4.2 - Water access, use and security (ESS)

Water scarcity

having access to sufficient amounts of safe drinking water. 

Meeting SDG 6 Clean Water and Sanitation by 2030

According to a report produced by the 2030 Water Resources Group, global freshwater demand will outstrip supply by 40% and according to the UN SDG Report 2022, an estimated 1.6 billion people will not have access to safely managed drinking water. Only 12% of rivers still run freely from source to sea (WWF Rivers at RIsk 2004 Report, cited in Vince 2014^[1]). Mexico's Rio Grande, China's Yellow River, and Australia's Murray River frequently don't reach the sea.

Water is needed for

essential for life and sustainable societies but if we look beyond the obvious health need for drinking water, water is needed for livelihoods through agriculture, energy production, and transportation. This combines to allow for stable and sustainable economies. Ecosystems depend on water and without these life-providing systems, human societies will not be sustainable. 

Sustainably managing water systes

also means planning for disaster risk reduction. 

Climate change

placing increased stress on systems and increasing droughts and floods.

Infrastructure and leakage

a lack of investment in infrastructure can mean that there is not a distribution network to supply water but also old infrastructure can mean that large amounts of water are wasted through leaks and broken pipes.

Response to droughts

societies and individuals may respond differently to the need for water to maintain agricultural production. Do producers adapt to changing climates and shift production to more drought-resistant crops or do they just pump more ground water for irrigation?

Perception and values

some societies have strong relational values with water. Water can have aesthetic, spiritual and emotional value to people. It is often strongly connected to indigenous cultures with spiritual values.

Heritage Values

Water can be a very important part of the culture and heritage of a place. Think about the role of water in Islamic gardens.

Gender Roles

n many cultures, women are associated with the work of water. In countries with a water infrastructure, this means women and children may be carrying water from a well.

Agricultural Commodities

if a country chooses to import water-intensive crops, such as rice or cotton, then it is indirectly affecting water availability in the export country. Conversely, a country that chooses to produce crops that are water-intensive for export, may be deprioritizing the water security of its citizens. This is a direct reflection of the global economic market.

Market Adaptation

markets will respond to shortages by adjusting prices which can affect the availability of water to consumers. This can result in economic instability.

Pricing Water

 many societies charge for water but this may result in inequitable access to water. Is water charged by use or is there a flat rate? Is it sold or is it paid for through taxation?

Losses due to scarcity

 Lack of water can impair the economy of a society. As we learned earlier, with clean water and sanitation, health and livelihoods are impacted impacting economic development.

Political factors

Many countries are using water that is a shared transboundary resource. Without political solutions and signed treaties, this can impact the water security of a country. Examples include the shared water of the Colorado, the Nile, the Indus and La Plata. Agreements need to include the rights to use the water for energy production, drinking water and for agriculture.

Global Trade

trade of commodities moves hidden water around the world. Southern Spain doesn't have abundant water yet it is one of the biggest producers of vegetables for the European market. These are political decisions linked to economic productivity. Water security is intrinsically linked to these decisions, often promoted by financial support in the form of subsidies or tax breaks to build infrastructure.

Law

Rivers in some countries have rights. They have the right to exist and flow freely.

Economics

Decisions associated with water security may not value the relational or intrinsic value of water. It is not built into the economic value of a resource. Environmental economics attempts to include these types of value through value surveys or willingness to pay surveys.

Ethics

Consider if a society has a dominant ethical value system, how does this mean that they manage their resources like water? Is it linked? How do the different approaches to ethics (virtue, consequentialism and rights-based affect how water might be managed?

Population growth and economic development

Human societies use water for domestic purposes, in agriculture for irrigation or for raising livestock, and in industry including energy production. As populations grow, more water is needed but water is a finite resource. Societies need to find ways of increasing the supply of water and the efficiency of its utilization.

Physical water scarcity

means that the climate in that region is dry and/or the water is being over-extracted for human use, either for domestic, agricultural or industrial use. This may be for industrial uses or irrigation. As usual, it is the poor that suffer from these problems, like Yemen.

Conflict between agricultural users and domestic users - california

In California during the severe drought continuing in 2016, domestic users, who make up 20% of the water demand, were asked to reduce their water consumption, but no such demands were made on agriculture which uses 80% of water demand.

Economic water scarcity

physical infrastructure is not in place to ensure that clean safe water is available to the population, for example, notice the large areas of tropical Africa, India and South East Asia which are categorised as having economic water scarcity (in 2007). In these areas, it generally means that the rich have access to clean water as they can afford to provide their systems for cleaning water, but the poor do not have access to clean water.

Managing water supplies

the construction of dams, reservoirs and desalination plants for high-tech, high investment strategies. Rainwater catchment systems and the enhancement of natural wetlands are low-tech, lower investment strategies, water diversion schemes, international sale of water, artificial recharge of aquifers, artificial glaciers and cloud seeding.

Dams and reservoirs

Dams are relatively cheap to build and are 80-90% efficient. They even come with their own battery where water can be pumped back upstream and stored ready for peak demand times. Once built they can be a haven for wildlife and provide new fisheries and much needed irrigation.

Problems with big dam projects

• flood fertile land

• if the area is not cleared first, the rotting vegetation produces methane (1/4 of all human methane emissions come from big dams)

• the massive weight of water can increase the risk of earthquakes in vulnerable regions, e.g. the Three Gorges dam

• seasonal flooding is prevented and this also prevents sediment from moving downstream. The loss of minerals, particularly silica, downstream is thought to have contributed to the decrease in productivity in marine fisheries.

• Hydropeaking - pulses of water moving downstream during peak electricity demand, disrupting habitats.

• Biodiversity loss can be a big problem in biodiverse regions, e.g. the Mekong River, Brazilian Amazon, or the Patagonian wilderness areas.

• Fish migration routes can be impeded. In the Mekong, 75% of fish are migratory.

• Large numbers of people can be displaced, e.g. the Narmada Dam in India and the Three Gorges Dam in China. This is sometimes the source of environmental justice problems. The excellent Ej Atlas provides us with a vast resource for learning about environmental justice cases around the world.

• In wilderness areas, the very essence of wilderness (aesthetic value) is lost, e.g. Patagonia

Desalination Plants

For some, desalinization is seen as the miracle solution for providing clean drinking water in physically water-scarce regions. There are two main ways of desalination, 1) heating-evaporation-condensation, and 2) reverse osmosis. The simpler process works by heating salty water until it evaporates then collecting the evaporating water vapour and allowing it to cool and condense. This means the salt is left behind and you have clean water remaining.

Reserve osmosis

requires high pressures meaning it is energy intensive. If this process is done with solar energy, as is increasingly the case in Australia and the Middle East, then it seems like a great solution. The water can be used for drinking or agriculture. MIT's technology review looks at the biggest desalination plant in Israel. The Scientific American reports that Israel gets 55% of its water for domestic use from desalination. This BBC link contains a video about the use of desalination for agriculture in Jordan.

EU and desalination plants.

The EU has over 2300 seawater desalination units with contribute to 10% of the global capacity^[2] and this is expected to grow as the EU is predicting that by 2050 many regions in the EU will be facing severe water scarcity. Additionally, a lot of these plants rely entirely on fossil fuels.

Seawater greenhouses

This is a very low technology solution for growing vegetables in hot desert areas with access to salt water. The water is pumped up onto the roof of the greenhouse where it passes over cardboard pads and slowly evaporates. This cools the air in the greenhouse by about 15 degrees and creates a humid atmosphere in the greenhouse. The water can then be enriched with the precise nutrients needed for the plants and the plants grown aquaponically (without soil).

Rainwater catchment

Rainwater harvesting is best done with the design of new buildings so that the infrastructure can be designed to be integrated into the building. It adds cost to the initial construction but is a water efficiency measure. The water can be used to flush toilets, water the garden, wash clothes and wash cars etc. It can also be added retrospectively but this would be complicated for integration into the house's plumbing system. It is more likely used for watering the garden.

Enhancement of Natural Wetlands

natural wetlands slow down the flow of water and act like sponges. They also have the ecological service of filtering the water. This is why beavers have proved so effective in flood prevention with the renaturalisation of ecosystems in water catchments. Slowing the flow of water also means that the ecosystem is able to hold more water, including in drought periods, helping to ensure water security for urban areas served by these water catchments. This is considered a nature-based solution.

Metering

users become more aware of their water use and the theory is that they then are able to reduce their water wastage.

Rationing

has been applied in water shortage situations. When Cape Town was heading to day zero, rationing was enforced to reduce their water wastage. It is the temporary suspension of water supply, or the act of limiting everyday water use.

Grey water recycling

the water from washing is collected, filtered and then used to flush toilets or water the garden. This has to be planned into the design of new buildings as with rainwater harvesting

Low flush toilets

allow the user to select a low flush when les water is requires to dilute the waste.

Companies - monitoring water usage

Companies that are focusing on their ESG (Environmental Social Governance) reporting (also called CSR - Corporate Sustainability Reporting) are monitoring their water usage and sometimes even proclaiming how much water they have saved by changing their industrial practices. For example, Nestle.

Agriculture - water conservation

Agriculture uses 70% of the world’s water. In food production, there are various water conservation strategies, including greenhouses that recycle harvested rainwater, aquaponic systems, hydroponic systems, drip irrigation systems, drought resistant crops, and switching to plant (vegetarian) food production.

Greenhouses Harvesting Rainwater

This is a fairly low-tech solution, requiring gutters along the roofs of the greenhouses that collect the water in a tank. More sophisticated systems have two tanks, one for the first wash from rain that collects dust and droppings etc and a second that collects the filtered water for use. 

Aquaponic systems

Combining fish production and vegetable/salad production.  The water from the fish is used as fertiliser for the plants in a closed-loop system. This reduces the inputs needed for the plants and makes efficient use of water. Aquaponics works well in places where the soil is poor and water is scarce, for example, in urban areas, arid climates, and on low-lying islands. The system may not be useful in areas without a reliable electricity supply as the system depends on pumps and needs a reliable source of parts for the system (plumbing and building parts) and fish food.

Environmental Impacts - Aquaponics

While aquaponics conserves water, it can consume significant energy for lighting, heating, and water circulation, especially in artificial or indoor environments. The risk of chemical use, non-native species introduction, and e-waste from equipment also raises concerns about long-term ecological sustainability.

Animal welfare - aquaponics

Aquaponics systems often raise fish in confined tanks where overcrowding, poor water quality, and limited environmental enrichment can cause stress and suffering. Ethical concerns arise when fish are treated as mere production units, with little regard for their capacity to feel pain or express natural behaviors.

Economic Feasibility - aquaponics

The high startup and maintenance costs of aquaponics systems make them inaccessible to many small-scale farmers and low-income communities. This economic barrier creates ethical tension between innovation and inclusivity, especially if such systems displace traditional, community-based food practices.

Health risks - aquaponics

Improper system management can lead to contamination of both fish and vegetables, posing food safety risks to consumers. Inadequate regulation and the potential misuse of antibiotics further heighten ethical concerns about transparency, accountability, and public health protection.

Hydroponic Systems

These are systems, often vertical farms, that grow plants in water and mineral solutions often in climate controlled conditions.

Drip Irrigation Systems

Using drip irrigation can increase the efficiency of water delivery many times over and reduce water loss. It requires low technology but quite some investment to start with.

Drop resistant crops

Growing crops more suited to the local climate will also help reduce water demands. There are no point growing water thirsty crops in a water scarce location. Crops are being developed which have low water demands and may even be salt tolerant, e.g. peanuts, chickpeas, pigeon peas, pearl millet and sorghum.

Changing to Vegetarian Food Production

Freshwater withdrawals for food largely map onto the carbon footprint of food items. By changing our diets to eating less meat then we can reduce the water demands of our diets.

Rajasthan - India

one of India's driest states, mitigates water scarcity through a mix of traditional and modern methods. Communities have revived ancient rainwater harvesting systems like johads, baoris, and tankas to capture and store monsoon rain. Watershed management, drip irrigation, and government schemes like the Jal Jeevan Mission support efficient water use and supply. NGOs such as Tarun Bharat Sangh have played a key role in community-based water conservation. These efforts improve groundwater recharge, support agriculture, and build long-term water resilience in the face of arid conditions.

Pacific Institute - USA

The Pacific Institute, based in California, is a nonprofit organization focused on promoting sustainable water management in the U.S. and globally. It develops practical, science-based solutions such as water efficiency, reuse, and stormwater capture to reduce urban water demand and increase resilience to climate change. The Institute also advocates for equitable access to clean water, working with vulnerable communities to build inclusive and climate-resilient water systems. Through research and policy guidance, it plays a key role in advancing water sustainability and justice.

Reassessment of Freshwater Charge in 2022

pushed the indicator beyond the safe operating space. Scientists said this was due to the inclusion of "Green Water" - the water available to plants - which is decreasing as soils become drier from climate change and deforestation. This is evident in the Amazon but is a global phenomenon. "Blue Water" is the extraction of water in rivers, lakes, and groundwater and the water frozen in glaciers and polar ice caps.

Water Planetary Boundary

indicates there is increased water stress and the risk of abrupt and irreversible changes to the hydrological system. Assessments of the freshwater boundary talk about the need to develop local boundaries and local management plans as, while water is a planetary boundary, it is distributed unequally. They talk about developing "fair-share" calculations where a share of the global boundary is allocated regionally. This would be a top-down approach. The bottom-up approach would be the use of a local safe operating space.

Examples of water management and governance approaches at different spatial scales targeting each store of water. Blue boxes are water management approaches, and green dashed boxes are management approaches that are not designed specifically for water but are likely to have a strong effect on that water store.

The Global Commission on the Economics of water in 2023 published a seven-point plan to save the water cycle.

1. Manage the global water cycle as a global common good, to be protected collectively and in the interests of all.

2. Adopt an outcomes-focused, mission-driven approach to water encompassing all the key roles it plays in human well-being.

3. Cease underpricing water.

4. Phase out some USD 700 billion of subsidies in agriculture and water each year, which tend to generate excessive water consumption and other environmentally damaging practices.

5. Establish Just Water Partnerships (JWPs) to enable investments in water access, resilience and sustainability in low- and middle-income countries, using approaches that contribute to both national development goals and the global common good.

6. Move ahead on the opportunities that can move the needle significantly in the current decade such as strengthening groundwater and wetland stores, developing the urban circular water economy, particularly in recycling urban and industrial wastewater, reducing water footprints in the industry, particularly the use of lithium in electrification, shifting agriculture to precision irrigation, less water-intensive crops and drought resilient agriculture.

7. Reshape multilateral governance of water, which is currently fragmented and not fit for purpose.

HL Law

Current multilateral structures for water governance include organizations like the United Nations Water (UN-Water), World Bank, and Global Water Partnership, which coordinate international efforts on water access, quality, and sustainability. However, they are often criticized as fragmented because there is no single global authority managing water comprehensively—responsibilities are spread across many agencies with overlapping mandates. This leads to gaps in coordination, inconsistent policies, and limited enforcement power, making the system ineffective for addressing transboundary water issues and global water security.

HL Economics

Urban circular water economies are emerging in cities like Rotterdam, Hamburg, and San Francisco, where innovative systems recycle wastewater for non-potable uses, recover energy, and repurpose nutrients, thereby reducing reliance on freshwater sources and minimizing environmental impact. To address the underpricing of water, strategies such as tiered pricing, polluter-pays principles, and full-cost recovery models have been implemented in regions like Australia's Murray-Darling Basin, promoting conservation and equitable access. However, these reforms often face barriers including political resistance, affordability concerns for low-income populations, and the complexity of overhauling existing infrastructure and regulatory frameworks.

OECD (Organization for Economic Co-operation and Development)

a global membership-based organisation but is not inclusive like the UN, containing no countries in Africa, only Chile and Colombia in South America and only Korea and Japan in Asia. It facilitates a multi-stakeholder network to share good practices in water governance that do appear to include less wealthy countries.

Local level - RWH (rainwater harvesting)

has been a popular measure to implement and improve access to water. An open-access paper by Yannopoulos et al. (2019)^[11] in the journal Water reviews the history of RWH with many examples of its legislated, historic and cultural use. Some form of RWH is compulsory for buildings and houses in some cities and states in India, e.g. Chennai and Rajasthan, in Bermuda and some states in Australia, e.g. South Australia. There are many other examples.

Controversial legislation - UK

the banning of domestic hose pipes while agriculture remains free from legislation.  In the UK, the local water companies are able to apply bans such as this one in 2023. There is even a UK website that monitors hosepipe bans.

Examples of international agreements

the Indus Water Agreement (this is considered one of the most successful water-sharing negotiations), The  La Plata Basin Treaty in South America, and others on the Nile, in Jordan and the Ganges.

Indus Water Agreement

Under the Indus Water Treaty (1960), India has control over the eastern rivers (Ravi, Beas, Sutlej) and can use the western rivers (Indus, Jhelum, Chenab) for limited purposes like irrigation, transport, and hydropower without altering flow. Pakistan has exclusive rights to the western rivers, which make up the bulk of its water supply, essential for agriculture. Both countries share data, allow joint inspections, and resolve disputes through a Permanent Indus Commission. This structure allows cooperation despite political tensions, but new dam projects and climate stress are increasing pressure on the agreement.

La Plata Basin Treaty (South America)

The La Plata Basin Treaty, signed in 1969 by Argentina, Bolivia, Brazil, Paraguay, and Uruguay, promotes the coordinated development and conservation of the La Plata River system—South America's second-largest basin. The countries agreed to share data, collaborate on navigation, hydropower, irrigation, and prevent harmful actions in shared waters. It established the Intergovernmental Coordinating Committee to manage cooperation. While not a strict allocation treaty, it fosters diplomatic dialogue and regional integration over shared water resources.

Nile Basin (Jordan and Others)

Although Jordan is not part of the main Nile Basin, the Nile Basin Initiative (NBI), formed in 1999, includes 11 countries like Egypt, Sudan, Ethiopia, and Uganda, aimed at cooperative management and sustainable developmentof the Nile's resources. Egypt and Sudan traditionally had greater water rights under the 1959 Nile Waters Agreement, but upstream countries like Ethiopia demand more equitable sharing, especially with projects like the Grand Ethiopian Renaissance Dam (GERD). Tensions remain high due to competing needs, population growth, and climate stress. While no binding new treaty has replaced the older agreements, the NBI provides a platform for dialogue.

Ganges River Agreement (India and Bangladesh)

The Ganges Water Sharing Treaty, signed in 1996 between India and Bangladesh, allocates water from the Ganges River during the dry season (Jan–May), focusing on the Farakka Barrage, which affects flow into Bangladesh. India controls upstream infrastructure and agreed to guarantee specific water flows to Bangladesh based on seasonal availability. The treaty lasts 30 years and includes joint monitoring mechanisms. While cooperation has improved, challenges persist around water scarcity, sedimentation, and ensuring fair distribution during low-flow years.

Water footprints

can be calculated and used at a variety of different levels. An individual or a country can calculate their water footprint but they are more commonly used for individual items or by businesses as part of a life cycle analysis or for sustainability auditing. This allows consumers and businesses to make decisions. At a national level, this informs decision-making by societies when thinking about water security.

Citizen Science - Managing Water Resources

There are an increasing number of projects which seek to use local communities to monitor water quality. The most common research is monitoring but mapping, modelling, and collection of narratives are valuable sources of data, particularly for the incorporation of local and indigenous knowledge for disaster risk reduction at community-scale. The volunteers require training to ensure that high quality data is captured reliably and helps provide researchers with greater data sets, filling in missing spatial data. On the other hand, it helps raise awareness and engagement in the community. Researchers hope that this will help SDG 6 to be met.

Citizen Science project in Chile

A citizen science project in Chile engaged local communities in monitoring water quality by collecting chemical data from rural water sources. This collaborative approach empowered residents to participate in environmental stewardship and provided valuable data for assessing water conditions. The initiative highlighted the effectiveness of combining scientific methods with community involvement to address water quality issues. Such projects can enhance environmental awareness and contribute to sustainable water management practices.

Benefits of Citizen Science (bullet points)

• public engagement

• raising awareness

• democratization of science

• Development of mutual trust, confidence, and respect between scientists, authorities, and the public

• knowledge gain

• increased scientific literacy

• social learning

• Incorporation of local, traditional, or indigenous knowledge

• Increased social capital

• empowerment

• behavior change

• improved environment

• Decreased risk or improved health

• Improved livelihoods

• Motivational benefits

Flint USA - citizen science project

concerned citizens teamed up with researchers to collect water quality data leading to behavior change (people stopped using lead-contaminated tap water), policy change (the city reverted to its former water source), and ultimately improved health.

Negative impacts of citizen science

• In low-income areas, does the participation place an unfair burden on the participants and are they simply providing cheap unpaid labour.

• There is a potential risk to participants.

• Intermittent funding can hinder communities' self-reliance.

• Communities can become too preoccupied with potential hazards.

• Certain groups may be excluded from the engagement.

• The use of technology can exclude some members of the community.

• The burden is passed from the authorities to the public.

• Creating conflict when results come from citizen science or there are very diverse stakeholders.

• Potential breaches in data privacy.

• Demotivation from project being time consuming, difficult or boring.

• Does the data match the goals of the citizens?

• Disappointment when no impact is realised.

• Erosion of confidence, trust and social capital when volunteers were not kept informed on the project outcomes.

• Ethical concerns about financial incentives

Water Stress - EU Environment Agency

Water stress occurs when the water demand exceeds the available amount during a certain period or when poor quality restricts its use. Water stress causes the deterioration of freshwater resources in terms of quantity (aquifer over-exploitation, dry rivers, etc.) and quality (eutrophication, organic matter pollution, saline intrusion, etc.). water stress not only takes into account the scarcity of availability but also the water quality, environmental flows and accessibility. A region may have enough water but be experiencing water stress because of low water quality. Water stress is defined as a clean, accessible water supply of less than 1,700 cubic metres per year per capita.

India - Water stress

Home to a large population, India experiences water stress due to overexploitation of groundwater reserves and uneven distribution of water resources. Pollution from industrial waste and agricultural runoff further complicates the situation. 

Pakistan - water stress

Water scarcity is a major challenge in Pakistan, particularly in areas dependent on the Indus River. Climate change and glacier melt are exacerbating the problem, while salinization of freshwater resources adds another layer of complexity. 

Libya

Considered to be under extreme water stress, Libya faces a critical situation. The country has very low natural water resources and relies heavily on the depleting Nubian Sandstone Aquifer System. Seawater intrusion and over-extraction further threaten this vital resource. On top of that, water infrastructure is aging and inefficient, leading to significant water losses.

Socio-economic context of water stress

In emerging economies, there is pressure to develop industrially and tension in the costs of putting in place adequate environmental protections. As industries develop they demand water for processes such as cooling, and manufacturing. particularly in textiles and sanitation. Without environmental technology, this can also result, not only in the increased demand for water but also increased pollution with wastewater not being treated and contaminating freshwater sources.

The effect of the rising population growth on water stress

This can result in over-abstraction of water, leading to depletion of groundwater and a lack of clean drinking water and water for sanitation. This is compounded by a lack of funds to support the infrastructure needed so pipes for distribution and wastewater treatment are also lacking.

Transboundary conflicts

Water is usually a resource that is shared between countries but can lead to conflict if the countries do not talk to each other. It is best thought of as a global commons. Many countries have developed water treaties and agreements as we have seen in the section on Water Governance.

Jordan river - regional dispute

between Israel, Jordan, Syria, Lebanon, and the Palestinian Territories. The river’s limited freshwater supply is crucial in this arid region, and competing demands have made it a source of tension since the mid-20th century. After Israel's establishment in 1948 and the subsequent Arab-Israeli conflicts, access to the Jordan River became a strategic and political issue, especially with water diversion projects in the 1960s. The 1994 Israel–Jordan Peace Treatyincluded agreements on water sharing, helping ease some tensions. However, disputes persist, particularly with Palestinian access to water, which remains heavily restricted under Israeli control. Political instability, unequal access, and growing demand continue to challenge sustainable and equitable water governance in the basin.

Dams (HL)

can provide a store of excess water during wet seasons for use during dry periods. The construction of dams can cause noise and air pollution.

Water transfer - pipelines and tankers

seek to solve water shortage problems in one area by moving water from another, possibly distant area by large scale infrastructure projects. China proposes to move water from the Yangtze in the south to the Yellow River in the north. This is to overcome over-extraction of groundwater in the north and supply industry and agriculture. Experts worry that pollution from factories will make the water unfit to drink anyway and that water quality in the Yangtze will further decline. Island states sometimes rely on delivering freshwater by tankers during droughts or disasters.

Estuary Storage Barrages

Estuary storage with barrages involves building barriers across river mouths to create freshwater reservoirs by preventing saltwater intrusion. This method stores river water during high flow periods and releases it during dry seasons, helping regulate supply for agriculture, industry, and domestic use. It supports water security in coastal regions but can impact ecosystems and fish migration if not carefully managed. Examples - Japan, Marina Barrage, Singapore.

Cloud Seeding

s a multi-billion dollar business undertaken in over 50 countries for a variety of reasons and using a variety of methods. Cloud seeding is a weather modification technique used to enhance rainfall by dispersing substances like silver iodide into clouds to encourage water droplet formation. It is used in water-scarce regions to boost precipitation for agriculture, drinking water supplies, and hydropower generation. However, its effectiveness is variable and it raises concerns about environmental impacts and ethical considerations. It is also used in Canada to reduce the risk of giant hailstorm storms which can be very destructive. The silver iodide helps smaller ice particles form. The technology used to detect and model clouds and storm formation has increasingly been used by the cloud seeders but it is a potentially dangerous job and pilots can die when they don't have the experience to deal with flying into a storm. The important fact is that there have to be some clouds present already. You can't get rain where there is no moisture. Problems identified but not strongly supported by evidence include the idea that water is being stolen from another region and that the chemicals used to seed the clouds can be toxic.

Desalination - further study

Currently, much of the desalinisation is conducted using the abundance of oil in the region but there is a process of conversion to solar and wind energy. More problems abound. Some desalinisation plants have had to close due to algal blooms caused by land reclamation, along with brine and industrial waste. The gulf water, already hypersaline is becoming more saline and threatening biodiversity. This is also affecting fish populations and aquaculture. Seagrass meadows and mangroves are struggling and it has the world's largest dead zone. You can read more in this New York Times article. The use of fossil fuels results in air pollution.

solar distillation

uses solar thermal energy to evaporate water from salt water or contaminated water (only the water molecules evaporate) and then condense the water to provide a clean source of water. It has been used for a long time at a small and community scale but requires large areas of land and has a lower capacity than desalinisation. It also produces brine.

Brine

salt water

Dew Harvesting

captures dew droplets from the air using special meshes. It is suitable for arid areas but the yields are low. Indian and French scientists are developing this technology along with other groups around the world. It is a relatively cheap and low-impact approach suitable for small communities.

dew

condensation of atmospheric water vapor into droplets of water.

Water Treatments Plants

process contaminated water (usually in sewage treatment) but also industrially contaminated water using a variety of stages.

Aquifer Storage and Recovery (ASR)

a method for storing water underground during wet periods for recovery when needed during dry periods. According to this USGS source published in 2018, there are more than 100 ASR facilities worldwide and it is being actively explored for California's water scarcity challenges.

Artificial Recharge of Aquifers (AR)

is similar to ASR but less controlled and doesn't necessarily have the goal of retrieving the water at a later stage. It is also called Managed Aquifer Recharge (MAR). The water sources can include drinking water from a public water treatment system, untreated groundwater and surface water, treated effluent and reclaimed or recycled water. The methods of recharge include surface spreading, infiltration pits and basins and injection wells. Risks from this method include contaminating the aquifer. A positive is the improvement of water quality (when carefully managed) in industrial zones and the prevention of saltwater intrusion.

The Dine Nation

the largest federally recognized tribe in the United States and have their homelands in Arizona, New Mexico and Utah. 30% of Diné homes lack basic plumbing which means that water has to be transported from distant distribution points or using potentially unsafe sources. Their lands have been exploited for uranium mining which has contaminated ground water. This leads to the spread of waterborne diseases and other health problems and can have knock-on effects on education.

US Alliance 2021 report

According to a 2021 report by the U.S. Water Alliance, Native American households are 19 times more likely than white households to lack indoor plumbing. On the Navajo Nation, around 30% of homes do not have running water, forcing families to haul water from communal sources, often at high cost and effort. This lack of access increases vulnerability to diseases and limits hygiene practices, particularly during health crises like COVID-19. Historical marginalization, underinvestment in infrastructure, and jurisdictional complexities between federal, state, and tribal governments contribute to the problem. Addressing this inequity requires targeted investment, tribal-led water projects, and stronger recognition of indigenous water rights.