Transcript IRRIGATION SYSTEMS PERFORMANCE IN GREECE

AGRICULTURAL WATER SAVING
IN GREECE
A. Karamanos, N. Dercas, P. Londra and S. Aggelides
Agricultural University of Athens
Valenzano, 14-17 February 2007
WATER USE IN GREECE
Annual water consumption
8,200 hm3
 agriculture (83%)
 domestic (13%)
 industrial (2%)
 other
(2%)
Irrigated land
1,430,000 ha
Public networks (40%)
Private networks (60%)
WATER SAVING IN AGRICULTURE
SUPPLY
CONSUMPTION
WATER SAVING TECHNOLOGIES WITH
REGARD TO SUPPLY
 Improvement of conveyance and distribution systems
In order to reduce the water losses, the conveyance and
distribution of irrigation water tend to be carried out more
efficiently using pipelines instead of channels.
65
350000
200000
3 5%
300000
250000
4 9%
5 1%
Irrigated area (ha)
%
Public networks
150000
100000
50000
0
1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
Year
Channels
Pipelines
Private networks
Irrigated area
(ha)
600000
94.5%
93.5%
500000
92.5%
400000
300000
200000
100000
6.5%
7.5%
5.5%
0
1990
1995
2000
Year
Channels
Pipelines
 Construction of reservoirs for water saving in irrigation
districts or regions
In Greece about 70 dams and off-stream reservoirs have been
created by several authorities, mainly the Ministry of Rural
Development (39), the Ministry of Environment and Public
Works and Public Electricity Corporation.
Dam of Ano Mera, Myconos Island
Capacity: 1,000,000 m3
Off-stream reservoir of Kaki Lagada, Paxi Island
Capacity: 138,000 m3
Water harvesting
 Structures which harvest runoff from ground surfaces. These
are micro catchments (contour earth bands) constructed for
irrigation of olive trees. The same approach can be found in
agricultural areas where the runoff of sloppy artificially
impermeable surfaces is collected in citterns and is used for
cattle breeding.
 Structures, which harvest the rain from the roofs and ground
surfaces and deposit water in rainwater tanks of a capacity 50500 m3, for domestic use and vegetable production in Aegean
islands and Crete.
 Techniques which collect discharge by diverting the ephemeral
water sources and spreading within irrigation channels for
olive trees (area of Amfissa).
Recharge of underground aquifers
Many aquifers suffer from over-pumping conditions, which
result to the decrease of the underground water table and sea
intrusion effect. The above-mentioned problem is aggravated
due to the very long greek coastline (16,000 km).
In Greece, recharging has been applied in the region of
Argos, East Peloponnesus, in 2000ha with very good results.
Non-conventional water use
• An alternative plan for saving water could include the use of nonconventional water resources such as the reclaimed wastewater
originating from the wastewater treatment plants. This alternative
water use may provide sufficient water for irrigation, in order to
prevent water shortage and intrusion of the pollution loads to the
sea, rivers and lakes.
• Greece has complied with EU Directive 91/271 concerning urban
wastewater treatment. In 2002 more than 350 Municipal
Wastewater Treatment Plants (MWTP) could serve about 65% of
the country’s population.
• Desalination systems based on renewable energy are used in
some islands of the Aegean Sea.
• Brackish water can be used under certain circumstances. A good
example is the use of brackish water mixed with fresh water and
used in lemon orchards near to Poros island.
Prices policy
• Water resources must be valued to reflect its status as a scarce
resource, instead of being treated as a free or nearly free resource.
• Agricultural water in Greece is undervalued. Water is not priced at
its economic value. Therefore, the water consumed exceeds the
needs of the users.
• The pricing of water is usually based on the size of the parcel.
• Costing on a water volume basis is not popular to farmers.
• The price per cubic meter should depend on the volume consumed.
• In addition in certain networks (e.g. Pinios, Alfios) the pricing
depends on the method of water application.
• In private networks, users pay the total amount of the cost of water
supply. However, they are not charged for the environmental cost
caused by over-pumping and they are also strongly subsidized for
using energy appropriate for the operation of the networks (oil,
electricity).
WATER SAVING TECHNOLOGIES WITH
REGARD TO CONSUMPTION
 Improvement of irrigation system design
In many cases the irrigation system design (furrow, sprinkler or
trickle) is not appropriate, resulting to low water efficiency. The
improvement of irrigation system design will allow to obtain better
application uniformity, save water, avoid high percolation losses
and reduce underground water pollution.
Increase of the drip irrigation systems
The irrigated land covers 1,430,000 ha and irrigation is made by
surface irrigation (19%), sprinkler irrigation (50.6%) and drip
irrigation (30.4%). The general trend in the existing public and
private networks is to gradually abandon the surface irrigation
systems giving place to sprinkler and especially to drip irrigation
techniques.
In Greece the total water use efficiency is estimated to 60%, as the
actual water use was 6.833 km3 and the maximum calculated crop
water requirements reached the value of 4.089 km3.
53%
Public networks
56%
37%
200.000
43%
250.000
150.000
10%
100.000
1%
50.000
1998
1996
1994
1992
1990
1988
1986
1984
0
Year
Surface irrigation
Sprinkler irrigation
Drip irrigation
Private networks
300000
Irrigated area
(ha)
Irrigated area (ha)
300.000
49%
51%
250000
47%
200000
44%
41%
43%
150000
100000
50000
8%
10%
7%
0
1990
1995
2000
Year
Surface irrigation
Sprinkler irrigation
Drip irrigation
Use of Sub-surface irrigation
Sub-surface irrigation is a highly effective and resource
preserving technique of micro-irrigation. It is compatible with
the disposal for irrigation of the low treated wastewater of
agricultural or municipal origin
This system is used in some hotels in Greece (irrigation of the
green spaces) and some farms allowing safe disposal of the
treated waste water. Research is carried out for its introduction
in various agricultural crops.
Reusing return flows in furrow irrigation
Furrow irrigation is often characterized by low efficiency. This
may result from unskilful management and operation or from
poor design (deep percolation and runoff losses).
WATER SAVING AND THE NEW LEGISLATIVE
FRAMEWORK
• Directive 2000/60 is environmentally oriented and its main
objective is to ensure good quality water resources. The
Directive fully implements the “polluter-pays principle”.
• The CAP reduces progressively the subsidies, and it orients the
farmers towards environment-friendly practices that are
included in the cross-compliance (e.g. reduction of nitrates
leaching, agrochemicals use, rational water use, management of
the packages, record/tracing of all the cultural practices etc). It
introduces the institution of “agricultural consultant”.
• Directive 2000/60 and the CAP have a common target, aiming
both at environmental protection and rational water use.
• It is necessary to introduce an effective mechanism in order to
ensure proper implementation of Directive 2000/60.
• In Greece, a National Water Committee was set up (political
decisions for water management). A National Water Board was
set up, whose members are representatives of political parties,
the Technical Chamber, the Public Power Corporation S.A., the
National Agricultural Research Foundation etc. (consultative
role). A Central Water Service was created in the Ministry of
Environment, Physical Planning and Public Works
(administrative role).
Furthermore, Water Boards (consultative role) and Direction for
Water (administrative role) were created in the Regions level
(Periferia level).
• It is essential to create an Agency or Company of Public Utility,
which will apply in practice the decisions of the Water
Committee (at governmental and regional level) and will act as a
technical consultant to those bodies and to the irrigation
networks operators.
• The farmers need irrigation consultants.
• The creation of Water Management Plan at river basin level will
allow to know the natural resources (qualities and quantities), the
consumptions, the efficiency of use, the water losses and to plan
more efficiently the necessary actions and the new investments.
• A proper water pricing policy in the public irrigation networks. At
the same time the farmers will be obliged to use more efficient
irrigation systems.
• The introduction of the environmental and the natural resources
costs in the water pricing policy for private drills water will
reduce the quantities pumped and it will improve the management
of the aquifers. Every member state of the EU must guarantee the
balance of water resources-consumption of its aquifers.
• Using treated waste water, the farmers will save water resources
and protect the environment.
• Directive 2000/60 and the CAP give a very good framework in
order to change substantially the water management situation.
CONCLUSIONS
1.
2.
3.
4.
5.
It is essential to forward rapidly in the following subjects
through an integrated planning framework:
Quick and complete harmonization of Greek law with
Directive 2000/60.
Development and fully operational organization of the bodies
and agencies involved in water management.
Immediate creation and application of the water management
plans at a river basin level.
Inform the farmers (and more generally all the population) on
the EU Directive 2000/60. Sensitize the population concerning
sustainable water management.
Pilot applications of the water management plans and
promotion of the results obtained.
6.
Increase the Water Use Efficiency by applying the following
measures:
a) Improve the maintenance and the operation conditions
of the public networks.
b) Increase the use of local irrigation systems where it is
appropriate.
c) Train the young farmers in improving irrigation
techniques.
d) Price the irrigation water in public networks according
to the volume consumed.
e) Introduce the environmental cost in water pricing.
7.
Construct dams and off-stream water reservoirs and recharge
the coastal aquifers.
8.
Use effluents to irrigate crops, forestry and amenities, and
for industrial needs.
9. Use of desalination water.
10. Encourage and subsidize any measure or technique that
affects positively the water balance.
11. Apply administrative measures in order to avoid the
environmental degradation of ground waters from nitrates,
herbicides, fungicides and pesticides
THANK YOU
A. Karamanos*, N. Dercas**, P. Londra ** and S. Aggelides**
*Laboratory of Crop Production, Agricultural University of Athens, 75
Iera Odos, 11855 Botanicos, Greece. E-mail: [email protected]
**Laboratory of Agricultural Hydraulics, Agricultural University of
Athens, 75 Iera Odos, 11855 Botanicos, Greece.
E-mails: [email protected], [email protected] and [email protected]