067 Pa Nouanchan Cirrhinus cirrhosus U U M S F B N E1,E2 Jun-Jul Oct-Nov 50 70 10068 Pa Khayeng Mystus albolineatus C U M S F B S A Jun-Jul Oct-Nov 50 70 10069 Pa Khayeng Mystus singaringan C U M S F B S A Jun-Jul Oct-Nov 50 70 10070 Pa Khayeng Mystus multiradiatus C U M S F B S A Jun-Jul Oct-Nov 100 250 20071 Pa Khayeng Mystus mysticetus C U M S F B S A Jun-Jul Oct-Nov 100 150 100

72 Pa Kheehia Pseudomystus siamensis U U M S F B S A Jun-Jul Oct-Nov 50 60 5073 Pa Kot Hemibagrus filamentus C U M S F B S A Jun-Jul Oct-Nov 150 200 20074 Pa Kot Hemibagrus nemulus C U M S F B S A Jun-Jul Oct-Nov 150 200 200

75 Pa PeekkaiKryptopterus

palembangensis C U M S F B S A Jun-Jul Oct-Nov 50 70 7076 Pa Peekkai Kryptopterus sp. C U M S F B S A Jun-Jul Oct-Nov 50 70 7077 Pa Doudfoun Pterygoplichthys leopardus C U M S F B N A Jun-Jul Oct-Nov 100 250 20078 Pa Sathong xenentodon sp. U U M S F T N A Jun-Jul Oct-Nov 100 150 15079 Pa Lot Macrognathus siamensis C U M S S B N E1,E2 Jun-Jul Oct-Nov 150 200 18080 Pa Larth Mastacembelus armatus C U M S S B N E1 Jun-Jul Oct-Nov 250 300 25081 Pa Bou Oxyeleotris marmorata C U M S S B N A Jun-Jul Oct-Nov 150 250 20082 Pa Kung Channa gachua C U M S S B N A Jun-Jul Oct-Nov 100 150 100

83 Pa SeuaDatnioides

undecimradiatus U U M S S M N E1 Jun-Jul Oct-Nov 100 150 15084 Pa Linmar Brachirus harmandi U U M S S B N E1 Jun-Jul Oct-Nov 50 70 5085 Pa Kajon Channa lucius C U M S S T W M Jun-Jul Oct-Nov 150 250 20086 Pa Siew Khao Rasbora aurotaenia U U M S S M W D Jun-Jul Oct-Nov 40 50 5087 Pa Siew NouadyaoEsomus longimana U U M S S M W D Jun-Jul Oct-Nov 30 40 3588 Pa Siew HangdengRasbora rubrodorsalis U U M S S M W D Jun-Jul Oct-Nov 20 35 3089 Pa Siew HangdengRasbora borapetensis U U M S S M W D Jun-Jul Oct-Nov 35 40 3090 Pa SiewkhanlaiyRasbora palustris U U M S S M W D Jun-Jul Oct-Nov 15 20 2091 Pa SiewhangmaiRasbora trilineata U U M S S T W D Jun-Jul Oct-Nov 25 35 3092 Pa Makben Nandus oxyrhynchus U U M S S M N D Jun-Jul Oct-Nov 30 50 3093 Pa Salith Trichogaster pectoralis U U M S S T N E1 Jun-Jul Oct-Nov 150 180 15094 Pa Muth Trichopsis vittata U U M S S T N A Jun-Jul Oct-Nov 35 50 4095 Pa Muth Trichopsis schalleri U U M S S T N A Jun-Jul Oct-Nov 30 40 3096 Pa Eat Nemacheilus pallidus U U M S S T N E1 Jun-Jul Oct-Nov 50 60 5097 Pa Moumun YAsuhikotakia lecontei U U M S F T N E1 Jun-Jul Oct-Nov 30 40 4098 Pa Kheokai Yasuhikotakia modesta U U M S S T N E1 Jun-Jul Oct-Nov 30 40 4099 Pa Mou Syncrosus helodes U U M S S T E1 E1 Jun-Jul Oct-Nov 30 40 40

100 Pa Hakkouay Acantopsis sp. U U M S S T N E1 Jun-Jul Oct-Nov 150 200 250101 Pa Seuam Ompok bimaculatus U U M S S T N E1 Jun-Jul Oct-Nov 80 200 150102 Pa Khupkhong Parambassis siamensis C U M S S T W E1 Jun-Jul Oct-Nov 20 40 30103 Pa Pao Monotrete fangi U U M S S M N E1 Jun-Jul Oct-Nov 50 100 150104 Pa Pao Monotrete cambodgiensis U U M S S M N E2 Jun-Jul Oct-Nov 50 100 150

Size (mm)Where When


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For the majority of the species recorded at the regulator, unimpeded movement between different habitats (riverine and floodplain wetland) is important to complete key life-history aspects. Many of these fish species are moving between different riverine and wetland habitats for spawning, feeding or to access refuge habitats; these migrations are cyclic, moving upstream, downstream and laterally onto floodplains or wetlands. The extent of spawning upstream is unknown but it is likely that many riverine species will produce larvae that drift downstream with the current, and that juveniles will move at different times (upstream and downstream) compared to adult life stages.

4.2 Fish size

Large adult fish migrate upstream to spawn and feed. Based on the participants surveys, it was suggested that adult fish at Houay Mak Hiew could vary in size from 100 mm long to >800mm long, but are most likely to be 100mm to 500mm long on average; also many small-bodied and juvenile fish migrate up into wetland environments, therefore fish species 20mm to 100 mm long also may need to use the fishway. These smaller fish are very important, as they often form the basis of the food chain for larger fish species, and also make up an important component of the subsistence livelihood-based species essential for food and nutritional security for local communities. All sizes of fish, therefore, will need to be considered in the design.

4.3 Migration and water levels

Peak migration upstream in the Houay Mak Hiew generally occur at the onset and then peak in the first half of the wet season (Figure 1.); which is typically from June to October. Downstream migration is reported from June to December. However, it is likely that there is some attempt to migrate throughout the year, whenever there is leakage under the gates or the gates are opened. This should be taken into account when designing the fishway.

There are no records for discharge from the Houay Mak Hiew, and longer-term water level records are limited to downstream water levels in the wet season, which are a reflection of adjacent Mekong River water levels (Figure 4.) However, in preparation for the masterclass, the NUOL commissioned the local village Niban (head of village) who is responsible for daily gate management in co-operation with local irrigation authorities, to record both upstream and downstream water levels on a reinstated staff gauge (zero elevation set to the culvert floor of the main regulator gates) (Figure 5). This allowed the historical 10-year Mekong River level records to be calibrated to the staff gauge, and all subsequent levels after Figure 4., dealt with in the design process are based on the staff gauge. The 2020 wet season was noted for the late onset of the wet and below average river levels (Figures 4 to 8).


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Figure 3. Historical data on water levels at Houay Mak Hiew are limited to records of Mekong River level fluctuations that determine downstream water levels at the regulators in the wet season.

Figure 5. Water levels at Houay Mak Hiew recorded (Top=upstream, Bottom=downstream of the structure) in the 2020 wet season as part of preparation for the masterclass.

Headwater and Tailwater Levels

Headwater (upstream) levels vary from an elevation (based on the staff gauge at the main regulator) of 1m to 6m, while tailwater (downstream) levels vary from an elevation of 0m to 6.5m; though some spot peak downstream water level records from the 2018, which was a relatively wet year reached 9.5m (DAFO). These levels are important to determine the minimum depth in the fishway and hence the fishway invert or floor level, which then determines the total fishway channel depth (Figures 6 and 7). It should be noted that in the dry season, the downstream water level drops approximately -1.5m below the base level of the staff gauge. Passage upstream to the regulator is still possible in the dry, as irrigation and urban discharge combined with gate leakage maintains a minimum 0.5m deep flow down to the Mekong River, and these minimum depths and water level need to be considered in the fishway design process.


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Figure 6. Frequency distribution of tailwater ranges based on long term Mekong River levels, corrected to the staff gauge at the Houay Mak Hiew Main Regulator

Figure 7. Frequency distribution of tailwater ranges based on records collected in 2020 levels as read from the staff gauge at the Houay Mak Hiew Main Regulator


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Culverts, Water Levels and Fish Passage

The ability of fish to pass through culverts is limited by water velocity and turbulence within the culvert, which rises rapidly once a head difference develops across the culvert; that is when the upstream water level is higher than the downstream water level, particularly when the headwater is higher than the roof of the culvert. However, at the Houay Mak Hiew site, once the tailwater rapidly rises after the onset of the wet season, in August in 2020 (Figure 8.) it starts to track the headwater level closely. This is due to the operators balancing maximum discharge through the regulator to minimum upstream flooding, and the need to close the gates to prevent water flowing into the wetland when downstream Mekong levels exceed those in the wetland.

We know from previous research undertaken by NUOL and CSU in Paksan District, which is about 2hrs drive south and similar species can be expected, that once the head loss across a culvert exceeds 0.1m some species struggle to pass upstream, and by 0.2m head loss, only large fast swimming species can pass. Local knowledge indicates that large strong swimming fish can pass upstream through the regulator gates at time when the water levels are very close, though the operation of the gates at very narrow openings may physically prevent passage.

The managers of the gates also take the opportunity at the start and end of the wet season to reduce upstream water levels to close or below the roof of the regulator culverts to flush floating plants rafts downstream to the Mekong. As long as the upstream water levels are close, and particularly when below the culvert roof, fish passage can be achieved through a gate management arrangement. This opportunity means that the overall head water range that a fishway would need to work for can be greatly reduced if a new management system for the gates is implemented as part of the fishway commissioning phase (Figure 9.). All stakeholders at the masterclass considered this to be a reasonable solution and would be willing to develop a new gate management plan.

Figure 8. Water levels at Houay Mak Hiew recorded (Top=upstream, Bottom-downstream of the structure) in the 2020 wet season and potential upstream and downstream pathways.


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Figure 9. Frequency distribution of head loss ranges at Houay Mak Hiew recorded (Top=upstream, Bottom-downstream of the structure) in the 2020 wet season and potential upstream pathways for migrating fish.

Downstream passage of fish also needs to be considered, particularly as fish passing through gates and culverts under high head differences can be injured and possibly killed by high water velocities (shear) and coming into contact with gates and concrete edges (strike). Figure 8. shows the peak downstream migration periods, which in August and September in 2020 are in low head conditions, a low injury risk scenario for downstream passing fish. When head loss across the structure rapidly increases in the later wet and the whole of the dry season, provided leakage under the gates can be reduced, the current levels of dry season flows are enough to operate the fishway as the mains downstream migration pathway.

Development of Fishway Design Criteria

From fish biology information, the largest fish migrating upstream is approximately 800 mm long, though this is rare and the common upper size is 500mm. Fish of this size generally need 1.5 m depth to freely ascend fishways, which are a more confined space compared to the river. However, these large fish migrations are generally at the peak of the wet, and the minim depth of the fishway should reflect downstream channel depths of 0.5m at the onset of the wet season when smaller fish are much more common.

To provide this minimum depth the floor level (invert) of the fishway exit would need to be at EL 153.5 or -1.m on the staff gauge. A fishway exit invert of EL 158 m provides 0.5 m depth for a minimum fishway operating level of 158.5 or 3.5m on staff gauge (Figure 10.). This results in a maximum head loss operating range of 5.5m.

Summary of Design Criteria

• Maximum head differential for fishway design = 5.5 m

• Fishway channel exit invert = EL 158m

• Fishway channel entrance invert (downstream) = EL 153 m


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Figure 10. Summary of design levels for the Houay Mak Hiew fishway.


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5. Fishway Design

5.1 Passage - Fishway Options

The water levels and fish community strongly influence the Houay Mak Hiew fishway design. Houay Mak Hiew has highly variable water levels and a range of differential heads (difference in upstream and downstream water levels). The fishway design that most suits these conditions are the vertical-slot type (Figure 11 and 12).

Figure 11. Vertical-slot fishway design.

Two other fishway designs with potential are the cone design (13) and dragon’s teeth design (Figure 14). However, these have not been used at sites with highly variable headwater. There is potential to provide a tiered baffle in a cone or dragon’s teeth fishway (15) but this would need to be considered experimental and would need intensive monitoring with the capacity to modify the baffles if they were not suitable. The major draw-back of these designs is they require a larger foot print than a vertical slot and may involve private land acquisition issues at Houay Mak Hiew It is important for the demonstration fishway at Houay Mak Hiew, to have a fishway that is a low-risk design, with very high certainty of passing the majority of fish. Hence, for Houay Mak Hiew we recommend a vertical-slot design.

High River Flow Low River Flow


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Figure 12. Example of a vertical slot fishway.

Figure 13. Example of a cone fishway.


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Figure 14. Example of a dragon’s teeth fishway.

Figure 15. Potential baffle arrangement for a cone or dragon’s teeth fishway to a accommodate variable water levels.


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5.2 Application of Preferred Fishway Design

Design specifications for a vertical-slot fishway for Houay Mak Hiew are summarised in Table 2 and Figure 16. A characteristic of the site are the highly variable water levels; these result in a fishway channel that is at least 4 m high, and will need 6 m high outside walls to prevent downstream water levels drowning out the lower sections of the fishway channel, which would greatly reduce entrance attraction conditions. The fishway internal baffles will need to be 4 m tall.

Table 2. Design specifications for the Houay Mak Hiew Regulator fishway.

Functional Objective Hydraulic/Physical Design Specification PASSAGE DESIGN – WATER LEVELS Fishway operational Headwater EL 158.5 m to 162 m range Tailwater EL 153.5 m to 159 m Head differential 5 m max. Fishway floor levels Invert of upstream exit EL 158 m Invert of downstream

entrance EL 153 m

PASSAGE DESIGN - BIOLOGY Smallest fish: approx. 0.100mm

Pool Head Loss: (determines max. water velocity)

160 mm (max. velocity 1.8 m/s)

Turbulence: (determines min. pool size)

61 Watts per cubic metre (W/m3) (assuming a Cd of 0.7)

Largest fish: 0.8 m Minimum Depth:

0.5 m for small fish, 1+m for large

Pool size: 3 m long by 2m wide (internal) Biomass: unknown but expected to be high

Discharge: 0.96 cumecs 83.1 ML/day

Fishway Length 80 m (assuming a baffle thickness of 0.2 m), but not including new culvert under road

Fish behaviour Pass species requiring light ( Open to light Open channel and high roof culvert under

road Pass benthic species catfish Benthic (floor) passage in

channel Vertical-slot to floor of channel

OTHER LIKELY REQUIREMENTS Upstream gates to prevent wetland back flooding at flood peaks

Essential – dual 2.5m high gates with electric motors

Trap for monitoring Essential – design to be determined

Upstream concrete pad for trap

Essential – design to be determined


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Figure 16. Recommended baffle arrangement for a vertical slot fishway

6. Fishway Layout

After considerable discussion on potential placement for the fishway, the preferred location for the fishway is the left-hand bank abutment, on the downstream side, and connected to a new culvert across the road. The layout is determined by:

i) the entrance location at the base of the downstream flap gates, which is where migrating fish will be attracted to;

ii) the exit located away from the upstream slide gates, to ensure that fish migrating upstream are not swept back through the regulator;

iii) the fishway will be in a public area to reduce opportunities for fishing within the fishway, connected to an existing no fishing and no public access area upstream of the regulator; and

v) no acquisition of private land is required.

Once these criteria are met the fishway layout has been wrapped to reduce the overall footprint and construction cost from shared internal channel walls. Figure 17 shows the preferred layout.

45O

1 3

internal distance between baffles = 3 m

sill in base of slot; height of sill equal to

head loss at baffle

2.0 m

0.6 m

0.2 m

0.48 m


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Figure 17. Preferred layout of the fishway at Houay Mak Hiew Regulator.

6.1 Attraction (fishway entrance)

When regulator gates are passing a low discharge (e.g. 1 to 2 m3/s), the upstream limit of migration and downstream flow patterns are relatively easy to predict, so locating the fishway entrance is clear. At high discharge sites, such as Houay Mak Hiew Regulator, it is more difficult to predict the upstream limit of migration and downstream flow patterns, especially as conditions change in low and high flows. At these sites the main method to understand the complex flow patterns is physical modelling (1:10 to 1:20 scale), which enables fish attraction to the fishway entrance to be optimised. 3D computer modelling (Computational Fluid Dynamics [CFD]) can be used but is limited in the number of variations that can tested. After physical or computer modelling wet commissioning is required to confirm flow patterns. If physical or computer modelling is not used then wet commissioning is much more extensive and time-consuming. Modifications, such as adding rock or wingwalls to an abutment, may be needed to modify flow patterns and prevent excessive recirculation. Wet commissioning involves testing combination of gates to ensure fish are guided to the fishway entrance, which is not masked by turbulence. The present Houay Mak Hiew Regulator uses undershot gates on the upstream end of the culverts under the road, with flap gates on the downstream side designed to help prevent upstream flood intrusion. Depending on the flows and operation of the gates, there would be different zones of fish attraction at different flows. Fish are attracted to the edge of high flows. When there is high discharge in the river, fish are likely to be attracted to the banks, while at other flows they are attracted to the low turbulence zones adjacent to the open gate. These features can be used to operate the gates to enhance fish attraction to the fishway. In general, gates can be operated to guide fish to one bank, so the fishway entrance can be on one bank (Figure 18). To provide access to the fishway entrance when flows are low, and the apron is perched above the downstream water levels, an entrance channel is required. In addition to that, in high tailwater conditions auxiliary water needs to be fed by pipe to just upstream of the entrance slot to maintain discharge through the entrance to attract fish into the fishway channel (Figure 19).


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Figure 18. Preferred gate operation to attract fish towards the fishway entrance

As noted earlier, wet commissioning with different gates being opened is an important part

of optimising the final fishway installation.

Figure 19. Preferred gate operation to attract fish towards the fishway entrance

7. Potential Construction Techniques

Fishways are often poured in-situ concrete. An alternative and effective construction technique is to use pre-cast concrete baffles which have the advantage of giving uniformity of vertical slot dimensions, something critical to creating uniform water velocity and turbulence conditions throughout the fishway channel. A single extra high velocity and turbulence cell in a fishway can greatly reduce its effectiveness.


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8. Fishway Entrance and Gate Management Plan

Once the fishway is completed, operation of the Houay Mak Hiew in harmony with the fishway will be essential to ensure attraction of fish to the fishway entrance and to optimise fish passage (Figure 10.). A small operating manual in Lao language needs to be developed and a “fishway commissioning” period needs to be undertaken with regulator local village operator and PAFO/DAFO managers at the completion of construction, and start of operation over the first wet and dry season. The aim of the commissioning process would be to explain the value and purpose of the fishway, and to show the critical role these operators play in optimising the function of the fishway.

The workshop would explain that the fishway effectiveness is very dependent on operation and would outline: the objectives for fish attraction and passage, and the different configurations of gates needed to optimise these aspects. Sluice operators would also be trained in when to open, close and maintain the fishway.

Some initial principles for the operating manual include:

i) the fishway should be left open for as long as possible

ii) the fishway should be left either fully open or fully closed, never partially open

iii) at the start of the wet season the first water should be released down the fishway and entry and exit to the main river channel established before opening other gates.

iv) as gates are closed as the dry season approaches, the fishway should remain fully open and gates closed in a sequence of closing gates at the opposite bank to the fishway first, and gate by gate towards the fishway.

9. Community Management Plan

To prevent the fishway from becoming a target for unauthorised fishing, a community management plan, agreed upon by local village leaders and endorsed by PAFO and DAFO, needs to be negotiated as an early part of the fishway commissioning phase. The general features of such a plan need to cover the following:

i) people should keep clear of the fishway entrance, channel and exit for their own safety;

ii) the entrance and exit of the fishway should be kept clear of fishing gear and traps

iii) before the start of the wet season the fishway should be checked for debris and cleared if needed as part of the irrigation committees’ duties; and

iv) the irrigation committee should allocate responsibility for managing the fishway gates as an integral part of managing the over structures gates.

It should be noted that the aim of any community management plan is not to limit fishing

below the regulator in general, as this is along established livelihood practice, particularly

important in the rice growing season when labour demands on households are high. The

aim is to keep people safe and to give fish a chance to migrate upstream once they have

reached the apron of the structure.


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10. Trash Racks and Site Security

To prevent public access into the fishway, and to prevent the channel becoming blocked with debris, a trash rack with minimum bar spacing of 200mm needs to be fitted to the upstream fishway channel. In addition, if unauthorised access is obtained, each slot in the fishway should have a series of horizontal steel bars placed as ladder rungs just upstream of the slots, to prevent entrainment in the slots and to provide a ladder to exit the channel. To improve overall security at the fishway, a fence should be built on the upstream side of the fishway and the existing headwater pumping basin security fence should be extend to cover the fishway exit structures.

11. Fish Monitoring

Monitoring of the fishway is important to assess the fishway effectiveness, improve the operations of the fishway after wet commissioning, and inform future designs. The Houay Mak Hiew fishway will act as a demonstration fishway so monitoring forms an essential component of the project. Monitoring should be considered in the design of the fishway from the beginning. Monitoring of fish in the river should occur before and after the fishway is built, to provide a baseline of species downstream and upstream. The data would provide size and relative abundances of different species, from which the population structure and age classes can be determined. Once the fishway is built, monitoring should also occur directly within the fishway at the bottom and at the top, and sampling should be stratified to take into account different times of the day and tide. Fisherman could be utilised in the monitoring of the fishway, so they feel ownership of the fishway and are less likely to illegally fish at the entrance and within the fishway.

12. Conclusion

Fish passage in Lao and more specifically the Vientiane floodplain catchment is important to sustain fish populations that provide nutritious food and important livelihoods and industry for Lao people. We have provided fishway design criteria that we consider suit the ecology and biology of fish species in this river, based on our collective experience, including specific experience in Lao and the broader Lower Mekong Basin.

Our assessment of the possible options is that a vertical-slot fishway is the preferred design (see Appendix). The full set of concept design plans for a 1:20 slope, 3m x 2m cell fishway have been prepared, including with a estimated cost and are being submitted as part of this report to the Department of Irrigation Vientiane and the Asian Development Bank. A costing for an alternate, less effective fishway design at 1:16 slope that where prepared as part of the process of developing the selected plans has been included at the end of the appendix for reference.


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13. Acknowledgements

This report would not have been possible without the enthusiastic support and contributions of the following people who attended the workshop:

14. References

Baumgartner, Lee J., Craig A. Boys, Tim Marsden, Jarrod McPherson, Nathan Ning, Oudom Phonekhampheng, Wayne A. Robinson, Douangkham Singhanouvong, Ivor G. Stuart, and Garry Thorncraft. "Comparing fishway designs for application in a large tropical river system." Ecological

Engineering 120 (2018): 36-43.

Baumgartner, L. J., T. Marsden, D. Singhanouvong, O. Phonekhampheng, I. G. Stuart, and G. Thorncraft. "Using an experimental in situ fishway to provide key design criteria for lateral fish passage in tropical rivers: A case study from the Mekong River, central Lao PDR." River Research and Applications 28, no. 8 (2012): 1217-1229.

Baumgartner, Lee J., Nathan Reynoldson, and Dean M. Gilligan. "Mortality of larval Murray cod (Maccullochella peelii peelii) and golden perch (Macquaria ambigua) associated with passage through two types of low-head weirs." Marine and Freshwater Research 57, no. 2 (2006): 187-191.

No. Name Organization Position1 Assoc.Prof.Dr. Oudom Phonekhampheng National University of Laos Vice President2 Assoc. Thonglom Phommavong National University of Laos Vice Dean (FAG)3 Mr. Garry Torncraft National University of Laos Project Expert4 Assoc. Fongsamouth Southammavong National University of Laos Dean Faculty of Agriculture5 Mr. Phousone Vorasane National University of Laos Technical7 Dr. Wayne Robinson Charles Sturt University Expert6 Mr. Khamhou Phanthavong Dept of Irrigation Deputy Director Planning, DoI8 Ph.D. Khampachanh Vongsana Dept of Irrigation National Project Coordinator Of FDM Project9 Mr. Khansawanh Sisopha Dept of Irrigation Chief of Technical and Planing10 Mr. Bounthanome Chamsing Dept of Fisheries Deputy Director Fisheries Management

11 Ph.D. Larsaiy NouanthasingProvincial Agriculture and Forestry Office Director Department AF Vientiane Capital

12 Mr. Saiykham PhengkhammyProvincial Agriculture and Forestry Office

Project Manager Irrigation Development South of Vientiane Capt Project

13 Mr. Khamla ThoummakesoneProvincial Agriculture and Forestry Office Head of Unit Technical

14 Mr. Thotsakan KaisonephetDistrict Agriculture and Forestry Office Director of DAFO

15 Mr. Vilai SimmalavongDistrict Agriculture and Forestry Office Head of Unit Irrigation

16 Mr. Douangkham Shinghanouvong LARReC Director17 Mr. Mon Sueda Ban Mak Hiaw Niban18 Mr. Orn Xaiyakoummane Ban Mak Hiaw Fisher19 Mrs. Manyvanth Souvanthkham Ban Mak Hiaw Fisher20 Mr. Int Manyvong Ban Mak Hiaw Retirement Niban

Fish Pass Design Master Class - That Luang Marsh, NUoL 17,24-25/11/2020


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15. Appendix

Estimated Costs for Construction Preferred 1:20 Slope Fishway

# Work Description Unit Quantity Unit Price Cost

I Site Clearing and Preparation

1 Clearing natural land suface 20cm depth m2 3,000 5,107 15,321,000

2 Debris Removal m3 1,875 21,886 41,036,250

3 Removing existng concrete structure m3 213 396,250 84,401,250

Sub-total I: 140,758,500

II Fish Passage Structure

1 Land Excavation m3 7,560 21,886 165,458,160

2 Land filling on the weir site >=95% S.P.C.T m3 8,625 44,402 382,967,250

3 Base Concreting M#100 m3 48 644,763 31,135,605

4 Ferro-concreting M#350 m3 466 3,315 1,544,985,581

5 Lining and surfacing by natural rock m3 278 1,128,907 313,271,693

6 Gabion net and rock bank protection (0.5x1x2) m3 263 683,200 179,340,000

7 GEO Wall for slope protection prior Gabion net installation m2 1,080 40,000 43,200,000

8 Drainage Pipe HDPE Ø400mm PN8 m 40 1,174,500 46,980,000

9 Connectors 90 HDPE Ø400mm PN8 pcs 3 3,826,200 11,478,600

10 Welding Pipe connection HDPE Ø400mm PN8 point 6 4,000,000 24,000,000

11 Metal sheet works for reducing water flow current sheet 4 3,366,000 13,464,000

12 Reguratory gate set 60x60x4mm set 1 8,000,000 8,000,000

13 Pipe guard net set 1 2,000,000 2,000,000

Sub-total II: 2,766,280,889

III Regulatory Gate House Building

1 Ferro-concreting M#350 m3 6 3,315,562 18,965,015

2 O-shape stell structure (50x100x2.3x6000)mm pcs 5 190,000 950,000

3 O-shape stell structure (50x50x2.3x6000)mm pcs 3 150,000 450,000

4 Aluzink roofing sheet m2 15 40,000 600,000

5 Rafter wood pcs 15 25,000 375,000

6 Topping Aluzing roof m 7 15,000 105,000

7 Screws box 2 25,000 50,000

8 Welding incense box 1 35,000 35,000

9 Paint bucket 1 125,000 125,000

10 Safety protection structure 5cm m 90 100,000 9,000,000

Sub-total III: 30,655,015

IV Regulatory Gate works

1 Installing Electric Factory made regulatory gate 1mX2.5m set 2 75,000,000 150,000,000

Sub-total IV: 150,000,000

V Road resurfacing work (approx 60mlength)

1 Pre-base sub-surface layering CBR>25% 20cm depth m3 103 162,000 16,686,000

2 Base sub-surface layering CBR>80% 20cm depth m3 115 270,000 31,050,000

3 Spraying pre-asphalt solution MC70 m2 480 150,000 72,000,000

4 Asphalt sufacing 2 layers 3cm depth m3 60 450,000 27,000,000

5 Side road protection structure m 60 30,000 1,800,000

Sub-total V: 148,536,000

VI Bypass Road work

1 Land filling m3 2,550 21,326 54,381,300

2 Drainage pipe installation Ø100 2 Channels m 36 650,000 23,400,000

Sub-total VI: 77,781,300

Total : (I+II+III+IV+V+VI) 3,314,011,704

a Construction supervision 1.5% 49,711,472

b Project Management 2% 66,281,962

c Tax 10% 343,009,154

Grand Total 3,773,100,690

BCEL Rate 9,288Kip/$

Grand Total in USD 406,234

Fish Passage BOQ


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Estimated Layout for Preferred 1:20 Design


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- 31 -



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- 37 -


Estimated Costs for Construction Alternate 1:16 Design Vertical Slot Fishway

ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ ສັນຕິພາ

ບ ເອກະລາດ ປະຊາທິປະໄຕ ເອກະພາບ ວັດທະນະຖະວອນ ບລິສັດ ແດນສະຫວັນຈະເລີນຊັບ ວິສິວະກາທີີ່ປຶາຈາກັດ ເລກທີ.........../ດຈຊ ໂທ:020 59314748 .020 56793458 ນະຄອນຫວງວຽງຈັນ,ວັນທີ18/12/2020

ໃບຄິດໄລລາຄາມູນຄາການກີ່ສາງ

ໂຄງການກີ່ສາງທາງຜານປາ ຫວຍໝາກຮຽວ

ບານນາລອງ ເມືອງ ປາກງືີ່ມ ນະຄອນຫຼວງວຽງຈັນ


- 38 -


ລາດັບ ລາຍການວຽ

ກ no I ວຽກອານາໄມ

1 ອານາໄມລອກໜາດີນທາມະຊາດ20cm 2 ຂຸດດິນບວມພອຂົນໄປຖີີ້ມ

3 ທຸບມາງອາຄານເບຕົງເກົີ່າ

II ວຽກໂຄງສາງອາຄານທາງຜານປາ 1 ດິນຂຸດ 2 ດິນຖົມຕົວຝາຍ≥95% S.P.C.T

3 ເບຕົງກັນເປືີ້ອນM#100

4 ເບຕົງເສີມເຫັກ M#350

5

ກຫິນພູດີ່ວຍເບຕົງC15ດານໜາ,ດານທາຍໜາ

30cm

6

ກະຕາກວາຍຫີນ+ຫີນເຮັດກັນເຈືີ່ອນ(0.5x

1x2)

ຝາGEOປອງກັນການເຈືີ່ອນສະຫຼົບກອນໃສວາຍຫີນ

7 ແລະຫີນກີ່

8 ທີ່ລະບາຍHDPE Ø400mm PN8

9 ຂງ 90 HDPE Ø400mm PN8

10 ຄາເຊືີ່ອມທHDPE Ø400mm PN8

ເຫຼັກແຜນໂຕນເຈາະຮູຫດຜອນແຮງດັນນີ້າ ຂະໜາດ 11 (1200x2400x20)mm ນີ້າໜັກ467kg/ແຜນ

12 ຊຸດປະຕູເຫຼັກເປີດປິດທີ່ລະບາຍນີ້າ60x60x4mm

III ໂຄງສາງຫລັງຄາມຸງອາຄານປິດ-ເປີດປະຕູນີ້າ

1 ເບຕົງເສີີ່ມເຫຼັກ M#350 2 ເຫຼັກໂຕOຂະໜາດ

(50x100x2.3x6000)mm 3 ເຫຼັກໂຕOຂະໜາດ

(50x50x2.3x6000)mm 4 ແຜນອາລູຊ

5 ໄມປານລົມປານຊາຍ 6 ຫຼົບຫຼັງຄາອາລູຊິງ

7 ນັອດກຽວ

ຫົວໜວຍ ຈານວນ ໜວຍລາຄາ ລວມເປັນເງິນ

(ກີບ) (ກີບ)

140,758,500

m2 3,000 5,107 15,321,000

m3 1,875 21,886 41,036,250

m3 213 396,250 84,401,250

2,213,544,557

m2 7,560 21,886 165,458,160

m3 8,625 44,402 382,967,250

m3 20 644,763 12,943,617

m3 310 3,315,562 1,028,871,938

m3 278 1,128,907 313,271,693

m3 263 683,200 179,340,000

m2 1,080 40,000 43,200,000

m 35 1,174,500 41,107,500

ອນັ 2 3,826,200 7,652,400

ຈຸດ 6 4,000,000 24,000,000

ີ່

2 3,366,000 6,732,000

ແຜນ

ຊຸດ 1 8,000,000 8,000,000

21,105,375

m3 3 3,315,562 9,880,375

ໂຕ 5 190,000.00 950,000

ໂຕ 3 150,000.00 450,000

m2 10 40,000.00 400,000

m 5 25,000.00 125,000

m 6 15,000.00 90,000

ກັ 2 25,000.00 50,000


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8 ທູບຈອດເຫຼັກ ກັ

9 ສີກັນໝຽງ ປັອ

10 ຫຼັກແປັບຮາວກັນຕົກ 5cm m

IV ວຽກປະຕູນີ້າປິດ-ເປີ

1

ຊຸດປະຕູນີ້າດານໜາພະລິດຈາກໂຮງງານ ປິດ-

ເປີດດວຍ ຊຸ

ດ ໄຟຟາ ຂະໜາດ 0.5mx2.5m

ພອມຕິດຕັີ້ງ

V ວຽກປູທາງຢາງຫນາທາງຄືນໃໝ

1

ດິນຖົມຊັີ້ນຮອງ CBR>25% ໜາ

20cm m3

2 ດິນຖົມຊັີ້ນ CBR>80% ໜາ 20cm m3

3 ສີດຢາງກັນຊMC-70 m2

4 ປູທາງຢາງສອງຊັີ້ນ 3 cm m3

6

ຕິດຕັີ້ງເຫຼັກຮາວກັີ້ນຂອບທາງສອງຂາງໃຊໂຕເ

ດີມ m

VI ວຽກທາງເວັ

1 ດິນຖົມາມະດາທ m3

2 ວາງທລອດທາງເວັີ້ນØ100 2ເຊວ m

1 35,000.00 35,000

1 125,000.00 125,000

90 100,000.00 9,000,000

100,000,000

2 50,000,000 100,000,000

148,622,400

103 162,000.00 16,718,400

115 270,000.00 31,104,000

480 150,000.00 72,000,000

60 450,000 27,000,000

60 30,000.00 1,800,000

77,781,300

2,550 21,326.00 54,381,300

36 650,000 23,400,000


- 40 -


ລວມມູນຄາກີ່ສາງ(I+II+III+IV+V+VI) 2,701,812,132

a. ຄາຄຸມງານກີ່ສາງ1.5% 40,527,182

b. ຄາສາຄຸມຄອງໂຄງການ 2 % 54,036,243

c. ຄາອາກອນ 10 % 279,637,556

ລວມມູນຄາກີ່ສາງທັງໝົດkip 3,076,013,11

2

ອັດຕາແລກປຽນ BCEL $ 9,288.00

ລາຄາເປັນເງີUSD $ 331,181.43

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