With the global population projected to reach 9 billion in 2050, demand for food is expected to increase by over 50% in 2030 and 70% in 2050. Already agriculture is the largest user of water with irrigation Click & Tweet! accounting for nearly 70% of all freshwater withdrawals.
It is estimated that to meet this increased demand for food, global agricultural water consumption will increase by around 19% by 2050, but this figure could be higher if crop yields and the efficiency of agricultural production does not improve dramatically.
At the same time, global demand for water is projected to exceed supply by 40% in 2030 Click & Tweet! and 55% in 2050 as a result of climate change and non-climatic trends including rapid urbanization, economic growth and rising income levels and increased demand for energy.
Reducing water-food nexus pressures by managing water
To reduce water-food nexus pressures water managers can implement demand management strategies to balance rising demand for limited, and often variable, supplies of good quality water, where demand management involves the better use of existing water supplies before plans are made to further increase supply.
Demand management promotes water conservation Click & Tweet! , during times of both normal conditions and uncertainty, through changes in practices, cultures and people’s attitudes towards water resources. Demand management aims to:
- Reduce loss and misuse
- Optimize water use by ensuring reasonable allocation between various users while considering downstream users, both human and natural
- Facilitate major financial and infrastructural savings
- Reduce stress on water resources by reducing unsustainable consumption levels
- Reduce water quality degradation
Tariff simulator in Portugal
The Alqueva Multi-purpose Undertaking (EFMA) in the south of Portugal is Europe’s largest irrigation project. Around 120,000 hectares of irrigation area has been set up in a region where soils are highly suitable for irrigation and the number of hours of sunshine is above the European average. As part of EFMA, irrigators are offered a tool for simulating water consumption and estimating its cost. The irrigation tariff simulator calculates the cost of water consumption based on the location and type of supply, year of introduction of the crop, amount of crop expected and the area covered.
Water quality trading in the Ohio River Basin
The Ohio River Basin Water Quality Trading Pilot Project is a first-of-its-kind interstate program that spans Ohio, Indiana and Kentucky to evaluate the use of trading by industries, utilities, farmers and others to meet water quality goals while minimizing costs. The water quality trading program, a market-based approach to achieving water quality goals, allows permitted discharges to generate or purchase pollution reduction credits from another source. The premise of the water quality trading program is that:
- Facility A, for example, a wastewater treatment plant, needs to meet nutrient limits for its water quality permit and therefore water quality trading is one option
- To reduce nutrients in the watershed, Facility A pays Farmer B to do a variety of things, for instance, reduce fertilizer user, plant stream side buffers with trees or keep livestock manure from getting into the waterways, with each conservation practice verified
- Nutrient reductions are quantified as credits, for example, equal to one pound of nutrient reduction. Credits are then reviewed and approved by a regulatory agency
- Facility A can then use those credits to meet permit requirements
To reduce water-food nexus pressures, water managers can use a variety of demand management tools to reduce agricultural impacts on both water quantity and quality.
*Robert C. Brears is the author of Urban Water Security (Wiley). Urban Water Security argues that, with climate change and rapid urbanization, cities need to transition from supply-side to demand-side management to achieve urban water security. Facebook: UrbanH20