VERTIKAL analyses the increasing potential of conflict between drinking water supply and agricultural irrigation. Based on this, approaches and procedures are developed for managing conflicts of use over the limited resource of water.
For several years now, Germany has seen an increase in the cultivation of agricultural crops requiring irrigation. At the same time, a trend of increasing summer droughts has been observed. This combination leads to a rising demand for water for irrigation and, consequently, might result in an increasing competition for water between the public water supply and agriculture. The aim of this project was to develop concrete starting points and procedures for the management of conflicts of use for the resource groundwater in regions with irrigation at the catchment level.
Therefore, we carried out a literature research and conducted interviews with various experts and stakeholders. Among other things, two examples of associations that have been facilitating large-scale irrigation in their areas for many years and are striving for sustainable use of groundwater resources were examined in more detail. One of these example regions is in Rhineland-Palatinate, the second one in Lower Saxony. Both their organisation and development as well as their approach and boundary conditions were described.
In the research area in Rhineland-Palatinate, the “Vorderpfalz”, vegetable fields as well as early potato and fruit fields are supplied with irrigation water from an old branch of the Rhine via an elaborate pipe system by the Water and Soil Association for the Irrigation of the Vorderpfalz (Wasser- und Bodenverband zur Beregnung der Vorderpfalz).
In the research area in Lower Saxony, Uelzen, potato, cereal and sugar beet fields are mainly supplied with irrigation water from groundwater, water from the Elbe side canal and/or from a water reservoir via the Water and Soil Association.
Based on the findings from our literature research and interviews with experts, a concept paper for the successful management of conflicts was developed, in which the necessary prerequisites, but also the possibilities for action of the individual players (agriculture, approval authorities, water suppliers) are compiled. This will serve as an aid in developing case-specific solutions in affected regions.
The key points of low-conflict or conflict-free management of groundwater resources include
(1) a robust planning basis with quantitative information on the local water balance, including all groundwater abstractions and their use,
(2) participatory planning processes,
(3) the availability and financial viability of alternative water sources, and
(4) the association of farmers in an association through which irrigation is organised and coordinated with the licensing authorities.
Through the approaches described, the needs of the public water supply and its development opportunities (e.g. new wells/replacement wells) can be taken into account and the priority of the public water supply can be maintained without having to impose significant restrictions on irrigation.