WATER CHANNELS - The traditional irrigation culture using water channels as model for sustainable water management

Open water channels have been used for centuries in the arid mountain regions of the world for the transportation and distribution of scarce water for use as drinking water and, in particular, process water in agriculture (irrigation water). Many of these channels are collectively owned and established a historically grown and regulated system of well defined use rights to guarantee a sustainable water management for all water users.To test the capacity of cooperative collectively owned water channel systems for the maintenance or improvement of biodiverse land, we use the concept of institutional regimes, enabling us to identify existing or absent use-rights to goods and services produced by the three different resources shaped, each one, by different social-ecological systems more or less capable to produce responses to external and internal threats defined by their resilience and due to a changing system vulnerability. The channel system is situated in between supplying hydric resources (institutional regime of the concerned water) and the natural resource (more or less biodiverse) soil. Even though the project focuses on the man-made (artificial) resource channel system, it must also consider the existence of rights to more or less permanent water flows feeding the channel system. The main concern of the project is about hydrological ecosystem services of the resource “water channel system", especially the so-called providing services for biotic production as well as cultural services (recreation) and supporting services such as nutrition cycle, soil formation, photosynthesis. These services are produced, amongst others, by the water flowing through the channels and they are supposed to be necessary for sustainable cultivation and maintenance of agricultural and forest lands in the proximity of these channels.Up to now, there are assumptions but little empirical evidence in relation to the ecological significance of the water channels (channel-associated flora and fauna, diffusion effect of the water for surrounding vegetation in the mountain forest) and meadow irrigation (balancing of the water supply, biodiversity, influence mainly on meadow-breeding birds and vascular plants) as compared with the irrigation system by means of a network of pumps and hydrants. Should it be possible to substantiate these advantages, options for the targeted promotion of the traditional or re-activated meadow irrigation should be examined and proposed, for example, in the context of the overhaul of the system for direct agricultural payments. This will also involve the confirmation of the exemplarity of the complex regulation of the water use rights for a democratic and legally fair system of agricultural water distribution in areas with scarce water resources. Thus, the water channels can constitute a model for an efficient and effective approach to the future management of the scarce good water. The following hypothesis will be tested on the basis of four case studies (for the biodiversity aspects in the Lower Engadine and Mals/Val Müstair; for the mountain forest aspects in the central Valais: region of Crans-Montana and Lötschberg Region): (1) The water channels and the traditional meadow irrigation originally based on it provide ecological advantages for the forest vegetation as well as for the meadow biodiversity (represented by birds, vascular plants and terrestrial gastropods) in the arid mountain regions, (2) The cooperative basis of the water distribution system constitutes an integrated resource regime which can guarantee the ecological and socio-cultural significance in the meaning of hydrological ecosystem services (HES) of the water channels and their complex maintenance in the long-term and can thus become a model for a sustainable and fair approach to the management of the scarce good water in arid mountain regions. The hypotheses will be tested on the basis of empirical case study analyses. In two case studies in the canton Valais (Crans-Montana and Lötschberg region) the growth of dominant trees and the biodiversity of the ground vegetation at three sites along abandoned bisses will be analysed. The bisses should have been shut down in different dates during the last four decades. In addition nearby but still running bisses within the forest are selected as control sites for the vegetation survey to estimate the changes in ground vegetation due to irrigation stop. The spatial expansion of irrigation and trees’ growth reaction to irrigation stop will be anayzed based on tree-ring width and stable isotope composition of the woody tissue. In addition, tree height and needle length will be measured and tree mortality after the irrigation stop will be reconstructed with the local forester. The analysis will follow the classical dendrochronological routines. The forest vegetation analysis will concentrate on species richness and abundance with focus on diagnostic attributes of species.The effect of different irrigation systems on the species richness and abundance of vascular plants and terrestrial gastropods of hay meadows will be assessed. In the regions of Lower Engadine and Mals/Val Müstair the design of the field survey will consist each of nine pairs of areas (replicates) consisting of a traditional irrigated hay meadow and a sprinkler-irrigated meadow. The selection of pairs of meadows is based on similar elevation, exposure, inclination and size to minimize confounding factors. On a larger scale the density of breeding birds will be examined on either type of meadow following the monitoring methods of the Swiss Ornithological Institute. The bird assessment will be conducted in the case studies Lower Engadine and Mals/Val Müstair where bird monitoring data are available since the late 1980ies.The second hypothesis concerns the analysis of the use rights situations, the use rights holders (actor analysis), the legal acts and the relevant policies in all the case studies. Considering the channel system as a resource, the project will identify the whole range of goods and services produced by this resource. Each channel system will not only produce the interesting HES, but many other services which might compete with the latter. In a second step, this institutional part of the project will question these uses by looking at existing or not existing use-rights (in the hands of legitimate user actors) and focus, in a last step, on regulations addressing these use-rights and their user actors. Not all of the uses are rival uses. There might exist many complementarities, which even should be exploited when looking at sustainability and its enforcing actor’s coalitions. On the basis of the most recent literature on institutional economics, Costejà Florensa from the Universitat Autònoma de Barcelona (UAB, 2009) developed an interesting list of practices affecting the capacity of channel systems to solve such rivalries within related social-ecological systems, which might be used as a common basis for the analysis.The exemplarity of the institutional regime system of the water channels concerning use rights, the regulatory framework and the actors behaviour will be compared with an example outside the Alpine region, in Catalonia, Spain, where the above mentioned research studies from the UAB (cooperation partner of the project) in the field of institutional economics are analysing the differences between (central) state owned and run water channel systems as opposed to cooperative local systems. The study will therefore give an important and urgent answer to the scientific and practical question of forest and agricultural strategy how and with which kind of institutional regime we are able to face the increasing forest decline and vegetation shift problems leading to biodiversity losses by water shortage using either traditional water channel or sprinkler irrigation systems.