2010-8.pdf

INTER

NA

TION

AL W

ATER

PO

WER

& D

AM

CO

NS

TRU

CTIO

N AU

GU

ST 2010

AUGUST 2010

Serving the hydro industry for over 60 years

Earthquakes and dam safety

The rise in multi-purpose projects

Restoration schemeReplacing post-tensioned anchors at Catagunya Dam

I N T E R N A T I O N A L

& DAM CONSTRUCTIONWWW.WATERPOWERMAGAZINE.COM

AUGUST 2010& DAM CONSTRUCTIONWWW.WATERPOWERMAGAZINE.COM

Water Power

001wp0810fc.indd_CS.indd 1 13/8/10 16:43:58

Bearing locations inside dams must withstand the pressure generated by immense quantities of rushing water. Our bearings are specifically designed for these conditions, as they can effort-lessly handle even the peak loads that are produced during earthquakes. After all, safety is our top priority.

ELGES large spherical plain bearings with Elgoglide®, for example, are used for the main bearing supports in the dams’ tainter gates. Despite their compact size, these low-friction bearings can handle extremely high loads, while delivering maintenance-free performance – for life. Our FAG-brand spherical roller bearings, are used in cable winches and pulleys as well as turbine intakes. These low-friction bearings combine high load-carrying capacity with long maintenance and lubrication intervals.

Harness our special bearing expertise for your hydraulic steel structure applications.

www.schaeffler.com

939

014

Nature Creates the Rushing Waters We Create the Bearings That Harness Them

939014_Staudamm_A4_US.indd 1 18.08.2010 10:41:26 Uhr


& DAM CONSTRUCTIONWater PowerWWW.WATERPOWERMAGAZINE.COM

CONTENTS

Editor Carrieann Stocks Tel: +44 20 8269 7777 [email protected]

Contributing Editors Patrick Reynolds Suzanne Pritchard

Editorial Assistants Elaine Sneath, Tracey Honney

Advertising Sales Scott Galvin Tel: +44 20 8269 7820 [email protected]

Deo Dipchan Tel: +44 20 8269 7825 [email protected]

Tim Price Tel: +44 20 8269 7822 [email protected]

Classified Advertising Diane Stanbury Tel: +44 20 8269 7854 [email protected]

Senior Graphic Designer Natalie Kyne

Production Controller Lyn Shaw

Publishing Director Jon MortonOfficesUnited Kingdom: Global Trade Media, Progressive House, 2 Maidstone Road, Foots Cray, Sidcup, Kent DA14 5HZ, UK. Tel: +44 20 8269 7700, Fax: +44 20 8269 7804, Email: [email protected]: Ediconsult Internazionale, Piazza Fontane Marose 3, 16123 GENOVA, Italy Tel: +39 010 583 684, Fax: +39 010 566 578Japan: Masayuki Harihara, Yukari Media Inc., 3-4 Uchihiranomachi, 3 Chome chuo-ku, Osaka 540-0037, Japan. Tel: +81 6 4790 2222, Fax: +81 6 4793 0800. Email: [email protected]

Subscription OfficeFor subscription enquiries, single copies or back issues:Global Trade Media, PO Box 99, Sidcup DA15 OEN, UKTel: +44 845 155 1845, Fax: +44 20 8269 7877 Email: [email protected]

North America onlyInternational Water Power & Dam Construction (ISSN 0306-400X) is published monthly by Global Trade Media, Progressive House, 2 Maidstone Road, Foots Cray, Sidcup DA14 5HZ, UK. Periodicals postage paid at Rahway, NJ. Postmaster: send address corrections to International Water Power & Dam Construction c/o BTB Mailflight Ltd, 365 Blair Rd, Avenel, NJ 07001. US agent: BTB Mailflight Ltd, 365 Blair Rd, Avenel, NJ 07001.

Subscription Rates 1 YEARUK UK£258 USA/Canada airspeed US$478Europe, inc EU, airspeed Euro 439Rest of world airspeed US$541 These rates include the Yearbook and digital edition. Digital edition only UK£232.20

Published by Global Trade Media, a trading division of Progressive Media Group Limited. Registered address: Progressive House, 2 Maidstone Road, Foots Cray, Sidcup, Kent DA14 5HZ, UK.

© 2010 Global Trade Media. Printed by Williams Press Ltd.

MEMBER OF THE AUDIT BUREAU OF CIRCULATION

The paper used in this magazine is obtained from manufacturers who operate within internationally recognised standards. The paper is made from Elementary Chlorine Free (ECF) pulp, which is sourced from sustainable, properly managed forestation.

olume Number AUGUST 2010 3

DAMENGINEERING

ModernPowerSystemsCOMMUNICATING POWER TECHNOLOGY WORLDWIDE

COVER: Ageing post-tensioned anchors have been replaced at Hydro Tasmania’s Catagunya Dam In Australia. See p24 for details

26

30

16

12

46 PROFESSIONAL DIRECTORY 48 WORLD MARKETPLACE

R E G U L A R S 4 WORLD NEWS 8 DIARY

F E A T U R E S

COMMENT 10 The resurgence of hydropower Dr Peter Mason of MWH explains why he thinks hydropower in now back in fashion

DAM SAFETY 12 Dam safety and earthquakes We present a position paper on earthquakes and dam

safety prepared by the International Commission on Large Dams

AUSTRALASIA 16 Wyaralong Dam design and construction Details on the design of the Wyaralong roller compacted

concrete dam, currently under constriction in south-east Queensland, Australia

20 The key link in the Waitaki chain Refurbishment work is well underway on the Benmore

hydropower station on New Zealand’s South Island. Johan Hendriks from Meridian Energy provides details on this important project

24 Catagunya Dam restoration The stability of the Catagunya Dam has been restored

over the past two years using modern, large diameter and corrosion protected post-tensioned anchors

MULTI-PURPOSE PROJECTS 26 Multiple benefits A number of multi-purpose projects are being

developed in Ethiopia. Patrick Reynolds details some of the largest schemes

GATES 28 On-site machining at Markland A portable milling machine will be used at the

Markland locks and dam in the US

NEW HYDRO DEVELOPMENTS 30 Sudanese development New hydro plants, both large and small, will have a

role to play in meeting Sudan’s energy demands

33 Watershed analysis An analysis of conventional and in-stream hydropower

in the Yukon River watershed

4 AUGUST 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

WORLD NEWS

THE FIRST REVENUES FROM the Nam Theun 2 hydropower project in Laos have started to

!ow into the country, with the money being spent on education, health, rural roads and electrification and environmental programs, an annual joint report to the boards of the World Bank and the Asian Development Bank has found.

The report also notes that the project’s environment protection and social development program in Nakai Plateau, Nam Theun and Xe Bang Fai Downstream Areas and the NT2 Watershed are overcoming sev-eral implementation challenges and making good progress.

With the commencement of com-mercial operations of the Nam Theun 2 facility in April, Laos received the first revenues of US$600,000 in June from the sale of electricity to Thailand. By late September 2010, this is expected to go up to around $US6.5M in additional revenues from the project to "nance poverty reduction and development pro-grams in Laos – the central tenet of the World Bank’s involvement in

the project. Over the 25-year conces-sion period, the country will receive nearly US$2B in revenues from the project.

“With close to three quarters of the population of Laos still living on less than $2 a day, the money generated by Nam Theun 2 is provid-ing a signi"cant boost to the coun-try’s economy and helping improve people’s lives,” said John Roome, World Bank Director for Sustainable Development in the East Asia & Paci"c Region.

The World Bank’s recently released Economic Monitor for Lao PDR showed that over 3 percentage points of the expected 7.8% growth rate expected in 2010 comes from Nam Theun 2.

In its Update on progress with the Nam Theun 2 project, the World Bank and ADB report that on the Nakai Plateau – where resettlement of around 6200 people was com-pleted in 2008 – villagers greatly appreciate their new surroundings, with the majority (over 80%) report-ing they are now “much better off”.

The report says people’s yearly

incomes have almost doubled, rising from a baseline of about US$140 a year in 1998 to about US$260 a year. It says villagers in the resettled area are taking advan-tage of improved education, health and transportation facilities. The median value of household assets increased from $US120 in August 2006 to $480 by May 2009.

Along with the successes how-ever, a number of challenges remain, the Update says. Chief among them is safeguarding the area’s natural resources for the bene"t of resettlers. The report warns that pressure on nat-ural resources has been growing as a result of local population growth and extraction of timber, mineral and "sh resources by outside commercial inter-ests. These issues are receiving the careful attention of the Government of Lao PDR, the report says.

Over the past year, the Government stepped up action to stop mining and logging in the national protected area – a conservation area on the Nakai Plateau, nearly seven times the size of Singapore – which was set aside as a requirement for Nam Theun 2’s

approval. But, the report says, close attention to outside encroachment will need to continue.

In the downstream area on the Xe Bang Fai river, the report says most of the impacts from increased water !ow (such as erosion, chang-es in water quality and loss of some riverbank gardens) had been anticipated well in advance and mitigation measures put in place. A downstream program which started several years ago with strong com-munity participation was acceler-ated in 2008 and 2009. This has resulted in good progress with fund-ing for villages, compensation for lost riverbank gardens, and water sanitation and hygiene programs. The monitoring program continues to watch for unanticipated impacts downstream.

The report says the project has helped Laos put in place tools for transparent and accountable manage-ment of public resources. It has also helped build the capacity of the govern-ment to manage large infrastructure projects and has helped to strengthen the country’s investment climate.

First Revenues from Nam Theun 2 benefits communities, says report

OPT in new groundbreaking agreement for Oregon wave project

OCEAN POWER TECHNOLOGIES, Inc (OPT) has signed a his-toric settlement agreement

with 11 federal and state agen-cies and three non-governmental stakeholders for its utility-scale wave power project at Reedsport, Oregon, representing a major step towards the granting of the first ever license issued by the Federal Energy Regulatory Commission (FERC) for a commercial-scale wave power project in the US.

The settlement agreement sup-ports the phased development by OPT of a 10-PowerBuoy, 1.5MW capacity wave energy station. Manufacturing of the "rst 150kW PB150 PowerBuoy is already underway at Oregon Iron Works under its contract with OPT. The 10-buoy wave farm is expected to be connected to the grid after receipt of the FERC license and addi-tional funding.

This "rst-ever wave energy settle-ment agreement was reached after extensive technical, policy, and legal discussions regarding appro-priate prevention, mitigation and enhancement measures, and study requirements. It covers a broad array of resource areas including aquatic resources, water quality, recreation, public safety, crabbing and "shing, terrestrial resources, and cultural resources.

The agreement includes an inno-vative Adaptive Management Plan that will be used to identify and implement environmental studies that may be required, and to provide a blueprint for the application of this new information as the wave power station develops.

“The Settlement Agreement is a groundbreaking document that dem-onstrates the State’s commitment to partnering with the private sector

and coastal communities to explore how we can tap into the renewable resource of ocean waves to power our communities,” said Oregon Governor, Ted Kulongoski. “The manufacture of the first buoy has already created dozens of green-energy jobs in Oregon and when the 10-buoy wave power project is built, a whole new industry will be created to bene"t our coastal communities.”

Dr. George W. Taylor, Executive Chairman of OPT, added: “This agreement shows how the private sector can work together effectively with federal, state, municipal and local groups to attain important common goals of sustainable devel-opment. I commend the State of Oregon, the City of Reedsport, and all of the stakeholders for support-ing the use of OPT’s innovative wave power technology as it transitions to a fully commercial product.”

Unit 4 online at Russian plant

RUSHYDRO HAS ANNOUNCED that the 640MW turbine unit no 4 has begun operations at

the Sayano-Shushenskaya hydroelec-tric project, almost a year after a fatal accident caused extensive damage to the plant.

Unit no 4 is the third unit to be con-nected to the grid, with units 5 and 6 having been launched into operation earlier this year, giving the project a current capacity of 1920MW.

Turbine unit no 3 will be launched at the end of the this year, giving the project an installed capacity of 2560MW. This will enable the project to operate during the 2010-2011 fall-winter period without usage of the operational spillway.

Restoration work is currently on schedule and the project is expected to be fully operational in 2014.

The plant was damaged during an incident on 17 August 2009, in which 75 people were killed.

WWW.WATERPOWERMAGAZINE.COM AUGUST 2010 5

WORLD NEWS

DBP signs emission agreement for three mini hydro plants

THE DEVELOPMENT BANK OF THE Philippines (DBP) has signed an emissions reduction purchase

agreement with Tricorona Carbon Asset Management of Singapore for the sale of certi!ed emission reduc-tion (CER) credits to be generated by three mini hydro power plants funded by the Bank.

President & CEO Reynaldo G. David said the agreement represents a major step in the Bank’s Clean Development Mechanism (CDM) activities and underlines its key role in the global Climate Change Program initiative.

The three projects are the Cantingas plant which is owned and operated by Romblon Electric Cooperative Inc; the Hinubasan power plant owned and operated by the municipality of Loreto,

Dinagat Island; and Sevilla mini-hydro power plant owned and operated by Bohol Electric Cooperative (BOHECO) I, with the municipality of Sevilla, Bohol as co-owner. The three projects are expected to reduce emission of about 111,000 tons of carbon diox-ide during the !rst seven-year credit-ing period.

The emission reduction pur-chase agreement was facilitated by CarbonAided, Ltd. of London, which DBP tapped in 2008 as !nancial man-ager and agent in the sale of carbon credits of the three projects.

The development bank is cur-rently working on the registration of the projects with the United Nations Framework Convention on Climate Change CDM Executive Board in Bonn, Germany.

PRE-FEASIBILITY STUDIES carried out for Reservoir Capital Corporation’s Brodarevo 1 and

Brodarevo 2 hydroelectric plants on the River Lim in southwest Serbia have recommend an increase in the projects planned capacity.

The studies, carried out by Energoprojekt Hidroinzenjering Co. Ltd (EHC), recommended a capacity increase from the original application case of 48MW to 58.4MW, with a cor-responding increase in output from 189GWh/yr to 232GWh/yr. The study has also de!ned dam sites, provided recommendations for the design of the hydroelectric power plants and calculated preliminary cost estimates for their construction, as summarized in the table opposite.

The estimated construction costs are budgeted into three areas: EUR46.3M for construction works; EUR51.2M for equipment purchases; and EUR42.4M for other investments related to the hydroelectric power plant. EUR33.7M of the EUR42.4M that is anticipated to go into other investments is related to deviation of 7.31km of the state road M21, on the section Prijepolje - Bijelo Polje. The Company is currently working with local authorities for the permits required for the relocation of parts of the road along the River Lim, acquisi-tion of surface rights affected by the project and construction of the hydro-

electric installations.The Italian and Serbian govern-

ments have signed a bilateral agree-ment whereby Serbia may export green energy into Italy and be issued green certi!cates (the cost of which are paid by consumers not govern-ment) for each kilowatt hour of electricity sold. The market price for electricity in Italy is presently approxi-mately 5.5 Euro cents per kilowatt hour (EURcent/kWh) and the green certi!cates 8.5EURcent/kWh, imply-ing a combined price for renewable energy of approximately 14EURcent/kWh. The electricity price and the green certi!cate price fell during the recent global recession, but these prices are expected to recover in the coming years with increased econom-ic activity. From the Pre-Feasibility Studies EHC has determined that the breakeven price of electricity for the Brodarevo project is 7.65EURcent/kWh over a 25-year exploitation period using a discount rate of 8%. Reservoir continues discussions with various groups with the intent of securing cer-ti!cation and indicative agreements for the transmission and sale of elec-tricity into the Italian market.

The EHC report also determined that the planned construction of Brodarevo 1 & 2 would bring a number of bene!ts, including posi-tive environmental, development and economic effects.

Capacity increases for Serbian schemes

From the EditorDear readers,

At the recent Hydrovision International conference and exhibition in Charlotte, North Carolina, the major discus-sion amongst the majority of delegates was the role that hydro has to play in the renewable energy sector. At the event’s keynote presentation, delegates were given information on the immense potential for develop-ment, with Andrew Munro of the National Hydropower Association in particular detailing the results from a study by Navigant Consulting (commissioned by the NHA) which suggests that the US hydro power industry could install 60,000MW of new capacity by 2025, creat-ing up to 700,000 new jobs.Much of this new potential can be found at existing dams - with only 3% of the country’s dams currently producing hydroelectric power, delegates were told. A session at the show which I found particularly interest-ing dealt with the subject of building hydro at non-hydro dams. Here the panellists explored the technical and regulatory concerns with regards to energy production at existing assets, and addressed the role of state agencies in encouraging such development. A major incentive to encourage such development is hydro’s ability to work with other renewable energy sec-tors. There is little doubt that hydro (particularly pumped storage hydro) is a perfect fit with wind, with pumped storage plants key players for future grid stability. I once heard the relationship between wind and hydro described as being ‘symbiotic’, and this is certainly an fitting description, with wind benefitting from the opera-tional benefits of hydro, and hydro in turn benefitting from the good PR of wind.But what about the challenges to new hydro develop-ment? This issue was also addressed at the Hydrovision conference in the session ‘New Hydro Development’. Here the panellists - Linda Church Ciocci (NHA), Richard Taylor (International Hydropower Association), Jacob Irving (Canadian Hydropower Association) and Alexandra McCann ( Export-Import Bank of the US) - discussed what they thought were the biggest risks to development. Though many were highlighted, some of the major risks seemed to be regulatory uncertainty (would the project get a licence?), the country market risk for finance (export issues), and time (difiiculty it developing the project withing a competitive time frame). However, the risk discussed most often was the actual perception of hydro - both by policymakers and the public. All panel-lists agreed there was a need for greater communica-tion of the benefits of hydropower, and a need to let the policymakers know that hydro can be developed in a sustainable way. Only then can hydro really start playing a major role in the renewable energy mix!

Best wishesCarrieann StocksEditorEmail: [email protected]


WORLD NEWS

ContractsNORWEGIAN FIRM Rainpower has won a NOK140M contract from Swiss hydro power compa-ny Of!cine Idroelettriche della Maggia (OFIMA) for delivery of equipment to the Robiei power plant. The company will provide complete replacement of the plant’s electromechani-cal equipment, mainly consisting of four revers-ible pump turbines with a head of 284 to 395m, and maximum performance of 41MW, and one Francis turbine with a head of 270 to 390m and maximum performance of 27MW. The deliveries are com-plete with inlet and outlet valves and oil pressure units. The total project will be carried out by a consortium of Rainpower and Alstom Switzerland, with Alstom supplying the generators/motors and the inlet valves for the pump turbines.

SCOTTISH AND Southern Energy (SSE) has appointed MWH to provide engineering and technical consultancy services in connection with delivering the feasibility and outline design for two proposed pumped storage hydropower schemes in Scotland. MWH services will include outline design of dams and intakes, geo-technical and underground works, power station, elec-trical / hydro-mechanical equipment and substa-tions, as well as health, safety, environmental, cost, and quality manage-ment services. In addition to providing hydropower expertise, MWH will deliver engineering design and project management skills from the UK.

Marine projects share funds from Scottish Government

FiVE INNOVATIVE MARINE ENERGY projects are to share £13M in support from a Scottish govern-

ment fund that aims to help develop emerging energy technologies.

The five successful companies have been awarded funding from WATERS, a collaboration between the Scottish government, Scottish Enterprise and the Highlands and Islands Enterprise.

They include RWE npower renewa-bles, which has been awarded £6M to support construction of the 4MW Siadar wave power station off the Western Isles, and Aquamarine Power, which will receive £3.15M to support the demonstration of its Oyster 3 project at the European Marine Energy Centre in Orkney.

The projects will ‘help to put Scotland on the map as the world’s leading centre for marine renewable energy’, says Scotland’s energy min-ister Jim Mather.

‘Our seas have unrivalled potential to generate clean, green energy and bring jobs, investment and know-how to Scotland,’ said Mather. ‘We have a quarter of Europe’s potential tidal energy resource and a tenth of the wave capacity.’

Around £1.85M of the funds will go to OpenHydro to support development of a power conversion and control system that connects marine energy devices in tidal arrays. AWS Ocean Energy is to get £1.39M to support tests in Loch Ness and the Cromarty Firth of a doughnut-shaped wave energy converter.

Ocean Flow Energy will build and deploy its ‘Evopod’, a 35kW !oating tidal energy turbine at Sanda Sound with £560,000 of funding.

‘Initial costs for marine energy are high and capital is needed - these grants will help attract further private investment,’ added Mather. ‘Our sup-port will ensure a continuous stream of ideas and technologies can be tested, developed and re"ned at our world class testing centre on Orkney and elsewhere around Scotland.’

Mather continued: ‘Scotland is one of the most attractive markets for investment in wave and tidal power anywhere. Working with our enterprise agencies and other partners to develop our full potential, we will make Scotland a global leader in marine energy.’

New turbines for Jocassee PS plantUS UTILITY DUKE ENERGY HAS

announced that its Jocassee pumped storage project will

receive two new turbines for units 1 and 2 in August and September, increasing the project’s capacity by 50MW.

Following a seven-day trek, the first turbine will arrive near Salem on August 9, with the second turbine expected to arrive at this location in early September.

The turbines, manufactured by Voith Hydro, are approximately 23ft in diameter and weigh nearly 150 tons. They will be transported via interstate highways on 20-axle, dual-lane trailers about 250ft long.

Guy M. Turner, Inc. will manage the delivery, and the units will travel with police escort to help manage traf"c along the route. Once near the town of Salem, the "rst turbine will be parked temporarily until the second arrives. Then both will make the slow and winding seven-mile journey to the facil-ity on a hydraulic platform trailer while escort personnel walk alongside.

“Essentially, we’re improving the output of the facility and making it more efficient with state-of-the-art design technology,” said Greg Lewis, technical manager - Hydro Fleet. “This extends the life of the station and helps our system respond to peak cus-

tomer demands with a fast, !exible, clean and ef"cient energy resource.”

These will be the "rst upgrades to Jocassee units 1 and 2 since they began commercial operation in 1973. Replacing the turbines will enhance hydro generation from the current maximum capability of 170MW to 195MW each. They will also increase pumping capacity by 37MW each. Units 3 and 4 were upgraded in 2006 and 2007. Lake Jocassee will be operated at least four feet below full pond during the upgrades to units 1 and 2, which are planned for September 2010 through May 2011.

THE WORLD BANK HAS APPROVED a $200M loan to the People’s Republic of China to support the

Huai River Basin Flood Management and Drainage Improvement Project. The loan will "nance construction or rehabilitation of dikes, !ood control works, waterways and other infra-structure, enhancement of disaster assessment and support systems.

The Huai River Basin is one of the seven large river basins in China, and covers 270,000km2 in "ve provinces of Henan, Hubei, Anhui, Jiangsu and Shandong with a total population of 165 million. However, major !ood and water-logging disasters occur every three to "ve years, causing huge eco-nomic losses in the !ood plains of the

Huai River Basin. Following the disas-trous 2003 !oods which caused direct economic losses equivalent to $4.5B and made thousands of people home-less, the Government of China gave pri-ority to the development of !ood control and drainage infrastructure in the basin and has carried out a number of major programs with an aim to upgrade the !ood control standards from the cur-rent once in less than "ve to 50 years to once in 20 to 100 years.

The Huai River Basin Flood Management and D ra inage Improvement Project will supplement the Government’s efforts and focus on relatively medium and small size works on the lesser tributaries in the poorer rural areas in the Huai River Basin in

the provinces of Jiangsu, Shandong, Anhui and Henan to provide the local population with better and more secure protection against !oods and water log-ging, increase farmland productivity, and reduce property losses.

“Rather than focusing on infrastruc-ture construction only, we will adopt a new approach for integrated !ood man-agement and drainage improvement for this project. The new approach will focus on integration of structural and non-struc-tural measures at both river-basin level and local level, and involve greater rural community participation in the design, construction and management of the lower-level works,” said Jiang Liping, World Bank Senior Irrigation Specialist and task team leader for the project.

Finance approved for flood project

Let IWP&DC’s readers know about your forthcoming conferences and events. For publication in a future issue, send your diary dates to: Carrieann Stocks, IWP&DC, Global Trade Media Ltd, Progressive House, 2 Maidstone Road,

Foots Cray, Sidcup, Kent, DA14 5HZ, UK. Alternatively, email: [email protected], or fax:+44 208 269 7804

DIARY OF EVENTS


DIARY

September12-16 September21st World Energy CongressQuebec, Canada

CONTACT: Organsing Committee, 740 Notre-Dame Street West, 8th Floor, Montréal, Québec, Canada H3C 3X6.Tel: + 1 (514) 397-1474.www.wecmontreal2010.ca.

14-15 SeptemberPower Plant and Heavy Lifting ConferenceLondon, UK

CONTACT: Arena International Events Group, Brunel House, 55-57 North Wharf Road, Paddington, London W2 1LA. [email protected].

15-17 SeptemberAfrican Hydro SymposiumArusha, Tanzania

CONTACT: African Hydro Symposium, PO Box 32774, Lusaka 10101, Zambia.Tel: 260 211 371 007.Email: [email protected].

19-24 SeptemberIWA World Water Congress & ExhibitionMontreal, Canada

CONTACT: International Water Association (IWA), Koningin Julianaplein 2, NL-2595 AA Den Haag, The Netherlands.Tel: +31 703 150 785.Fax: +31 703 150 799.Email: [email protected].

19-23 SeptemberDam Safety 2010Seattle, WA, US

CONTACT: Association of State Dam Safety Of!cials (ASDSO), 450 Old Vine Street, Lexington KY 40507, US.Tel: +1 859 257 5140.Fax: +1 859 323 1958.Email: [email protected].

www.damsafety.org.

22-23 September8th ICOLD Euopean Club Sympos ium: Dam Sa f e ty - Sustainability in a Changing EnvironmentInnsbruck, Austria

CONTACT: IECS2010 Organizing Committee, Stremayrgasse 10/II, A-8010 Graz, Austria.Fax: +43 316 873 [email protected].

23-24 SeptemberWate r Managemen t 2010 : Integrating Renewable Energy SourcesStockholm, Sweden

CONTACT: CEATI International, 1010 Sherbrooke Street West, Suite 2500, Montreal, Quebec, Canada H3A 2R7.Fax: +1 514 904 5038.Email: [email protected]/meetings/WM2010.

27-29 SeptemberHydro 2010Lisbon, Portugal

CONTACT: Hydropower & Dams, Aqua~Media International Ltd, PO Box 285, Wallington, SurreySM6 6AN, UK.Tel: +44 (0)20 8773 [email protected].

27 September - 2 OctoberSmall Hydro ResourcesTrondheim, Norway

CONTACT: International Centre for Hydropower (ICH), Klaebuveien 153, N-7465 Trondheim, Norway.Tel: +47 73 59 0780.Email: [email protected].

28-30 September2nd International Congress on Dam Maintenance and RehabilitationZaragoza, Spain

CONTACT: Daniel Ariza, TILESA OPC, Londres, 17 - 28028 Madrid.Tel: +34 91 361 2600Fax: +34 91 355 [email protected]

http://www.damrehabilitationcon-gress2010.com

October3-7 OctoberCanadian Dam Association 2010 Annual ConferenceNiagara Falls, Canada

CONTACT: CDA, PO Box 2281, Moose Jaw, Saskatchewan, Canada, S6H 7W6.www.cda.ca/2010conference.

13-14 OctoberBritish Hydropower Association Annual Conference 2010Glasgow, UK

CONTACT: Ellan Long, British Hydropower Association, Unit 6B Manor Farm Business Centre, Gussage St Michael, Dorset, BH21 5HT UKTel: + 44 (0)1258 840934.Email: [email protected].

17-22 October14th Hydro Power Engineering Exchange 2010Snowy Mountains, Australia

CONTACT: Snowy Hydro, Level 37, AMP Centre, 50 Bridge Street, Sydney, NSW 2000, Australia.Email: [email protected].

18-21 OctoberRotordynamics and Bearings TechnologiesCologne, Germany

CONTACT: ARLA Maschinentechnik GmbH, Hansestr 2, D-51688 Wipperfuerth, Germany.www.arla.de.

19-21 OctoberEuropean Future Energy ForumLondon, UK

CONTACT: Turret Middle East, ADNEC House, PO Box 94891, Abu Dhabi, United Arab Emirates.www.europeanfutureenergyforum.com

25-29 OctoberRisk Management in Hydropower DevelopmentTrondheim, Norway

CONTACT: International Centre for Hydropower (ICH), Klaebuveien 153, N-7465 Trondheim, Norway.Tel: +47 73 59 0780.Email: [email protected].

November2-3 NovemberForum on Hydropower 2010Ontario, Canada

CONTACT: Canadian Hydropower Association.Tel: +1 613 751 6655.Email: [email protected].

2-5 NovemberHydro 2010Rostock-Warnemunde, Germany

CONTACT: DHyG, c/o Sabine Muller, Schutower Ringstr 4, D-18069 Rostock, Germany.Email: [email protected].

16-17 NovemberFlood Management 2010London, UK

CONTACT: Flood Management Conference Registration, Emap Networks, First Floor,Greater London House, Hampstead Road, London, NW1 7EJ.Tel: +44 0845 056 8069.Fax: +44 20 7728 [email protected]"oodmanagement.com

24-26 November16th International Conference on Hydropower PlantsVienna, Austria

CONTACT: Dr. Eduard Doujak, Institute for Waterpower and Pumps, Karlsplatz 13/305, ViennaAustria, [email protected].

25-27 NovemberRENEXPO AustriaSalzburg, Austria

CONTACT: REECO Austria Gmbh, Josef-Schwer-Gasse 9, A - 5020 Salzburg, Austria.

Let IWP&DC’s readers know about your forthcoming conferences and events. For publication in a future issue, send your diary dates to: Carrieann Stocks, IWP&DC, Global Trade Media Ltd, Progressive House, 2 Maidstone Road,

Foots Cray, Sidcup, Kent, DA14 5HZ, UK. Alternatively, email: [email protected], or fax:+44 208 269 7804

DIARY OF EVENTS


DIARY

Tel: +43 (0) 662 8226 - 3.www.renexpo-austria.at

26-28 NovemberWorkshop on Optimization of Construction Method for CFRDsYichang, China

CONTACT: HydrOu China, No. 41-210 Three Gorges Community, Zhenping Road, Yichang city, Hubei 443002, ChinaTel: +86717 672-1379Fax: +86717 672-1379Email: [email protected]://www.hydrou.com/index.php?option=com_content&task=view&id=166&Itemid=1.

February 201115-17 February6th International Conference on Dam EngineeringLisbon, Portugal

CONTACT: Eliane Portela , LNEC, Concrete Dams Department, LNEC, Av. Brasil 101, 1700-066, Lisbon, Portugal.Tel: (351) 218443361.Fax: (351) 218443026.Email: [email protected]://dam11.lnec.pt.

April 201115-17 FebruaryEnergy Ef!ciency and Renewable Energy Sources for South-East EuropeSo!a, Bulgaria

CONTACT: Via Expo Ltd, 3 Chehov Square, Plovdiv 4003, Bulgaria.Fax: +359 32 945 459.Email: [email protected]://viaexpo.com.

May 201116-20 June2 5 t h E u r o p e a n R e g i o n a l Conference of ICIDGroningen, The Netherlands

CONTACT: Bert Toussaint, Chairman of the Organizing Committee, Ministry of Transport, Public Works & Water Management, Rijkswaterstaat Centre for Corporate Services, PO Box 2232,

NL-3500 GE Utrecht, NetherlandsTel: +31 62 079 1372Email: [email protected].

29 May - 3 June79th Annual Meeting of ICOLDLucerne, Switzerland

CONTACT: Swiss Committee on Dams, c/o Stucky Consulting Engineers.Email: [email protected]://www.swissdams.ch

14-17 JuneIHA’s 2011 World Congress

Iguassu Falls, Brazil

C O N T A C T : I n t e r n a t i o n a l Hydropower Association , Nine Sutton Court Road, Sutton, Surrey, SM1 4SZ, UK.Tel: +44 20 8652 5290.Email: [email protected].

Worthington Products is the leading global provider of waterway barriers, buoys and customized floats. Worthington offers a full range of waterway barriers for debris control, ice booms, walking platforms, counter-terrorism, public safety boat barriers, and regulatory buoys. With a global installation base, we have the experience and under-standing to assure your barrier project is designed and installed for long term success. You can trust Worthington to provide expert advice, common sense engineering, and unrivaled customer service. Call us direct or visit us

online at www. .com

Africa (continental), Australia, Bhutan, Brazil, Canada, France, India, Indonesia, Italy, Malaysia, New Zealand, United Kingdom, USA, Philippines, Singapore, South Korea, Thailand, Switzerland.


COMMENT

SO, hydropower is back in fashion and business is booming, but why? Well there are two obvious reasons. Firstly it is fashionably renewable

and secondly it is the oldest tried and tested form of large-scale renewable energy.

Earliest accounts of water wheels in Roman and Chinese literature date back about 2000 years. A 4th Century !our mill in Barbegal, near Arles, in France featured 16 overshot water wheels. Accounts of using water to power mills and hammers for crushing ore abound in mediaeval literature with the 1086 Doomsday book listing almost 6000 water-mills in England alone. However, mechani-cal transmission meant that power had to be used close to the mills.

The development of electrical genera-tors and transmission lines enabled us to use water power hundreds of miles from its source. So it is not surprising that today almost 20% of the world’s energy currently comes from hydropower.

The Carter administration in the US cat-egorised hydropower as solar energy on the basis that solar evaporation leads to rain and hence the rivers which feed hydropower. Indeed research by myself and many others is showing that variations in rainfall and runoff often correspond to variations in solar energy levels. But of course the de"nition of hydro-power is much wider. Mills driven by the tide also date back to Roman times. A tidal mill was located at Killoteran in Ireland in the 6th Century and by the 18th Century there were 76 tide miles in London alone. Wave energy is also a form of hydropower. Perhaps we should be looking at the complete mix as ultimately solar and lunar power.

G#$%& '()%*+,'%* -(. ./0- ( 1,,2 +%2#1*%%, '-() '%&)

'*,&13The 1980s and 1990s saw what can best be described as some quasi-political mischief making. Under a banner of environmen-talism a number of pressure groups sought in!uence by attacking anything from nucle-ar power and pesticides to GM crops, with dams in there too. Additionally, the waves caused by the World Commission of Dams are still being felt.

The resulting pressure caused funders like the World Bank to withdraw from fund-ing dams until they realised that only the very poorest in the world, who it was their prime mandate to help, were being affected by the moratorium. Realising that not all the World Commission on Dams guidelines

were achievable they looked back at their internal guidelines for project approval. Noting these were entirely compatible with the Commission’s, they simply reverted back to their own. Organisations such as the IHA are now also bringing much needed clar-ity to the debate with their Sustainability Assessment Protocol.

Recent years have seen all the major funders return to funding dams and hydro-power. However, a rear-guard action is still being fought in Europe with arbitrarily low limits to what capacity of new hydropower is seen as acceptable.

The same pressure groups raised the spec-tre of greenhouse gases and in particular C02 in an attempt to sti!e fossil fuel use. While ultimately this is almost certainly a good idea, the same groups’ attempts to claim reservoirs are similarly damaging seem to be ill founded. Submerged land cannot release more carbon than is already trapped on it. It follows a natural pattern of release as plants die and sequestration as they grow. A mature stable forest is carbon neutral.

To some extent the focus on greenhouse gases almost certainly helped the prospects of both hydropower and nuclear power, some-thing unintended by those who raised the spectre in the "rst place. In fact the need for an increased use of pumped storage plants to offset the natural variation in forms of other renewable energy such as wind, waves and solar power have also given a welcome boost to hydropower.

Many governments are now encouraging small hydropower developments by promis-ing to buy subsidised electricity from those

connected to their grids. Many large grids such as those in America were originally formed by simply connecting a multitude of small, home-grown schemes. Many of these were later abandoned in favour of larger and cheaper central generating centres. The latest changes are seeing the bene"cial re-es-tablishment of many of those smaller, diverse installations as well as developing a feeling in many of increased self-reliance.

But all this has come together at an interest-ing time. The last few years have seen easy credit and an expansion of speculative fund-ing. Some of this has helped hydropower. We are now moving into a period of austerity and lower interest rates. But low interest rates in particular can also help investment into projects like hydropower which require ini-tial up-front funding but then a relatively low annual investment thereafter. The longer the realistic discount period the more favourable it is to hydropower. It has always seemed irra-tional to many in the industry, including me, that conventional "nancial analyses of projects pay little regard to bene"ts accruing beyond about 20 to 30 years, whereas a well main-tained and refurbished hydropower project can still be operational after 100 years.

It is also now being realised that hydro-power cannot always be "nanced solely by the sale of electricity. Many schemes will have strategic signi"cance for the country involved and, where a dam and reservoir are featured, there may be supplementary bene"ts such as; water supply, irrigation, navigation and !ood control. These warrant supplementary funding and an analysis based on economic value as well as "nancial return. In that sense perhaps we are returning to earlier days of multilateral, or multi-stakeholder, funding but hopefully without the excesses which tended to see the largest possible scheme being built in each case.

If properly managed the future is indeed rosy for hydropower in all its forms, but it will need concurrent support from affected parties and that may in turn need public education by those involved in the industry.

Dr Peter J Mason can be contacted at [email protected]

If you would like to submit a comment

for inclusion in International Water Power & Dam Construction,

please contact the editor, Carrieann Stocks, via email:

[email protected]

The resurgence of hydropowerDr Peter Mason, Technical Director of International Dams and Hydropower at global envi-ronment and water specialists MWH explains why he thinks hydropower is back in favour

IWP& DC

ADVANCING SUSTAINABLE HYDROPOWER14-17 June 2011 - Iguassu, Brazil

W O R L D C O N G R E S S

w a t e r

s u s t a i n a b i l i t y

c l i m a t e

i n v e s t m e n t

e n e r g y

WWW.HYDROPOWER.ORG Main Congress Sponsors:

Media Partner:

Tel: +44 208 652 5290 | Fax: +44 208 643 5600 | Email: [email protected] | Web: www.hydropower.org

The IHA 2011 World Congress: Don’t miss this opportunity to attend the hydropower

sector’s most challenging and enriching event of 2011!

Contact IHA today to register your interest in attending.

2010-08-06_IHA_Congress_Advert_1_Final.indd 1 06/08/2010 10:01:23


DAM SAFETY

UNTIL now no people have died from the failure or damage of a large water storage dam due to earthquake. Earthquakes have always been a signi!cant aspect of the design and safety of dams.

A large storage dam consists of a concrete or !ll dam with a height exceeding 15m, a grout curtain or cut-off to minimise leakage of water through the dam foundation, a spillway for the safe release of "oods, a bottom outlet for lowering the reservoir in emergencies, and a water intake structure to take the water from the reservoir for commercial use. Depending on the use of the reservoir there are other components such as a power intake, penstock, powerhouse, device for control of environmental "ow, !sh ladder, etc.

During the Richter magnitude 8 Wenchuan earthquake of 12 May 2008, 1803 concrete and embankment dams and reservoirs and 403 hydropower plants were damaged. Likewise, during the 27 February 2010 Maule earthquake in Chile of Richter magnitude 8.8, several dams were damaged. However, no large dams failed due to either of these two very large earthquakes.

WHAT EARTHQUAKE ACTION DOES A DAM HAVE TO WITHSTAND?

In order to prevent the uncontrolled rapid release of water from the reservoir of a storage dam during a strong earthquake, the dam must be able to withstand the strong ground shaking from even an extreme earthquake, which is referred to as the Safety Evaluation Earthquake (SEE) or the Maximum Credible Earthquake (MCE). Large storage dams are generally considered safe if they can survive an event with a return period of 10,000 years, i.e. having a one percent chance of being exceeded in 100 years. It is very dif!cult to predict what can happen during such a rare event as very few earthquakes of this size have actually affected dams. Therefore it is important to refer to the few such observations that are available. The main lessons learnt from the large Wenchuan and Chile earthquakes will have an impact on the seismic safety assessment of existing dams and the design of new dams in the future.

There is a basic difference between the load bearing behaviour of buildings and bridges on the one side, and dams. Under normal con-ditions buildings and bridges have to carry mainly vertical loads due to the dead load of the structures and some secondary live loads. In the case of dams the main load is the water load, which in the case of concrete dams with a vertical upstream face acts in the horizontal direction. In the case of embankment dams the water load acts normal to the impervious core or the upstream facing. Earthquake damage of buildings and bridges is mainly due to the horizontal earthquake component. Concrete and embankment dams are much better suited to carry horizontal loads than buildings and bridges. Large dams are required to be able to withstand an earthquake with a return period of about 10,000 years, whereas buildings and bridges are usually designed for an earthquake with a return period of 475 years. This is the typical building code requirement, which means the event has a 10% chance of being exceeded in 50 years. Depending on the risk category of buildings and bridges, importance factors are speci!ed in earthquake codes, which translate into longer return periods, but they do not reach those used for large dams.

Moreover, most of the existing buildings and bridges have not been designed against earthquakes using modern concepts, whereas dams have been designed to resist against earthquakes since the 1930s. Although the design criteria and analyses concepts used in the design of dams built before the 1990s are considered as obsolete today, the reassessment of the earthquake safety of conservatively designed dams shows that in general these dams comply with today’s design and performance criteria and are safe. In many parts of the world the earthquake safety of existing dams is reassessed based on recommen-dations and guidelines documented in bulletins of the International Commission on Large Dams (ICOLD).

SEISMIC HAZARD IS A MULTI-HAZARD

Earthquakes represent multiple hazards with the following features in the case of a storage dam: Ground shaking causes vibrations and structural distortions in dams, appurtenant structures and equipment, and their foundations; Fault movements in the dam foundation or discontinuities in dam foundation near major faults can be activated, causing structural distortions;

IWP&DC presents a position paper of the International Commission on Large Dams (ICOLD), prepared by the Committee on Seismic Aspects of Dam Design

Dam safety and earthquakes

Left: Maigrauge gravity dam built in 1872 in Switzerland. After a recent rehabili-tation its service life has been extended by another 50 years. Photo shows the main elements of a storage dam for power production: spillway, reservoir, con-crete dam body, power intake and powerhouse (left) ; Below from left to right: Downstream view of the 106 m high Sefid Rud buttress dam in Iran damaged by the magnitude 7.5 Manjil earthquake of June 21, 1990. Bottom irriga-tion outlets were opened after the earthquake to lower the reservoir (left). Rockfall damage near left abutment (middle) and right abutment (right).


DAM SAFETY

Fault displacement in the reservoir bottom may cause water waves in the reservoir or loss of freeboard; Rockfalls and landslides may cause damage to gates, spillway piers (cracks), retaining walls (overturning), surface powerhouses (crack-ing and puncturing and distortions), electro-mechanical equipment, penstocks, masts of transmission lines, etc. Mass movements into the reservoir may cause impulse waves in the reservoir; Mass movements blocking rivers and forming landslide dams and lakes whose failure may lead to overtopping of run-of-river power plants or the inundation of powerhouses with equipment, and damage downstream; Ground movements and settlements due to liquefaction, densi!ca-tion of soil and rock!ll, causing distortions in dams; and Abutment movements causing sliding of and distortions in the dam.

Effects such as water waves and reservoir oscillations (seiches) are of lesser importance for the earthquake safety of a dam. Usually the main hazard, which is addressed in codes and regulations, is the earthquake ground shaking. It causes stresses, deformations, cracking, sliding, overturning, etc. However, some of the other hazards, which are nor-mally not covered by codes and regulations, are also important.

Therefore, in the earthquake design of dams all seismic hazard aspects must be considered and depend on the local conditions of a storage dam project.

WHAT COULD HAPPEN IN STRONG EARTHQUAKES?The experience with the seismic behaviour of large dams is still lim-ited. Four dams – two concrete, an earth core rock!ll and a con-crete face rock!ll dam – with heights exceeding 100m were damaged during the Wenchuan earthquake. Elsewhere, there are another !ve concrete dams over 100m in height, which were damaged due to strong ground shaking. In concrete dams the damage was mainly in the form of cracks but also joints can open up leading to the release of water from the reservoir. In modern embankment dams the damage is mainly by deformations and cracks along the crest that can eventually lead to internal erosion and piping through the dam.

However, we have to be aware that each dam is a prototype located at a site with special site conditions and hazards. Therefore, based on the observation of the earthquake behaviour of other dams it is still very dif!cult to make a prediction of the damage that could occur in a particular dam. At this time we are still in a learning phase as very few large modern dams have been exposed to strong earthquakes. In the

case of the Wenchuan earthquake, a large number of rockfalls took place, which caused signi!cant damage to dams and appurtenant struc-tures. Surface powerhouses were particularly vulnerable to rockfalls in the steep valleys in the epicentral region of the Wenchuan earthquake.

COULD RESERVOIRS BE LOWERED IN CASE OF SUC-CESSFUL EARTHQUAKE PREDICTIONS?

If earthquakes could be predicted, one could attempt to lower the reservoir prior to the occurrence of a large earthquake. There are two problem areas related to this concept. First, despite some 40 years of research on earthquake prediction, it is still not possible to predict the time, location and size of a large earthquake reliably. Small earth-quakes may be predicted but not large ones. The prediction is usually given in terms of the probability of occurrence, e.g. there is a 50% probability that a magnitude 7 earthquake occurs in a certain region within a period of 30 years. Such predictions are basically useless for warning purposes and for lowering a reservoir.

Even if a large earthquake could be predicted reliably, there would not be suf!cient time to lower large reservoirs. Lowering of a reser-voir would have to happen by low level outlets (bottom outlets) or the power waterways if the intake is at low elevation. Unfortunately, bottom outlets are not available everywhere. Therefore the lowering of a reservoir by say 50% may take weeks or months, and in some cases it may not be possible at all.

As a conclusion, earthquake prediction, which is a slowly develop-ing science, is not a viable option to improve the earthquake safety of dams. The only real option is to have a dam which can withstand the strongest earthquake effects to be expected at the dam site. This is the current practice in dam design.

The greatest hazard of a dam is the water in the reservoir. Therefore, in the seismic design of dams, we have to ensure the safety of the dam under full reservoir condition. Although an arch dam may be more vulnerable to the effect of ground shaking when the reservoir

Above left to right: Different types of damage of embankment dams caused by the magnitude 7.5 Bhuj earthquake in Gujarat province, India, January 26, 2001. Mainly small dams for irrigation and water supply were damaged. Right: Damage of reinforced concrete buildings on top of intake towers of the Zipingpu reservoir, May 12, 2008 Wenchuan earthquake


DAM SAFETY

is empty, this case is not critical for the safety of the people living downstream of the dam but it is, of course, an important economical issue for the dam owner if the dam should fail.

CAN EARTHQUAKES BE TRIGGERED BY STORAGE DAMS?There are a number of cases where earthquakes were triggered by the reservoir. The main prerequisites for reservoir-triggered seismicity (RTS) are (i) the presence of an active fault in the reservoir region, or (ii) existence of faults with high tectonic stresses close to failure. The !lling of the reservoir in a tectonically active region may merely cause the triggering of an earthquake which in any case would occur at a later date. The occurrence of RTS has been mainly observed in reservoirs with a depth exceeding 100m. Six events with Richter mag-nitudes of more than 5.7 have been observed up to now. The larg-est magnitude was 6.3. In two cases, concrete dams were damaged, i.e. Hsinfengkiang buttress dam in China and Koyna gravity dam in India. Since records did not exist on the local seismicity prior to dam construction, there are still doubts whether these large earthquakes have actually been triggered by the reservoirs.

If a large dam has been designed according to the current state-of-practice, which requires that the dam can safely withstand the ground motions caused by an extreme earthquake, it can also withstand the effects of the largest reservoir-triggered earthquake. However, RTS may still be a problem for the buildings and structures in the vicin-ity of the dam, because they would generally have a much lower earthquake resistance than the dam. In the great majority of RTS, the magnitudes are small and of no structural concern.

The issue of RTS is always discussed in connection with large dams. RTS was also considered in connection with the Wenchuan earthquake as the Zipingpu reservoir is located close to the ruptured segment of the Longmenshan fault. However, there is no conclusive evidence that the earthquake was triggered by the !lling and the operation of the reservoir.

WHAT ARE THE MAIN CONCERNS WITH RESPECT TO THE EARTHQUAKE SAFETY OF LARGE STORAGE DAMS?The main concerns are related to the existing dams, which either have not been designed against earthquakes – this applies mainly to small and old dams – and dams built using design criteria and methods of analyses which are considered as outdated today. Therefore, it is not clear if these dams satisfy today’s seismic safety criteria. There is a need that the seismic safety of existing dams be checked and modern methods of seismic hazard assessment be used such as the guidelines given in ICOLD Bulletin 120. This will result in a dam which will per-form well during a strong earthquake. To follow these guidelines is more important than to perform any sophisticated dynamic analysis, which is only a tool to help understand how a dam will perform.

THE ROLE OF ICOLDHoover Dam in the US built in the 1930s was the !rst concrete dam designed against earthquake where both the inertial effects of the dam and the hydrodynamic pressure of the reservoir were taken into account. Embankment dams were designed against earthquakes as early as in the 1920s in Japan where the seismic action was taken into account in the stability analyses.

ICOLD has discussed the effects of earthquakes on dams at several Congresses and Annual Meetings. At the 5th ICOLD Congress in Paris, France in 1955 the following subject was discussed: ‘Settlement of earth dams due to compressibility of the dam materials or of the foundation, effect of earthquakes on the design of dams’.

In June 1968 the ICOLD Committee on Earthquakes was estab-lished. This committee now exists under the name: Committee on Seismic Aspects of Dam Design. Thirty-one countries from all conti-nents are represented in this important committee. In recent years the following Bulletins have been published by the committee:

Bulletin 62 (1988 revised 2008): Inspection of dams following earthquakes – guidelines; Bulletin 72 (1989 revised 2010): Selecting seismic parameters for large dams - guidelines; Bulletin 112 (1998): Neotectonics and dams - guidelines; Bulletin 113 (1999): Seismic observation of dams - guidelines; Bulletin 120 (2001): Design features of dams to effectively resist seismic ground motion - guidelines; Bulletin 123 (2002): Earthquake design and evaluation of structures appurtenant to dams - guidelines; and Bulletin 137 (2010): Reservoirs and seismicity – state of knowledge.

CONCLUSIONS The technology is available for building dams and appurtenant struc-tures that can safely resist the effects of strong ground shaking.

Storage dams that have been designed properly to resist static loads prove to also have signi!cant inherent resistance to earthquake action. Many small storage dams have suffered damage during strong earth-quakes. However, no large dams have failed due to earthquake shaking.

Earthquakes create multiple hazards at a dam that all need to be accounted for. There are still uncertainties about the behaviour of dams under very strong ground shaking, and every effort should be made to collect, analyze and interpret !eld observations of dam per-formance during earthquakes.

For further information, contact: Martin Wieland, Chairman, ICOLD Committee on Seismic Aspects of

Dam Design, Poyry Energy Ltd., Hardturmstrasse 161, CH-8037 Zurich, Switzerland. [email protected]

IWP& DC

Above left: Damage of the Shapei powerhouse caused by rockfall during the May 12, 2008 Wenchuan earthquake; Above right: Sheared off pier of Futan weir at the Minjiang river due to the impact of large rocks, May 12, 2008 Wenchuan earthquake

instrumentation, data acquisition andstructural monitoring systems fordams, tunnels, rockslopes, anchoring

HUGGENBERGER AG, Tödistrasse 68, CH-8810 Horgen, SwitzerlandPhone +41 44 727 77 00 Fax +41 44 727 77 07Email [email protected]://www.huggenberger.com

The World Leader in Pendulum MeasuringSystems· manual: Coordiscope KK84· automatic: Telependulum VDD2V4

automatic reading for plumb line

Telependulum VDD2V4

manual reading for plumb line

Silvretta Dam, Austria 2010 - Exposed PVC geomembrane to waterproof a 70 m high gravity dam. Hydropower.

CARPI SYNTHETIC GEOMEMBRANES HAVE STOPPED LEAKAGE IN 100 + DAMS

1,200 + projects completed. Design and supply of waterproofing systems fordams, canals, hydraulic tunnels, reservoirs. Dry and underwater installation.

CARPI TECH Via Passeggiata 1 6828 Balerna - SwitzerlandPh. +41-91-69540000 Fax. +41-91-6954009www.carpitech.com e-mail: [email protected]

Carpi_July10:Carpi ad Oct07 28/7/10 08:49 Page 1


AUSTRALASIA

WYARALONG dam site is located in south-east Queensland, Australia, near the township of Beaudesert. The project is part of the south-east Queensland water grid, providing water supply for

this region of Australia. When completed, the dam will have the capacity to store approximately 103,000 ML of water.

The Wyaralong Dam Project is being delivered as an Alliance, where the Client, Designer and Contractor work together in a contractual arrangement which shares the risks and the rewards associated with deliv-ering the project. Following the completion of the preliminary design, a value engineering process occurred during the months of February and March 2009 as part of the bidding process chosen by the client, Queensland Water Infrastructure Pty Ltd, to select their Alliance partner. The selected Alliance partners consisted of Macmahon, Wagners, ASI Constructors, Hydro Tasmania Consulting, SMEC and Paul C. Rizzo Associates – which combined with Queensland Water Infrastructure to form the Wyaralong Dam Alliance. The design consultancy services are being provided by Hydro Tasmania Consulting, SMEC and Paul C. Rizzo Associates, while construction is being undertaken by the contract-ing partners Macmahon, Wagners and ASI Contractors.

Detailed design of the roller compacted concrete gravity dam com-menced in May 2009, with initial early works construction starting on site in October 2009 in parallel with the design. Construction is planned to be completed during early 2011. This paper provides some of the details of the dam, along with some reasons behind the !nal design adopted at Wyaralong.

DAM - GENERAL

Wyaralong Dam is a 47m high (above lowest foundation level), 490m long, roller compacted concrete (RCC) dam, with a centrally located ungated primary spillway and a secondary spillway on the left abut-ment. The total volume of RCC will be approximately 190,000m3. The general arrangement is shown in Figure 1.

The dam has a wet intake tower attached to the upstream face of the dam, located on the right abutment. This intake tower allows water to be drawn from various levels within the reservoir. Water is then discharged back in the river channel through the outlet works at the base of the dam through two submerged, vertical discharge valves.

The dam is also designed to provide fish passage in both the upstream and downstream direction. An innovative bi-directional

!sh lift is being incorporated to provide this capability.An aerial view of construction during June 2010 is shown in !gure

2. In the photo, RCC placement has started in the spillway section. The upstream side of the dam is on the left side of the photo.

FOUNDATION

The initial geotechnical investigation was carried out in 2006/07 and in the !rst half of 2009. This investigation consisted of boreholes across the damsite and two dozer trenches were excavated, one on each abutment of the dam. The dozer trenches involved removing soil and overburden and mapping the top of the rock surface. After the initial investigation was complete, 14 additional borings were drilled and the dozer trenches were extended. The geotechnical investigation also included water pressure testing, uncon!ned compressive strength testing, direct shear testing, and acoustic televiewer surveys.

Geological sections were developed based on the investigations conducted and rock was classi!ed based on the degree of weather-ing on the sections. Weathering classi!cations used were distinctly weathered with seams, distinctly weathered without seams, and slightly weathered to fresh. Speci!c weak layers were also identi!ed on these geologic sections. Based on the geologic sections, the design foundation level for the dam was developed.

The design foundation level was selected to provide a surface that balanced the amount of time and treatment required to prepare the foundation for RCC placement with the amount of rock that would need to be removed and replaced with RCC. The foundation level was chosen so that rock that was classi!ed as ‘distinctly weathered with seams’ was removed from the dam foundation. It was judged that it would take too much time and treatment to prepare this rock to provide a competent base for the dam and it would be removed. Distinctly weathered rock without seams was generally left in place in the foundation because it provides a competent foundation for the dam. The dam is generally founded on distinctly weathered sand-stone in the abutments and on slightly weathered to fresh sandstone in the primary spillway section. Photos of foundation preparation at the right and left abutments are shown in !gures 3 and 4.

Through the development of the geological sections, the orienta-tion and dip of the typical bedding at the site was identi!ed. The sec-tions also showed that any weak layers identi!ed at the site generally followed bedding. The slope of the foundation at the left abutment

With construction work well underway on the Wyaralong Dam project in Queensland, Australia, Richard Herweynen, Colleen Stratford and Jared Deible provide details on the design of the roller compacted concrete gravity structure

Wyaralong Dam design and construction

Secondary spillway apron Primary spillway apron

Secondary spillway Primary spillway Outlet works and fishway

Below: Figure 1 – General arrangement; Right: Figure 2 – Aerial view of construction (June 2010)

is generally consistent with the bedding dip and dip direction, and the right abutment forms a stepped pro!le.

Using the geologic sections, it was possible to look for potential interpolations of similar weak seams between boreholes in 2D (along sections) and 3D (between sections). Potential planes of weakness were identi!ed between groups of boreholes and surface exposures. A total of eight surfaces of potential weakness were identi!ed at the site, and these surfaces were named surface A-H. Their location rela-tive to the dam is shown in Figure 5.

Stability analyses were undertaken along each of the surfaces iden-ti!ed. Surfaces A and C are located deep below the foundation and were left in place. During construction it was found that surfaces D, E, G, and H were identi!ed at approximately the anticipated loca-tions in the right abutment and spillway section. These surfaces were treated in accordance with the plan developed during design. Surface B was identi!ed in the left abutment, and the foundation in this area was initially blasted to the design level and the presence of Surface B was con!rmed. The geometry of Surface B was slightly different from the geometry used in the design, so based on actual survey, additional stability analyses were undertaken. Based on this analy-sis it was determined that Surface B needed to be removed over the majority of the footprint of the dam. An additional blast was done to remove the rock above Surface B, !gure 6 is a photo of the surface after the additional rock removal.

The design also includes a grout curtain to seal potential seep-age paths in the foundation. The double line grout curtain is being installed using the GIN method, and grouting is generally being per-formed from the approved RCC foundation level. In the abutment sections the grout curtain is located in the footprint of the dam and is being done in advance of RCC placement. In the primary spillway section of the dam, grouting is being done from an overbuilt RCC plinth upstream of the heel of the dam, allowing RCC placement to proceed independently of grouting.

RIVER DIVERSION AND DEWATERING

Flows in the Teviot Brook are similar to those in many Australian rivers and streams, where there are periods of low "ows, punc-tuated by high "ow events. Taking this "ood risk into account, the !nal diversion arrangement consisted of a 6m high cofferdam which was designed, with reno mattresses, to be overtopped and had a sheetpile cuttoff down to foundation rock through the more permeable alluvial materials in the main river channel.

The river has been diverted into a buried steel conduit for the duration of construction. The diversion pipe consists of a 2.4m diameter steel pipe, which is concrete encased under the foot print of the dam. The capacity of the diversion is approximately 25m3/sec. In the event the cof-ferdam is overtopped during the !rst year of construction, various design measures have been adopted to control the "ow into the dam excavation area, minimising the clean up and ensuring rapid dewatering.

In addition, a series of dewatering wells are provided to dewater the alluvial material and rock in the foundation area, so as to mini-mise the ground water in"ow into the 15m deep excavation.

DAM SECTION AND DESIGNAnalyses performed for the dam included static and dynamic stabil-ity analyses. Stability analyses were performed along RCC lift joints within the dam, along the RCC/Rock interface, along typical bedding planes in the foundation, and along speci!c defects identi!ed in the foundation. A !nite element model was developed to estimate stress-es in the dam during an earthquake, and seismic deformation analyses were performed to estimate displacements during an earthquake.

The dam section was governed by stability analysis along bedding planes and speci!c defects in the foundation. Shear strength prop-erties for the RCC/Rock interface were developed using the Barton criteria for rough surfaces. Shear strength properties for bedding planes were developed using a combination of the Barton criteria and measured roughness values. Shear strength properties for weak layers in the foundation were developed using direct shear testing. A section with a crest width of six meters and a downstream slope of 0.8H:1.0V was selected based on the analysis. A typical section for the primary spillway shown in Figure 7.

Design features at the dam include a 400mm thick layer of conven-tional concrete facing, a drainage gallery, crest to gallery drains, foun-dation drains, and reinforced concrete crest sections. Typical monolith joints in the RCC are located at 30m spacing, with intermediate joints in the facing concrete at 7.5m spacing. The thermal analysis indicates the monolith joint spacing can be adjusted, so the actual location of monolith joints are being adjusted to suit foundation conditions.

SPILLWAY

The spillway at Wyaralong dam is required to pass the probable maximum "ood, which has a design in"ow of around 7680m3/sec. Various spillway options were investigated during the value-man-agement phase of the project, including combinations of primary, secondary and tertiary spillways located both within the dam section and remote from the main wall.

The adopted arrangement comprises a centrally located, un-gated primary spillway with a smooth downstream face. A 25m wide still-ing basin is located at the base of the primary spillway. The design also incorporates a stepped faced secondary spillway on the left abut-ment of the main wall, which is designed to operate at "oods less frequent than the 1 in 100 AEP event. Flows over the secondary spillway are directed along the toe of the secondary spillway in a concrete-lined apron channel to the main stilling basin. For "ood events greater than the 1 in 2000 AEP event, the capacity of the sec-ondary spillway apron channel is exceeded and "ows spill out across the left abutment towards the river channel.

Extensive investigations were undertaken during the design phase to assess the behaviour of the spillways, with particular attention to the erosion potential of the left abutment for "ood events which exceed the secondary spillway apron channel capacity. Two physical model studies were conducted, comprising:

1 in 80 scale model of the dam 1 in 30 scale model of the primary spillway, used to assess the performance of the !shway, outlet works and stilling basin under low "ow events.


AUSTRALASIA

Above: Figure 3 – Foundation preparation on left abutment; Right: Figure 4 – Foundation preparation on right abutment


AUSTRALASIA

The hydraulic models indicated that the spillways and stilling basin perform as intended up to the PMF event. The 1 in 80 scale model is shown in Figure 8.

Results from the model studies for !ow over the left abutment for !ood events greater than the 1 in 2000 AEP were used in an analysis of the erosion potential of the left abutment. A decision model was developed to assess the acceptability of the design with regard to ero-sion potential. The decision model took into consideration scour potential based on geological and hydraulic characteristics, likelihood of occurrence, storm duration, and impacts on dam stability if a scour hole develops at the toe of the dam. The conclusion of this assess-ment was that erosion was judged to be acceptable and the dam will remain stable should a deep scour hole develop.

In order to provide an additional level of protection against scour holes undermining to toe of the dam, a grid of passive anchors were adopted throughout the reinforced concrete apron and stilling basin slabs to ‘stitch’ the concrete slab to the rock and provide additional resistance across rock joints.

An ogee pro"le was adopted for the crest of the primary spillway with an elliptical curve on the approach to the crest. The secondary spillway crest has been designed as a broad-crested pro"le, however top forms used in construction of the primary spillway will be reused on the secondary spillway to provide an elliptical curve approach to the crest. Smaller step heights and lengths beyond the second-ary spillway have been adopted to provide a transition into the large 1.8m high steps. This arrangement will ensure that !ows over the secondary spillway do not pull away from the steps, thus providing improvement in energy dissipation over the steps.

RCC MIX DESIGN & PLACEMENT

The proposed mix design is an 85:85kg (cement:!y ash) mix, using sandstone aggregate quarried on site. With specialist advice from Dr Ernie Schrader, this mix was selected as the result of extensive labo-ratory testing during the design phase of the project. The sandstone aggregate has delivered improved performance due to its stiffness properties, despite presenting some initial challenges for the design team. Early petrographic analyses and tests on the sandstone indi-cated that it was cemented with clays, potentially of a swelling nature, providing some concerns with the long-term durability and suitabil-ity of the aggregate for RCC. Additional petrographic analyses and numerous durability tests were undertaken on cores of sandstone and RCC samples, including wet-dry cycles, soak tests in ethylene glycol, heating and cooling cycles, breakdown tests and abrasion resistance tests. Results indicated that the RCC mix performs remarkably well,

Above: Figure 5 – Surfaces A – H; Top right: Figure 6 – Surface B after additional excavation


AUSTRALASIA

with the exception that erosion testing on the samples suggested that a more erosion resistant aggregate is required for the faces of the spillways. Basalt aggregate is being locally imported for use in the conventional concrete facing to address this aspect.

The bulk of the RCC is being placed during night shift over the winter months. Mass gradient and surface gradient thermal analy-ses indicated that even without forced cooling, the use of sandstone aggregate will minimise the risk of cracking. The main contributing factor to the excellent thermal properties of the RCC is its high tensile strain capacity, which allows the mix to ‘stretch’ more than most con-cretes without cracking. The mix also has a low modulus of elasticity (~9GPa). The high tensile strain capacity and the low modulus are a direct function of the use of sandstone aggregate.

The RCC is being mixed with an Aran pug mill, capable of produc-ing 400m3 per hour. The RCC is being delivered to the dam site with 40t articulated trucks to enable it to be delivered directly down the left abutment foundation. These trucks have ejector bodies with a spreader box !tted to their rear. The specially designed tail gate sections of the ejector trucks prevent RCC segregation. The delivery from the pug mill to the dam is via a concrete lined ramp, following the secondary

spillway apron pro!le which is at a slope of 1 in 6.Two trial sections have been constructed for the project, one was

constructed with the 85kg:85kg mix and the second test pad was constructed with a 75kg:75kg mix. The !rst trial section was built to evaluate the water tightness of lift joints and to serve as a practice and training area. The second trial section was constructed to evaluate the RCC mix with less cementitious content.

At the time of writing RCC was being placed in the spillway section of the dam and progressing upward into the abutments. Figure 9 is a photo of the placement area.

INTAKE WORKS AND OUTLET WORKS

The outlet works are located on the right side of the primary spillway and comprises a wet well rectangular intake tower on the upstream face of the dam with selective withdrawal capacity, a DN 1750mm MSCL main outlet conduit that passes through the base of the dam, and outlet works valve pit at the toe of the dam. Two vertical submerged discharge valves of DN 600mm and DN 1200mm are located in the outlet works valve pit, and discharge directly into the spillway stilling basin. Butter"y guard valves are provided upstream of both discharge valves.

The outlet works and !shway are capable of making regulated releases in accordance with the water resource plan. The largest regu-lated release "ow required is 2.33m3/sec. The outlet and !shway combined has been designed to release 165ML/day with a reservoir level 2.0m above dead storage level. The outlet capacity has also been designed to allow the storage to be drawn down from full supply level to 10% of the storage over a maximum period of 100 days with median in"ows.

The 2.8m by 6.6m intake tower will ultimately be attached to the upstream face of the dam with passive anchor bars, however it has been designed to be stable as a free-standing tower during the construction phase to enable its construction to precede the RCC placement. Detaching the construction of the intake tower from the RCC placement has allowed increased "exibility in the construction program.

FISHWAY

Fish passage was required to be provided as part of the design of the Wyaralong Dam project. The design criteria, options and evalua-tion of options were developed through a series of workshops, which included all the relevant stakeholders. Due to the extensive operation range for both upstream and downstream !sh movement, and due to the fact that the !sh density is relatively low in the river, the preferred option adopted was a bi-directional !sh lift. With this design a single !sh lift is used to provide !sh movement in both the upstream and downstream directions. This design has signi!cant operational "ex-ibility. It is envisaged that the !sh hopper will be in the upstream attracting position most of the time, attracting !sh for downstream !sh movement. However, the same attraction "ow used for attract-ing !sh in this upstream position will also be attracting !sh into the trapped area for moving !sh upstream. Extensive hydraulic model-ling was undertaken to ensure appropriate attraction "ows during all of the design conditions.

Jared Deible, Senior Project Engineer, Paul C. Rizzo Associates, Inc., 500 Penn Center Boulevard, Suite 100,

Pittsburgh PA 15235 USA. [email protected]

Richard Herweynen, Principal Dam Consultant, Hydro Tasmania Consulting, 89 Cambridge Park Drive,

Cambridge, Tasmania 7170. [email protected]

Colleen Stratford, Dams Consultant, SMEC Australia, 71

Queens Road, Melbourne, VIC 3004. [email protected]

Conventionalconcrete facing

Spillway apron

0.8

1.0

Crest togallery drains

Drainagegallery

Foundationdrains

Rock surface

IWP& DC

Below, from top to bottom: Figure 7 – Spillway section; Figure 8: Hydraulic model; Figure 9: RCC in spillway section


AUSTRALASIA

BENMORE hydropower station is located in the South Island of New Zealand and is the sixth out of a chain of eight power stations on the Waitaki river. At 540MW it is the second largest hydro station in New Zealand in terms

of installed capacity and annual generation. The station provides around 2200GWh annually which is 17%

of the energy delivered from Meridian Energy’s power portfolio. Moreover, the station ensures hydrology !exibility for Aviemore and Waitaki power stations and provides essential support serv-ices for the operation of the Transpower owned HVDC link. Reduction in the station performance would not only decrease energy output, but also the ability to transfer energy to and from New Zealand’s North Island.

POWER SUPPLY

The six Francis turbines at Benmore are of an identical hydraulic design and were commissioned between 1965-6. The six genera-tors are each rated at 112.5 MVA. They are capable of running at 100MW at 0.9 pf but are limited to 90MW output due to opera-tional constraints. Currently the total 540MW, 600MVA output of Benmore is provided to Transpower’s 16kV bus which in turn can supply either or both of Pole 1 of the HVDC, or the 220kV grid via Transpower’s two 232MVA transformers (T2 and T5). The bus is

normally run split with three generators on each side to limit the fault level. This con"guration can be seen in Figure 1. Benmore is used to provide voltage support for Pole 1 of the HVDC link.

SCOPE OF DEVELOPMENT

Several of the essential operating systems at Benmore are nearing the end of their design/operating life. Signi"cant risks and opportunities were identi"ed in a series of risk management workshops during 2003. The ensuing investigations and remnant life assessments iden-ti"ed components of the generation plant to have either: Posed a signi"cant health and safety risk; Failed, in respect to no longer operating within the original design performance parameters; Reached the end of their supportable economic life, or are due to within the next few years; The potential to cause a substantial impact on revenue through reduction in plant and HVDC availability.

Technical and commercial analysis of various refurbishment options were completed to derive the optimum scope and timing of work to maximise bene"ts from the investment, and ensure an appropriate "t with Meridian’s long term corporate goals and strategies. This led to a business case being presented to the board of directors.

The refurbishment of Benmore hydropower station in New Zealand is on track for completion by January 2011. Johan Hendriks gives more details about the work taking place

The key link in the Waitaki chain

RISKS AND OPPORTUNITIESThe following risks and opportunities were identi!ed as those which are critical and will be addressed through implementation of the refurbishment project:

Risk mitigation: Mitigate the risk of catastrophic equipment failure which has the potential to cause substantial secondary damage to associated plant and pose a risk to operations and maintenance staff. Avoid plant becoming unavailable for long periods while parts are being procured or where obsolete repairs are affected. Ensure that the plant remains compliant with legislative and regula-tory requirements. Avoid stranding the assets and constraining generation due to a failure of either pole 1 or the interconnecting or converter transformers. Avoid constraining the HVDC as a result of multiple unit outages due to plant and local service failures.

Asset management: Implement changes that ensure plant performance targets can be maintained or enhanced through the replacement of ageing assets and/or recon!guration to provide segregation and diversi!cation of critical systems. Implement changes that will ensure future compatibility with Transpower’s proposed HVDC upgrades. Support the operational life of Benmore for a further 40 years. Ensure that life cycle costs are minimised through avoiding escalat-ing maintenance requirements and costs and minimising the revenue earning impact due to the reduced reliability of ageing assets.

The scope of works for this !ve-year refurbishment project is exten-sive and began in January 2006. The following are the main aspects of the project.

TURBINE RUNNERS The turbine runners in each of Benmore’s six turbines are the origi-nal runners designed and manufactured by Dominion Engineering (now part of General Electric), Ontario, Canada. To the original designer’s credit, the turbines have remained in service continuously from commissioning in 1965-6, except for planned maintenance activities.

Of the six Benmore machines, three have never been completely dismantled whilst three have undergone refurbishment in the mid 1990s. However, the runners on all six machines have required cavi-tation damage repair every three years, which has resulted in distor-tion of the runner blades.

Ef!ciency testing in 2002 compared the existing runner ef!ciency to that of the as- commissioned turbines in 1965. From the results it was evident there had been a signi!cant loss in turbine ef!ciency due, predominantly, to the distortion of the runner blades. An opportu-nity also existed to further improve station ef!ciency over and above the original design. This gain was proven following CFD analysis and model testing. The replacement of the runners will eliminate the maintenance burden associated with cavitation repairs through using available advanced design techniques.

The plots in figure 2 show the reduction in turbine efficiency between 1965 and 2002 together with a shift in the peak ef!ciency point to higher turbine loads. The shift in peak ef!ciency load has the effect of decreasing the time when the turbine is operating around its best ef!ciency. The above comparison was the basis for implementing a runner and associated turbine components replacement programme at Benmore.

Subsequent tendering for replacement turbine runners returned a large range of turbine enhancement options ranging from replacing the turbine runners only, through to replacing the runners and wicket gates together with modifying the stay vane pro!les and turbine "ow passage shape. All of the above options had an increased cost together with an increase in turbine ef!ciency, but following extensive evalua-tion of the bid options from various turbine manufacturers, a replace-

ment runner and wicket gate option supplied by Toshiba was deemed to give the best return to Meridian.

16 KV GENERATOR CIRCUIT BREAKERS

The 16kV circuit breakers provide a critical protection function, but are nearing the end of their life (normal life expectance of a circuit breaker is 35 years according to international statistics). Forced out-ages are becoming more frequent and severe and present a signi!cant risk to plant, personnel and the station availability.


AUSTRALASIA

VG4

G690MW

G590MW

G490MW

G390MW

G290MW

G190MW

16kVBus B

16kVBus A

VG3

T5232MVA

T2232MVA

VG2 VG1

T6 T4

9 8 7

T3 T1

220kV

Pole 2

500MW

Top: Figure 1 – Existing grid injection configuration at Benmore power station; Middle: Figure 2 – Existing runner efficiency curves; Bottom: Figure 3 – Proposed configuration for Benmore

Generation durations1966 base efficiency curve2002 base efficiency curve

100908070605040302010

0

Effic

ienc

y (%

)

40 50 60 70Runner output (MW)

80 90 100

Position ofmaximum efficiencies

Newoverhead220kVcircuit

461 (relocated)

465

462 482

483

521523

Bus A

Transpower 220kV AC switchyard220kV

220kV

220kV

220kV overheadcircuits225 MVA 3winding trfs

16kV newcompact IPB16kV GCB’s16kV existing IPBGenerators

Bus B

Bus C

485

522

T46 T44T5

CB6 CB5 4 3 2 1

T42T2

G3G4G5G6 G2 G1

BENRP:Completed

BENFCP (Final configuration project):Stage 1 Stage 2 Stage 3


AUSTRALASIA

The 16kV circuit breakers, designated CB1 to CB6, connecting the generators to the main bus are Brown Boveri model DB 20RC 1500/1 single phase air breaker type. They have a 5000A load rating with a fault rating of 2500MVA. They are originally-installed equipment and although routine maintenance is conducted they have not been refurbished or upgraded since commissioning.

Based on analysis of historical forced outage data and discussion with maintenance staff it was estimated that the circuit breakers would reach the end of their operational life by 2009. The acqui-sition of spare parts is dif!cult and lengthy – a breaker failure in February 2003 caused a six-week forced outage which resulted in a six-fold increase in annual forced outage factors and 5% reduction in annual availability for that year. The types of faults occurring are increasingly due to age deterioration of components. Spare parts are very expensive to obtain and it is dif!cult to determine what parts to hold as the age-related failures are hard to predict.

Efforts have been made to limit the number of circuit breaker operations in recent years in an attempt to reduce degradation by encouraging operators to run the units on tail water depressed mode when not required, rather than stop the units. This is not an adequate long-term solution as running the units in this mode is not an ef!cient way to use water. To maintain adequate service in the short term, it is critical to address the issue of spare parts availability as soon as possible.

The circuit breakers will be replaced with ABB HEC-80S SF6 cir-cuit breakers, 8500A rated continuous current, 80 kA rated short circuit breaking current.

EXCITATION AND AUTOMATIC VOLTAGE REGULATION The excitation system suffers from age related faults and requires an increasing maintenance effort. The equipment is based on 1950s technology that is no longer supported and future failures will result in protracted unit outages due to the reduced availability of spare parts and maintenance expertise. The market driven increas-ing number of stop/starts will also further escalate the rate of deterioration.

Maintaining power quality and compliance with Electricity Governance Rules have become increasingly dif!cult and opportu-nities exist for improving voltage support performance and reduc-ing synchronising time with modern equipment. The excitation upgrade will increase the asset life and maintain operational ef!cien-cy and availability by reducing the risk of failure of obsolete ageing equipment.

This project will replace the electromechanical AVR with digital controlled types and replace the existing motor driven Amplidynes with controlled bridge recti!ers. The exciter !eld supply will be from new unit excitation transformers. The existing generator slip rings and brush gear will be retained and DC interrupting devices will be installed. Grid power system stabilisers will also be installed.

The excitation project will: Extend the life of the excitation and AVR by 25 years. Reduce the risk of failure of the aging excitation and AVR system. Improve spares availability. Reduce the maintenance requirement on the system by 50%. Not impact the current generator capability with respect to achiev-ing 100 MW output, or the ability to interface to existing voltage control signals.

The excitation components are supplied by Basler Electric from France and installed by Trans!eld Services New Zealand. The new excitation systems are commissioned concurrently with the commis-sioning of the new turbine runners.

MECHANICAL REFURBISHMENT

In the late 1990s units 2, 3 and 6 underwent a mechanical refurbish-ment to address the deteriorated state of critical items of plant. The remaining three units now require refurbishment to maintain target levels of station availability and minimise lifecycle O&M costs.

This work includes all systems associated with each hydro unit (eg governors, stator coolers, bearings, brakes, rotors, etc), but excludes the stators. The stators will have at least ten years remaining life left and where appropriate will undo selected re-wedgings of the windings.

3.3KV AND 415V LOCAL SERVICE SUPPLIES

The lack of diversity and segregation of the essential supplies presents a signi!cant risk of multiple unit or even whole station forced outages, particularly as the component parts are reaching the end of their operational life. There was also a requirement to maintain the equipment in a live state, which does not align with safe working practice and presented a health and safety risk that could result in a fatality.

The existing con!guration relies on the interconnecting trans-formers (T2 and T5) and the HVDC Pole 1 to be available to avoid constraining the Benmore power station. The existing Pole 1 will be decommissioned by 2012 and replaced with a static converter pole supplied from the 220 kV grid. This has forced Meridian to recon!g-ure the grid injection point.

The existing interconnecting transformers and their associated 16 kV circuit breakers are at the end of their life and have a high likelihood of failure. So as part of the recon!guration, Meridian is replacing the interconnecting transformers and adding extra trans-former capacity.

This project will install three new 225MVA winding transformers through which the generators G1 to G6 will connect directly to the 220kV grid by means of a strung bus. The proposed con!guration is shown in Figure 3. The two low voltage windings in each trans-former are loosely coupled to reduce fault levels. This allows for more economical generator circuit breakers to be used.

All 16 kV connections are made by isolated phase bus duct. This pro-vides a fully phase segregated con!guration, a high reliability and low maintenance. The bus duct will be supplied by Alfa Standard in Italy.

PROJECT PROGRESS

The project is well underway with four of the six units refurbished. The excitation and local services upgrade have been completed, one new 225 MVA transformer installed and supply contracts for isolated phase bus duct and circuit breakers awarded.

Once complete, Benmore will provide a reliable generation capacity of 540MW at an increased ef!ciency. It will continue supporting the HVDC link to New Zealand’s North Island.

The author is Johan Hendriks, Strategic Electrical Engineer with Meridian Energy Ltd. New Zealand.

Email: [email protected]

This article is based on two papers originally presented at the EEA conference in New Zealand. The conference technical papers are available from Electricity Engineers’

Association, New Zealand www.eea.co.nz

IWP& DC

The Waitaki systemName Commissioned Generation

(GWh/yr)Output (MW)

Net head (m)

Tekapo A 1951 160 25.5 30.5

Tekapo B 1977 833 160 145.7

Ohau A 1979 1140 264 59

Ohau B&C 1984/5 958 212 47.5

Benmore 1965 2215 540 92

Avlemore 1968 942 220 37

Waitaki 1935-54 496 105 21.5

* Facts are the same for each station Ohau B&C

www.neimagazine.com August 2010

Reactor pressure vesselsCondition monitoringComprehensive VVER dosimetry review page 13Borssele RPV embrittlement tests support PLEX plan page 20

AnalysisLoad factor league tables: 2010 quarter 1 page 28ASME N-stamp holder breakdown page 36

WWW.MODERNPOWERSYSTEMS.COM AUGUST 2010

Solar thermalProfile of Ivanpah –400 MW of CSP The problem of storage –is salt a solution?

BiomassDrax wants more biomass and biggerincentives RWE looks at the powerof pelletisationFuel from algae shows its green credentials

Offshore windHVDC platform for NorthSea clusters

O&M and upgradeEmissions reduction,maintenance, and I&Cupgrade

ReciprocatingenginesMobil starts a revolution in oilThe World Cup –Aggreko wins again

T&DENTSO-E aims atEuropean harmony

COMMUNICATING POWER TECHNOLOGY WORLDWIDE

ModernPowerSystems

Reflections on the world’s largest CSP plant

EXPPERTS2010

AUGUST 2010

Serving the hydro industry for over 60 years

Earthquakes and dam safety

The rise in multi-purpose projects

Restoration schemeReplacing post-tensioned anchors at Catagunya Dam


& DAM CONSTRUCTIONWWW.WATERPOWERMAGAZINE.COM

Water Power

Subscribe Nowto one of our Power magazines

Individual focus,combined powerThe Power GroupA subscription to one of the above titles will deliver

A full colour magazine every monthRegular industry e-mail newsletterFull access to online archives

Subscribe online at:www.waterpowermagazine.comwww.modernpowersystems.comwww.neimagazine.comor call our subscriptions hotline on:+44 845 155 1845email: [email protected]

Global Trade MediaProgressive House 2 Maidstone Road Foots Cray Sidcup Kent DA14 5HZ, UK

subs_hp 18/8/10 11:45 Page 1


AUSTRALASIA

CATAGUNYA Dam is located on the Derwent River in the southeast of Tasmania, Australia. It is the third in a cascade of six dams forming the lower Derwent power develop-ment. Designed in the late 1950s and completed in 1962,

Catagunya is a 49m high concrete gravity dam which relies on a large number of 200 ton capacity post-tensioned steel cables to provide the necessary structural stability against the stored water load. Its design was considered leading edge, being the highest post-tensioned dam in the world at the time of its construction, and the designers adopted a 50-year design life for the anchors. It was estimated that the use of post tensioning provided a saving in the order of 20% compared with a conventional gravity dam.

During construction of the dam in the early 1960s, 412 post-tensioned anchors were installed but the integrity of the original anchors can no longer be assured. The stability of the dam has been restored over the past two years using 92 modern, large diameter and corrosion protected, post-tensioned anchors that can be monitored for deterioration. These are the most highly stressed anchors applied to a dam at this time.

CONSTRUCTION CHALLENGES AND SOLUTIONS

A number of challenges were addressed during implementation, including: Installing more than half the anchors within an operating spillway, utilising a limited construction window over the summer months.

Providing access for drilling equipment and installation of the anchors well below the spillway crest on a 54˚ degree slope, 25m above the riverbed, and demobilising these platforms suf!ciently to allow "oods to pass during the winter months. Replacing severed surface reinforcement with 9m long carbon !bre rods.

In order to gain access to the spillway of Catagunya dam for instal-lation of the temporary access platform brackets on the spillway and the carbon !bre tensile reinforcing on the spillway face, a purpose designed and built travelling gantry was suspended from the spillway crest. This gantry had !ve working deck levels, with four of these providing access to the full length of the 9m long carbon !bre rods which were to be installed.

Two 200m long temporary platforms were constructed to access the spillway. The upper platform was designed to provide access for the drilling, installation, and stressing equipment, as well as to pro-vide safe and ef!cient egress in times of "ood. The lower platform was used to give direct access to the anchor hole locations for instal-lation of anchorage assemblies.

With the unique cross-section of Catagunya dam, tensile steel rein-forcing is required on the top surface of the downstream face of the spillway to support the large cantilevers overhanging the spillway. This steel was to be severed as the large diameter holes for the spillway head-blocks were cored, so a replacement was required prior to the coring.

Ageing post-tensioned anchors have been replaced at Hydro Tasmania’s Catagunya Dam in Australia.

Catagunya Dam restoration


AUSTRALASIA

A major innovation of the project was the design and installation of carbon !bre reinforcing into the spillway face to provide tensile reinforcing for the cantilever section of the dam. Used widely in the bridge industry as a method to upgrade and restore structures, epoxy bonded carbon !bre strips are a very cost effective and simple solution. However, to date, these have not been used for a similar application in the dams industry.

The 9m long carbon !bre rods were installed in the face of the spill-way by wall sawing a 9m long, 15mm wide, and 90mm deep slot in the concrete. Each of the six 8mm diameter rods were installed indi-vidually, guided into place on a bed of epoxy adhesive injected into the slot and bonded to the concrete. The overall solution took around four months to complete, installing over 10km of carbon !bre rod.

A requirement of the design of Catagunya dam was to maintain the hydraulic performance of the ogee crest spillway. This meant anchors installed within the spillway were required to be constructed within the current pro!le. Coring of 1.2m diameter holes into the slope, 3m into the dam was undertaken to install the precast reinforced concrete headblocks to distribute loads into the structure. Abutment anchors were installed onto a specially designed concrete beam, located above the level of the parapet walls.

The drilling was undertaken using a 350mm downhole hammer (DHH) from a Rotomech drilling rig. The longest drill hole was circa 78m through the concrete and into the dam foundation, and in total 6.2km was drilled throughout the project.

The modern post-tensioned anchors were all fabricated on site using specialist equipment to open and grease the cable, and then install into a 20mm HDPE sleeve over the free length. The bond length is cleaned back and left bare, with all 91 lengths of cable twisted into an hour glass shape to increase the bond with the dolerite rock in the area.

The complete anchor is installed into a part corrugated, part smooth polyethylene sheath within the anchor hole, and grouted into the hole using Class G Oilwell and GP cement. Once the grout reaches its strength, a purpose built 2200 tonne capacity hydraulic jack is used to load the anchor to over 70% of its minimum breaking load, making these anchors the highest stressed ground anchors in the world.

LONG TERM MAINTENANCE The newly installed post tensioned anchors will be monitored !ve-yearly by Hydro Tasmania, with the !rst of these checks to be under-taken between November 2010 and March 2011. To undertake these tests, the travelling gantry has been modi!ed to carry all load moni-toring equipment.

The tests for the !rst four anchors installed on the spillway have already been completed and found the anchors in excellent condi-tion. The lift off tests performed on these anchors has found only a very small loss in load over the past year, well within a tolerable margin and below what has been observed in other anchoring jobs of this size.

Gantry on the dam face

Catagunya Dam on spill at 370m3/sec on 27 Jul 2010

Installing cables on block P, right abutment

IWP& DC


MULTIPUPOSE PROJECTS

A MULTIPLICITY of water needs can be served by hydro and multipurpose projects, and in the near- to medium-term there is going to be relatively greater demand to employ them as an adaptation strategy to the anticipated

increase in weather instability, as projected from the effects of cli-mate change, notes The World Bank Group in its Directions in Hydropower report, which was published last year.

The World Bank says it ‘is keenly aware of this timely and impor-tant period for hydropower’ though adds that this particular use of water resources will be only part of the picture in future. It says that given the increasing importance of climate change, water security, and regional cooperation, the bank has consequentially a wider view that ‘encompasses water infrastructure that serves multiple objectives, among which energy may be a subsidiary goal’.

The Directions report adds, ‘As part of a !exible, well-planned water resources infrastructure, hydropower can help countries manage !oods and droughts and improve water resources alloca-tions across a complex set of users’.

It goes on, ‘Multipurpose hydropower can also support adaptation to increasingly dif"cult hydrology by strengthening a country’s ability to regulate and store water and so resist !ood and drought shocks.’

But before facing any climate change impact on hydrology, some countries are already experiencing great water-stress, prime among them

being Ethiopia, Haiti and Niger, the World Bank said in March, when releasing an internal review of support given to water-related activities over 1997-2007. Almost a third of all projects worldwide approved by the World Bank for funding since 1997 have been water-related.

In every country, from the most water-stressed to those far less strained – possibly even with an abundance of hydrological resources, there is far more attention demanded, and being given now, to a wider range of planning factors, including strategies being developed around river basins, large and small. One such major planning initia-tive is underway for the river Nile – the world’s longest – and its many regional, national and local sub-catchments.

THE NILE & ETHIOPIA

Africa holds immense untapped water resource and hydropower potential, and yet in the north it also has some of the most water-stressed regions anywhere. Also in the north is the Nile, one of the world’s longest rivers, and in the Horn of Africa is Ethiopia which, despite facing signi"cant water-stress, ranks as one of the countries on the continent with most hydropower potential, notes its Ministry of Water Resources (MoWR).

The Nile Basin Initiative (NBI) was established just over a decade ago and is one of the largest river basin strategies in the world. The

Hydro and multipurpose projects are being sought more due to climate concerns and are vital in regions of high water stress, such as Ethiopia. Report by Patrick Reynolds

Multiple benefits

The EPB-DSU TBM used on the Beles II Headrace tunnel


MUTIPURPOSE PROJECTS

Nile’s extensive catchment area extends over parts of many countries in northeast Africa. Draining through Egypt to the Mediterranean Sea, south of Sudan the river is fed by two branches – the White Nile, which arises in east central Africa, and the Blue Nile, which rises near Lake Tana in the highlands of Ethiopia.

With so many competing visions and needs for the water resources, and the cross-border nature of the !ows, it is vital to have co-opera-tion. Like so many river basins elsewhere, the need for effective part-nerships and co-operation will become increasingly important when countries and people become presented with weather instability and other foreseen impacts from predicted climate change.

NBI provides a mechanism for the shared visions, and needs, to have the Nile basin developed to deliver multiple and widespread bene"ts. Having formally launched the Initiative in 1999, the partici-pating countries held their 18th Council of Ministers meeting in late June this year, in Addis Ababa, Ethiopia. The Council leads the NBI to help deliver the socio-economic bene"ts that are commonly, and separately, sought while helping to promote peace and security in the region where water is relatively scarce.

The development efforts on the White Nile and Blue Nile are handled under two units within NBI – the Nile Equatorial Lakes Subsidiary Action Programme (SAP) and the Eastern Nile Subsidiary Action Programme (ENSAP), respectively.

Ethiopia has 12 basins – eight river basins, one lakes basin and three that are, in effect, dry as they have insigni"cant !ows, if any, says MoWR. Under NBI, developments in water-stressed Ethiopia fall within the function and partnership discussions enabled by ENSAP.

There have been a range of water projects developed over many years, both prior to and since NBI was established. A number of countries and foreign "rms have worked on plans and schemes, and over the last couple of years the Norwegian Water Resources and Energy Directorate (NVE) has been measuring sediments and hydrology to support reservoir development on the Blue Nile, which is known as Abay in Ethiopia.

Presently, there are a series of hydro, multipurpose and various other water schemes either in studies, construction or operations, and these include the multipurpose Mandaya and Beko Abo projects, the Genale-Dawa basin development, the Gilgel Gibe III addition to the Gibe cascade scheme, and the Beles Multipurpose (Beles II) project.

MANDAYA & BEKO ABO

The Mandaya and Beko Abo projects are being studied as potential major developments, some 300km apart, on the Blue Nile in west/central Ethiopia. While they are being examined together and would be neighbours in the river basin, and operationally they would in!u-ence each other, the projects would be developed separately.

The study into the projects is being undertaken by a consortium of companies comprising consultants Norplan/Multiconsult, Norconsult and Scott Wilson with energy utility Electricte de France (EdF). They are being supported by local "rms Shebelle Consult and Tropics. The work is to be completed by mid-2012.

In the study, a full technical and economic assessment of the 2GW Mandaya project is being undertaken. The surface plant is envisaged to generate 12.100GWh per year. Planning for the 2.1GW Beko Abo scheme is proceeding with, "rst, a techno-economic pre-feasi-bility study. The Beko Abo underground plant would generate about 12,600GWh annually.

Both projects are anticipated to have large RCC dams, and at the Mandaya site the structure would impound a reservoir extending 300km upstream to the location of Beko Abo. The reservoir behind the Beko Abo dam would be about half the length, at approximately 150km long.

Mandaya was examined at the pre-feasibility stage by a joint ven-ture of Scott Wilson and EdF, and they completed the work almost three years ago. Around the same time a separate JV of Norplan/Multiconsult, Norconsult and Lahmeyer "nished reconnaissance-level studies for Beko Abo.

The RCC dams to be built at Mandaya and Beko Abo have been estimated will be 200m and 285m high, respectively. At Mandaya,

the structure will have a crest length of approximately 1400m and a volume of 13Mm3, and at Beko Abo the comparable "gures are 880m and 10.5Mm3.

Bids are being sought by 31 August to undertake the geotechnical site investigation works for the studies underway for each project.

The Beko-Abo and Mandaya plans are complementary to the NVE’s technical support to MoWR for the Blue Nile measure-ment studies, which are part of the Joint Multipurpose Programme Identi"cation Phase 1 (JMP1 ID) that is to develop an optimum cas-cade scenario.

GENALE-DAWA

Planning for development of the water resource of the Genale-Dawa river basin comprises studies for six potential projects ranging from irrigation (Lower Genale, Welmel), water supply (Negele Yabelo) and multipurpose hydropower (GD-3) to an integrated watershed man-agement project (Bonora).

The studies are being advanced by MoWR, and planning has been underway over much of the last decade. The bulk of funding for the early studies was provided by the African Development Bank (AfDB), and the work was mostly carried out by consultant Lahmeyer with local "rm Yeshi-Ber Consult. A separate task, to accelerate planning for the 357MW GD-3 project, was performed by consultant Ardico-Rodio through government resources.

In addition, Norwegian consultants Norplan and Norconsult undertook a feasibility study for the GD-6 multipurpose hydropower project, which is estimated to have an installed capacity of approxi-mately 257MW in a surface powerhouse, an 18km long headrace tunnel and require a 39m high RCC dam. It is expected to generate 1230GWh of electricity annually.

AfDB notes that there have been expressions of interest from poten-tial investors from Turkey, Japan and China for both the GD-3 and GD-6 projects and that they are ready for investment. It further notes that the Ethiopian government, in addition to fast-tracking the hydro projects, is pushing for rapid development of the Welmel irrigation and Negele water supply schemes, although it is the Lower Genale project that is furthest in the requirement for immediate investment.

The Genale-Dawa basin is estimated to have economically exploita-ble hydropower energy potential of 15.7TWh annually, says MoWR.

GIBE CASCADE, BELES

The largest hydropower project under construction in Ethiopia is Gilgel Gibe III, the latest – though it won’t be the biggest – addition to the cascade development on the Omo-Gibe basin, which is one of the signi"cant water resources in the country. There are four Gibe projects in the cascade and they constitute one of the country’s most attractive hydro developments, says EEPCo.

Gilgel Gibe III will have a surface plant with an installed capacity of 1870MW and housing 10 Francis turbines, which are to generate about 6400GWh of electricity annually from the reservoir that is be impounded by a RCC dam (231m high, 580m long). The average net head is 186m, the design !ow is 950m3/sec and the plant load factor is 0.46. Extensive studies were undertaken to examine the environ-mental impact of the scheme and potential mitigation measures.

The dam and powerhouse are being built approximately 155km downstream of the Gilgel Gibe II plant, which has an installed capac-ity of 420MW and recently became operational, although there’s a short-term outage to clear and repair a rockfall blockage in the head-race tunnel. It is to generate 1635GWh per year.

Gilgel Gibe I was smaller again, but still a large development, at 184MW and generating 722GWh per year.

Planning is continuing for the Gilgel Gibe IV project, which will be the farthest downstream in the cascade. It is estimated the plant will have an installed capacity of 2GW and generate 8000GWh annually.

Also under recent development is Beles, which involved signi"cant tunnelling works, like Gilgel Gibe II. The plant capacity is 460MW and it will tap the waters of Lake Tana, and so be one of the furthest upstream of hydro plants along the Nile. IWP& DC


GATES

THIS project details the design and development of a port-able milling machine and the innovative process that will be used by the Army Corps of Engineers (USACE) to machine, drill and tap the four quoin blocks that are

positioned between the Markland lock walls and doors. By using the portable milling to machine the quoins in situ, USACE will signi!cantly shorten the machining time and reduce the overall costs of future repairs, making it possible to replace lock quoins more ef!ciently. This method of machining represents a paradigm shift in the way quoins are repaired or replaced, but promises to

be a best practice for changing worn and corroded parts on other locks on waterways.

PROJECT BACKGROUND

The Markland locks and dam are vital to the Ohio River navigation system in the US. Over the past !ve years, it passed an average of 55M tons of commodities annually. The project is located 5.6km down-stream of Warsaw, Kentucky. USACE operates and maintains the locks on this inland waterway out of its Louisville, Kentucky District of!ce.

Lawrence E Rentz and Karl Williams from Climax Portable Machine Tools report on the design of the portable milling machine that will be used at the Markland locks and dam in the US

On-site machining at Markland

Climax tests the linear mill on a mock-up of the lock gate


GATES

The main lock chamber has clear dimensions of 33.53m x 365.76m and the auxiliary lock 33.53m x 182.88m. Each lock has two doors – an upstream and downstream pair – which are 19.81m x 2.13m, each with two quoin blocks. In both cases the doors close against a slightly concave surface and seal up to prevent excess water from entering the locks. The pivot point in the door is slightly back and has support arms on the top and a pintle hemisphere at the bottom.

The Markland locks are more than 50 years old and because its doors’ quoin blocks are made of carbon steel material, they experi-ence corrosion. This corrosion causes the door seals to close improp-erly resulting in a substantial amount of water leakage. As a stop-gap, USACE has traditionally repaired corroded quoin blocks by putting epoxy materials on the face of the blocks to build them back up so they meet the door again. Alternatively if these blocks were to be replaced, the Army Corps would cut out a very large piece of the concrete and remove that material, weld in new quoin blocks and then re-cast around the blocks with concrete, similar to original construction.

Because the old process could take months, USACE sought a better way to repair and replace the quoins and issued a request for pro-posals. Its !rst criteria was for the best technical and more ef!cient method for machining the carbon steel quoin blocks so that they could easily be unbolted and replaced with stainless steel ones that resist corrosion and last longer. Secondly, any new machining method had to enable USACE machinists to do the work in the shortest amount of time, eliminating the need for a long term shutdown.

A PARADIGM SHIFT

Out of all the responses, USACE found in Climax’s proposal a para-digm shift to the current method used to repair quoins. Climax pro-posed to design and manufacture a portable, custom-made vertical milling machine that would enable USACE’s machinist’s to machine the quoins in situ. The machine would be delivered and set up at the Markland locks, then be attached to the lock wall. It would be capable of travelling up to 21.34m in height in a single pass, removing up to 63.5mm of metal material over multiple passes. The machine would also drill and tap the quoin blocks. Using this method, the entire job could be completed within a 17-day period.

In situ machining has been used successfully throughout the power industry and for infrastructure maintenance and repair when critical pieces of heavy equipment are too large or impractical to disassemble and ship offsite to a machine shop. Climax engineers were con!dent they could build a custom milling machine precise and powerful enough to do the work in the time allotted. They provided proof of similar suc-cessful in-situ machining projects such as line-boring the bushings on the wicket gates at the Hoover dam, then demonstrated how a similar machine operated, and was ultimately awarded the job.

At the Markland locks there are two different styles of quoin blocks – an extended design and an embedded design. The extended blocks are 203.2mm wide and protrude 76.2mm from the lock wall. The milling machine will remove metal 63.5mm x 203.2mm. It will also drill and tap holes as speci!ed by USACE so the machinist can bolt the replacement pieces on.

The second style is a 254mm wide embedded block design that protrudes about 12.7mm from the wall. The milling machine will put a pocket into this area – cutting a 203.2mm x 63.5mm deep slot in the existing quoin block. Drilling and tapping will also be done so the replacement quoin blocks can be bolted into the lock walls.

The portable linear mill was speci!cally designed to work on both embedded and extended quoin blocks.

DESIGNING THE PORTABLE LINEAR MILL

Climax collaborated with USACE throughout the linear mill’s design process, conducting both a 30% design review and then another when the machine’s design plans were completed. In addition, alternative control and alignment systems were discussed and selected. There were some technical risks associated with being able to move the machine "at across sections of beds that had interlocking devices. These too

were discussed to ensure that the !nal product !t the project’s needs.The portable milling machine developed for USACE was modular

for easy transportation and assembly at the job site. It consisted of six 4m long sections that connect end-to-end. The milling machine consisted of two separate sleds – a utility sled that houses the electrical and power components, and a machining sled. These sleds would be attached to each other. Dual rack and pinion drives using the NEXEN roller-pinion system were proposed to drive the machine vertically up and down the entire length of the lock doors. Servo-mechanisms were used for position control and to eliminate machining errors.

Its heavy duty beds are extremely rigid to provide precision mill-ing within a +/- 7.6mm tolerance. A robust spindle design provides the power to utilize 203.2mm diameter cutter heads. Its user-friendly wireless controls included a wireless antenna that communicates to the device and a touch screen interface that is used to manage the entire machine’s programmed functions. The system operates for up to six hours, and a battery charger was also provided.

TESTING AND TRAINING

Before the portable milling machine could be delivered USACE required a factory acceptance test during which Climax had to dem-onstrate all the capabilities of the portable milling machine and its ability to meet all the functional requirements of the job. An extensive functional test requirement procedure was conducted by Climax at its facility. This procedure included a mock-up of the lock wall, test blocks and surrogate quoins that were machined to demonstrate how the portable mill would operate in the !eld.

During this time, USACE requested some changes to the machine such as revising the drilling and tapping head from a horizontal to a vertical orientation for better reach. These changes were easily made and the milling machine was retested and passed the stringent acceptance test.

At the same time, seven members of USACE’s team were also trained by Climax on how to set-up and safely operate the machine since they would be doing the actual work.

COMPLETING THE REPAIR All the components of the portable milling machine were delivered in June 2010. The machining is scheduled to take place in 2011.

USACE’s machinists will take about 7-8 days to set-up the machine, three days to do the actual machining, and 4-5 days to dismantle the equipment. To install the machine, USACE machinists will set down the !rst bed section on the concrete "oor of the lock then drill and mount it to a concrete wall adjacent to the quoin blocks.

A laser system supplied with the machine will be used to indicate if and where the machine is out of alignment, and then a series of individual jacking screws will be used to adjust the mill to within a tolerance of 0.5mm to ensure that the beds are straight and "at. Once the !rst section of the mill is levelled up, other sections will be added and aligned until the machine is ready to operate. The operator will use the wireless controls to drive the milling machine vertically up and down, enabling them to hold a very tight +/-7.6mm overall machining tolerance over the entire 619.81m length of the door.

EFFICIENT AND COST-EFFECTIVE

The expected outcome of the repair is that USACE will have the ability to repair or replace the quoin blocks more ef!ciently and cost-effectively by just unbolting and replacing the blocks whenever wear and corrosion necessitate a change-out. In addition, replacing the carbon steel blocks with stainless steel ones that are more corrosion resistant will greatly extend the mean time between repairs and replacement.

The authors are Lawrence E Rentz, Vice President of Engineering/Quality and Karl Williams, Senior Design

Engineer at Climax Portable Machine Tools. More information can be found at www.cpmt.com

or via email at [email protected]

IWP& DC


NEW HYDRO DEVELOPMENTS

SUDAN is blessed with the largest supply of fresh water in the eastern Africa region. However, with an annual growth rate of 2.8%, it is also considered to be one of the least developed countries. At the backbone of the Sudanese econ-

omy is its agricultural sector which determines to a great extent economic performance.

Seventy percent of the country’s 40M population live in rural areas with electricity only providing a small percentage of energy needs. The main energy sources are wood fuel and petroleum. Hydropower supplies about 50% of electricity.

Like many tropical countries, Sudan has ample water resources that can be ef!ciently exploited in a manner that is both pro!table and sustainable. Small hydropower offers cost-effective and environ-mentally friendly energy solutions for Sudan, with the added bene!t of providing sustainable livelihoods in rural areas. The use of hydro energy resources could play an important role in this context. It rep-resents an excellent opportunity to offer a higher standard of living to the local people and will save local and regional resources.

WATER AND POWER RESOURCES

Annual average rainfall in Sudan ranges from about 1mm in the northern desert to about 1600mm in the equatorial region. The total annual rainfall is estimated at 1093.2 x 109 m3. The Ministry of Irrigation and Water Resources (MIWR) is in charge of water resources and total water storage available at all dams is 18km3.

Sudan’s installed capacity on the grid is 640MW, of which about 520MW is available. The country has a generation and transmis-sion programme, according to which total capacity will increase to 3383MW in 2016.

Some of the major hydro plants in operation are: Roseires (280MW)

and Sennar (15MW), both on the Blue Nile, Rumela (20MW) and Khashm El Girba (13MW), on the Atbara River. However, in May 2010, Sudanese President, Omer Al-Bashir, inaugurated a !fth project. The Merowe hydropower station had swung into operation earlier in the year after completion of the tenth Francis unit, and the addition of 1250MW of capacity to the national electricity network.

The scheme has been described by Sudanese of!cials as a great accomplishment and good evidence of genuine development in the country. The generation of 600GWh of electricity annually will boost different agricultural, industrial and services sectors in the country. It will also help to enhance living conditions and bolster the develop-ment process in Sudan, especially in the northern states.

Up to 2000MW of hydropower capacity could also be developed in

The development of hydropower resources in Sudan will help meet increasing energy demands. New hydro plants, both large and small, will play their role along with untapped power potential at existing structures

Sudanese development

Hydropower for existing damsRaising Roseires Dam

The Roseires Dam is located on the Blue Nile about 500km southeast of the Sudanese capital of Khartoum. The 280MW hydroelectric plant supplies nearly half of Sudan’s power output, and also provides irrigation water for the Gezira Plain.

The Nile rises dramatically in the !ood season between July and September when the dam’s "ve massive sluice gates are opened, allowing silt to !ow down the Nile and to avoid siltation of the reservoir. Since the dam’s completion in the mid-1960s the steel lining of the gates has become corroded. To date repair work has been undertaken at the three of the dam’s "ve gates.

As of June 2010 work was progressing rapidly on a project to raise the height of Roseires dam. The project has been undertaken to increase the dam height by 10m and storage capacity from 3Bm3 to 7.3Bm3. This is set to double power capacity at the project. In addition it will also double generation at the 15MW Sennar dam on the Blue Nile, as well as increase the power potential at the 1250MW Merowe hydro station.

Concrete works at the project for Roseires Dam are reported to be 34% complete and the daily land"ll rate has increased to more than 40,000m3. Good project progress is important as a number of engineering works have to be implemented before the rainy season starts; as the accompanying increase in humidity will subsequently stop the work. The project is set for completion by mid 2013.

Hydromatrix solutions

Jebel Aulia dam is southwest of Khartoum. Built in 1937 its original purpose was for irrigation. However the dam has since been equipped with Hydromatrix turbines to utilise power potential at the existing structure.

VA Tech Hydro (now Andritz Hydro) was awarded a contract in December 2000 to equip the dam with 40 Hydromatrix modules. Each of these has two turbine generating units which were installed in front of the existing discharge openings on the dam. The project was divided into lots. The "rst was commissioned in 2002 with the project becoming fully operational in 2005.

The Jebel Aulia is now a 30.4MW hydropower project which generates 116GWh annually, producing US$80M of income a year for the Sudanese economy.

Jebel Aulia dam area

Site of Merowe dam

Merowe community


the future. There is also great potential (about 3000MW) for increas-ing capacity at existing hydropower sites (See shaded panel).

SMALL HYDRO POTENTIAL

The small hydro potential in Sudan is promising. A number of prospective areas have been identi!ed by surveys, and studies are being carried out to explore mini hydro resources. Mini and micro hydro can be developed by using waterfalls with heads ranging from 1-100m. In addition, the current "ow of the Nile water could be used to run in-stream turbines; water could then be pumped to riverside farms. There are more than 200 suitable sites for the use of in-stream turbines along the Blue Nile and the main Nile. The total potential of mini hydro can be considered to be 67GWh/yr for the southern region, with 3785MWh/yr in the Jebel Marra, and 44895MWh/yr in El Gezira and El Managil canals.

In the past, Sudan was badly affected by rapidly rising fuel costs, although the country is now in a position to export oil. The country intends to implement new hydro projects to meet increasing demand

and to avoid power shortages. Small-scale, decentralised hydropower can provide valuable reserve power and potentially make major con-tributions to local energy needs, especially the southern region along the White Nile from Malakal to the border with Uganda.

Article by Abdeen Mustafa Omer, Researcher, Energy Research Institute (ERI), University Of Nottingham, UK,

Email: [email protected]

Merowe dam

IWP& DC

ReferencesOmer, A.M. (2000). Water and environment in Sudan: the challenges of the new millennium. NETWAS 7(2): 1-3

Omer, A.M. (2008). Water resources in the Sudan. Water International 32 (5): 894-903.

Omer, A.M. (1995). Water resources in Sudan. NETWAS 2(7).

Noureddine, R.M. (1997). Conservation planning and management of limited water resources in arid and semi-arid areas. In: Proceedings of the 9th Session of the Regional Commission on Land and Water Use in the Near East. Rabat: Morocco.

James, W. (1994). Managing water as economic resources. Overseas Development Institute (ODI). UK.

Overseas Development Administration (ODA). (1987). Sudan profile of agricultural potential. Surrey. UK.

Omer, A.M. (2009). Dams, hydropower potential, future prospects and sustainable water resources management in Sudan, The International Journal on Hydropower and Dams, p.95-96, Surrey, United Kingdom, December 2009.

New issue ofDAM ENGINEERINGThe latest issue of Dam Engineering is on its way to subscribers. This issue contains the following papers:

Dam Engineering is an academic journal, published quarterly by International Water Power & Dam Construction. It contains refereed papers on subjects related to all areas of dams and hydro power. At present there is no restriction on the length of submitted papers.

VOLUME XXI ISSUE 1

DAM ENGINEERING

VOLUME XXI

ISSUE 1

DEngFC_BLACK_0810:fc 13/8/10 17:23 Page 1



THE Yukon River is 3700km long, draining a watershed with an area of 832,700km! (Figure 1). It is the fourth largest river system in North America, and a signi"cant contributor to the Bering Sea ecosystem. Spanning the

east-west length of the US state of Alaska and much of Canada’s Yukon Territory, the Yukon River supports the longest inland run of Paci"c salmon in the world, with over 70 different indig-enous Tribes and First Nations dependent on the "sh and other natural resources.

The majority of the river’s length, and over 60% of the water-shed drainage (508,900km!), is in the US state of Alaska, with the rest (321,800km!) in Canada’s Yukon Territory and a small part of the headwaters located in British Columbia. By compari-son, the watershed’s total area is more than 25% larger than the nations of France or Ukraine. With an average #ow volume of 6430m$/sec at its mouth, the river empties into the Bering Sea at the Yukon-Kuskokwim Delta, one of the largest coastal alluvial plains in the world.

As a bi-national resource, the Yukon River is managed by and subject to international treaties, e.g., the Paci"c Salmon Treaty and the Jay Treaty, as well as US and Canadian federal, state, provincial, territorial, tribal, land claims and municipal laws and practices. These complementary and at times competing mandates result in a patchwork of management regimes and potentially con-#icting priorities. Calls for a watershed-wide approach to resource management, including for hydro power development, are becom-ing more common (Indian Law Resource Center, 2003).

HISTORY OF HYDROPOWER IN THE YUKON RIVER WATERSHED

Historically, the mining and smelting industries have been the largest factor in#uencing hydropower development in the Yukon River watershed. Many of the early hydropower installations in the region provided mechanical energy for mining equipment, as opposed to hydroelectric power generation. Placer gold mines throughout the Yukon River watershed relied on hydraulic extrac-tion methods. In the early 20th century, two hydroelectric plants were developed in the Dawson City area, Twelve Mile and North Fork, to serve local mining operations. The 1.2MW Twelve Mile plant operated between 1907 and 1920, on the Twelve Mile (now Chandinau) River, and the 5.4MW North Fork plant (later expanded to 8.1MW) operated between 1911 and 1966, on the Klondike River.

Not long after, some hydropower facilities were developed in interior Alaska for gold mining operations in the Yukon River watershed.

Soon after the Fairbanks gold rush of 1902, several hydropower installations for Tanana Valley gold mines were constructed, oper-ating seasonally. Early mining operations also harnessed energy from the Yukon River’s headwaters in northwestern BC. In the mid-1920s, the Wann River hydroelectric plant was built to power the nearby Engineer gold mine, near the southern end of the Taku Arm of Tagish Lake.

Between the 1940s and the 1970s, several large-scale hydro-electric projects were proposed for the Yukon River watershed, yet never built. In addition to Rampart – the largest prospect of all and further discussed later – other large dams were proposed for the Yukon River in interior Alaska, and four different Upper

Yukon headwater diversions were proposed through the coastal mountains. Three of the proposed tunnel routes were diversions to the Taiya River in Alaska, while one was to divert waters to the Taku River in British Columbia.

As described in “The economics of an Upper Yukon basin power development scheme” (Schramm, 1968): “The overall development scheme of all four plans is essentially the same. It is based on the use of existing lakes, plus, in some cases, addi-tional storage and diversions of lakes and rivers adjacent to the primary storage area, the drilling of one or more tunnels through the coastal mountains and the construction of one or more power plants in the valleys below. The main differences lie in the number of additional storage lakes created and the routing of the main tunnel or tunnels.”

As lake-tap projects, Yukon-Taiya and Yukon-Taku would have had far less potential environmental impacts than the Rampart or other large dam proposals for the Yukon River described below. Therefore, these large-scale proposals to divert water from the Yukon’s headwaters may be resurrected in the future.

YUKON-TAIYA DIVERSION

R.C. Johnson, an engineer with US Bureau of Reclamation, "rst proposed in 1946 what was initially called the Tagish-Lynn project. The proposal’s name was soon changed to Yukon-Taiya, after the Taiya Inlet, in northern Lynn Canal. A joint US-Canada effort, the Yukon-Taiya project would have consisted of an under-ground tunnel (ranging between 23km and 27km in length) under-neath the Chilkoot Pass area, going from Bennett Lake in British Columbia, to a powerhouse site in the Taiya River Valley near Skagway, Alaska. The plant would intake water from a series of connected lakes in the Yukon and British Columbia.

Through channel dredging, six existing lakes in Canada – Marsh, Tagish, Atlin, Little Atlin, Bennet and Lindeman lakes – would be merged into one interconnected reservoir of over 1200km2 in size, with a surface elevation about 670m above sea level (Bureau of

Brian Yanity and Brian Hirsch present an analysis of conventional and in-stream hydro power in the Yukon River watershed

Watershed analysis

Figure 1: Map of Yukon River watershed: (courtesy of Yukon River Inter-Tribal Watershed Council, www.yritwc.org. Map edited by Paula Hansen of WHPacific)



Reclamation, 1955). The minimum diverted !ow of the three different Yukon-Taiya

proposals ranged between 79m"/sec and 524m"/sec, or between 1% and 8% of the total Yukon River average !ow volume. The proposed power plant would have ranged between 320MW and 4000 MW of estimated generation capacity, representing 2.8 to 25 TWh in annual #rm energy (Wardle, 1957). As originally pro-posed, the powerhouse would be located in what is now Klondike Gold Rush National Park, near the historic Dyea town site.

In the late 1940s, the joint US/Canada Yukon-Taiya Commission studied the project, but it was halted in 1951 at the request of the Canadian government. During the 1950s, the Aluminum Company of America (Alcoa) expressed serious interest in devel-oping Yukon-Taiya to power a smelter to be built at Dyea, near Skagway. Alcoa dropped all plans for Yukon-Taiya in 1957, after the Canadian and BC governments decided against cooperating on the project. There were several reasons, mostly relating to unre-solved international waters issues that made the Yukon-Taiya pro-posal unpopular in Canada.

In particular, the Alcoa aluminium smelter proposed for Skagway was seen as direct competition to the Alcan smelter at Kitimat, BC, which was under construction during in the early 1950s. However, despite the Canadian opposition, busi-ness interests in Alaska continued to advocate for Yukon-Taiya for the entire decade of the 1960s. To advance the project, the Alaska Legislature created the Yukon-Taiya Commission in 1967. However, its work stopped in 1972 after being unable to gather meaningful support for the project in either the US or Canada (Norris, 1996).

YUKON-TAKU DIVERSION

The massive Yukon-Taku scheme would have consisted of three separate tunnels with a combined length of about 31km. All of the facilities would be completely located within Canada, and would have required multiple dams, with far greater arti#cial reservoirs compared to Yukon-Taiya. Yukon-Taku would have had three powerhouses in different locations, with a total of 3600MW of total generation capacity, and a #rm annual energy output of 31.2 TWh (Wardle, 1957). The minimum !ow diverted was to be

793m"/sec, representing about 12% of the total Yukon River aver-age !ow volume. However, in addition to the Yukon River water-shed, some water was to be diverted into the Upper Yukon from the Alsek River watershed. As part of the Yukon-Taku project, a large aluminium smelter was proposed for Tulseqah, BC, on the Taku River.

RAMPART DAM AND OTHER LARGE DAM PROPOSALS IN ALASKA

The US Army Corps of Engineers first proposed the 5040MW Rampart Dam project in the early 1950s. The plan was to dam the Yukon at Rampart Canyon, near the town of Rampart about 160km from Fairbanks, creating a reservoir over 28,000km$ in area (US Department of the Interior, 1965 and 1967). The project was designed to produce about 34TWh annually, or about #ve times the amount of electricity the entire state of Alaska consumes today. The resulting “Lake Kennedy” would have required almost 30 years to #ll up completely, and would been the largest arti#cial reservoir in the world. The proposed dam would have been 162m high and 1430m long.

More than a quarter million salmon pass through Rampart Canyon each year, and millions of ducks make their homes in the wetlands of the Yukon Flats, which would have been !ooded under the reservoir. About 1500 people would have been directly dis-placed by the huge reservoir, and the lives of thousands more would have been negatively impacted by the loss of #sh and animal life. Conservationists, indigenous peoples in the region, and poor project economics combined to eventually quash the proposal (Nash, 2001; O’Neill, 1995). USACE formally decided against proceeding with the Rampart project in 1971.

In 1980, the Yukon Flats National Wildlife Refuge was created, protecting most of the proposed reservoir area from development. Other large dam proposals in the watershed discussed during the 1950s and 60s included Woodchopper (3200MW), Holy Cross (2800MW), Ruby (460MW) on the main stream of the Yukon River, and a 530MW project on the Porcupine River, a major tributary of the Yukon (Alaska Power Administration, 1980).

CONVENTIONAL HYDROPOWER GENERATION Despite all of the failed attempts at mega-projects reviewed above, several conventional, utility-scale hydroelectric facilities in the watershed were built in the Yukon Territory, the largest being the 40MW Whitehorse Rapids Dam. Today, there is nearly 76MW of conventional hydro power generation capacity in the Yukon Territory. It should be noted that 30MW of this capacity, the Aishihik development, is located outside of the Yukon River water-shed in the headwaters of the adjacent Alsek River watershed. Not counting micro-scale installations on private property, there are no conventional hydroelectric facilities in the Yukon River watershed installed in Alaska.

In addition to the hydro power capacity, the Yukon Territory also has about 52MW of installed diesel generation capacity, and 0.8MW of wind, for a total installed capacity of 130MW. The vast majority of this capacity is owned by the Yukon Energy Corporation, and the remainder by the Yukon Electrical Company Ltd. (and several private installations with one contained in the table), as shown in Table 1.

The three largest hydroelectric plants are owned by Yukon Energy, while Fish Lake is owned by the Yukon Electrical Company Limited. The three larger plants were originally developed by the Northern Canada Power Commission, which turned over these assets to the Yukon Energy Corp. in 1987. Also note that six tur-bines totalling 17.9MW, over 23% of installed capacity, are over 50 years old.

Micro-hydroelectric development, both in the Yukon Territory and northwestern BC, started attracting more interest in the 1980s and 1990s. A 250kW hydroelectric plant in Fraser, BC (south of Haines Junction in the Yukon Territory) powers the Canadian

Table 1: Existing hydro generation capacity in the Yukon Territory (Yukon Energy Corp., 2001):

FacilityInstalled capacity (MW)

Turbine sizes (MW/yr installed)

Head (m)

Owner

Whitehorse Rapids

40.00

#1: 5.8 / 1958

#2: 5.8 / 1958

#3: 8.4 / 1969

#4: 20 / 1985

18Yukon Energy Corp.

Aishihik Lake

30.00#1: 15 / 1975

#2: 15 / 1975175

Yukon Energy Corp.

Mayo Lake 5.00#1: 2.5 / 1952

#2: 2.5 / 195232

Yukon Energy Corp.

Fish Lake 1.30#1: 0.6 / 1950

#2: 0.7 / 1950

Plant #1: 128

Plant #2: 61

Yukon Elect. Co. Ltd.

Rancheria 0.16 0.16 / 1990 38 Beverly Dinning

Total 76.46



border station, and was completed in 1990. It is owned and operat-ed by a small private corporation and sells power to the Federal and provincial consumers of power at Fraser. The Rancheria 155kW microhydro plant in the Yukon Territory was also installed in 1990, and is also privately owned (by the operator of the Rancheria Lodge and RV Park). The 2MW Pine Creek hydropower plant in Atlin, BC, came online in April 2009.

Yukon Energy’s 20-year resource plan (Yukon Energy Corporation, 2006) states that the two industrial sectors of mining and gas pipeline development will drive future electricity demand. In the mid-1990s, the report Yukon Energy Resources: Hydro (Yukon Economic Development, 1997) listed eleven unde-veloped small hydroelectric sites (each under 10MW of potential) that were considered feasible, shown in Table 2, partly due to their proximity to existing transmission lines. Note that the total installed capacity of all these undeveloped hydroelectric sites, 43.9MW, would still not equal the current diesel installed capac-ity of 52MW, but the additional hydropower would go a long way toward displacing almost all diesel electric generation in the Yukon Territory.

Other hydro projects were also considered in the past such as Chutla Creek and Tank Creek near Carcross (on the Whitehorse-Aishihik-Faro, or WAF, power grid); and Copper Joe Creek, Nines Creek and the Donjek River, all near the (diesel-electric) communi-ties of Burwash Landing and Destruction Bay (about 30km apart and sharing the same diesel plant). Currently Yukon Energy is plan-ning the “Mayo B” project which will more than double the output of the Mayo hydro plant (at Wareham dam) by building a new powerhouse 3km downstream of the existing powerhouse ( http://www.yukonenergy.ca/about/projects/mayob/ ). Another option cur-rently being considered is called the Southern Lakes Enhancement, which would utilize Atlin Lake as a reservoir for the Marsh Lake/Yukon River system that supplies the Whitehorse Rapids hydro facility in Whitehorse (http://www.yukonenergy.ca/about/projects/slenhancement/).

Both Atlin Lake and Marsh Lake would be used for greater seasonal storage to supply more hydro and for the peak demand months of December and January. The environmental impacts of such altered hydrology would require substantial study for better understanding.

In Alaska, there are several small-scale conventional hydro-power proposals presently being pursued within the Yukon River watershed. Contrary to previous trends noted above, these projects have been driven primarily not by industrial demand, but by a need for clean and affordable power to displace diesel generation in remote communities. In 2008, as the Alaska state government was reaping the windfall of high oil prices which produced sig-ni!cant tax revenues, the state legislature established the Alaska Renewable Energy Fund (AREF) with a $100M investment, fol-lowed by $25M in 2009.

The AREF has funded both feasibility studies and preliminary construction of small hydropower throughout Alaska, includ-ing some projects in the Yukon River watershed. Golden Valley Electric Association received AREF funding to study the Little Gerstle site on the Tanana River, and a run-of-river site on the Nenana River. The Alaska Power and Telephone Company (AP&T) also received AREF funding for design and construction costs of the Yerrick Creek hydro development near Tok. AP&T has previously developed village-scale (2-10MW), high head, low impact hydropower in other parts of Alaska, namely the Southeast, as well as projects in Central America, and are now bringing this expertise to the Yukon River watershed. As of the time of writing, the state of Alaska’s 2010 investment in the AREF has not yet been determined.

IN-STREAM (HYDROKINETIC) POWER PROJECTS Because many isolated small communities in the watershed still rely on costly diesel power as well as local resources such as !sh, a vari-ety of small-scale, low impact hydroelectric technologies are attract-

ing great interest, including in-stream, or hydrokinetic turbines that do not require dams or diversions of water. In the summer of 2008, a 5kW hydrokinetic turbine was installed in the Yukon River village of Ruby, Alaska – one of the !rst in-stream turbines successfully installed in the US. Other Yukon watershed-based hydrokinetic projects in Alaska include planned installations in the communi-ties of Nenana, Eagle, Tanana, and Whitestone, and at least one project slated for the Canadian side of the watershed. All of these projects are in various stages of planning, permitting, design, and/or installation.

The Ruby project has provided valuable information regarding “proof of concept” for the viability of in-stream hydrokinetic power generation and has also identi!ed challenges that will need to be overcome before widespread deployment occurs. Speci!cally, the 5kW turbine installed at Ruby by the Yukon River Inter-Tribal Watershed Council (www.yritwc.org) and designed and manufac-tured by New Energy Corporation (www.newenergycorp.ca) based in Calgary, Alberta, incorporated an inverter that was originally used for wind energy projects.

The inverter software was successfully adapted for expected power parameters more typical of a slow moving river than rap-idly changing wind currents. This system properly integrated into the village’s diesel electric grid, thus demonstrating the technical feasibility of the technology. Alternatively, mechanical diversion of stream debris without obstructing river "ow and cost-effective anchoring of the turbine and support structure in the fastest moving part of the river still present challenges to this particular installation and all in-stream hydrokinetic projects on the Yukon River. Impacts to migrating and resident !sh populations are another ongoing area of investigation.

The hydrokinetic project proposed in Eagle, Alaska, by AP&T is in !nal design stages and will also use a New Energy Corporation in-stream turbine, but instead of a 5kW version like in Ruby, this will be a 25kW turbine. Both of these turbines employ a unique design that incorporates a robust, slow moving, vertical axis turbine housed on a pontoon boat that aims for minimal impact to !sh and durability from the elements.

Both the Ruby and Eagle projects, if successful, would eventu-ally include a series of turbines that could meet a large portion of the community’s electrical load during the ice-free summer months, thus allowing diesel generators to be completely turned off much of the time and only starting up when high demand exceeds the power production of the hydrokinetic turbines. This would require sophis-ticated switchgear to integrate the diesel generators and hydroki-netic turbines, but such technology is already available and in use in Alaska villages integrating wind turbines and diesel generators. Because the Yukon River freezes in the winter, hydrokinetic tur-bines such as these, set in pontoon boats anchored to the bottom of the river, would need to be removed from approximately October through mid-May. Maintaining anchors over the winter such that they would not need to be re-set each spring is another area of cur-rent investigation.

The hydrokinetic project planned for Nenana, Alaska, is a col-laboration among numerous entities, including the University of Alaska, Ocean Renewable Power Company, Yukon River Inter-Tribal Watershed Council, and the municipal and Tribal governments co-located in Nenana. As envisioned, this will be a full-blown research project with a test bed for various turbine technologies and anchoring systems. Currently, the research has focused on site characterization, effective means of mechanical debris diversion, anchoring systems, and !sh impacts. The !rst turbine that is slated for installation in the summer of 2011 or 2012 is a helical, cross flow design with an estimated output of 50kW manufactured by Ocean Renewable Power Company (www.oceanrenewablepower.com).

While potentially using different technology, all of these projects in Alaska employ a low environmental impact, robust technology approach to meeting community energy needs based on similar imperatives and design criteria, including: relatively slow moving, high volume water; high conventional energy costs; protection



of !sh and other water resources; signi!cant debris in the water column; integration with existing diesel generators and mini-grids; Maximum displacement of diesel fuel; and severe seasonal icing and extremely energetic spring break-up

Some “lessons learned” from these early deployments are already in"uencing next generation technologies. For example, New Energy Corporation is re-designing its turbine to produce more power at lower current speeds based on initial performance of the turbine installed at Ruby. Similarly, the Nenana project is incorporating information about river debris learned at Ruby in designing a !lter, or “trash rack,” to divert incoming material before it reaches the turbine in Nenana.

Numerous !sh impact studies are now underway that will pro-vide essential data to help resolve this concern, possibly streamlin-ing future development efforts. The Alaska Energy Authority has also created a “Hydrokinetic Working Group” that includes state and federal permitting and resource agencies, developers, commu-nities with potential project sites, and others to identify concerns and possible bottlenecks before they become costly obstacles. As this is a new process for most agencies, they are also identifying studies that will be necessary for developers to comply with per-mitting requirements.

While these technologies are also being deployed throughout North America and the world, the combination of the Yukon River resource potential, community and government initiative throughout the watershed, and availability of funding through the AREF seems to have created a burgeoning development cluster within the region.

Within Canada, at Fort Selkirk, Yukon, the Ampair micro-scale hydrokinetic turbine was tested in 2000 on the Yukon River, near the mouth of the Pelly River. This was a project sponsored by the Heritage Branch of the Yukon government (Yukon Energy Corp., 2001). The turbine is now out of the water. Also, New Energy Corporation has donated a 5kW turbine identical to the turbine in Ruby, Alaska, for installation on the Yukon Territory side of the watershed, to the Yukon River Inter-Tribal Watershed Council, but this project is not yet deployed.

OTHER RESOURCE OPPORTUNITIES AND CHALLENGES WITHIN THE REGION

Both traditional drivers of hydropower development in the water-shed, i.e., mining and other industrial activity, and new imperatives such as high fossil energy costs and preference for cleaner energy, are now providing impetus to develop not just hydropower but

other renewable energy resources found in the watershed. Because hydropower is the most apparent, seemingly abundant, and his-torically used renewable resource in the region, it has received the most attention to date.

However, as efforts to develop locally available wind, tidal, solar, biomass, and geothermal resources advance, new technical, economic, and institutional solutions will be necessary to opti-mize the mix among hydropower (conventional and in-stream), other renewables, and fossil fuel. Entities such as the Yukon River Inter-Tribal Watershed Council, a coalition of 70 Tribes and First Nations in Alaska and Canada and lead developers in the Ruby hydrokinetic project, are now looking beyond just hydropower and are involved in community-based solar, wind, and bio-mass projects along with “green collar” workforce training for indigenous peoples and net-zero energy ef!cient residential con-struction.

Successful past projects and ongoing investigation and dissemi-nation of “lessons learned” from new hydropower technology in the region can accelerate and facilitate future renewable energy development within the watershed and beyond. The AREF, as described above, has also played an important role over the past two years in accelerating renewable energy deployment and an expectation that if technology is properly developed, there will be funding for its deployment. This is an example of how targeted programs can be used to achieve policy ends – in this case, reduc-ing the use of diesel fuel and cost of energy throughout Alaska, especially the rural areas.

As more renewable energy resources are used to produce elec-tricity within the Yukon River watershed and elsewhere, concerns with “grid instability” can be expected to emerge. For example, as wind or solar energy becomes a higher proportion of the total amount of electricity generated at any moment in time, uncon-trolled "uctuations can make the overall electric grid unstable, compromising power quality and sensitive electronic equipment. Especially with diesel mini-grids such as those in remote Alaska villages, this can quickly become a problem as diesel generators are the primary means of regulating voltage and frequency control for acceptable power quality and a stable grid.

Hydropower, more than any other renewable energy resource except geothermal, has an important advantage as a “grid stabiliz-er” that, when properly con!gured, can allow for higher penetra-tion rates of renewables and maximize diesel displacement. Even with run-of-river or in-stream hydrokinetic power, because rivers vary in speed and hence power production much less and slower than wind or sun, hydro power is a uniquely valuable renewable energy resource.

While the Yukon River and tributaries present numerous hydro-power opportunities, the watershed also holds substantial mineral and fossil energy reserves and lies between some of the largest natural gas deposits on the continent just north of the watershed and large markets to the south. Thus, it is likely that the watershed will see increased development in the future once again driven by industrial opportunities and distant demand. Given the remote nature of the region and ongoing dependence, especially among the indigenous peoples, on locally available natural resources, any future hydropower development will need to carefully consider impacts to the people and environment and recognize trade-offs that such development will require.

Further, these proposed industrial activities will likely in"u-ence the demand and speci!c economics for any future hydro-power projects.

No hydropower discussion in remote, far northern reaches of the globe would be complete without some consideration of cli-mate change. Both Alaska and the Yukon Territory are widely recognized as global “hot spots” already experiencing signi!-cant temperature escalation much higher than the global average, wide ranging shifts in precipitation, melting permafrost, shore-line erosion, and increased intensity and frequency of !re events (IPCC, 2007).

Hydropower production projections based on historic precipi-

Table 2: List of feasible proposed conventional hydropower sites in the Yukon Territory and bordering areas of Northwestern BC (Yukon Economic Development, 1997)

Proposed ProjectDeliverable Annual Energy (GWh)

Installed Capacity (MW)

Surprise Lake 48.0 8.5

Moon Lake 44.9 8.5

Wolf River 37.6 4.8

Orchay River 26.6 4.0

Drury Creek 24.8 2.6

North Fork Klondike River 21.0 4.0

Morley River 16.0 2.0

Squanga Creek 10.7 1.8

Lapie River 10.5 2.0

McIntyre Creek #3 5.5 0.7

Aishihik 3rd turbine 5.0 5.0

Total: 250.6 43.9



tation patterns may not accurately predict future energy output, and in extreme cases, infrastructure such as dams, penstocks, and transmission lines may be compromised as well under conditions of melting permafrost and increase shoreline erosion.

Additional challenges to hydropower development in the Yukon River watershed include: Short construction and study season. Greater expense for everything due to cost of shipping. Limited access to many areas. Limited human capacity (technical experts, maintenance specialists, operators, etc.). Isolated grids. Unpredictable energy demand (from industries such as mining). Diesel-electric communities receive subsidies that reduce eco-nomic drivers to !nd alternatives to diesel generation in those communities. The Yukon River watershed is a large region with a small popula-tion and limited revenue from natural resources. This limits the capacity of communities, utilities and governments to invest in capital-intensive renewable energy solutions.

CONCLUSION

As one of the greatest watersheds of North America and the world, over the past century the Yukon River system has inspired a wide array of hydropower development proposals, ranging in capacity from several hundred to several billion watts. Only a small frac-tion of the watershed’s technically and environmentally feasible hydropower potential has been tapped, and the 21st century is certain to see pressure for additional hydropower development. A huge amount of environmental and technical information must be disseminated in the process of planning, policy development and implementation, and coordination across jurisdictions. Properly informing the public is necessary for the democratic, pro-active process of creating the future that the Yukon River watershed’s citizens and other stakeholders desire, and to protect publicly owned natural resources.

It appears that the Alaska portion of the watershed has trend-ed from proposed – but never completed – mega-projects from the middle of the last century to more recent environmentally sensitive and community-driven small-scale projects, some of which are employing new technologies. High diesel fuel prices, environmental concerns, and ongoing local dependency on har-vesting natural resources such as !sh are driving this transition to a clean energy economy in which village-scale conventional and hydrokinetic in-stream developments are uniquely suited to reduce diesel use and minimize !sheries impacts. Other renew-able energy options are also being actively explored. As commu-nities throughout the watershed bene!t from improved regional cooperation and resource management, such technologies and approaches – if successful – can be expected to rapidly expand. Government support such as the Alaska Renewable Energy Fund appears to be creating a development cluster that could bene!t the watershed and far beyond.

Organizations such as the Yukon River Inter-Tribal Watershed Council and cooperative structures such as the Yukon River Salmon Agreement are improving watershed-wide communication and opportunities for regional resource management and coordination. Successfully balancing the competing needs and desires of the vari-ous watershed stakeholders will require, among other things, good information, long term planning, cross-jurisdictional coordination, resource protection, and enlightened policy, and could provide important lessons and role models for all of us.

Brian Yanity, EIT, is an electrical engineer with WHPaci!c, Inc. in Anchorage, Alaska, and an adjunct faculty member

at the University of Alaska Anchorage (UAA) School of Engineering. His work focuses on village-scale renewable energy projects and energy planning for rural Alaska. Mr.

Yanity received his B.S. degree in electrical engineering from Columbia University, and his M.S. in arctic engineering from

UAA, with a focus on small-scale hydropower systems for cold-climate applications. Email: byanity@whpaci!c.com

Brian Hirsch, PhD, is the Senior Project Leader for the National Renewable Energy Laboratory’s (NREL)

Alaska initiative, a part of the US Department of Energy Of!ce of Energy Ef!ciency and Renewable Energy. Dr.

Hirsch received his doctorate in Land Resources from the University of Wisconsin-Madison, with a focus on energy issues and indigenous communities in northern regions of

the world. Email: [email protected]

ReferencesAlaska Power Administration, US Department of the Interior (1980). Hydroelectric Alternatives for the Alaska Railbelt.

Bureau of Reclamation-Alaska District, U.S. Department of the Interior (1955). Yukon-Taiya Project: Alaska-Canada.

S. Huntington (1993). Shadows on the Koyukuk: An Alaskan Native’s Life Along the River. Alaska Northwest Books.

Indian Law Resource Center (2003). International Opportunities for the Protection of the Yukon River Watershed: A Handbook of Strategies.

http://www.indianlaw.org/sites/indianlaw.org/files/AK%20Yukon%20Handbook.pdf

IPCC (2007). Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, A. (eds.)]. IPCC, Geneva, Switzerland, 104 pp.

R. Nash (2001). Wilderness and the American Mind. Yale University Press.

F.B. Norris (1996). Legacy of the Gold Rush: An Administrative History of the Klondike Gold Rush National Historic Park. National Park Service, Alaska System Support Office, Anchorage.

D. O’Neill (2006). A Land Gone Lonesome: An Inland Voyage Along the Yukon River. Basic Books.

D. O’Neill (1995). The Firecracker Boys. St. Martin’s Griffin.

G. Schramm (1968) “The economics of an Upper Yukon basin power development scheme” The Annals of Regional Science. Volume 2, Number 1/ December 1968, pages 214-228.

US Department of the Interior (1967). Alaska Natural Resources and the Rampart Project.

US Department of the Interior (1965). Rampart Project, Alaska, Field Report, Vol. II. January 1965.

J.M. Wardle (1957) “A major power plan for Yukon River waters in the Canadian Northwest”, Proceedings of Institution of Civil Engineers, London, England, Vol. 7, July 1957, pages 441-464.

Yukon Economic Development (1997). Yukon Energy Resources: Hydro.

Yukon Energy Corporation (2006). 20-Year Resource Plan: 2006-2025. May 2006.

Yukon Energy Corporation and Yukon Development Corporation (2001). The Power of Water: The Story of Hydropower in the Yukon. November 2001.

AcknowledgementsSpecial thanks to following reviewers: Sean MacKinnon of the Yukon Energy Solutions Centre (Yukon Department of Energy, Mines and Resources), and Neil McMahon of the Alaska Energy Authority.

IWP& DC

PROFESSIONAL DIRECTORY


CLA

SSIFIED

www.w

aterpo

wermag

azine.co

m

MORE THAN 100 YEARS OF HYDROPOWER ENGINEERINGAND CONSTRUCTION MANAGEMENT EXPERIENCE

260 Dams and 60 Hydropower Plants (15,000 MW)built in 70 countries

Water resources and hydroelectric development• Public and private developers• BOT and EPC projects• New projects, upgrading and rehabilitation • Sustainable development

with water transfer, hydropower, pumping stationsand dams.

COYNE ET BELLIER9, allée des Barbanniers92632 GENNEVILLIERS CEDEX - FRANCETel: +33 1 41 85 03 69Fax: +33 1 41 85 03 74e.mail: [email protected]: www.coyne-et-bellier.fr

COYNE ET BELLIERBureau d’Ingénieurs Conseils

www.coyne-et-bellier.fr

Over 40 years experience in Dams.CFRD Specialist Design and Construction

! Dam Safety Inspection! Construction Supervision! Instrumentation! RCC Dam Inspection! Panel Expert Works

Av. Giovanni Gronchi, 5445 sala 172,Sao Paulo – BrazilZIP Code – 05724-003Phone: +55-11-3744.8951Fax: +55-11-3743.4256Email: [email protected][email protected]

Lahmeyer International GmbHFriedberger Strasse 173 · D-61118 Bad Vilbel, GermanyTel.: +49 (6101) 55-1164 · Fax: +49 (6101) 55-1715E-Mail: [email protected] · http://www.lahmeyer.de

Your Partner forWater Resources andHydroelectric Development

All Services for Complete Solutions• from concept to completion and operation• from projects to complex systems• from local to multinational schemes• for public and private developers

• hydropower�transmission and high voltage systems�power economics�power management consulting

www.norconsult.com

Multidisciplinary consultancyservices through all project cycles

�dams and waterways�turbines/pumps and generators�water resources�environmental and social safeguards

AF-Colenco LtdTäfernstrasse 26 • CH-5405 Baden/SwitzerlandPhone +41 (0)56 483 12 12 • Fax +41 (0)56 483 17 [email protected] • http://www.af-colenco.com

Consulting / Engineering and EPC Services for:• Hydropower Plants• Dams and Reservoirs• Hydraulic Structures• Hydraulic Steel Structures• Geotechnics and Foundations• Electrical / Mechanical Equipment

Construction and refurbishment of small and medium hydro power plants.

. turnkey / EPC plants. design & engineering. turbines

. feasibility studies. operation services. financing

www.hydropol.cz

# (47) 67 53 15 06 in Norway# (55) 11 3722 0889 in BrazilE-mail: [email protected]: http//www.qtbm.com

3355 yyeeaarrss eexxppeerriieennccee ffrroomm mmoorree tthhaann 3300 ccoouunnttrriieess

PROFESSIONAL DIRECTORY


CLA

SSIFIEDwww.w

aterpowerm

agazine.com

Yolsu Engineering Services Ltd. Co.Hürriyet Caddesi No:135 Dikmen, 06450 Ankara,TURKEYTel: +90 312 480 06 01 (pbx) Fax: +90 312 483 31 35

www.yolsu.com.tr [email protected]

Prefeasibilty, Feasibility,Final & Detail Design,Consulting Services:

• Basin development• Dams and hydropower plants• Irrigation and drainage• Water supply and sewerage• River engineering• Highways and railways

Successful projects inHydropower and Water Management

For further information please contact [email protected] and visit www.poyry.com

Stellba Hydro AG Stellba Hydro GmbH & Co KGLanggas 2 Badenbergstrasse 30CH-5244 Birrhard D-89520 HeidenheimSwitzerland GermanyTelefon +41 (0)56 201 45 20 Telefon +49 (0)7321 96 92 0Telefax +41 (0)56 201 45 21 Telefax +49 (0)7321 6 20 73Internet www.stellba-hydro.ch Internet www.stellba.deE-Mail [email protected] E-Mail [email protected]

721www.r izzoassoc.com

WATER RESOURCES POWER GENERATIONMINING TUNNELS

TECBARRAGEMSLIPFORM

Phone/Fax: + 5511 [email protected]

Website: www.tecbarragem.com.br

• Faster Constructive System for Civil Works• Specialists in Hydroelectric and Dam Projects• Qualified Projectists, Engineers and Technicians• Special Formworks and Slipforms

To advertise in the Professional Directory orWorld Marketplace section, or for moreinformation contact Diane Stanbury.

tel: +44 (0)20 8269 7854or email:[email protected]

Copy deadline for September 2010 issueis 13 September 2010


& DAM CONSTRUCTION

Water Power

www.waterpowermagazine.com

The classified section in Water Power & DamConstruction is a well established and popularsection with the magazine’s combined print anddigital circulation of 16,000. Commonly knownas where “the buyer meets the seller”.

Industry ShowcasesThe industry showcase section is made upof eighth page adverts (95x65mm) with amaximum of eight key suppliers to a page. Itis an ideal section to promote productsand services, raise brand awareness andshout about company successes. Showcaseadverts are also an ideal way to promoteproduct literature and generate interest.Recommended duration:minimum 3 months

RecruitmentThe ideal way to promote a company vacancyand reach experienced professionals lookingfor the next opportunity to advance theircareer in the hydro power & dam constructionindustries.

For more information, please contactDiane StanburyTelephone:+44 (0)20 8269 7854or email:[email protected]

WORLD MARKETPLACE


CLA

SSIFIED

www.w

aterpo

wermag

azine.co

m

CYLINDERS

CRANES GATES

• Custom Design Hydraulic Cylinders• Servomotors• Piston Accumulators'• Hydraulic Power Units• Control Panels

www.doucehydro.comDouce Hydro FRANCE, USA and GERMANY

Tel France: + 33 / 3 22 74 31 08 ; E-mail: [email protected] USA: + 1 / 586 566 4725 ; E-mail: [email protected]

Tel Germany: + 49 / 177 398 37 78 ; E-mail : [email protected]

BEARINGS

PAN® bronzes and

PAN®-GF self-lubricating bearings

Since 1931

- Superior quality with • Highest wear resistance • Low maintenance

• Or maintenance free - Extended operating life

PAN-Metallgesellschaft

P.O. Box 102436 • D-68024 Mannheim / Germany Phone: + 49 621 42 303-0 • Fax: + 49 621 42 303-33 [email protected] • www.pan-metall.com

BEARING OIL COOLERS

HEXECO, Inc. ... a Heat Exchanger Engineering Co.Tel: +1 (920) 361-3440 • Fax: +1 (920) 361-4554E-Mail: [email protected] • Web: www.hexeco.com

OIL COOLERSFor

THRUST andGUIDE

BEARINGS

CONCRETE COOLING

FILTRATION EQUIPMENT

WWW.WATERPOWERMAGAZINE.COM

CIVIL ENGINEERING:

www.montanhydraulik.com

Providing water control solutions through thoughtful engineering,innovative design, attention to detail and outstanding customerservice. Contact us for inflatable water control gates and rubberdams.

PO Box 668, Fort Collins, CO 80522 USATel: 970-568-9844www.obermeyerhydro.com

HYDRO CASTINGS

• Water turbine components• Castings from 100 kg to 30 tons• Latest CAD-CAM capabilities• Certified Quality Assurance ISO 9001• Environmental Management System ISO14001Your contact: Mr. Timo Norvasto, Sales ManagerLokomo Steel FoundryTel: +358 204 84 4222Fax: +358 204 84 4233Email: [email protected]: www.metsofoundries.com

CONCRETE COOLING• COLD & ICE WATERPLANTS• FLAKE ICE PLANTS• ICE DELIVERY & WEIGHING SYSTEMS• ICE STORAGES

KTI-Plersch Kältetechnik GmbHCarl-Otto-Weg 14/288481 Balzheim

Germany

Tel:/Phone: +49 - 7347 - 95 72 - 0Fax: +49 - 7347 - 95 72 - 22Email: [email protected]

Website: www.kti-plersch.com

WORLD MARKETPLACE


CLA

SSIFIEDwww.w

aterpowerm

agazine.com

HYDROMECHANICALEQUIPMENT

HYDRO POWERPLANT EQUIPMENT

HYDRO POWERPLANT EQUIPMENT

ANDRITZ HYDRO GmbHPenzinger Strasse 76, A-1141 Vienna, AustriaPhone: +43 (1) 89100-0, Fax: +43 (1) [email protected] • www.andritz.com

Your Partnerfor renewable and clean energy

We focus on the best solution – from water to wire.

Voith Hydro Holding GmbH & Co. KGAlexanderstrasse 1189522 Heidenheim/Germanywww.voithhydro.com

A Voith and Siemens Company

! Water power plant equipment (electrical and mechanical)! Pumps! Governors! Automation! Modernization of existing power plants! Hydro power services! Ocean energies

INSTRUMENTATION(DAM MONITORING)

Vikas Kothari: Executive Director Tel: 91 11 29565552 TO 55Om Metals Infraprojects Ltd. Fax: 91 11 295655514th Floor, NBCC Plaza, Mobile: 91 98110 68101Tower III, Sector 5, Email: [email protected] Vihar, [email protected], New Delhi, 110 017, INDIA Web: www.ommetals.com

Turnkey EPC contracts for:•Radial Gates •Trash Racks & TRCM

•Vertical Gates •Gantry Cranes & EOT

•Penstocks •Mechanical/ Hydraulic Hoists

•Stoplogs •Draft Tubes

Turnkey EPC contracts for:•Radial Gates •Trash Racks & TRCM

•Vertical Gates •Gantry Cranes & EOT

•Penstocks •Mechanical/ Hydraulic Hoists

•Stoplogs •Draft Tubes

Om Metals! World wide referenced water to wire General Contractor! Turbines and Generators! Electromechanical Equipment! Switchgears! Control Protection Monitoring and SCADA Systems! Balance of the Plant! Turn key projects! Rehabilitation

S.T.E. S.p.a. - Via Sorio, 120 - 35141, PADOVA(Italy)tel. +39 049 2963900 - fax. +39 049 2963901

Email: [email protected] Web: www.ste-energy.comISO 9001 CERTIFIED

Geokon, Incorporated manufactures a full range of geotechnical instrumentation suitable for monitoring dams. Geokon instrumentation employs vibrating wire technology that provides measurable advantages and proven long-term stability.

The World Leader inVibrating Wire Technology TM

Geokon, Incorporated48 Spencer StreetLebanon, New Hampshire03766 • USA

Dam Monitoring Instrumentation

1 • 603 • 448 • 15621 • 603 • 448 • [email protected]

Dam Safety Instrumentation • Fiber Optic and Vibrating Wire Technologies • In-Situ Testing

and Turn-Key Solutions

• Piezometers• Pressure Cells• Extensometers

• Crackmeters• Inclinometers• Tiltmeters

[email protected] • www.roctest.com

[email protected] • www.telemac.fr

WORLD MARKETPLACE


CLA

SSIFIED

www.w

aterpo

wermag

azine.co

m

SMALL HYDROELECTRICPOWER SETS

SMALL HYDROELECTRICPOWER SETS

Turbines up to 20 MWAlternators up to 22 MVA GovernorsSwitchboards

79261 Gutach /GermanyTel. + 49 7685 9106 - 0 · Fax: - 10

www.wkv-ag.com

Water-to-Wire Solutions Made in GermanyTurbine & Alternator Manufacture

W

TRASHRACK RAKES

MICRO/SMALLHYDROELECTRIC POWER SETS

Turbines up to 20 MWAlternators up to 22 MVA GovernorsSwitchboards

79261 Gutach /GermanyTel. + 49 7685 9106 - 0 · Fax: - 10

www.wkv-ag.com

Water-to-Wire Solutions Made in GermanyTurbine & Alternator Manufacture

W

INSTRUMENTATION(GEOTECHNICAL)

Partial Discharge?www.pdix.com

PARTIAL DISCHARGE DETECTION

+43 - 7234 - 83 902

WORLD MARKETPLACE


CLA

SSIFIEDwww.w

aterpowerm

agazine.com

VALVES FOR HYDROELECTRIC POWER PLANTS! Butterfly Valves! Spherical Valves! Cone Jet Valves! Needle Valves! Sleeve Valves! Pressure Reducing Valves! Airation Valves

Adams Schweiz AGAustrasse 49, CH 8045 Zürich, SwitzerlandPhone: +41 (0) 44 461 54 15Fax: +41 (0) 44 461 50 20e-mail: [email protected]: www.adamsarmaturen.ch

VALVES VALVES WATER TURBINES

WATERPROOFING

Stronger together.

Member of the Group of companiesGlen!eld Valves Ltd your specialist manufacturer of Discharge,Control, Non-Return and Isolating Valves (including Butter"yValves and Gate Valves) for:• Dams and Reservoirs• Water Transmission Pipelines• Power Stations.For a world wide network ofmanufacturing and serviceorganisations offering localsupport please contact :Glen!eld Works, Queens Drive,Kilmarnock, Ayrshire,KA1 3XF, UKT: +44 1563 521150F: +44 1563 545616E: enquiries@glen!eld.co.ukFor details of our full productrange please refer to our website:www.glen!eld.co.uk

!"# $% &'# ($)*+,-*#.+/"0 1."2%.3&2)#)-$% '/0'452.*/&6 7.*7#-%$) +.1- ."+'6+)$8$(#)9 #7#" /"

(((:7.040)$28:3$1!!"!!"

WATERPROOFING AND PROTECTIONof concrete and RCC dams,

embankment dams, hydraulic tunnels,canals, reservoirs

WITH FLEXIBLE SYNTHETIC MEMBRANESTurnkey projects: design manufacturing,

supply, installation.CARPITECH

Via Passeggiata 16828 Balerna - Switzerland

T: +41-91-6954000 F: +41-91-6954009E: [email protected] www.carpitech.com

INDUSTRY SHOWCASE EQUIPMENT FOR SALE

BOLTIGHT Bolt Tensioners

Special and Standard Bolt Tensioners for Waterand Wave Energy, Structural and other CriticalBolting Applications.

Reliable and superior quality bolt tensionersavailable on fast delivery.

[email protected]: +44 845 500 5556

Website: www.boltight.com

Large Hydrois much more than a big idea

[email protected]

ANDRITZ HYDRO GmbHPenzinger Strasse 76, 1141 Vienna, AustriaPhone: +43 (1) 89100, Fax: +43 (1) 8946046

ANDRITZ HYDRO has more than400,000 MW of turbine capacity andapprox. 160,000 MVA of generator

capacity installed worldwide. The

combination of experience, innova-

t ion and g loba l manufac tur ing is

ANDRITZ HYDRO’s driving force for

technology and customer satisfaction.

We focus on the best solution – fromwater to wire.

2010-8.pdf

Documents

Transcript of 2010-8.pdf