Preserve and sustain urban water resources and infrastructure.Investing in their preservation or restoration can provide long-term benefits while boosting short-term job creation. And alongside built infrastructure, green infrastructure such as watersheds and their associated forests that store, filter, and distribute both surface water and groundwater, can enhance the resilience and quality of water supplies. Climate-smart agriculture and farmer-led irrigation can play similar roles while minimizing the environmental footprint. Water storage and supplemental irrigation, weighed carefully to avoid unintended consequences, can effectively buffer vulnerable rural communities against water variability and scarcity. Protect livelihoods in the place of origin.Active labor market policies that build skills are also needed, alongside investments in worker education and training. Investing in water supply and sanitation, education, health care, and safe housing benefits poor migrants in urban areas and broader city populations. Safety nets, such as cash and in-kind transfers, can help to protect communities facing severe water shocks. A complementary range of policies can improve livelihoods and turn water-induced crises into opportunities. Governments need to protect people, livelihoods, and resources. By making water so cheap, they promote overuse, which threatens the sustainability of water services. Such subsidies entrench inequality and reward inefficiency. Globally, 6 percent of water and sanitation subsidies go to the poorest 20%, while 56% goes to the wealthiest 20%. This means designing incentives for efficient water use – and reforming inequitable and inefficient subsidies. Smart cities need smart water policies.“Sponge city” concepts that improve flood protection and capture run-off create more water sources for city dwellers. Recycling wastewater and harvesting storm water provides alternative water supplies that have environmental benefits. Although adapting to these events can be expensive, it is crucial to invest in policies and infrastructure that enhance urban water resilience because cities drive economic growth. Water shocks are costly – a drought can reduce a city’s economic growth by up to 12%.

Alongside recent acute water shortages in Cape Town, Chennai, and São Paolo, dozens of smaller cities face similar fates. Risks to the sustainability of cities include changes in the global hydrologic cycle and water deficits in rural areas that drive agricultural workers to urban areas.

Urban water supplies are under threat from rising heat stress and water scarcity. Global warming will make “day zero” events more common in the world’s cities, which are now home to 55% of the human population. Labor migrants who leave regions with lower rainfall and frequent dry shocks usually possess lower educational levels and skills and face a wage gap of up to 3.4% at their destination, with significant policy implications for receiving cities. Water shocks affect not only the number of people who move, but also the skills they bring with them.These trapped populations can encounter a triple whammy of water deficits, evaporating economic opportunities, and lack the means to move to places with better prospects. Moreover, migration in response to water deficits varies significantly based on country income, with residents of poor countries four times less likely to move relative to residents of wealthier countries. In fact, it is the poorest who often lack the means to migrate, even when doing so might improve their livelihoods and prospects. The notion of a “water migrant” is an overly broad generalization not supported by the evidence.Those countries most affected are usually more dependent on agricultural labor. Scientists project that worsening droughts will affect about 700 million people by the end of this century.

Rainfall variability disproportionally impacts the developing world, with more than 85% of people affected living in low- or middle-income countries.

Dry rainfall shocks have five times the effect on out-migration than wet rainfall shocks. Rainfall shocks – when rainfall is significantly above or below the long-term average for a region – are expected to be the driving force in water-induced migration in the years ahead.

The absence of water has a greater impact on migration than an abundance of water.

Climate change is accelerating the global water crisis: 17 countries that are home to 25% of the world population already face extremely higher levels of water stress. Water deficits are linked to 10% of the rise in global migration. Volume 1 – Ebb and Flow: Water, Migration, and Development

Flow water