The final process step of this module is based on the results of the preceding steps 2 – 5 in which important factors related to a sustainable utilization of the water resources designated for the irrigation system have been evaluated. None of these process steps should be skipped and it is very important that the underlying analysis along the logic of these process steps is carried out before the envisaged SPIS is finally designed and planned.
The results of the process steps 2 – 5 almost certainly result in limitations and restrictions with regard to the design and outlay of all system components and also the options for the agricultural production. As water resources are limited and increasingly constrained, sustainability criteria with regard to the exploitation of water resources must always prevail. The determining factor for the irrigation system development is therefore the sustainable water availability – system and production are designed and planned according to the safe yield of the targeted water source!
No or insufficient water withdrawal license: In the worst case, an irrigation development would not be possible due to the non-availability of water abstraction rights or abstraction quotas that are too small to allow for a feasible production. Very often, limits and conditions laid out in withdrawal licenses require a down-sizing of a system design (due to limited water availability) and/or the adaption of crop rotation (due to limited water availability, restriction of crops that can be cultivated seasonally, restriction of use of agricultural inputs due to soil and water protection). This may also impact the management and operation of the system.
Low water availability and seasonal variations: The evaluation of the safe yield of a water source may further limit the options for irrigation and production – often, there are seasonal restrictions (e.g. during dry seasons). It is important to keep in mind that the safe (sustainable) yield of a water sources may be inferior to the quota indicated in a withdrawal license.
Overlapping demands on a shared water resource: Further limitations and thus the need for adaptations/adjustments to system design/outlay, production and operation may result from an analysis of neighborhood effects in the area of influence of the irrigation project. The interest and rights of all affected farmers/users need to be taken into account and need to be harmonized. This can be done by bilateral user agreements between neighboring farmers or under the umbrella of water user associations and result in restrictions of seasonal cultivable crops, rotating water distribution, reduced flow rates).
Design requirements from a financing entity: A particular issue are conditions and restrictions of financing/subsidizing organizations. These conditionalities are often linked to the utilization of a particular technology (e.g. water saving micro irrigation) or the cultivation of particular crops (e.g. x % of crop rotation must be oilseeds or other crops) and may also limit the options for system design and a viable production.
Recommendation: Any irrigation system should be designed and laid out based on a thorough planning from the scratch based on a careful analysis of the framework conditions and the design parameters as further explained in the DESIGN module.
Changes in water availability may also occur when the irrigation has been installed according to the given licenses. Given the global increase in climate variability, it is recommended to design a flexible irrigation system that is resilient towards water scarcity. Steps towards drought resilient irrigation may include e.g. selection of crops with low water demand, high water use efficiency and coping mechanisms such as water buffering or insurances. In this context, the role of collective action and risk sharing among water user should be taken into account.
Important: Ignoring the various limiting framework conditions and restrictions may lead to an over- or under-dimensioned system capacity and an unsustainable operation. As far as an over-dimensioned system is concerned, water abstraction above the safe yield will negatively impact the environment and may result in a violation of the allotted water license/permit. A too small water abstraction may result in a low system utilization rate, or under-irrigation, thus having an impact on financial viability. Sustainability in environmental and financial terms can only be achieved if water availability, system design/outlay, crop production and irrigation management and operation are harmonized from the design stage.
In the sense of an adaptive management, it is important to reevaluate the framework conditions in regular intervals as some factors can change, such as the seasonal restriction of particular (water intensive) crops or changed water allocation patterns/quantities. These changes may require adjustments in system operation and production planning after the irrigation system has been constructed.
Results of process steps 2 – 5.
Adjustment/adaptation does not stop after the construction of the SPIS but is an iterative process.
This page was last modified on 6 June 2018, at 16:26.