Creating the right environment for success
Alain Vidal of IPTRID - International Programme for Technology & Research in Irrigation and Drainage - reports on a project which is assessing the technologies, policies and practices required for efficient water conservation
Key role of agriculture
Irrigation continues to play a major role in agricultural production, and has wide-ranging socio-economic impacts in terms of marketing and exporting products; in terms of rural development versus migration to urban areas; and the environmental degradation of water quality.
Around the Mediterranean, large scale irrigation development began to take place after World War II and accelerated in the 1960s. The total area irrigated in the region has increased from about 6.0-8.0 million ha between 1960 and 1980 and now is reaching 11.8 million ha.
Mediterranean countries, like many others, benefitted from the post-war technological advances in hydraulics, automation and construction; and in water-application techniques at a local farm level. The advanced techniques of canal regulation adopted in the region should have made it possible to deliver water on demand for farmers - a prerequisite to achieve the highest level of agricultural productivity and to meet precise crop requirements.
However, poor implementation and management have seriously limited expectations on land and water productivity. Today, there are several areas of intervention planned in terms of policies for water and food supply:
- water policy reforms
- irrigation management transfer
- increasing role of virtual water
- creation of a regional free-trade area
In addition, food production capacity was either horizontal or vertical - horizontal through extension of irrigated areas based on mobilisation of new resources or savings from existing irrigated areas; while vertical growth is based on water productivity increases and improvement of water management.
Water resource management is the final piece in the jigsaw - making existing resources sustainable, limiting exploitation of fossil aquifers, creating new resources (surface and underground storage) and the use of non-conventional sources (brackish and wastewater).
Focus on five countries
Case studies in five countries were analysed in terms of main successes as well as limiting factors, reported water savings and crop yield increase, as well as increase of water use efficiency:
In Jordan, farms in the Jordan Valley using drip irrigation were studied. This showed that the use of tensiometers with drip irrigation saved 20-50 % water, increased crop yields by 15-20% (cucumber, tomato), resulting in an increase of water use efficiency of 44-14%. However the existing rigid irrigation system does not presently allow the spreading of these techniques unless farmers build their own reservoirs.
In Morocco, the case study was in the Tadla region, where the Public Irrigation Agency (ORMVA) in partnership with private companies, promotes laser-levelled basin irrigation, resulting in water savings of 20%, crop yield increases of 30% (cereals), and an increase of water use efficiency of 62%. This technique is still not applicable for all areas, and the present land consolidation model may be inappropriate for better water application and distribution within service areas.
In Middle Egypt, the case study of Beni Ibeid command area showed that both modernised lined mesqa (tertiary canals) and management transfer to Water Users Associations (WUAs) have been successful - mainly because farmers were already informally organised and working together before modernisation.
Crop yield increases of 10% (cereals, cotton) were reported, resulting in an estimated increase of water use efficiency of 10%. However, improvements in terms of night storage was more complex than expected.
In Turkey, a case study was conducted in the Antalya region on a system recently transferred to WUAs, and modernised using the drip, sprinkler and California system. This combined system saw water savings of 34%, and resulted in an estimated increase of water use efficiency of 51%. Further progress might be limited by the ability of many WUAs to modernise their systems and improve performance.
In Tunisia, Public Irrigation Agencies (CRDA) and WUAs are managing
drip, sprinkler and modernised surface irrigation. Public water saving programmes
and other incentives resulted in estimated water savings of 25% and increase
of water use efficiency of 33%. Stronger financial incentives through water
pricing and strengthening the capacity of farmers in water saving
techniques should improve the results already achieved.
Lessons learnt can be summarised as follows:
Localised irrigation is not a miracle technology. Excellent as well as poor results were obtained from these technologies, and their adoption depends on farmers' capacity to finance and operate them, as well as on the type of crop production.
Modernised surface irrigation can be a water saving technique, which can be compared to the often less affordable drip or sprinkler irrigation. It is also more easily adopted by farmers since it is closer to traditional practices.
An enabling environment is necessary to achieve successful water conservation and improve water use efficiency. This should include public incentives, irrigation management transfer to users and the involvement of the private sector to relate the marketing of crops to water savings.
Sustainability of water management depends on carefully selected measures that complement each other. A substantial loss in water productivity is due to the poor quality of irrigation water service in surface irrigation systems.
Rigid delivery of water, at long intervals (as in Jordan, Egypt, Turkey), or
a land consolidation model not compatible with more liberal agriculture policies
(Morocco) precludes the adoption of water-saving application techniques and
the change from staple food to high-value water sensitive crops.