Water Power and Dam Construction. Issue January 2010

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12 JANUARY 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

ENVIRONMENT

AVAGE Rapids diversion dam is located on the Rogue river

about 8km upstream from Grants Pass, Oregon, in the US.

The purpose of the dam was to seasonally raise the surface

of the Rogue River by an additional 3.4m through the use

of stoplogs on the crest of the dam. This would provide a sufﬁcient

reservoir head to efﬁciently operate a gravity canal headworks and a

hydraulically-powered pumping plant. Although the 88-year-old dam

was over 172km from the Paciﬁc Ocean, it blocked a major migration

route for several species of salmon – that is until October 2009.

The dam was originally constructed in 1921-2 by private develop-

ers to divert river flows to irrigate up to approximately 73km

land. For economic reasons, only about 51km

was irrigated, with

that number declining to about 31km

today.

Species of anadromous fish are present in the Rogue River, some-

times in very large numbers. Steelhead trout are present in the river

year round, while Chinook and Coho (salmon) are present in the

non-winter months. In 1997, the National Marine Fisheries Service

(NMFS) listed the Southern Oregon/Northern California (SONCC)

Coho salmon as threatened under the Endangered Species Act.

Consequently Savage Rapids Dam was considered to be a major

impediment to fish migration in the Rogue River.

PROJECT DETAILS

The dam was owned, operated and maintained by the Grants Pass

Irrigation District (GPID) and was their primary irrigation diver-

sion facility. In 1949, GPID sought Federal assistance to rehabilitate

the dam crest gates and install ﬁsh screens. Congress subsequently

directed the Bureau of Reclamation (USBR) to address these issues

at the dam.

The structure was a combination reinforced concrete gravity and

multiple-arch diversion facility. It had an overall length of 142m and

consisted of the north fish ladder and pumping plant on the right

abutment; an overflow portion or spillway across the river channel;

Fish passage and screening methods had

been a concern at Savage Rapids dam in the

US since construction. The final outcome

for the 88-year-old structure proved to be

dam removal. Richard D Benik, Robert

Hamilton and John Redding from the US

Bureau of Reclamation give more details

Removing Savage

Rapids Dam

WWW.WATERPOWERMAGAZINE.COM JANUARY 2010 13

ENVIRONMENT

and the headworks to the gravity canal and south fish ladder on the

left abutment. The pumping plant used hydraulically-driven pumps

to supply water to canals on the right and left sides of the river by

way of a 1m diameter pipe through the dam. The dam had a struc-

tural height of 10m from its foundation to the concrete crest of the

overflow portion.

The overﬂow portion of the dam was 120m long; it extended from

the gravity canal headworks to the pumping plant and was divided

into 16 bays. Each bay was separated by a 61cm wide pier or buttress,

located on 8m centers. Bays on the right side (looking downstream)

were located within the deepest portion of the river channel and were

supported by the multiple-arch portion of the dam, each bay supported

by one arch. These bays were underlain by a foundation of cemented

river gravels. The maximum base width of the multiple-arch portion

of the dam, including an approximately 8m wide downstream con-

crete apron, was approximately 26m. Bays on the left side were sup-

ported by the gravity portion of the dam, with a maximum base width

approximately 9m. These bays were founded on bedrock.

REHABILI TATIO N WO RK

USBR rehabilitated the dam in 1953-4 by installing metal stoplogs

to replace the original crest gates across the overﬂow portion of the

dam. The original dam did not include an outlet works. During the

rehab, two of the bays on the left side were completely removed,

the foundation was excavated, and the bays were rebuilt to house

two 5m wide by 2m high top-seal radial gates that served as the

river outlet works. A diversion channel upstream and downstream

of the new radial gates also was excavated. These gates were used

to lower the reservoir for installation and removal of the stoplogs.

In 1957-8, a new pumping plant intake structure with ﬁsh screens

was constructed by the USBR.

FISH PASS AGE AND SCREE NING

Fish passage and screening at Savage Rapids Dam have been a con-

cern since original dam construction. A fish ladder was construct-

ed on the right abutment at the time the dam was built (north fish

ladder). However, the downstream entrance to the north fish ladder

was masked by flows through the existing pumping plant. A second

This is the ﬁnal stages of demolition on bay #9 of the north side at Savage

Rapids dam. Slayden Construction crews tear down the dam and build a pilot

channel for on the Rogue River to ﬂow (River left). Photo by Andy Pernick

The Rogue river begins to gain momentum as sediments, boulders and debris

ﬂow past the former dam site on the river right side. Photo by Dave Walsh

14 JANUARY 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

ENVIRONMENT

fish ladder was added in 1934 (south fish ladder) on the left abut-

ment in an attempt to improve passage at the site. The fish ladders

were outdated and did not meet current criteria of either NMFS or

Oregon Department of Fish and Wildlife (ODFW).

Early attempts to provide fish screening of the pumped irrigation

diversion were unsuccessful until 1958 when fish screening facilities

were added to the pumping plant intakes. These screens also do not

meet current criteria. Fish passage improvements made in the late

1970s helped reduce losses, but fish passage problems continued.

During high flows, fish tended to jump out of the fish ladders and

become stranded on the rocks below. Water overtopping the dam,

especially during high flows, distracted the adult fish from locating

the attraction flows at the fish ladder entrances.

In 1971, Congress authorized USBR to undertake a feasibil-

ity study to address lingering ﬁsh passage and protection issues

at the dam. Evaluation of ﬁsh issues at the dam resulted in a

number of recommendations, including replacing the north ﬁsh

ladder. Final designs were prepared, but the only bid received

for the work signiﬁcantly exceeded available funding and the

attempt to replace the north ﬁsh ladder failed. Dam removal

seemed an ever likely solution.

The USBR feasibility study that led towards dam removal started

in October 1988. The planning report/final environmental statement

documenting the study results was published in August 1995.

The recommended least-cost alternative in the report to improve

fish passage and maintain irrigation diversions was to construct

two pumping plants (one on either side of the river) and remove the

dam. The other action alternative considered included rehabilitating

the hydraulically-driven pumping plant and constructing new fish

screens to retain the dam.

Above left: An excavator removes a temporary berm to allow the Rogue River

to run freely past the dam – the ﬁrst time in 89 years. The radial gates near the

centre of the dam were closed slowly permitting crews to work on dismantling

the south side of the dam. Photo by Dave Walsh; Above right: Aerial view of the

undammed Rogue River channel at the former Savage rapids dam site, 9 October

2009. Photo by Andy Pernick; Left: Savage Rapids dam and pumping plant

aerial view shows the pumping plant ground ﬂoor is incomplete. Intake tubes are

back ﬁlled over and rip rap has been added. Photo by Dave Walsh

WWW.WATERPOWERMAGAZINE.COM JANUARY 2010 15

ENVIRONMENT

DAM REMOV AL

In 1998, NMFS sought a Federal Court injunction against GPID

for unlawful take of Coho salmon. The state of Oregon also filed

a lawsuit against GPID (in state court) for failure to comply with

its water rights (which required GPID to resolve fish passage issues

at the dam by removing it). These legal actions culminated in an

August 2001 Federal Court consent decree wherein GPID agreed

to proceed with dam removal.

Planning subsequent to the consent decree resulted in decisions to:

UÊÊConsolidate the pumping facilities on the south side of the river.

UÊÊConstruct a pipe bridge to deliver water from the pumping plant to

the canals on the north side of the river.

UÊÊRemove a major portion (but not all) of the dam (ten of 16 bays).

In 2004, Congress authorized USBR to proceed with dam removal.

However initial funding for construction was not provided until 2006.

USBR awarded the construction contract to Slayden Construction

of Stayton, Oregon in August 2006. Notice to Proceed was issued

to the contractor on 2 September 2006 with construction starting

in October 2006. Notice of substantial completion was issued to

Slayden Construction in November 2009.

Fish passage and the natural flow of the Rogue River had to con-

tinue uninterrupted through the site during construction of the new

diversion facility and partial removal of the dam. The dam and exist-

ing pumping plant had to continue to operate to maintain irrigation

releases until the new diversion facility was completed. Demolition

of the dam could not begin until the new diversion facility became

operational. Construction of the new pumping plant and bridge

began in 2006 and these were completed in time for the 2009 irriga-

tion season.

Partial removal of the dam began in April 2009 when the outlet

works were used to draw the reservoir down for construction of a

cofferdam around the right portion of the dam. The fishery agen-

cies asked that reservoir drawdown and construction of the coffer-

dam occur in early April to minimise impacts on the spring Chinook

salmon run. Once the cofferdam was completed, the outlet works

were closed to raise the reservoir over the left side of the dam for

river and fish passage through the south fish ladder. The outlet works

then were used as needed to pass excess river flows and maintain fish

passage through the south fish ladder. The right side of the dam was

removed behind the cofferdam down to the foundation using exca-

vators equipped with hoe rams. The hoe rams would break up the

concrete bays of the dam and the rubble would be hauled away.

After the right side of the dam was removed, removal of the left side

could not take place until the end of the 2009 irrigation season to pre-

vent reservoir sediments from damaging the new pumping plant. In

addition, moving the river to the right side was set for early October

to minimize impacts to the end of the spring Chinook salmon run and

the start of the Coho salmon run.

In October 2009, the reservoir was drawn down again using the

outlet works and the cofferdam was removed. Low flows in the

river allowed the remaining portion of the left side of the dam to be

removed without a second cofferdam. A large pilot channel excavated

through the upstream reservoir sediments facilitated moving the river

from the outlet works to the original channel on the right side and

through the removed portion of the dam. It was anticipated that the

river would return to the original channel on the right side once the

dam had been removed and reservoir sediments had been eroded.

The large pilot channel minimized downstream turbidity and ero-

sion of reservoir sediments. It is anticipated that reservoir sediments

would be completely eroded downstream during winter flooding.

Permanent fish passage through the site was restored when the river

was moved to the right side of the channel. Partial removal of the

dam was completed in November 2009.

Prior to the start of construction, USBR formed an interagency

coordination team comprised of representatives from the regulatory

agencies, GPID, WaterWatch of Oregon, and the contractor. The

purpose of this group was to make sure that all parties were kept in

the loop on construction activities and to assure they could work in

concert to address needed course corrections. This coordination was

critical to the success of the project.

The new pumping plant and pipe bridge across the river are located

on the left abutment immediately downstream of where the south fish

ladder was located. The intake to the new pumping plant is located

just upstream of a riffle in the river to take advantage of deep, slow

moving water. The new pumping plant consists of 12 vertical turbine

pumps which can deliver water to canals on both sides of the river.

The pumping plant will typically operate during irrigation season

from mid-May to mid-October.

ENVIRONM ENTAL CON SIDERATIONS

Various environmental considerations have to be taken into account

with the removal of a dam. A basic premise of the sediment manage-

ment plan was that the river would be allowed to naturally erode the

trapped sediment once the dam was removed. Project permits were

written around that concept. The initial erosion phase was set to occur

at the end of the irrigation season (to avoid causing problems for the

new pumping plant and before the start of the annual upstream Coho

migration (to minimise ﬁshery impacts). The major sediment erosion

phase is expected to occur during the 2009 winter ﬂood season.

Of the 153km

of sediments that were deposited in the reservoir

behind the dam, approximately 134km

were located within an 8m

deep gravel bar on the right side of the reservoir. This was immediate-

ly upstream of the dam, in the deepest part of the original river chan-

nel. The dam was removed and water was diverted to the right side of

the river channel in a pilot channel after the irrigation season ended,

in order to prevent eroding sediments from damaging the intakes of

the new pumping plant. Removal was also scheduled to accommo-

date the annual salmon runs to limit stress on the fisheries.

Turbidity from the initial erosion cleared up within three days.

Turbidity from the remaining erosion will be overshadowed by tur-

bidity from future flood events.

The dam removal project was completed in November 2009.

Construction of the new pumping plant and pipe-support bridge

began in 2006, and was successfully completed in time for the 2009

irrigation season. Dam removal began in April 2009, after the new

pumping plant became operational.

Although the primary benefactors for removing the dam are the spe-

cies of anadromous fish in the Rogue river, including the threatened

SONCC Coho salmon, replacement of the antiquated pumping facilities

and noncompliant fish screens mean GPID is now in compliance with

regulatory requirements. In addition, the economy benefitted from the

funds expended on the project, both locally and nationally. The total

estimated project cost of the new diversion facility and removing the

dam was about US$39.3M, with US$3M for dam removal provided

by the Oregon Watershed Enhancement Board.

The authors are Richard D. Benik, rbenik@usbr.gov;

Robert Hamilton, rhamilton@usbr.gov;

and John Redding jredding@usbr.gov

For more details visit: http://www.usbr.gov/pn/programs/

lcao_misc/savage/

Project partners

Major participants in the removal of the Savage Rapids dam included:

Grants Pass Irrigation District (GPID)

US Bureau of Reclamation (USBR)

Oregon Department of Fish and Wildlife (ODFW)

Oregon Water Resources Department

National Marine Fisheries Service (NOAA Fisheries)

US Fish and Wildlife Service (USFWS)

WaterWatch of Oregon

IWP& DC

16 JANUARY 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

PROJECT FINANCE

HE hydro power industry led the US out of the Great

Depression of the 1930s and, according to the National

Hydropower Association (NHA), it has the capabilities

to play a key role in economic growth and expansion

over 80 years later. Hydro industry development will not only help

steer the country towards energy security, but it will also create

thousands of new jobs.

The above ﬁndings of a recently commissioned NHA study outline

how the industry can expand its contribution to energy, environ-

mental and economic goals over the next 15 years. Energy Secretary

Stephen Chu believes that such development of the US’ lowest cost

energy option is an ‘incredible opportunity’. An opportunity, the

NHA believes, for the environment, the US economy and its people.

GROWTH POTENTIAL

Early in 2009 NHA commissioned Navigant Consulting to conduct a

study examining the hydro power industry’s job creation and capac-

ity growth potential. Information gathered from industry members

and government ofﬁcials demonstrated the industry’s true potential:

the creation of 700,000 new jobs and the addition of 60GW of hydro

power by 2025. The study examined the industry’s potential under

two different scenarios. Both scenarios assume that hydro power con-

tinues to provide about 7% of total US electricity, and that electricity

demand grows by 2% annually. The scenarios are: Business as usual

– where renewables generate 10% of total US generation; Accelerated

case – where national policies mandate 25% renewable generation.

Industry supporters welcomed the report but promoted more action

in its wake. Pennsylvania Governor Edward Rendell urged policy

makers to support the development of hydro in the US. “It’s time to

invest in renewable energy resources that generate electricity in this

country and that provide jobs for Americans,” he said. “Hydro power

presents elected ofﬁcials across the country with an opportunity to

bring thousands of long term, family wage jobs to our states.”

Voith Hydro CEO Mark Garner agrees. “This study conﬁrms what

our experience at Voith Hydro has already shown – investments in

hydro lead directly to good paying, long lasting American jobs.”

The US hydro industry currently employs over 300,000 people but

the creation of additional jobs means that over one million could be

working in the industry by 2025. According to James Kautar, interna-

tional representative for the International Association of Machinists

and Aerospace Workers, hydro power is already an important source

of good paying, high quality jobs for workers across the country. ‘A

national investment in hydro power will help grow American jobs for

decades to come,’ he added.

Key areas which will experience new job creation include:

U Environmental sciences – the US hydro industry is already one of

the largest natural resource stewards in the country and employs

hundreds of people in the management of ﬁsh, wildlife, forest land

and other ecosystems. Additional jobs will include biologists, forest-

ers and environmental scientists.

U Engineering – The addition of 60GW of hydro power will create

new opportunities for those working in electrical, mechanical,

marine, civil, hydrological and systems engineering.

U Manufacturing and construction – Extensive support will be

required from manufacturers, construction workers and skilled

labourers to build new equipment and facilities. Both permanent

and recurring jobs will be created in all regions of the US.

U Financial services

U Public policy – Expanding hydro power resources requires public

policies that encourage development and investment. Policy ana-

lysts, biologists, environmental scientists and regulatory specialists

will be key workers involved in this.

U Outreach and education – Educators, public relations specialists,

writers, designers and artists will be required to provide communi-

cations support for such hydro power expansion.

U Historic preservation – The US hydro industry operates some of

the oldest historic facilities in the energy industry. Maintaining the

historic integrity of these sites, while ensuring that they operate to

the most efﬁcient modern standards, will require historians and

preservation experts amongst others.

U Management – Co-ordinating the efforts of over one million

employees will require the concerted effort of good management

teams. They will oversee a huge array of organisations from small,

entrepreneurial companies to larger multinational corporations.

In order for the above expansion to take place, the NHA says that

the government must act now to support renewable power. It should

implement the following policies:

Adopt a federal renewable energy standard that:

U Recognises hydro power and hydrokinetics as qualiﬁed renewable

energy resources.

U Backs existing hydro power out of a retailer’s base, acknowledging

the beneﬁts of existing hydro power.

U Set 1988 as the in-service data for incremental hydropower and

hydro at non-powered dams.

Pass the following tax incentives that:

U Make hydro power production tax credits equal to those of other

renewables.

U Provide an investment tax credit for pumped storage and other

energy storage options.

U Provide at least US$5B in funding for the clean renewables energy

bonds programme.

Enact climate policy that:

U Recognises hydro power’s clean air beneﬁts, including the 225Mt

of carbon dioxide it helps avoid each year.

U Provides allowance value to hydro power resources under a cap and

trade programme.

U Includes support for incremental hydro power, development at

non-powered dams, and ocean, tidal and instream hydrokinetic

resources in all climate measures.

Bolster federal research and development programmes into water-

power resources:

U To provide US$500M for the US Department of Energy’s water-

power R&D programme to support new technology advancements,

environmental studies, and additional resource assessments for

hydro power, pumped storage and hydrokinetic technologies.

‘Hydro power must play a critical role in our national energy,

environmental and economic policy, says NHA Executive Director

Linda Church Ciocci. ‘The NHA stands ready to work with all

policymakers who pursue the development of the US’ critical

hydro power resources.’

Hydro set to ease economic woes

A recent study in the US is urging the government to support hydro power to help it steer

the country back to economic recovery through the creation of thousands of new jobs

IWP& DC

WWW.WATERPOWERMAGAZINE.COM JANUARY 2010 17

PROJECT FINANCE

HE Copenhagen climate change summit in December 2009

was a key point on the world’s road to a low carbon future.

On top of the political impetus there are also many long

term commercial drivers for the low carbon sector.

Culminating over a 20-30-year period, all of these drivers now

provide a highly attractive and sustainable investment opportunity

that offers exposure to long-term, non-cyclical investment themes.

As the economics of investing in the sector have become increasingly

attractive, ﬁnancial investment into it has grown from US$35B in

2004 to US$155B in 2008 [1].

However, the current level of investment still contrasts markedly

with the scale of investment required to transition to a low carbon

economy. The Stern Review’s [2] central estimate of the costs of sta-

bilising greenhouse gases at levels of 500-550ppm of CO2 equivalent

is, on average, around 1% of the annual global GDP by 2050 (the

2008 IMF estimate of global GDP was US$69T [3]).

The International Energy Agency (IEA) estimates that cumulative

energy investment of over US$26T is required between 2007 and

2030 [4]. New Energy Finance considers that US$7.3T of this amount

will be required for renewable energy and US$5.7T for energy efﬁ-

ciency, equivalent to an annual investment of US$542B [5] across all

asset classes. The UN estimates that more than 80% of the required

investment will need to come from the private sector [6].

ACCESSING PRIVATE EQUITY

Although there is an increasing interest from institutional investors

looking to beneﬁt from the signiﬁcant opportunities offered by the

low carbon sector, the low carbon economy is still regarded by some

as an emerging sector and remains a challenging asset class in terms of

access. Osmosis Capital LLP is the specialist private equity asset man-

agement arm of Osmosis Investments LLP, focused on the develop-

ment of low carbon investment solutions for institutional investors.

When investing and ﬁnancing renewable projects, good manage-

ment skills are essential. Strong funds in the development capital

sector are based around management teams with speciﬁc geography,

sector and development skills which enable them to construct asset

development platforms to build and then exit infrastructure in energy

and water. The execution of these asset origination strategies requires

the understanding of key issues such as: the management of greenﬁeld

development risk; the regulatory drivers in each jurisdiction and local

access to knowledge in key markets to judge how the political and

regulatory environments will change over a 5-10 year period; and the

viability of debt ﬁnancing for each technology in each jurisdiction at

any point in time.

Furthermore, each management team has its own unique strategy and

network. There has been no commoditisation of investment skills in the

low carbon sector and it is highly unlikely that there ever will be.

The current economic climate has presented various challenges for

this area of work. Investments have been held up due to problems in

other sectors and unrelated markets, while the availability of bank debt

has also been a problem, although the situation is now improving.

There is no doubt that the credit crunch has had a severe impact on the

market but as project ﬁnancing gradually returns it will become easier

to get ﬁnancing for proven technologies. Many regions are looking to

develop a diversiﬁed mix of renewable energy solutions and we expect

to see infrastructure rollout in wind, solar PV, solar thermal, geother-

mal, biomass, hydro and many other generation technologies.

DIVERSIFICATION

Osmosis Capital is interested in geographic diversiﬁcation within its

area of expertise, with a main focus on Europe and North America.

There are good project developers who the company would expect to

generate strong returns in many countries. In regions where there has

been a history of development with strong drivers and support for the

low carbon sector, there will be signiﬁcant investment opportunities.

Looking to the future, and ﬁnancing aside, the company acknowl-

edges that there are other challenges which lie ahead for the renewa-

bles sector. For example in order to make the most of new renewable

generation, the appropriate grid connections must be developed along

with smart grid infrastructure. Improvements will also be required in

storage capacity and technology.

Dr Jim Totty, Partner, Osmosis Capital LLP, 8-9 Well Court,

London EC4M 9DN, UK, email: jim.totty@osmosiscapital.com

The renewables sector is an attractive and

sustainable investment opportunity. However,

the current level of investment still contrasts

markedly with that required for the transition

to a low carbon economy, says Jim Totty

Aiming high in the

low carbon economy

The low carbon economy is a highly attractive investment arena

The big global issues of security, scarcity, volatility, demand and ultimately climate

change are driving changes around the world economy in a virtuous circle

Alternatives become more competitive

This Global drive has created a rapidly evolving low industry which offers investors long term return opportunities

Global Drivers

Energy security

Energy demand & price volatility

Green Collar jobs

Climate change

Water and resource scarcity

Rising resource cost and price volatility continue to make

renewable and sustainable alternatives more and more viable

Behaviour changes

Changes in behavioural

preference across both

corporate and

consumer sectors, nurture and

sustain investment in climate

change innovation

Policy changes

Incentives, subsidies, targets,

standards, penalties,

tax credits and general regulation

aid in stimulating

investment into climate

change innovation

lternatives become more com

etitive

Gl b l D i

isin

resource cost and

rice volatilit

continue to make

ene

able and sustainable alternati

es more and more

iable

ehaviour chan

han

es in behavioural

erence across bot

orate an

consumer sectors, nurture and

sustain in

estment in climat

chan

e innovation

Polic

chan

ncentives, subsidies, tar

ets,

tandards,

enalties

tax credits and

eneral re

ulation

aid in stimulatin

estment into climate

chan

e innovation

References

1 New Energy Finance – Global Trends in Sustainable Investment, 2009.

2 The Stern Review, The Economics of Climate Change, October 2006.

3 International Monetary Fund, Gross Domestic Product based on

purchasing-power-parity (PPP) valuation, 2008, www.imf.org.

4 IEA World Energy Outlook, 2008.

5 New Energy Finance, private communication, September 2009.

6 UNFCCC (2007) Investment and Financial Flows to Address Climate Change.

7 OPEC share of world oil reserves, www.opec.org 2007.

8 Repsol, August 2009.

9 Ambrian Capital ‘Cleantech 2009’, February 2009.

10 UN Population Division Press Release, March 2009.

11 US Energy Information Administration (EIA) Press Release, May 2009.

Commercial drivers for the sector

U Energy independence and security. 78% of oil reserves are owned by OPEC

countries [7]. 31% of natural gas reserves are owned by former Soviet Union

countries and 41% by Middle Eastern nations [8].

U Fossil fuel, water and resource scarcity. Less than 3% of the world’s

available water is fresh, and 70% of this is frozen [9]. Two hundred and forty

water basins around the world cross national borders and therefore pressure

on scarce water resources is expected to increase [9].

U Demand increase from population and developing economy growth. The world

population is currently 6.8B people and is forecast by a recent UN report [10]

to rise to over 9B by 2050. The US Energy Information Administration forecasts

world energy use to increase by 44% between 2006 and 2030 [11].

U Climate is recognised as a threat to the global economy and political stability.

U The falling cost of renewable energy generation.

U ‘Green collar’ job creation and long term national growth strategies.

IWP& DC

18 JANUARY 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

EQUIPMENT

URKEY’S Akköy II hydro power project is located

approximately 150km from Trabzon, close to Gümüshane

in the Eastern Black Sea region of Turkey. The project

encompasses the Aladereçam regulator, the Gökçebel and

Yasmaki dams and an electric power plant close to the Akköy 1

scheme also under construction, to produce a total of 890GWh.

The Aladereçam regulator is being constructed at a ‘thalweg’ eleva-

tion of 1797m directing water to the Gòkçebel dam lake through a

4.5km long link tunnel with an inner diameter of 3.2m. The dam has

been designed as a rockﬁll construction with a concrete coated front

and a ﬁnal height of 140m.

Served by the Gelaver stream in the Gumushane and Giresun

Province borders, Gòkçebel lake will hold an estimated 65.07Mm

The dam is in turn linked to the Yasmaki dam lake area at a ‘thalweg’

elevation of 1527m via a 6.65km long tunnel.

Yasmakli dam is a 100m high concrete gravity dam on the Gavraz

scheme in Giresun Province. The dam has a storage capacity of

15.51Mm

to channel water into a 4km long surge tank and tunnel.

The dam includes a 1219m high penstock, making it the highest head

on an hydro scheme in Turkey.

VIRTUAL QUARRY

In a ‘virtual’ quarry style application, ﬁve Sandvik drill rigs will be

used to produce rock for the Gòkçebel dam plus further rock for

access roads and eventually the concrete production equipment.

Project contractor Kolín Construction is currently using two

DX700 and the new DX800 to prepare access roads at an elevation

of 1856m. They will also be used, together with two Sandvik rigs

in drill and blast operations to provide inﬁll material for the rockﬁll

dam; producing 300-450 drill metres every 10 hour shift.

Featuring a base of 140m x 340m rising to 6m x 250m at 140m

height, the dam will require almost 4.5Mm

of rock.

Rock conditions feature a mix of very hard and abrasive volcanic basalt,

granites, granite diorite and quartz with a hardness factor of between 5 –

7.5. Blasting is carried out twice daily at shift change and lunch.

All ﬁve hydraulic rigs are ﬁtted with Sandvik T51 3.6m long mf rods.

Depending on the rock conditions three different Sandvik bits are used.

Retrac ‘normal face’ 89 mm diameter bits are predominantly used, par-

ticularly in the harder rock. Retrac ‘drop center’ and ‘ﬂat face’ bits are

also used when the rock conditions dictate. If the contractor is drilling

less than 10m in soft ground, standard drop center 89’s are used.

Kolín is also shortly to introduce Sandvik guide tubes for poor

ground conditions to also achieve straighter holes.

ABRASIVE ROCK

It is the abrasiveness of the rock which is the prime consideration

where the drill bit life can be as low as 100 drill metres.

The rig operators conﬁrmed however that the bits are frequently

lasting each 10 hour shift with around 400 drill metres.

“This performance is very high and quite exceptional consider-

ing the abrasiveness and inconsistencies of the rock,” said Machine

Manager Mehmet Tuncay, adding, “Another challenge is being able

to meet the speed of the drill and blast cycles. The MF rods are also

providing high performances and exceptional life.”

Each Sandvik drill rig is producing 200m

/h per rig to ensure the speci-

ﬁed 2000m

/rig is produced each 10 hour shift. Drilling to 15m depths,

each hole takes an average 20 minutes depending on the rock conditions.

THE DX800

The Sandvik DX800 is a hydraulic self propelled, self contained and

crawler-based surface rig with an ergonomic high visibility cabin and

rod handling system. It is powered by a Cat C7 diesel engine rated at

168 kW (225 hp) at 2200 rpm.

The rig has been developed to offer excellent stability even in uneven

terrain and is designed for use in drilling 64-127mm diameter holes.

Additional features include up to 12 hours continuous drilling, high

suction capacity dust collectors, advanced boom design and ROPS–

and FOPS-certiﬁed safety cabin.

www.sandvik.com

Turkey’s Kolín Construction has taken delivery of a purpose-ordered DX800 drill rig,

bringing its ﬂeet of Sandvik rigs on Akköy hydro power project to ﬁve units – producing

almost 4.5Mm

of rock ﬁll for the schemes Gökçebel dam

Rockfill production in Turkey

IWP&DC brings you details on some of the latest product developments

in the hydro power and dam construction industry

NEW TECHNOLOGY

WWW.WATERPOWERMAGAZINE.COM JANUARY 2010 19

EQUIPMENT

Eliminating grease lines and fittings

Scanning sonars assist underwater searches

MANY BEARINGS are located in difﬁcult areas

and greasing them can be a tough task. Over the

years, new technologies have emerged to help

reduce time spent on greasing bearings. Grease lines

and ﬁttings help to get to those difﬁcult areas that

are hard-to-reach but just a crucial as the rest. An

automatic grease lubrication system can also free up

a signiﬁcant amount of time for maintenance that

could be used to focus on other aspects of the plant.

In either situation, it is still necessary to apply grease

and spend time on cleaning; grease can leak, be

messy and must be attended to in order to decrease

polluting or corroding other materials. There are

options for greaseless bearings that eliminate com-

plex lubrication systems and undesired cleaning in

a number of areas throughout a plant.

Columbia Industrial Products offers self-lubricat-

ing materials, CIP Composites, for bearing and wear

applications. These composite materials eliminate

the need for grease and reduce maintenance in high

load and slow speed applications. As a laminated,

polyester based composite, manufactured with solid

lubricants, CIP Composites have low coefﬁcients of

friction in both wet and dry running applications.

CIP Hydro Composite is a proprietary material

blend of textiles and additives, designed speciﬁcally

for inside the generating plant. CIP Hydro has been

tested with excellent friction and wear results along

with excellent performance when edge loaded at

Power Tech Labs (Surrey, Canada), says the com-

pany. This 100% bearing material, which has no

ﬁberglass or metallic shell, is stable where shock

and misalignment may be present. Manufactured

with no abrasive ﬁller, such as calcium carbonate,

CIP Hydro has been designed to be non-abrasive

to mating surfaces, with a long wear life and easy

to machine.

Where long wear life is a requirement in the

high loaded bearings with limited rotation, such

as wicket gates and their linking mechanisms, this

is one of many applications where the lubrication

system can be eliminated. For every wicket gate

there are three possible bushings where CIP Hydro

can be installed and the grease ﬁttings removed.

CIP Hydro can be installed by freeze or press ﬁtting

with the option to machine in place. With options

of eccentric inner diameters, the composites are

custom manufactured to customer speciﬁcations.

One unit at the John Day Dam (Columbia River,

US) has replaced all wicket gate bearings and link

bushings, eliminated grease and applied a new coat

of paint. CIP Hydro bushings, ﬂange bearings and

thrust washers were installed during refurbishment

of this particular unit.

In other units and power plants, CIP Hydro has

been utilized as operating ring wear pads, servo-

motor connecting rod bushings, screen bushings/

wear pads, pump bearings, lock and control gate

bushings, and trunnion bearings. At Foster Dam

(Oregon, US) the US Army Corps of Engineers

(USACE) decided to use CIP Hydro as a replace-

ment of the original bronze trunnion bushing and

graphite plugged bronze thrust washer on the spill-

way gates. “We had three reasons for choosing self-

lubricating materials,” said Ronald S Wridge, chief

of mechanical design section of the USACE Portland

District. “First trunnion friction will be reduced by

upwards of 50 percent. Second they eliminate or

signiﬁcantly reduce maintenance requirements for

the trunnion. And third, this eliminates the envi-

ronmental issues associated with using grease near

a waterway.” (Hydro Review, May 2009).

www.cipcomposites.com

SCANNING SONAR is fast becoming one of the

tools of choice for underwater search operations

by a diverse group that includes public safety dive

teams, universities, and commercial diving compa-

nies. Scanning sonars are in demand because they

create a “picture” of the underwater environment

regardless of water clarity. Although these sonars

lack the long range and very high resolution of side

scan, they can often still give a larger picture of the

underwater environment than that of an underwater

camera or diver. Even in areas where there is zero

visibility, the sonar can produce a detailed image of

objects on the bottom or in the water column.

Scanning sonar works by transmitting a sound

wave from a transducer. This sonar beam sweeps

an area underwater much like radar does in air.

The beam reflects off underwater objects and

returns to the transducer where it is received and

sent to a topside computer for display and storage.

Other information can be saved with the sonar

data such as GPS coordinates and notes made by

the operator.

The operator controls the size of the search area

through the computer. The sonar beam can sweep

a 360 degree circle around the transducer or any

portion of the circle.

Another reason scanning sonar is so popular

is its versatility. It can be operated as a “stand-

alone” search system or mounted on an ROV.

With the stand-alone version, the transducer is

lowered from a boat on a pole, or mounted on a

tripod and lowered to the bottom. After an area

is searched, the sonar is retrieved and moved to a

new area where the process is repeated.

With the ROV mounted version, as the underwa-

ter vehicle moves slowly along the sonar continu-

ally scans the course ahead. The sonar can “see” a

much greater distance than the camera which lets

the operator navigate around obstacles and helps

in guiding the vehicle toward the target. Once it’s

within visual range the ROV’s camera can take over

and perform a close up inspection.

The University of Alaska is using a JW Fisher

ROV with scanning sonar to help in its study of

marine ecosystems. The school is part of a national

cooperative program that promotes research in

the management of ﬁsh and wildlife. It also has a

Coastal Marine Institute. As part of an agreement

between the university and the US Department of

the Interior’s Minerals Management Service, the

institute’s researchers explore coastal sites and

assess the potential for development of natural

gas, oil, and minerals.

Fishers scanning sonars are available in two types;

the SCAN-650A designed for use as a stand-alone

search system or for mounting on larger ROVs, and

the SCAN-650B for use on smaller ROVs.

www.jwﬁshers.com

Scanning sonar image of car on a river bottom;

Inset photo – SeaOtter-2 ROV with sonar trans-

ducer mounted on top

20 JANUARY 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION

DESIGN

N northern Europe and the Alps, where communities and

infrastructure can face snow avalanche hazards, the research

efforts have increased in recent years into the effective design

of dams as planned defence structures.

While dams and associated braking mounds can often mitigate the

impacts in the avalanche run-out zones, there remains some uncer-

tainty about their effectiveness in deﬂecting and, in particular, stop-

ping the ﬂows. The bottom line is they can reduce risk but cannot

totally guarantee safety.

The European Commission (EC) recently published a report on

the theory and practice in the ﬁeld – “The Design of Avalanche

Protection Dams: recent practical and theoretical developments” –

which is recognized as representative of the state of the art, establish-

ing a new design framework. Some of the research that informs the

most recent developments and production of the report was helped

by EC projects CADZIE and SATSIE, and support also came the

Icelandic Avalanche and Landslide Fund.

Researchers also note, though, the parallel but independent work

in Switzerland that has produced a new set of design rules for catch-

ing dams. The Swiss work and EC report – which covers both catch-

ing and deﬂecting dams – are compatible, the researchers add. They

are being used alongside one another and both are to be employed

in a forthcoming commercial avalanche dam design software tool,

which is being developed in Austria.

However, despite the progress, there are still many areas of broad

research to be advanced as well as uncertainties to be reduced.

SNOW AVAL ANCHES

The main focus of research and dam design has been in relation to

dry-snow avalanches, the conceptual model of which comprises a

dense core (approximately 300kg/m

) with a ﬂuidised layer on top,

and in front too, and the mass is enveloped by a suspension layer

called the powder cloud.

In the moving mass, transitions between the layers are variable and

take place over a range of ﬂow depths. The three layers are progres-

sively less dense, and the model takes the avalanche core to have per-

sistent contact between particles. It is estimated to be approximately

1m-3m in depth, and possibly greater where there are channelling

effects in the running ﬂow.

The ﬂuidised layer has less contact between particles and the range

of density is approximately 10kg/m

-100kg/m

. It typical depth is

2m-5m and its front can precede the dense core by tens of metres. The

ﬂow depth of the powder cloud is at least this magnitude though can

extend to 100m or more.

Wet-snow avalanches differ in several ways from dry-snow events, not

least in having more moisture and being slower, which also leads them

to follow depressions in the terrain. The ﬂows may have a long tail, can

spread and split around obstructions, and they also carry loose materials

and rocks, which may be deposited near dam and ﬂow channels.

When it comes to powder-snow avalanches, however, they have

such large run-up heights and speeds – observed to be hundreds of

metres high and 50m/sec-70m/sec, respectively – that they cannot be

stopped by man-made dams.

DAMS AND MOUN DS

Two principle types of dams are employed as avalanche defence

structures – deﬂecting dams, to divert ﬂow, and catching dams to halt

Dam design to defend communities against avalanches has been advancing, but there is still

great scope for research. Patrick Reynolds reports

Catching dam

Snow deposit

Retarding mounds

Avalanche dams

A schematic ﬁgure of a catching dam showing the contributions of the velocity

of the avalanche, h

, the thickness of the ﬂowing dense core, h

, and the thick-

ness of snow and previous avalanche depositsvon the ground, h

, to the dam

height, H

. The ﬁgure is adapted from Margreth (2004). Courtesy of the EC