Treated Wastewater for Irrigated Agriculture in the Jordan Valley. Analysing Water allocation and Willingness to Pay for reused water

Water-scarcity in the Hashemite Kingdom of Jordan seriously affects the social and economic development of the country. Water availability per capita ranks lowest in the world and all renewable water resources of suitable quality are fully exploited. The situation is likely to exacerbate as population doubles in the coming decades and climate change scenarios indicate a significant reduction in water quantity. Indeed, the threat of depleting water resources that can no longer meet the increasing demand might create political instability in the kingdom and wreak havoc on future generations. Inter basin transfers could provide the necessary relief, yet, the political situation in the region impedes a
constructive solution in this direction. Hence, answers must be found at an intra-country level. This also is the motivation of the current thesis where we investigate the use of Treated Waste Water (TWW) in the agricultural sector as a key scenario to reduce the strain on water resources. This thesis focuses on
the Jordan Valley (JV), an important regional supplier of crops and vegetables, where much of the freshwater resources are consumed. Yet, 40 percent of the Valley’s potential remains untapped due to lack of water, while the expansion is urgently required to meet the growing food demand. This growth can only be realized with additional water volumes as the widely implemented drip irrigation leaves little room for efficiency gains at the farm level. A chemical water analysis showed that TWW in Jordan meets the national and international standards of water quality and can be a valuable contribution for irrigated agriculture. We also found using a new Water Reuse Index (WRI) that there still is considerable
room for an increase of TWW volumes as currently only 34 percent of the waste water is being treated. A forward-looking evaluation of various water resource allocations with fresh and TWW sources, effectuated by the WEAP model, shows that historical reservoir water volumes could be reproduced with confidence and can be used for further scenario evaluation. The results of an extensive survey
among 400 farmers showed that 96 percent are willing to accept the TWW. Furthermore, farmers are willing to pay four to five times more of the current water price. The results of our ordered logit model show that it is recommendable to make site specific pricing and extension programs when TWW is introduced or further expanded. Finally, we simulated various pricing regimes for four archetypes of farming systems considering nutrients in TWW for its cost saving effects on fertilizers and crop specific effect of salinity. The results show that additional TWW volume increases farmer incomes considerably and while fertilizer costs could be saved saline TWW levels affect citrus and banana production negatively. We also found that it is difficult to cover the costs of new TWW plants and sewage infrastructure with farmer contributions alone. This is also not necessary as the environmental and health effects of TWW will benefit the society as a whole. We conclude that there are good prospects for further agricultural development in the JV when the use of TWW in Jordan is expanded. A gradual increase in farmer contributions seems justified as additional profits per water volume outweigh the increase in costs by far.