Agriculture Reference
In-Depth Information
An issue requiring close attention when choosing between pollution control
instruments is that of implementation costs. Measures that appear to be suitable may
nevertheless be associated with implementation problems relating to their political
acceptability or transaction costs. Policy-makers should therefore evaluate the trade-off
between cost-efficiency and ease of implementation.
5. Conclusions
High demand for irrigation water resources in Mediterranean countries results in
significant water quality problems compounded by water scarcity. The heated policy
debate that has been taking place in Spain over ways to solve water scarcity and resource
degradation in south-eastern basins highlights the difficulty of achieving sustainable
water resource management because of the conflicting interests of diverse stakeholders,
including regions, economic sectors and political and environmental groups.
Two distinct general policy approaches for dealing with water quantity and quality
problems in the Mediterranean, are the traditional approach of expanding water supply
and the newly emerging water management initiatives. Examples of the traditional
approach are inter-basin transfers and seawater desalination. The newly emerging
initiatives rely on measures such as water pricing, revision of water rights, surface and
subsurface water abstraction limits, development of regulated water markets, water
resources reuse and regeneration, and subsidies to upgrade irrigation systems.
The effects of these measures on water quantity and quality are difficult to ascertain.
For example, increasing water supply appears to have negative effects on nonpoint
agricultural pollution, by encouraging the expansion of high-profit irrigation by farmers
in Mediterranean coastal areas, who are able to pay for this additional water supply.
Another example is upgrading irrigation systems that reduce drainage returns and
pollution loads. However, farmers may use the water thus saved to introduce water
demanding crops or expand irrigation acreage. This could reduce river streams in
watersheds because of the reduction in irrigation return flows. In order to avoid this,
public subsidies to upgrade irrigation systems need to be coupled with cutbacks in
concession volumes to irrigation districts.
Several water quantity and quality issues in Mediterranean irrigated agriculture have
been examined by presenting empirical evidence from Spain on alternative policy options
and measures. The water policy measures examined cover two cases: the evaluation of
alternatives to solve water scarcity in the basins of south-eastern Spain, and the ranking of
agricultural pollution control instruments by their cost efficiency.
The first case involves the recent Ebro transfer project and the new AGUA project
designed to replace the Ebro transfer. Both projects are highly illustrative examples that
highlight the failure of approaches based on expanding water supply. Results from
analysing the Ebro transfer show that an alternative combining an aquifer overdraft ban,
water trading, and a small volume of desalination is by far a better alternative than
building the Ebro transfer. This combined alternative reduces farmers' quasi-rent by a
smaller amount than the subsidies required by the Ebro project, and this alternative can be
coupled with compensations to prevent losses to farmers.
Augmenting water supply by publicly financed desalination is politically appealing
for the new Spanish government after the cancellation of the Ebro transfer, and its AGUA
project seems a straightforward measure. But the problem with the AGUA project is
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