A STUDY ON RAINWATER HARVESTING IN IRAN

AcknowledgementThrough the means of PowerPoint presentation slides, we students of Batch 2011-15, Civil Engineering Department, MANIT, have made a small effort to study the employed techniques in the field of Rainwater Harvesting in IRAN. We express gratitude towards our respective professor ‘Dr. Ruchi Khare’, Civil Engg. Dept, MANIT for guiding us to complete the assignment.

Thank you

NAME OF STUDENT SCH.NO

Mayank Mishra 111111037

Tarun Bhatia 111111038

Tarun Solanki 111111039

Palash Jain 111111040

Deepak Munda 111111041

Why do we need water harvesting?

“Earth provides enough to satisfy every man's needs, but not a single man's greed.”

-Mahatma GandhiWater scarcity is the lack of sufficient available water resources to meet the demands of water usage within a region. According to United Nations Development Programme, this currently affects around 2.8 billion people around the world, on all continents, at least one month out of every year and more than 1.2 billion people lack the access to clean drinking water.

Over-consumption/excessive or unnecessary use of resources, Overpopulation, Slash and burn agricultural practices in developing countries, Technological and industrial development, Erosion, Habitat degradation leads to the loss of Biodiversity (i.e. species and ecosystems with its ecosystem services), Irrigation, Mining for oil and minerals, Aquifer depletion, Pollution or contamination of resources are the major factors responsible for the eminent water crisis.

ANATOMY OF RAINWATER HARVESTING

SO WHAT IS THE SOLUTION?.........

WATER HARVESTING TECHNIQUESWater Harvesting refers to collection and storage of rainwater and also other activity such as harvesting surface water extracting ground water , prevention of loss through evaporation and seepage.

Rainwater harvesting has been practiced for more than 4,000 years, it is also a good option in areas where good quality fresh surface water or ground water is lacking. In doing so, water harvesting assures a continuous and reliable access to water. The role of rainwater harvesting systems as sources of supplementary, back-up, or emergency water supply will become more important especially in view of increased climate variability and the possibility of greater frequencies of droughts and floods in many areas.

MULTIPLE BENEFITS

1. Improvement in the quality of ground water

2. Rise in the water levels in wells and bore wells that are drying up

3. Mitigation of the effects of drought.

4. Attainment of drought proofing

5. An ideal solution to water problems in areas having

6. inadequate water resources

7. Reduction in the soil erosion as the surface runoff is reduced

8. Decrease in the choking of storm water drains and flooding of roads

9. Saving of energy, to lift ground water. (One-meter rise in

water level saves 0.40-kilowatt hour of electricity)

Techniques of Water Recharge

STORAGE OF RAINWATER ON SURFACE FOR FUTURE USE

RECHARGE TO GROUND WATER

Overview of IRAN

Iran, also known as Persia is a democratic country in Western Asia. It is bordered on the north by Armenia, Azerbaijan and Turkmenistan ;with Kazakhstan and Russia

across the Caspian Sea; on the east by Afghanistan and Pakistan; on the south

by the Persian Gulf and

the Gulf of Oman; on the west by Iraq; and on the northwest by Turkey.

With a land area of 1,648,195 km2 (636,372 sq mi), this country in the 

Middle East is the 18th-largest country in the world, and with over

77 million people, is the world's 17th-most populous nation. Iran is home to

one of the world's oldest civilizations.

WATER RESOURCES OF IRAN

Arid and semi-arid regions occupy more than 80 percent of Iran’s land. The average annual precipitation is

estimated to be 250 mm and the range varies from 50 mm in some parts of the central water basin to more than 1600 mm in

some coastal areas near the Caspian Sea. Meanwhile with respect to the average annual precipitation in the world with

average rainfall of more than 830 mm, Iran is classified among the semi-arid and arid countries.

High density, short duration rainfall often generates destructive floods. At present in many parts of the country, the water levels have been falling rapidly. The demand for drinking water is also has been increasing manifold in the last three decades due to rapid increase in the population.

THUS, Meeting the water demand is a major challenge in Iran.

Rivers and Water Resources

Water Resource Potential of Iran

400 BCM • Average annual precipitation

130 BCM • Renewable water resources

270 BCM • Average annual evaporation & transpiration

92 BCM • Surface currents

38 BCM • Seepage to alluvial aquifers

According to studies carried out for formulation of the Iran Water Comprehensive Plan, the main characteristics of annual precipitation and its conversion to water resources are shown

Annual Water Resources in Billion Cubic Meters (BCM)

Water Consumption

1

98.6

1.3 1.4

92.4

6.2 5

86

9

0102030405060708090

100

Perc

enta

ge

1961 2005 2021

Industry Agriculture Domestic

FRESHWATER CONSUMPTION

At present Iran is using 70% of the

t total

renewable freshwater while u

due to the international norms the u

upper limit should be 40% of renewable freshwater; it means that the

remain unexploited renewable fresh water is only 30 % total fresh water

resources including environmental basic needs.

30

70

. MAJOR CHALLENGES AND TRENDS IN IRANIAN WATER RESOURCES MANAGEMENT

Excessive withdrawal of groundwater resources

Unbalance sequence between demand and supply of water resources

Demand Management in accordance to priorities set in the National Water Plan

Assessment of total value and cost of water relevant to each basin

Pollution of water resources and its economic and environmental consequences

Efficiency in water irrigation systems

Risk Management of water related natural disaster ( i.e. drought and flood )

Implementation of National Integrated Water Resources Management

Efficient and equitable water price for various uses

Land use planning

Unaccounted for water (UFW)

Iranian Solution to Water Crisis

Iranians have a long and notable history of water resources development relying on traditional techniques. The exploitation of floods and rainwater harvesting have been practiced through flood spreading and groundwater recharge systems using BandSars, recharge ponds and Ab- Anbars by ancient Iranians

Major Accomplishments

1. Construction of a 50 Km water transfer tunnel (Aqueduct) from the Karkheh River to Chogha-Zanbil south west of Iran more than 3000 years ago;

2. Hydraulic structures - Chogha-Zanbil temple, 3000 years ago;

3. Invention and development of 80000 Qanats for groundwater extraction and utilizationover the last 3000 years;

4. Dam construction over the last 2000 years;

5. Mizan dam in Shooshtar and bridge-dam of Shooshtar, 500 meters long with 40 bays;

6. Bahram dam on Gharah-Aghage, south of the city of Shiraz, 2000 years ago;

7. Sheikh-Bahaii water allocation scheme, 400 years ago.

8. In recent years, dams with a total capacity of around 20000 MCM have been built in Iran.

HYDRAULIC STRUCTURES& DAMS

• One of the items in Iran's water resources development plan is the control

and regulation of water resources through dams. In accordance to the ICOLD

identification of large dams, the country has over 220 large dams in operation

and also more than 85 dams under construction which totally control over

46.4 billion cubic meters of country's water resources.

DAMS UNDER OPERATION

No Major Dams

Total Capacity(BCM)

Regulating Volume (BCM)

220

32

46.4

85

30

10

SOWMA

Sowma is practiced in northeast of Iran near

the southern border of Turkmenistan. This

area suffers from arid and semi-arid

climatic condition with average annual

precipitation of about 200 mm and

mean annual potential evapotranspiration

rate of greater than 1000 mm.

BANDSARS

Bandar is composed of a small stream that conducts water from Ephemeral River toBandsar’s inner part. This decreases water speed and supplies soil moisture. In the method, natural location of floodwater spreading is formed on alluvial fans. Bandsar is allot or pond formed by embankment construction in direction of water flow. So flood is taken, water is retained until infiltrated.Bandar has a very simple construction. It is made of the following parts:

• A shallow water drainage (ephemeral stream called Kale)

• A check-dam made of river sediment called Tarkehband Embankment (the main wall of the dam)

• Some parallel subsidiary walls for balancing water spreading called Mewband

• A waterway for overflow of water called Goushband

Bandsars covers different areas e.g. 1000 square meters in valleys to 30 ha in low slope

lands.

Thank you for your attention