Water security

Global climate change will probably make it more complex and expensive to ensure water security.[2] It creates new threats and adaptation challenges.^[1] This is because climate change leads to increased hydrological variability and extremes. Climate change has many impacts on the water cycle. These result in higher climatic and hydrological variability, which can threaten water security.^[11]: vII Changes in the water cycle threaten existing and future water infrastructure. It will be harder to plan investments for future water infrastructure as there are so many uncertainties about future variability for the water cycle.^[1] This makes societies more exposed to risks of extreme events linked to water and therefore reduces water security.^[11]: vII

It is difficult to predict the effects of climate change on national and local levels. Water security will be affected by sea level rise in low lying coastal areas while populations dependent on snowmelt as their water source will be affected by the recession of glaciers and mountain snow.^[12]: 21

Future climate change must be viewed in context of other existing challenges for water security. Other challenges existing climate variability in areas closer to the equator, population growth and increased demand for water resources. Others include political challenges, increased disaster exposure due to settlement in hazard-prone areas, and environmental degradation.^[12]: 22 Water demand for irrigation in agriculture will increase due to climate change. This is because evaporation rates and the rate of water loss from crops will be higher due to rising temperatures.^[7]: 4

Climate factors have a major effect on water security as various levels. Geographic variability in water availability, reliability of rainfall and vulnerability to droughts, floods and cyclones are inherent hazards that affect development opportunities. These play out at international to intra-basin scales. At local scales, social vulnerability is a factor that increases the risks to water security, no matter the cause.^[5]: 6 For example, people affected by poverty may have less ability to cope with climate shocks.^[5]

Challenges and threats

There are many factors that contribute to low water security. Some examples are:^{[7]: 4 [6]: 9}

• Water scarcity: Water demand exceeds supply in many regions of the world. This can be due to population growth, higher living standards, general economic expansion and/or greater quantities of water used in agriculture for irrigation.
• Increasing water pollution and low levels of wastewater treatment, which is making local water unusable.
• Poor planning of water use, poor water management and misuse. These can cause groundwater levels to drop, rivers and lakes to dry out, and local ecosystems to collapse.
• Trans-boundary waters and international rivers which belong to several countries. Country borders often do not align with natural watersheds. One reason is that international borders result from boundaries during colonialism.^[2]
• Climate change. This makes water-related disasters such as droughts and floods more frequent and intense; rising temperatures and sea levels can contaminate freshwater sources.^[6]: 9

Water scarcity

A major threat to water security is water scarcity. About 27% of the world's population lived in areas affected by water scarcity in the mid-2010s. This number will likely increase to 42% by 2050.^[42]

This section is an excerpt from Water scarcity.[edit]

Water scarcity (closely related to water stress or water crisis) is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity namely physical and economic water scarcity.^[44]: 560 Physical water scarcity is where there is not enough water to meet all demands, including that needed for ecosystems to function. Arid areas for example Central Asia, West Asia, and North Africa often experience physical water scarcity.^[45] Economic water scarcity on the other hand, is the result of lack of investment in infrastructure or technology to draw water from rivers, aquifers, or other water sources. It also results from weak human capacity to meet water demand.^[44]: 560 Much of Sub-Saharan Africa experiences economic water scarcity.^[46]: 11

There is enough freshwater available globally and averaged over the year to meet demand. As such, water scarcity is caused by a mismatch between when and where people need water, and when and where it is available.

floods), deforestation, water pollution and wasteful use of water can also cause insufficient water supply.^[51] Scarcity varies over time as a result of natural variability in hydrology. These variations in scarcity may also be a function of prevailing economic policy

and planning approaches.

Weather and its related shocks can affect water quality in several ways. These depend on the local climate and context.^[55] Shocks that are linked to weather include water shortages, heavy rain and temperature extremes. They can damage water infrastructure through erosion under heavy rainfall and floods, cause loss of water sources in droughts, and make water quality deteriorate.^[55]

Climate change can reduce lower water quality in several ways:^[8]: 582

• Heavy rainfall can rapidly reduce the water quality in rivers and shallow groundwater. It can affect water quality in reservoirs even if these effects can be slow.^[56] Heavy rainfall also impacts groundwater in deeper, unfractured aquifers. But these impacts are less pronounced. Rainfall can increase fecal contamination of water sources.^[55]
• Floods after heavy rainfalls can mix floodwater with wastewater. Also pollutants can reach water bodies by increased surface runoff.
• Groundwater quality may deteriorate due to droughts. The pollution in rivers that feed groundwater becomes less diluted. As groundwater levels drop, rivers may lose direct contact with groundwater.^[57]
• In coastal regions, more saltwater may mix into freshwater aquifers due to sea level rise and more intense storms.^{[11]: 16 [4]} This process is called saltwater intrusion.
• Warmer water in lakes, oceans, reservoirs and rivers can cause more eutrophication. This results in more frequent harmful algal blooms.^[8]: 140 Higher temperatures cause problems for water bodies and aquatic ecosystems because warmer water contains less oxygen.^[58]
• Permafrost thawing leads to an increased flux of contaminants.^[59]
• Increased meltwater from glaciers may release contaminants.^[60] As glaciers shrink or disappear, the positive effect of seasonal meltwater on downstream water quality through dilution is disappearing.^[61]

Poverty

People in low-income countries are at greater risk of water insecurity and may also have less resources to mitigate it. This can result in human suffering, sustained poverty, constrained growth and social unrest.^[2]

Food and water insecurity pose significant challenges for numerous individuals across the United States. Strategies employed by households in response to these pressing issues encompass labor intensive methods, such as melting ice, earning wages, and occasionally incurring debt, all aimed at water conservation. Additionally, families may turn to foraging for water-based plants and animals, seeking alternative sources of sustenance. Adjusting consumption patterns becomes imperative, involving the rationing of servings and prioritizing nutritional value, particularly for vulnerable members like small children. The phenomenon of substituting more expensive, nutritious food with cheaper alternatives is also observed.^[62]

Furthermore, individuals may consume from sources considered "stigmatized" by society, such as urine or unfiltered water. Migration emerges as a viable option, with families fostering children to relatives outside famine zones and engaging in seasonal or permanent resettlement. In certain instances, resource preservation involves the challenging decision of abandoning specific family members. This is achieved through withholding resources from non-family members, prioritizing the health of some family members over others, and, in extreme cases, leaving individuals behind. As the climate changes, the impact of food and water insecurity is disproportionately felt, necessitating a re-evaluation of societal misconceptions about those making survival sacrifices. Larger entities, including the government and various organizations, extend assistance based on available resources, highlighting the importance of addressing information gaps in specific data.^[62]

Destructive forces of water

Water can cause large-scale destruction due to its huge power.^[2] This destruction can result from sudden events. Examples are tsunamis, floods or landslides. Events that happen slowly over time such as erosion, desertification or water pollution can also cause destruction.^[2]

Other threats

Other threats to water security include:

• Disasters caused by
  natural hazards
  such as hurricanes, earthquakes, and wildfires. These can damage man-made structures such as dams and fill waterways with debris;
• Some climate change mitigation measures which need a lot of water. Bioenergy with carbon capture and storage, afforestation and reforestation may use relatively large amounts of water if done at inappropriate locations.^[8]: 4–8 The term for this is a high water footprint.
• Terrorism such as water supply terrorism;^[63]
• Radiation due to a nuclear accident;^[63]
• New water uses such as
  hydraulic fracturing for energy resources;^[64]
• Armed conflict and migration. Migration can be due to water scarcity at the origin or it can lead to more water scarcity at the target destinations.[6]^: 9

Management approaches

There are different ways to tackle water insecurity. Science and engineering approaches can increase the water supply or make water use more efficient. Financial and economic tools can be used as a

The right institutions are important to improve water security.[2] Institutions govern how decisions can promote or constrain water security outcomes for the poor.^[3] Strengthening institutions might involve reallocating risks and duties between the state, market and communities in new ways. This can include performance-based models, development impact bonds, or blended finance from government, donors and users. These finance mechanisms are set up to work jointly with state, private sector and communities investors.^[3]: 37

Sustainable Development Goal 16 is about peace, justice and strong institutions. It recognizes that strong institutions are a necessary condition for sustainable development, including water security.^[3]: 35

Drinking water quality and water pollution are linked. But policymakers often do not address them in a comprehensive way. For example, pollution from industries is often not linked to drinking water quality in developing countries.^[3]: 32 Keeping track of river, groundwater and wastewater is important. It can identify sources of contamination and guide targeted regulatory responses. The WHO has described water safety plans as the most effective means of maintaining a safe supply of drinking water to the public.^[65]

Information flows

It is important for institutions to have access to information about water. This helps them with their planning and decision-making.^[1] It also helps with tracking how accountable and effective policies are. Investments into climate information tools that are appropriate for the local context are useful.^[5]: 59 They cover a wide range of temporal and spatial scales. They also respond to regional climate risks tied to water.^[5]: 58

Seasonal climate and hydrological forecasts can be useful to prepare for and reduce water security risks. They are especially useful if people can apply them at the local scale.^[66][67] Applying knowledge of how climate anomalies relate to each other over long distances can improve seasonal forecasts for specific regions. These teleconnections are correlations between patterns of rainfall, temperature, and wind speed between distant areas. They are caused by large-scale ocean and atmospheric circulation.^[68][69]

In regions where rainfall varies with the seasons and from year to year, water managers would like to have more accurate seasonal weather forecasts. In some locations the onset of seasonal rainfall is particularly hard to predict. This is because aspects of the climate system are difficult to describe with mathematical models. For example, the long rains in East Africa which fall March to May have been difficult to simulate with climate models. When climate models work well they can produce useful seasonal forecasts.^[70] One reason for these difficulties is the complex topography of the area.^[70] Improved understanding of atmospheric processes may allow climate scientists to provide more relevant and localized information to water managers on a seasonal timescale. They could also provide more detailed predictions for the effects of climate change on a longer timeframe.^[71]

One example would be seasonal forecasts of rainfall in Ethiopia's Awash river basin. These may become more accurate by understanding better how sea surface temperatures in different ocean regions relate to rainfall patterns in this river basin.^[69] At a larger regional scale, a better understanding of the relationship between pressure systems in the Indian Ocean and the South Atlantic on the one hand, and wind speeds and rainfall patterns in the Greater Horn of Africa on the other hand would be helpful. This kind of scientific analysis may contribute to improved representation of this region in climate models to assist development planning.^[73] It could also guide people when they plan water allocation in the river basin or prepare emergency response plans for future events of water scarcity and flooding.^[69]

Infrastructure

Water infrastructure serves to access, store, regulate, move and conserve water. Several assets carry out these functions. Natural assets are lakes, rivers, wetlands, aquifers, springs. Engineered assets are bulk water management infrastructure, such as dams.^[2] Examples include:^[1]

• Improved water storage: using natural water storage systems such as aquifers and wetlands or built infrastructure such as storage tanks and dams.
• Using new water sources to add to the existing water supplies. This can be done through
  groundwater pumping
  .
• Embankments (or levee or dike) for flood protection.

Public and private spending on water infrastructure and supporting institutions must be well balanced. They are likely to evolve over time.^[2] This is important to avoid unplanned social and environmental costs from building new facilities.

For example, in the case of Africa, investments into groundwater use is an option to increase water security and for climate change adaptation.^[74] Water security in African countries could benefit from the distribution of groundwater storage and recharge on the continent. Recharge is a process where water moves to groundwater. Many countries that have low recharge have substantial groundwater storage. Countries with low storage typically have high, regular recharge.^[75]

Consideration of scales

People manage water security risks at different spatial scales. These range from the household to community, town, city, basin and region.^[3]: 11 At the local scale, actors include county governments, schools, water user groups, local water providers and the private sector. At the next larger scale there are basin and national level actors. These actors help to identify any constraints with regards to policy, institutions and investments. Lastly, there are global actors such as the World Bank, UNICEF, FCDO, WHO and USAID. They help to develop suitable service delivery models.^[3]: 11

The physical geography of a country shows the correct scale that planners should use for managing water security risks. Even within a country, the hydrologic environment may vary a lot. See for example the variations in seasonal rainfall across Ethiopia.

Reducing inequalities in water security

Inequalities with regards to water security within a society have structural and historical roots. They can affect people at different scales. These range from the household, to the community, town, river basin or the region.^[3]: 20 High risk social groups and regions can be identified during political debates but are often ignored. Water inequality is often tied to gender in low-income countries. At the household level, women are often the "water managers". But they have limited choices over water and related issues.^[3]: 21

Improving climate resilience of water and sanitation services

Many institutions are working to develop WASH services that are resilient to climate.^{[3]: 27, 37 [76][77]}

Measurement tools

There is no single way to measure water security.^[8]: 562 There are no standard indicators to measure water security. That is because it is a concept that focuses on outcomes.^[1] The outcomes that are regard as important can change depending on the context and stakeholders.

Instead, it is common to compare relative levels of water security by using metrics for certain aspects of water security.^[8]: 562 For example, the Global Water Security Index includes metrics on:

• availability (water scarcity index, drought index, groundwater depletion);
• accessibility to water services (access to sanitation and drinking water);
• safety and quality (water quality index, global flood frequency);
• management (World Governance Index, transboundary legal framework, transboundary political tension).^[83]

Scientists have been working on ways to measure water security at a variety of levels. The metrics roughly fall into two groups. There are those that are based on experiences versus metrics that are based on resources. The former mainly focus on measuring the experiences of households and human well-being. Meanwhile the latter focuses on the amount of available freshwater.^[9]

The Household Water Insecurity Experiences (HWISE) Scale measures several components of water insecurity at the household level. These include adequacy, reliability, accessibility and safety.^[84] This scale can help to identify vulnerable subpopulations and ensure resources are allocated to those in need. It can also measure how effective of water policies and projects are.^[84]

Global estimates

The IPCC Sixth Assessment Report summarises the current and future water security trends. It says that increasing weather and extreme climate events have led to acute food insecurity and reduced water security for millions of people. The largest impacts are seen in Africa, Asia, Central and South America, Small Islands and the Arctic.^[10]: 9

The same report predicted that global warming of 2 °C would expose roughly 1-4 billion people to water stress. This would depend on regional patterns of climate change and the socio-economic scenarios.^[8]: 558 On water scarcity which is one factor in water insecurity the report finds 1.5-2.5 billion people live water scarce areas.^[10]: 660

Water scarcity and water security are not always equal. There are regions with high water security even though they also experience water scarcity. Examples are parts of the United States, Australia and Southern Europe. This is due to efficient water services that have a high level of safety, quality, and accessibility.^{[83][8]: 562} However, even in those regions, groups such as Indigenous peoples tend to have less access to water and face water insecurity at times.^[8]: 562

Country examples

Bangladesh

Too much water can also cause water insecurity. Left: Flooding in Bangladesh; right: People on an island in a flooded river in Bangladesh.

Risks to water security in Bangladesh include:^[5]: 45

• natural hazards that related to the climate (
  climate hazards
  )
• some impacts of urbanization
• impacts from climate change such as changes to precipitation patterns and sea level rise.

The country experiences water security risks in the capital Dhaka as well as in the coastal region.^[5] In Dhaka, monsoonal pulses can lead to urban flooding. This can pollute the water supply.^[5] A number of processes and events cause water risks for about 20 million people in the coastal regions. These include aquifers that are getting saltier, seasonal water scarcity, fecal contamination, and flooding from the monsoon and from storm surges due to cyclones.^[5]: 64

Different types of floods occur in coastal Bangladesh. They are: river floods, tidal floods and storm surge floods due to tropical cyclones.^[85] These floods can damage drinking water infrastructure. They can also lead to reduced water quality as well as losses in agricultural and fishery yields.^[5] There is a link between water insecurity and poverty in the low-lying areas in the Ganges-Brahmaputra tidal delta plain.^[85] Those low-lying areas are embanked areas in coastal Bangladesh.

The government has various programs to reduce risks for people who live in coastal communities. These programs also lead to increases in economic wellbeing.^[85] Examples include the "Coastal Embankment Improvement Project"^[86] by World Bank in 2013, the BlueGold project^[87] in 2012, UNICEF's "Managed Aquifer Recharge" program in 2014 and the Bangladesh Delta Plan in 2014.^[85] Such investments in water security aim to increase the continued use and upkeep of water facilities. They can help coastal communities to escape the poverty trap caused by water insecurity.^[85]

A program called the "SafePani framework" focuses on how the state shares risks and responsibilities with service providers and communities.^[5] This program aims to help decision makers to address climate risks through a process called climate resilient water safety planning.^[5] The program is a cooperation between UNICEF and the Government of Bangladesh.

Ethiopia

Ethiopia has two main wet seasons per year. It rains in the spring and summer. These seasonal patterns of rainfall vary a lot across the country.^[69][89] Western Ethiopia has a seasonal rainfall pattern that is similar to the Sahel. It has rainfall from February to November (which is decreasing to the north), and has peak rainfall from June to September. Southern Ethiopia has a rainfall pattern similar to the one in East Africa. There are two distinct wet seasons every year, February to May, and October to November.^[72][89] Central and eastern Ethiopia has some rainfall between February and November, with a smaller peak in rainfall from March to May and a second higher peak from June to September.^[89]

In 2022 Ethiopia had one of the most severe

In the Awash basin in central Ethiopia floods and droughts are common. Agriculture in the basin is mainly rainfed (without irrigation systems). This applies to around 98% of total cropland as of 2012. So changes in rainfall patterns due to climate change will reduce economic activities in the basin.^[91] Rainfall shocks have a direct impact on agriculture. A rainfall decrease in the Awash basin could lead to a 5% decline in the basin's overall GDP. The agricultural GDP could even drop by as much as 10%.^[91]

Partnerships with the Awash Basin Development Office (AwBDO) and the Ministry of Water, Irrigation and Electricity (MoWIE) have led to the development of new models of water allocation in the Awash basin. This can improve water security for the 18.3 million residents in the basin. With this they will have enough water for their domestic, irrigation and industry needs.^[5]

Kenya

Kenya ranked 46th out of 54 African countries in an assessment of water security in 2022.^[92] Major water security issues in Kenya include drinking water safety, water scarcity, lack of water storage, poor wastewater treatment, and drought and flood.^[92] Large-scale climate patterns influence the rainfall patterns in East Africa. Such climate patterns include the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). Cooling in the Pacific Ocean during the La Niña phase of ENSO is linked with dryer conditions in Kenya. This can lead to drought as it did in 2016-17. On the other hand a warmer Western Indian Ocean due to a strong positive Indian Ocean Dipole caused extreme flooding in Kenya in 2020.^[93]

Around 38% of Kenya's population and 70% of its livestock live in arid and semi-arid lands.^[94] These areas have low rainfall which varies a lot from one season to the next. This means that surface water and groundwater resources vary a lot by location and time of year. Residents in Northern Kenya are seeing increased changes in rainfall patterns and more frequent droughts.^[95] These changes affect livelihoods in this region where people have been living as migratory herders. They are used to herding livestock with a seasonal migration pattern.^[95] More people are now settling in small urban centers, and there is increasing conflict over water and other resources.^[96] Water insecurity is a feature of life for both settled and nomadic pastoralists. Women and children bear the burden for fetching water.^[97]

Groundwater sources have great potential to improve water supply in Kenya. However, the use of groundwater is limited by low quality and knowledge, pumping too much groundwater, known as overdrafting, and salt water intrusion along coastal areas.^[98][99] Another challenge is the upkeep of groundwater infrastructure, mainly in rural areas.^[100]

Ukraine

Russian forces have destroyed one-third of Ukraine’s freshwater storage since February 2022 to 2024.^[101] Potable, industrial and irrigation water supplies have been cut across the south and east of the country. Occupation of the southern and eastern regions of Ukraine and destruction of the Kakhovka Reservoir have all but terminated irrigation. Irrigated cereals and technical crops are now unprofitable, even where practicable – not least because of the difficulty of selling and exporting the produce. The strategic development of irrigation should be based on optimal technology to minimize water costs and redesign cultivation systems, for example, by drip irrigation, diverse crop rotations and focus on vegetable farming, orchards, and viticulture.^[101][102]

See also

• Global Water Security & Sanitation Partnership
• Human right to water and sanitation
• Water footprint
• Water security in Australia
• Water security in the United States

References