Science for Environment Policy THEMATIC ISSUE: Managing water demand, reuse and recycling May 2012 Issue 33 Environment 2 Contents Editorial 3 ‘Overcoming troubled waters: a safe and secure supply, now and into the future’, from guest editor Jaroslav Mysiak. Allocating water resources – a systemic approach 5 A ‘watershed economics approach’ has been developed to help balance competing uses for water. Balancing river ecosystem protection and human demand for water 6 Researchers present a new method of determining water flow in river basins to balance water users’ rights with ecosystem protection. Challenges ahead for cities in search of self-sufficient water supply 7 The high energy demands of water treatment are a key challenge for water reuse and recycling, researchers argue. New model developed to optimise management of irrigation 8 For best balance of income and water efficiency, researchers advise farmers to combine crops that require little water with more profitable crops that need more water. Water efficient household appliances prove effective 9 US rebate and exchange programmes for showerheads, toilets and washing machines lead to six to 14% reduction in household water use, research finds. Reusing city wastewater in agriculture brings multiple benefits 10 Benefits of reusing city wastewater for agricultural purposes can far outweigh costs and reduce overall demand for freshwater, according to a recent study. Relationship between water and energy consumption calculated 11 5.8% of total electricity consumption in Spain is for water use, study finds, while 25% of water withdrawals are for energy generation. Related articles 12 A selection of recent articles from the Science for Environment Policy News Alert. 3 EDITORIAL Overcoming troubled waters: a safe and secure supply, now and into the future According to the Chinese Zodiac, 2012 is the year of the Yang Water Dragon; a mighty symbol said to be skilled in making smart decisions based on unbiased assessment of facts. As it happens, 2012 is also the year to thoughtfully assess European Water Policies and climate adaptation, to feed into the Blueprint to Safeguard European Waters1 to be adopted in November 2012. Acknowledging the critical importance of water, the European Commission has declared 2012 the European Year of Water. We must protect this most valuable of resources, which, Demand for water can be partly managed through through our inefficiency, is becoming more and more economic or market based policy instruments, but scarce. Pressures, including climate change, economic we must ensure that these instruments are fair and and population growth, further jeopardise our supply of effective. Two studies in this publication consider the water. This Thematic Issue of Science for Environment issue of water allocation. ‘Allocating water resources – Policy presents key pieces of research which address a systemic approach’ and Balancing river ecosystem the most pressing policy issues in this field, to help us protection and human demand for water’ take us to identify best practices for saving water and, perhaps Cyprus and Spain where, separately, researchers have much like the Yang Water Dragon would, make smart demonstrated new economic approaches to balancing decisions on how to manage water efficiently. competing uses for water – uses by farmers, urban areas, industry and wildlife. At the heart of both studies lies Europe is looking for an effective strategy to deal with stakeholder engagement; a better understanding of water supply and consumption, along with numerous water users’ needs helps managers preserve supply and other remaining challenges related to both water quality protect ecosystems within the realistic context of human and quantity. The Blueprint to Safeguard European demand. Waters will seek to identify policy options to deal with these issues, integrate water-efficiency priorities into To meet demand, more and more water is being policy and face up to the challenges presented by climate abstracted from the land and transported long distances. change. Cities, along with all other groups of users, need to reduce demand for water, and, ideally, would be able Additionally, the IPCC published the full special report to source their own water locally. ‘Challenges ahead on Managing the Risk of Extreme Events and Disasters for cities in search of self-sufficient water supply’ to Advance Climate Change Adaptation, the ‘SREX assesses projects around the world where urban areas report’, in March this year2. Of concern, it found have looked to methods, including rainwater harvesting mounting evidence that drought will intensify in the and wastewater recycling, to reduce their reliance on 21st century in southern and central Europe. What are distant and unsustainable sources of water. Progress in the best ways of managing demand for water in light of self-sufficiency has been noted, but the energy demands these worrying projections? of water treatment and our understanding of potential 4 health risks associated with these alternative sources need and saves extraction and treatment costs. The benefits of to be resolved if greater self-sufficiency is to become a water recycling schemes in this case study are estimated widespread reality. to far outweigh costs. Through the EU’s 2020 strategy, Europe has been firmly Water and energy are inextricably linked; effective placed on the path to a resource efficient future for policies cannot consider one without the other. This sustainable economic growth. The principles of resource ‘water-energy nexus’ is illustrated by ‘Relationship efficiency are explored in two articles here. ‘New model between water and energy consumption calculated’ developed to optimise management of irrigation’ which finds that, in Spain, 5.8% of total electricity presents a new decision support system that finds the consumption is for water-use and 25% of water right balance between farmers’ income and efficient water withdrawals are for energy generation. In future, demand use. Optimal results will be achieved if farmers combine for water and energy will intensify, with repercussive crops that require little water with more profitable effects for both sectors. crops that need more water, researchers suggest. In the home, everyday appliances can be upgraded to use less Many may think of Europe as plentiful in water, but, water whilst achieving the same job. ‘Water efficient in reality, scarcity and drought are already plaguing household appliances prove effective’ describes a series many Member States and this situation could very easily of programmes in the US to reduce water consumption, become much worse without careful management. whereby a water authority implemented rebates and Thankfully, the water policy agenda this year is bursting exchanges for water-efficient showerheads, toilets and and provides the prime opportunity to use scientific washing machines. The programmes were a success, and studies, such as those featured in this issue, to take stock research shows that they led to a 6 to14% reduction in of the challenges we face and implement robust plans to household water demand. meet them. ‘Reusing city wastewater in agriculture brings multiple benefits’ unites the needs of urban populations and farmers. For farmers, the supply of reclaimed water from cities reduces the cost of pumping freshwater, 1. http://ec.europa.eu/environment/water/blueprint/index_en.htm which, in turn, frees up some freshwater for urban areas 2. http://ipcc-wg2.gov/SREX/ Dr Jaroslav Mysiak Fondazione Eni Enrico Mattei, Italy MANAGING WATER DEMAND, REUSE AND RECYCLING 5 Contact: [email protected] Theme(s): Environmental economics, Water Allocating water resources – a systemic approach Researchers have developed a ‘watershed economics approach’ which could help water managers balance competing uses for water and understand the impact of different policies. To demonstrate the approach, it was applied to a watershed in Cyprus. “Pricing policies can be There are many competing uses for water, especially in countries with a dry and hot climate. To balance the uses for effective in managing this limited resource, integrated and systemic approaches are needed. water, but can lead to negative effects on low The proposed ‘watershed economics approach’ is composed of two stages. The study demonstrates it on the Kouris income households, which Watershed in Cyprus, which has a large number of diverse water users; farmers extract groundwater and divert surface should be considered water for irrigation, whilst water is diverted to storage dams for distribution to urban areas. It also contains coastal when developing wetlands that provide habitat for wildlife. allocation strategies.” The first stage of the approach applies economic techniques to place a value on the different uses of water to help achieve an optimal balance between users. For example, in the case of the Kouris Watershed, the agricultural value of water was estimated by the amount that farmers are willing to pay for irrigation water in order to ensure they will achieve a certain profit from their crops. In this case, farmers were willing to pay approximately one fifth of their expected profit which can inform how much it is possible to charge for irrigation. Alongside this, the environmental value of water was estimated from the public’s willingness to pay for the provision of water to protect an endangered species (the white headed duck) that uses the area’s natural wetlands. This was elicited from respondents