Transcript CE 458: Design of Hydraulic Structures

CE 458
Design of Hydraulic Structures
by
Dr. Nuray Denli Tokyay
1-3 Historical Perspective and Trends for Future
Ancient Hydraulics Works in Egypt and Other Early Civilizations:
Early civilizations developed in regions:
1. where an abundance of water could be
distributed over fairly flat land for irrigation, and
2. where a warm climate produced a fast growth of
crops.
Thus, it is hardly surprising that the earliest remains and
accounts of water control were to be found in:
– Egypt,
– Mesopotamia (Iraq),
– the Indus Valley (India and Pakistan), and in
– the Yellow River Valley of China.
Egypt is particularly interesting in this regard because the
natural features of the Nile River and even the prevailing winds
favored the development of a robust civilization.
The annual floods over the rich delta land allowed agriculture
to flourish even though many people had to move to higher
lands during flood season.
•To augment the flow of irrigation water during the low flow
season, there are signs that one of the early rulers,
•King Menes (about 3000 B.C.), had a masonry dam built
across the Nile near Memphis (about 23 km upstream from
present-day Cairo).
•This dam was apparently used to divert the river into a canal
and, thus, to irrigate part of the adjoining arid lands.
•As reported by Biswas (1), “the gravity dam seems to have
had a maximum height of about 15 m and a crest length of
some 450 m ”.
• Egypt was one of the first civilizations to develop an
extensive system of river navigation.
• The Nile traversed the entire length of the country and, in
the Delta, divided into seven delta channels, thus providing
an extensive system of waterways.
• A climatic factor favoring the development of water
transportation was that the prevailing winds (especially
during the summer months) blow from north to south (from
the Mediterranean Sea to the Sahara Desert).
• However, the river flows from south to north so that
boatmen used sails to navigate upstream and leisurely
drifted downstream (without sails) during the return trip.
This mode of transportation is still seen today.
Prevailing winds
(especially during summer)
River (direction of flow)
• Civilization in Mesopotamia started about the same time as in Egypt
(about 3000 B.C.), and the geography of the two areas is in many
ways similar. The Euphrates and Tigris rivers formed a network of
channels before finally emptying into the Persian Gulf. Furthermore,
the people of the area built many canals for irrigating crops, draining
swamps, and water transportation. Early hydraulic “engineering” in
this area included developing flood protection works and dam
construction.
• Ancient ruins in the valleys of the Indus River in Asia and the Yellow
River in China reveal evidence of water systems developed at least
3000 years ago; however, records of the extent of this development
are not as complete as for Egypt and other areas of the Middle East .
the Indus River in Asia and the Yellow River in China
Euphrates and Tigris rivers
• Arabic: Al Furat Turkish: Fırat
The Euphrates River is one of the most important
rivers in the world. Along with the Tigris, it provided
much of the water that supported the development
of ancient Mesopotamian culture.
The Tigris Euphrates valley was the birthplace of
the ancient civilizations of Assyria, Babylonian, and
Sumer.
In northern Iraq the Euphrates forms the western
boundary of the area known as Al Jazirah. To the
southeast the alluvial lands between the two rivers
was the site of the glorious Babylonian civilizations
of ancient times.
The Euphrates is important solely for its water supply.
The river is the source of political tension, as Turkey,
Syria and Iraq all compete for the use of its waters for
irrigation and the generation of hydroelectric power.
For centuries the river formed the east limit of Roman
control. During the supremacy of the Eastern Roman
Empire, numerous towns and centers of art and literature
flourished along its bank. Much historical data has been
yielded by archaeological excavations on the banks of
the Tigris and the Euphrates.
• A different type of ancient hydraulic engineering was developed in
eastern Turkey and Persia (Iran) from the seventh to fifth century
B.C.
• Underground canals, called qanāts, were dug to intercept
groundwater aquifers and to carry the water from the source areas to
cities. Figure below, shows the details of this system. Biswas (1)
notes the average length of a qanāt was about 42 km (26 mi), and in
some places it was as deep as 120 m (400 ft). Such ancient water
supply systems, some of which still exist, were truly remarkable.
Details of ganāt system
URARTUS (900-640 BC)
•Most probably the name Urartu comes from the Assyrian word “uriatri”
meaning mountainous area which perfectly fits the geography of Eastern
Anatolia where Urartus lived.
•Starting with the fourth king, Menua, construction became the main
engineering activity in the Urartu Kingdom. During his reign (810-780 BC)
besides fortresses, palaces and temples, irrigation canals and roads were
started to be built all over the kingdom.
•Archeological evidence indicate considerable technical skills of the
Urartian people on irrigation and water management, also.
•The Menua Canal which was built about 2800 years ago is still in
operation. Urartians first exploited a powerful spring in the valley of Ergil
Çayı (Ergil Creek) and conveyed about 45 million m3 of water annually to
Tushba (Van) for about 56 km.
•The seventh king of Urartu, Rusa I (730-713 BC), moved his capital to
Sardurihinili.
• For this new capital, another source of water had to be
found. An artificial lake was created by building two dams
in the mountains. The water collected was directed to the
city by a natural river bed. Additional water was stored by
the dams. Urartian water management system contained all
the elements which are used in modern systems: River
diversions, transfer of water from one catchment area to
another and water storage by dams [GARBRECHT 1987].
• It is obvious that the knowledge of hydrotechnology and
road construction passed from one king to another.
Therefore, the technical skills are taught by some means or
another. Unfortunately, no written evidence was found yet
on how this transfer of knowledge was done.
Roman Water Systems
• From about 200 B.C. to 50 A.D., the Romans developed elaborate
water-supply systems throughout their empire.
• For Rome itself, the usual practice was to convey water from springs
to an aqueduct and then to cisterns throughout the city from which
water was delivered to consumers through lead and baked-clay
pipes. Hadas (5) reports that 11 aqueducts supplied Rome with
about 750 million liters (750 000 cubic meter, 200 million gallons) of
water daily.
• The aqueducts consisted of one or more channels of rectangular
cross section and in some locations were supported on spectacular
masonry arches. The channels, which were from 60 to 180 cm (2 to 6
ft) in width and from 1.5 to 2.5 m (5 to 8 ft) in height (11), were
covered to prevent the water from being contaminated by dust and
heated by the sun. Inspection holes were in channel covers about
every 75 m (250 ft) (11).
Notable Dams Built in This Century
The need for more water resources during this century is the result of a
rapidly expanding world population and industrial growth.
New machines and methods for manufacturing and placing large
quantities of concrete and improved earth-moving equipment provided the
means to achieve the rapid growth in major hydropower, irrigation, and
flood control projects.
In almost all cases, dams are the backbones of these water-resources
projects. For hydropower development, a dam is generally needed to
develop the head to drive the turbines and to store water to allow power
generation.
For flood control, dams are used to form reservoirs, which reduce flood
peaks by storing the peak flows of flood water. Even a dike constructed to
prevent flooding of property near a river is a form of dam. Dams in the
United States that are over 15 m high or between 10 m and 15 m high and
impound more than 100,000 m3 (81 acre-ft) of water number about 3,000
(9). At the beginning of this century, only 116 of these dams had been built
(9).
Table 1-1, lists the world’s major dams.
The two highest dams are constructed of earth, which may be surprising
to many because we often think of concrete as the material from which
high dams are made. However, since availability of material and the
strength of the foundation dictate the type of dam to be designed and
constructed, earth is often used.
Abbreviations are as follows:
E= earthfill,
R= rockfill,
G= gravity,
A = Arch.
Table 1-1 Major Dams of the World (Highest Dams)
Abbreviations
are as
follows:
E= earthfill,
R= rockfill,
G= gravity,
A = Arch.
Name of Dam Country
Type*
Height (m)
Rogun
USSR
E and R
335
Nurek
USSR
E
300
Grand
Dixence
Switzerland
G
285
Inguri
USSR
A
272
Vaiont
İtaly
A
262
Chicoasen
Mexico
R
261
Kishau
India
E and R
253
Guavio
Colombia
R
250
Mica
Canada
E and R
245
Sayano
Shushensk
USSR
A and G
245
Mauvoisin
Switzerland
A
237
Chivor
Colombia
R
237
Oroville
USA
E
235
Greatest Volume
Name of Dam
Country
Type
Volume (106 x m3)
Chapeton
Argentina
E
290
New Cornenelia
USA
E
209
Tarbela
Pakistan
E
122
Fort Peck
USA
E
96
Guri
Venezuela
E&G&R
76
Greatest Hydropower
Name of Dam
Country
Type
Installed Capacity
(MW)
Grand Coule
USA
G
6500
Sayano Shushensk
USSR
A&G
6400
Krasnoyarsk
USSR
G
6000
Churchill Falls
Canada
E
5225
Bratsk
USSR
E&G
4500
Atatürk Dam
Atatürk Dam, largest dam built in Turkey, serves for:
• irrigation,
• power generation and water supply.
It is one of the dams built in GAP (South Eastern
Anatolian Project), one of the largest water resources
development projects in the world.
It is located in 70 km northwest of the city of Şanlıurfa on
the Euphrates River.
• Embankment type is rockfill with inclined clay core.
Ataturk Dam, having 184 m height from foundation, is
the fourth highest dam in Turkey following Keban,
Altınkaya, Karakaya and Altınpınar dams.
Among rockfill dams in the world, It’s
the 25 th, regards its height,
5 th, embankment volume,
21 st, reservoir volume and
32 nd installed power of HEPP.
Atatürk HEPP has been in operation since 1993. It has an
annual power generation capacity of 8.9 billion kWh. Its
capacity will fall to 8.1 billion kWh per year when irrigation
projects are completely implemented.
The dam will make it possible to irrigate approximately
882,000 hectares of land.
Atatürk Dam
TECHNICAL DATA FOR THE DAM
Volume of Embankment
84.5 million m 3
Average Annual Flow
26.654 km 3
Useful Storage Capacity
11.0 km 3
Total Storage Capacity
48.7 km 3
Reservoir Surface Area
817 km 2
Drainage Basin
92.338 km 2
HeightFrom Foundation
184 m
Height From River Bed
166 m
Crest Length
1 664 m
Crest Width
15 m
Crest Elevation
549.00 m
River Bed Elevation
380.00
Minimum Operation Water Level
526.00 m
Maximum Operation Water Level
542.00 m
TECHNICAL DATA FOR THE HEPP
Width
: 49 m
Height
: 55 m
Length
: 257 m
Total Volume
: 380 000 m 3
Number of Turbine Generators
:8
Installed Capacity of Each Group
: 300 MW
Total Installed Capacity
: 2400 MW
Loading Factor
: %30
Power Generation Capacity
: 8.9 x 10 9 kWh / year
Hydraulic Turbines
: 8 vertical type Francis
Turbines
Output Voltage of Each Generator
: 15 750 Volt
Frequency
: 50 Hz
Speed
: 50 Hz
Number of Power Transformers
: 24
Power of Each Transformer
: 105 000 kVA
Input-Output Voltage
: 15 750 380 000 Volt
The Şanlıurfa Tunnels and Irrigation Projects
• The two Şanlıurfa Irrigation Tunnels, longest
irrigation tunnels in the world, start from the
reservoir of Atatürk Dam and lie parallel to each
other from 5 km northeast of the city of Şanlıurfa
to Şanlıurfa-Harran plains.
• The tunnels are circular and concrete lined with
diameters of 7.62 meters and lengths of 26.4
kilometers each.
• With the addition lengths of access and
connection tunnels, total length of the tunnels
reaches 52.8 kilometers
• By means of the Şanlıurfa tunnels, the water
stored in the reservoir of Atatürk dam will be
used for Şanlıurfa-Harran and MardinCeylanpınar plains. Thus, irrigated agriculture
will take place in 476 000 hectares of land of
these plains, 150 000 hectares of ŞanlıurfaHarran plains, 326 000 hectares of MardinCeylanpınar plains.
• 328 cubic meters of water per second is drawn
from the Atatürk Dam Reservoir with these
tunnels.
• The water used to irrigate plains of ŞanlıurfaHarran will also be deployed for power
generation at the Şanlıurfa HEPP.
• The HEPP has a capacity of 50 MW and
generates 124 million kWh electricity annually.
TECHNICAL DATA FOR THE TUNNELS
Tunnel Type
: Circular reinforced concrete lining
Length
: Two parallel tunnels, 26.40 km each
Grade
: T1 – 0.62802 m/km
T2 – 0.62948 m/km
Excavation
Diameter
: About 9.50 m
Inner Diameter
: 7.62 m
Lining Thickness : Approximately 0.40 m
Excavation
: 3.00 hm 3
Concrete
volume
: 1 285 hm 3
Total discharge
: 328 m 3/s
Irrigation area
: 476 474 hectares
Geological
formation
: Calcareous marn
Hydraulic Load
: T1 – 40.25 m
T2 – 39.74 m
Rivers and Lakes
Turkey has about 120 natural lakes, including small lakes in the mountains.

The largest and deepest lake is Lake Van with a surface area of 3,712 km 2 and
an altitude of 1,646 m from sea level.

The second largest lake is Lake Tuz in central Anatolia. Being relatively shallow,
this lake is at an altitude of 925 m from sea level and has a surface area of
1,500 km 2.
 There are four main regions where lakes are intensively dispersed:
1. 1.
The “Lakes District” (Eğirdir, Burdur, Beyşehir, and Acıgöl Lakes),
2.
Southern Marmara (Sapanca, İznik, Ulubat, and Kuş Lakes),
3.
Lake Van and its environs, and
4.
Lake Tuz and its environs.

Although some of the lakes are only a few meters in depth, some of them are of
a depth of more than 30 meters. The depth of Lake Van is more than 100 m.
Turkey has 555 large dam reservoirs. The names and surface areas (km2) of the
large ones are Atatürk (817), Keban (675), Karakaya (268), Hirfanlı (263),
Altınkaya (118), Kurtboğazı (6).

• Turkey is rich in terms of streams and rivers. Many rivers rise
and empty into seas within Turkey’s borders. Rivers can be
classified in relation to the sea into which they empty.
• The rivers emptying into the Black Sea are the Sakarya,
Filyos, Kızılırmak, Yeşilırmak, and Çoruh.
• The rivers emptying into Mediterranean Sea are the Asi,
Seyhan, Ceyhan, Tarsus, and Dalaman.
• The rivers emptying into the Aegean Sea are the Büyük
Menderes, Küçük Menderes, Gediz, and Meriç. The rivers
empting into the Sea of Marmara are the Susurluk/Simav,
Biga, and Gönen.
• The Euphrates and Tigris rivers empty into the Gulf of Basra,
while the Aras and Kura rivers empty into the Caspian Sea.
• As far as the lengths of the some major rivers are
concerned, the Kızılırmak is 1,355 km, Yeşilırmak is 519 km,
Ceyhan is 509 km, Büyük Menderes is 307 km, Susurluk is
321 km, the Tigris is 523 km, the Euphrates River up to the
Syrian border is 1,263 km, and the Aras River up to the
Armenia border is 548 km.
LAND RESOURCES
Mha ( million
hectares)
Arable Land
: 28.05
Irrigable Land
: 25.75
Rainfed Agriculture
: 17.25
Economically
Irrigable
: 8.50
Presently Irrigated
: 4.90
Land Resources
 Turkey ’s total land area is 78 Mha.
 Almost one third of this, 28 Mha, can be
classified as cultivable land.
 Recent studies indicate that an area of
about 8.5 million ha is economically
irrigable under the available technology.
 Until now, an area of about 2.8 million ha
has been equipped with irrigation
infrastructures by DSİ.
Water Resources
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Mean Precipitation : 643 mm/m2
Turkey ’s Surface Area : 780,000 km 2
Annual Water Resources Potential Bm ³ (billion m ³ )
A Precipitation Volume : 501
B Evaporation : 274
C Leakage into Groundwater : 69
D Springs Feeding Surface Water : 28
E Surface Water from Neighboring Countries : 7
F=A-B-C+D+E
F Total Surface Runoff (gross) : 193
G Exploitable Surface Runoff : 98
H Groundwater Safe Yield : 14
I=G+H
I Total Potential (net) : 112
• The total water volume in the world amounts to 1.4 billion
km3, 97.5% of which is saline water in the oceans and
seas, 2.5% of which is fresh water in the rivers and
lakes.
• Due to fact that 90% of fresh water exists in the South
Pole and North Pole, human beings have very limited
readily exploitable fresh water resources.
• Annual mean precipitation in Turkey is 643 mm, which
corresponds to 501 Bm 3 (billion m 3) of annual water
volume in the country.
• A volume of 274 Bm 3 water evaporates from water
bodies and soils to atmosphere.
• 69 Bm 3 of volume of water leaks into groundwater,
whereas 28 Bm 3 is retrieved by springs from
groundwater contributing to surface water.
• Also, there are 7 billion m3 volume of water coming from
neighboring countries.
• Thus, total annual surface runoff amounts to a volume of
193 Bm 3 of water.
• Including 41 (69-28) Bm3 net discharging into
groundwater (covering safe yield extraction, unregistered
extraction, emptying into the seas, and transboundary),
the gross (surface and groundwater) renewable water
potential of Turkey is estimated as 234 (193+41) Bm 3.
• However, under current technical and economic
constraints, annual exploitable potential has been
calculated as 112 Bm 3 of net water volume, as 95 Bm 3
from surface water resources, as 3 Bm 3 from
neighboring countries, as 14 Bm 3 from groundwater
safe yield.
Water Resources versus Water
Consumption Needs of Population
Countries can be classified according to
their water wealth:
– Poor: Annual water volume per capita is less
than 1,000 m3
– Insufficient / Water Stress: Annual water
volume per capita is less than 2,000 m 3
– Rich: Annual water volume per capita is more
than 8,000- 10,000 m3
1500 m3/capita
Turkey is not a rich country in terms of existing water potential.
Turkey is a water stress country according to annual volume of water
available per capita.
The annual exploitable amount of water has recently been
approximately 1,500 m 3 per capita
The State Institute of Statistics (DİE) has estimated Turkey’s
population as 100 million by 2030. So, the annual available amount
of water per capita will be about 1,000 m 3 by 2030.

The current population and economic growth rate will alter water
consumption patterns. As population increases, annual allocated available
amount of water per person will decrease. The projections for future water
consumption would be valid on the condition that the water resources were
protected from pollution at least for the next 25 years. It is imperative that
available resources be evaluated rationally so as to provide clean and
sufficient water resources for the next generation.
Planning Studies in Turkey
• Under the scope of DSİ’ planning studies, the most
appropriate formulations of projects are prepared by
using long-term data collections and investigations.
• In 2003, 40.1 billion m3 volume of water was consumed
in various sectors in Turkey; 29.6 billion m3 in the
irrigation sector, 6.2 billion m3 in the water supply sector,
4.3 billion m3 in the industrial sector.
• This sum corresponds to development of only 36.5% of
the available exploitable potential of 112 billion m3.
• With ongoing studies, it is aimed at using the maximum
portion of available potential in the country.
Hydraulic Structures in Turkey
 According to the standards of ICOLD (International
Committee on Large Dams), providing a dam’s height
from foundation is more than 15 m or its reservoir
volume is equal or more than 3 hm3, this dam is
classified as a “large dam”. As seen from the table
below, the number of large dams constructed by DSİ is
544.
 If eleven large dams constructed by other institutions are
added to this, the total number amounts to 555 dams.
 DSİ has built 201 large dams within the framework of
large-scale water projects, while the remaining 343 dams
are within the framework of the smaller-scale water
projects.
 The total reservoir capacity of these 212 large dams is
about 139.5 km3. The details on water resources
development can be seen in the table:
UNDER CONSTRUCTION OR IN
PROGRAM
IN OPERATION
January 1, 2005
By DSİ
Other
Total
By DSİ
Other
Total
DAM (unit)
544
11
555
209
1
210
(large-Scale Water Projects)
201
11
212
85
1
86
(Small-Scale Water Projects)
343
-
343
124
-
124
HEPP (unit)
53
82
135
53
17
70
(Installed Capacity-MW)
10,215
2,416
12,631
8,982
465
9,447
(Annual Generation-GWh)
36,481
8,844
45,325
29,581
1,725
31,306
47
617*
664
1
43*
44
IRRIGATION (million ha)
2.77
2.12
4.89
0.8
-
0.8
WATER SUPPLY (billion m 3 )
2.50
0.46
2.96
1.09
-
1.09
FLOOD CONTROL AREA (million ha)
1.0
-
1.0
0.5
-
0.5
Small Dams (unit)
(*) Small dams built by the General Directorate of Rural Services
(GDRS abrogated now) for irrigation.
• According to ICOLD standards, there are at
present 555 large dams, in Turkey.
• According to crest types, these dams can be
classified as follows:
• Rock or earth-filled types: 537 dams
• Concrete gravity types: 8 dams (Çubuk I,
Elmalı II, Sarıyar, Kemer, Gülüç, Porsuk,
Arpaçay, Karacaören)
• Arch types : 6 dams (Gökçekaya, Oymapınar,
Karakaya, Gezende, Sır, Berke)
• Composite (Concrete Faced Rock-Fill Dam –
CFRD or RCC) types: 4 dams (Kürtün, Birecik,
Karkamış, Keban)
Dams and Hydropower Plants Developed
by other Organizations
Total installed capacity (MW) and annual average
generation (GWh) of hydroelectric power plants (run-off river
HEPPs) completed by the other organizations are 2,416
MW and 8,844 GWh respectively .
These values account for 20% of Turkey’s current
hydropower installed capacity (12,631 MW) and annual
hydroelectric generation (45,325 GWh).
The HEPPs put into operation by DSİ generate 80% of
Turkey’s current hydro energy needs.
According to DSİ’s investment program in 2005, there is a
total of 53 HEPPs, 24 of which will be realized with bilateral
agreements (6,136 MW and 20,203 GWh) and 5 of which
are to be realized with local bidding (124 MW and 458
GWh), and the remaining 24 of which are under construction
(2,722 MW and 8,920 GWh).
• The number of hydroelectric power plants being
constructed by other organizations under Law
No. 3096 is 17 (465 MW and 1,725 GWh).
These are being built as Autoproducer or BOT
(Build-Operate-Transfer) models by the private
sector.
• Since its establishment in 1954, DSİ has made
investments of US$ 33.5 billion, and the total
benefit from these projects realized by DSİ in the
sectors of energy, agriculture, services, and the
environment is estimated as US$ 81 billion.
These projects have made a more than two fold
contribution to the national economy when
considering their investment costs.
Dam & HEPP
Province
Year of
Comp.
Installed
Capacity
(MW)
Av. Annual
Generation
(GWh)
Berke
Adana
2001
510
1668
Sarıyar
Ankara
1956
160
400
Manavgat
Antalya
1988
48
220
Karacaören II
Burdur
1993
47
206
Elmalı II
İstanbul
1955
2
Darlık
İstanbul
1988
108
Alaçatı
İzmir
1997
3
Sır
K.Maraş
1991
Kirazdere
Kocaeli
1999
Gülüç
Zonguldak 1966
Birecik
Ş.Urfa
Total
2000
284
Water
Supply
(hm3)
Irrigation
Area (ha)
10,000
725
142
6
672
2518
1721
5737
92,700
261
102,700
Note: Run-off river/canal hydroelectric power plants that have been built
by various companies and institutions are excluded from this table.
• Since its establishment in 1954, DSİ has made
investments of US$ 33.5 billion, and the total benefit
from these projects realized by DSİ in the sectors of
energy, agriculture, services, and the environment is
estimated as US$ 81 billion. These projects have made
a more than two fold contribution to the national
economy when considering their investment costs.
• With the budget allocation for 2005, DSİ needs 19 years
to complete the projects in its investment program.
• For the full development of the water projects in Turkey,
as seen in the table below, US$ 71.5 billion is needed for
completion of the remaining projects.
• Considering development rates in the country, there is
still much work to do in the water sector.
• By taking into account the investment budget of DSİ
(annual US $1.65 billion), it is estimated that the
completion of the works (US$ 71.5 billion budget) to be
realized by DSİ could only be possible in the next 44
years.
DEVELOPMENT OF IRRIGATION, HYDROPOWER, AND WATER
SUPPLY SECTORS IN TURKEY
ULTIMATE
GOALS
BY 2030
EACH
SECTOR’S
DEVELOPMENT
RATES
Development of
4.9 million ha
Irrigation
8.5 million ha
58%
Development of
Hydro-electric
45.3 billion kWh
energy
127.3 billion
kWh
36%
Development of
Water Supply
for
Domestic 10.5 billion m3
and Industrial
use
38.5 billion m
3
27%
IN OPERATION
AS OF 2005
 In conclusion, the distribution of precipitation in Turkey is
rather uneven.
 The average annual precipitation ranges from less than
250 mm in inland areas to 2,500 mm in parts of the
Eastern Black Sea coast. Though
 Turkey generally has adequate amounts of water, it is
not always in the right place and at the right time to meet
present and anticipated needs.
 The rivers have generally irregular regimes and natural
flows cannot always be diverted directly.
 The average annual precipitation, evaporation, and
surface runoff vary with respect to time and geography.
 Approximately 70% of total precipitation falls from
October to March; there is little effective rain during the
summer months.
 Therefore, it is necessary to have storage facilities in
order to ensure domestic, industrial and agricultural
supply, and hydropower generation. In addition, dams
make a considerable contribution to control the floods
and erosion.
• The water resources development projects of DSİ are
accepted as crucially important works for the
improvement of the welfare and happiness of the people
in the country. It is a well-known fact that the main
source of daily food, drinking water, and electricity
depend on water resources development projects. That
is why Turkey has to develop all of her water potential to
maintain adequate living standards for the people.
• Agriculture in Turkey heavily depends on climatic
conditions, the adverse effects of which can only be
minimized by developing hydraulic structures.
• DSİ contributes to the development of agriculture in
which 35% of Turkey’s population is employed by
investing mostly in development of irrigation sector. As
the production and consequently the income of our
farmers increases because of irrigation development,
there are further inputs to agro-industries.
• Because of this, water resources development has a
crucial role to play in the socioeconomic development of
Turkey.
• Thus, DSİ’s investments in hydropower, which is a
national source of the electricity needed by industry are
important in that they are able to lessen the rate of
migration to the cities and to decrease the
unemployment in the country.
• DSİ needs a certain amount of financing to complete its
planned projects in the sectors of energy, agriculture,
services, and environment by 2030. This additional
financing requirement is estimated at US$ 71.5 billion
(as 27.5 in agriculture, 21.0 in energy, 20.0 in services,
and 3.0 in environment). With the completion of these
planned projects, Turkey foresees to have US$ 27.8
billion worth of gross income annually.