Solutions for a salty future

Liliana writes*

In September 2023, residents of New Orleans, Louisiana had salt water coming out of their taps (Sneath, 2023). The city declared a state of emergency as a “salt water wedge” moved up the Mississippi River from the Gulf of Mexico. Although the crisis was averted, the underlying issues remain for the city.

The source of the issue is clear: there is more room in the river and less fresh water to fill it. Much of the Mississippi lies below sea level in Louisiana, meaning that without enough fresh water flow, the river is vulnerable to salt water intrusion (NOLA). As yearly droughts increase in severity with global warming, the river’s flow is sometimes insufficient to stop the underflow of denser salt water (NOLA). Exacerbating this, the US Army Corps has dredged the Mississippi to increase cargo clearance for decades (Bliss and Hirji, 2023). Their most recent large-scale project in 2022, deepened parts of the river by 5 feet (1.5m), to 50 feet (15m) (Bliss and Hirji, 2023). These efforts have been touted as an economic success, allowing the Mississippi River Ship Channel to expand the already 450 million tons of exports that travel the route. However, with decreasing fresh water flow and rising sea levels as a result of climate change, these rewards are not worth the risks.

Salt water intrusion causes harm across every sector. For humans, high sodium concentrations can increase blood pressure (Chow, 2023). Salt water is much more corrosive than fresh water and could cause harmful chemicals to leach from pipes into drinking supply. Nearly all piping in New Orleans is made with lead, so corrosion could introduce serious public health risks, as was seen in Flint, Michigan (Chow, 2023). Salt can also corrode infrastructure, which could cost the city millions to replace. Finally, soil health and agricultural output would be at risk with farmers literally salting the earth (Chow, 2023).

Solutions vary. Current containment methods include constructing underwater sills (Bliss and Hirji, 2023). As salt water is much more dense than fresh water, the intrusion travels in the shape of a wedge along the base of the riverbed. Thus, what are essentially walls can be built along the riverbed to ensure that the wedge does not travel further upstream (see figure). Holes in the sills allow continued commerce along the river. Although effective short-term, this solution is unsustainable as it ignores the problem’s root causes and requires new sills each time the salt water wedge grows.

Source: Army Corps of Engineers

Other solutions include pumping water into the city, either from a pipeline constructed upstream or through a desalination plant (NOLA). Lastly, some propose new management of the city’s aquifers, currently drained annually during the rainy season as flood prevention. Instead, some suggest an increase in green spaces to mitigate the issue of floods and the use of the aquifer for drinking water (Sabo, 2023). This is a much more long-term solution but requires significant infrastructure changes. A combination of all the ideas mentioned above will likely constitute the city’s mitigation methods.

Bottom line: In New Orleans, the Mississippi River has far too much depth and not enough freshwater flow to fill it. As a result, salt water is infiltrating the city’s water supply, posing serious health and infrastructure risks. A variety of solutions including pumping water into the city and the construction of sills must manage these threats.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Clash between city and countryside

Mirjam writes*

Munich’s drinking water is known for its high quality, largely thanks to its geographic location near the Bavarian Alps. About 75% of the 330 million liters consumed daily comes from the Mangfall Valley, south of the city, which has served as Munich’s water source for over 130 years. However, this reliance has led to an enduring conflict with the local community of Miesbach.

Despite the exceptional water quality – so pure it requires chlorination on only a few days each year – Munich plans to expand the water protection zones in Miesbach to add a third zone. The city refers to legal obligations and the need to secure water quality for future generations. Thinking long-term is crucial, especially given the natural water cycle: in the Mangfall Valley, it takes about 20 years for rainwater to percolate through the ground before being extracted. This means that changes in the use of fertilizers or pesticides might impact the water quality only decades later.

Resistance from the Miesbach community

Farmers, entrepreneurs, and other stakeholders in Miesbach oppose the proposed protection zone. If implemented, the zone would further restrict the use of fertilizers and pesticides, as well as complicate the approval process for construction and industrial projects.

However, it’s worth noting that cooperation between Munich and local farmers has been ongoing for years. Since 1992, the Munich City Utilities (SWM) have supported farmers in transitioning to organic agriculture. To date, over 185 farms have adopted sustainable practices. In return, they receive financial assistance and support in marketing their products.

Still, tensions persist. To block Munich’s plans, Miesbach community members recently launched a petition calling for a review of the city’s historical water rights that were granted in 1852. These rights, still invoked by the SWM, are seen as outdated by Miesbach residents, especially since the construction of a connection tunnel in 1924 increased water extraction. Threfore they argue that the law should be reevaluated.

In early November 2024, the Bavarian State Parliament’s environmental committee accepted the petition, signaling progress for the Miesbach community. However, the review of these historical rights could delay any decision on the new protection zone – to the frustration of environmental groups.

broader debate: balancing urban and rural interests

The conflict over Munich’s water supply reflects a larger issue: how to reconcile urban resource security with the interests of rural communities and environmental conservation. With projections suggesting that by 2050, approximately 70% of the global population will live in urban areas, and with water scarcity expected to increase due to climate change and human impacts on ecosystems, disputes like the one between Munich and Miesbach may become increasingly common.

Finding solutions will require balancing the needs of urban populations with respect for rural livelihoods and ecosystems. The challenge lies in creating policies that protect the environment and secure resources for future generations while ensuring fairness for all parties involved.

Bottom line: The dispute over Munich’s water supply rights and water protection regulations highlights the growing tension between urban needs and rural rights, a challenge that will likely intensify as climate change and urbanization progress.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Protecting the Meuse from pollution

Merel writes*

The Meuse River, after which Maastricht is named, has important values for both humans and nature. Around 7 million people rely on drinking water from the Meuse River. However, the river is facing growing threats from water scarcity and pollution. Although the Netherlands is famous for their water management, these growing pressures are highlighting the urgent need for more action.

The Meuse flows from France through Belgium and the Netherlands and is an important source of drinking water, agriculture, industry, shipping, and ecosystems. In regions along the Meuse, including Maastricht, the river also has recreational and cultural values, and each year, it supplies around 500 billion litres of drinking water to Belgium and the Netherlands (NRC, 2024). However, pollution and climate change impacts are straining the river’s capacity to provide enough clean water.

The quality of water in the Meuse is under increased pressure because of pollution from agriculture, industry, and sewage systems. Harmful substances like pesticides, fertilizers, pharmaceutical residues, heavy metals, and PFAS are damaging water quality. Industry discharges their wastewater through sewage or directly into the river water. They need a permit for this, but many permits are outdated and often fail to account for new pollutants. These outdated permits, lacking transparency, allow industries to release harmful substances without proper oversight. RIWA-Maas, an association of Dutch drinking water companies, warns that these inadequate regulations endanger water quality, affecting both ecosystems and public health (NRC, 2024).

PFAS are a particular concern due to their long persistence and harmful health impacts, at even very low concentrations (RIWA-Meuse, 2024).

Additionally, longer and more frequent droughts also affect water quality in the Meuse, which is mostly fed by precipitation (RIWA-Meuse, 2024). Chemical discharges that are assumed to be sufficiently diluted with normal river levels are not when levels drop and concentrations persist. Drinking water companies such as WML in Limburg face higher purification costs or the need to rely on scarcer groundwater sources (WML, 2024).

Water knows no borders, and pollution in one area impacts regions downstream. Therefore, international cooperation is important. The International Meuse Commission, established in 2002, brings together France, Belgium, the Netherlands, and Luxembourg to improve water quality and manage flood risks in the Meuse. Through joint pollution standards, they aim to limit agricultural and industrial waste entering the river.

In the Netherlands, lots of different governmental organizations work together manage the water systems, such as Rijkswaterstaat, water boards (waterschappen), provinces, municipalities and the Ministry of Infrastructure and Water Management (Ministerie van Infrastructuur en Waterstaat, 2024).

In Europe, the Water Framework Directive (WFD) has set goals for water quality, both chemically and ecologically, with a deadline in 2027 (after postponing twice). It seems it seems very likely that many Dutch water bodies, including the Meuse, will not be able to meet the targets on time. This delay highlights the pressing need for stronger action against pollution and more sustainable water management practices. Meeting the WFD goals is crucial not only for ecosystems but also for ensuring safe drinking water and protecting communities that rely on rivers like the Meuse (Ministerie van Infrastructuur en Waterstaat, 2024a).

Both nationally and internationally, we need better enforcement of regulation. Additionally, we need to modernize discharge permits to include  new pollutants and ban PFAS altogether.

Bottom Line: The Meuse River is increasingly vulnerable to water scarcity and pollution. Addressing these challenges requires international cooperation and innovative approaches, and a shift in perspective – moving from fighting against the water to living in harmony together with clean water and nature, free from harmful substances.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Glasgow

Alex writes*

Glasgow is predicted to be Scotland’s fastest growing city for the next three years in terms of population and urban development (Scottish Financial Review, 2024). Four million people — 42% of Scotland’s population — live in the city and its surroundings (World Population Review, 2024). Current population and future growth are threatening the waters needed by Glasgow’s people and environment.

Glasgow’s population has seen minimal water source struggles, with little documentation on any sorts of related conflicts. The city had historically used the river Clyde, but quality deteriorated around 1800 and frequent cholera outbreaks forced the city to source its water from Loch Katrine in 1855, which improved quality (Institution of Civil Engineers, 2024).

Moving to modern times, leaks and aging pipes are reducing supply. Scottish Water claims to have “reduced leakage from 1,100 ML/d to 460 ML/d over the last 18 years” (Scottish Water, 2024), but population pressures are increasing, which could lead to conflicts over water allocation and availability in the future.

This outdated and leaky water system also threatens natural water bodies. Knightswood Park is an important green area for residents. Its iconic Knightswood pond provides both recreation and natural habitat (Glasgow City Council, 2024). But pond levels have been dropping for the past five summers and will probably also drop in 2025 (Ava Whyte, 2024). It was rumored that a leak was the cause of falling levels, but the Glasgow City council is still investigating. Residents are upset that swans and coots are pressured to leave or be relocated: “The swans couldn’t fly as they were moulting and had no flight feathers, they were dehydrated and had no natural food” (Ava Whyte, 2024).­

Bottom Line: Glasgow’s water system is outdated. It needs to be upgraded to meet growing urbanization while preventing environmental degradation. Can Glasgow balance urban demand with the needs of nature?


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Is the Segura River sustainable?

Ari writes*

The autonomous region of Murcia in the south-east of Spain exports a lot of crops. Murcia occupies 2.2% of Spain but produces 20% of its vegetable and fruit exports. This region has a population of 1.5 million and a long growing season.

Murcia’s watershed is the Segura River is the driest in the European Union, with an annual rainfall of 365mm. Murcia experienced a higher demand for its fruits and vegetables after Spain joined the EU, increasing water stress and environmental degradation (GWP).

The Segura River Project proposed to restore the watershed’s health and supply reclaimed water to the agricultural sector (GWP). One hundred wastewater treatment plants were built alongside a 350 km waste-water collecting system in 2001-2010. The EU provided 70% of the €650 million cost; a regional Wastewater Reclamation Levy paid for the remaining capital and ongoing operating costs (IWRM Action Hub).

The project improved water quality in the Segura River. In 2010, the water pollution was unnoticeable, and otters returned to their former habitats. The agricultural sector in Murcia received 110 million m3 of reclaimed water annually (GWP).

The Segura River Project restored the quality of the river, but can it be maintained? This question arises because the Tagus-Segura water transfer, which began in 1979, brings 600hm3/year from the Tagus to Murcia for irrigation and drinking (Tercera Del Gobierno). Since the Tagus River, which brings water to Portugal, is stressed, it is doubtful that the transfers can continue at past volumes.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Jakarta: The Drowning Giant

Jonathan writes*

Jakarta’s water distribution systems faces an existential threat. While 13 watersheds converge in Jakarta’s basin, only 1% of Jakarta’s surface water is utilized by its water distribution system due to high contamination (Ardhianie et al., 2021). Instead, the vast majority (67%) of the city’s water originates from groundwater reservoirs (Ardhianie et al., 2021). And excessive groundwater pumping threatens the city’s very existence.

Jakarta is one of the world’s fastest sinking cities, dropping by 1-15 centimeters per year. Experts project that 95% of the city will be underwater by 2050 (Jakarta…). Removal of groundwater results in increased compaction of soil, reducing the stability of the silty and sandy land and increasing soil erosion (Bakr, 2015).

These extraction woes originate from PAM Jaya’s (Jakarta’s water company) lack of distribution. Most Jakarta residents do not contract with PAM Jaya, instead taking groundwater from their own wells in ignorance or defiance of regulations. Whincup et al. (2023), using a conservative estimate of 30% of the population having a artisanal well, estimated that 300,000+ artisanal wells extract roughly 3000 Liters/second; 4,000+ illegal deep drill wells take even more.

PAM Jaya is trying to solve this issue by increasing the availability of piped water to the people of Jakarta. In 2024, PAM Jaya set out a goal of piping 71,207 households by the end of the year, ultimately aiming to have the entirety of Jakarta connected to its water grid by 2030 (PAM Jaya Kebut). It is also attempting to increase its overall water distribution capacity and the quality of the water provided through pipes, to incentivize usage. The company has been building more pumps and feeds directly extracting water from outside rivers such as the Jatiluhur to improve supply (PAM Jaya Perluas) and also contracted PT Air Bersih Indonesia (PT ABI, or “Clean Water Indonesia”) to build a new water treatment plant and more pipe connections (World’s Fastest…).

However, PAM Jaya faces multiple challenges to its objective. Most visibly, PAM Jaya has had numerous issues regarding the quality of its services. 50% of the water transported by PAM Jaya winds up leaking out of the system (Whincup et al., 2013). PAM Jaya water is also often contaminated or undrinkable due to mismanaged infrastructure, adding to the attraction of free groundwater (World’s Fastest…). Finally, the recent deal with PT ABI was criticized for its lack of transparency and failing to solve poorly maintained piping infrastructure and water contamination (World’s Fastest…).

Bottom Line: Jakarta is irreversibly sinking in part due to excessive unregulated groundwater use. Governmental efforts to solve this are extensive, but marred by a variety of issues regarding quality and regulation.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Delhi water… with a side of crap

Angad writes*

A thick layer of toxic foam covers a river which is the major source of water to a city of 33 million (Source). This is the reality of Delhi’s dying holy river, the Yamuna. It is estimated that 880 million litres of mostly untreated sewage water is dumped into the river per day. Largely due to this, the Yamuna contains a concentration of 1.1 billion faecal coliform bacteria per 100 millilitres of water. To put this in perspective, the standard for bathing is 500 coliform bacteria per 100 millilitres (Source).

Only a short section of the Yamuna River flows through Delhi, the majority is located in neighbouring states such as Haryana and Uttar Pradesh. The limited surface water in Delhi means it relies on external water sources. This has led to the establishment of various agreements with its neighbours, and as a result, many canals bring water from parts of the Yamuna from neighbouring states into the capital. The most important — the Munak Canal — brings a majority of the water from the Yamuna, but the canal’s poor condition contributes to water shortages (Source). In addition, disputes between governments at the state level lead to water supply issues, in a tussle of jurisdiction and blame (Source).

The river brings 1.7 billion litres a day of toxic water into the city, which contributes to cholera and diarrhoea (Source). A study in the city found that  28% of households experienced water-borne illness (Source).

Dehli’s population has doubled in the past 24 years, putting supply under greater strain (Source). The city faced a daily water deficit of 533 million litres in 2020 (Source). While this is partly due to disrupted supply during Covid-19, it still burdens the population. The government’s response — giving 20,000 litres of free water to 62.5% of households — has further strained supply and the finances of the water operator, Delhi Jal Board (Source).

The older source of water – groundwater – also seems to be running out (Source). As more and more solutions get used up, the burden on the consumers only increases. The city of Delhi is not only running out of time, it is running out of water.

Bottom Line: Delhi’s water supply is dwindling as rivers are polluted, infrastructure is a mess and the politics is truly Indian. There is an urgent need for a sustainable solution to this crisis.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Water & social divides in the UAE

Paulina writes*

Abu Dhabi is a hub of modernity and cultural diversity: home to a unique demographic makeup. Indeed, Emirati nationals form a minority, while expatriates make up 85% of the population (Global Media Insight 2023). This multicultural society thrives on economic contributions from its diverse residents; however, it is confronted by a complex web of resource management challenges. In the arid landscape of the UAE, water is a scarce and valuable resource, produced primarily through energy-intensive desalination. As urbanization and industrial growth surge, the demand for water continues to rise. Water scarcity thus stands out as a pressing issue that intersects with social inequalities, particularly through pricing policies.

In Abu Dhabi, water management falls under the jurisdiction of the Department of Energy (DOE), which operates with federal oversight. The DOE serves as the regulatory authority for electricity, water, wastewater, district cooling, and oil and gas activities. Water distribution itself is managed by the Abu Dhabi Distribution Company (ADDC), which oversees delivery, supply, and connection services. Pricing and tariffs are determined in coordination with the DOE.

The UAE employs a two-tiered water pricing system: Expats pay rates close to the actual cost of production whereas Emirati nationals pay about a quarter that price (ADCC 2024) . This system aims to safeguard Emirati welfare and cultural identity but it exacerbates economic divides by increasing the financial strain on low-income expatriate workers.

Water pricing is not the sole source of inequality in the UAE, but it exemplifies a system of social divides, citizen privileges, and disparities in resource allocation. A water pricing policy that considered income level rather than nationality would be fairer while still promoting sustainability. It would also make it easier to run water conservation campaigns based on shared responsibility, rather than special privileges.

The Emirates Diving Association (EDA), for example, engages both locals and expatriates by highlighting the Emirati heritage as seafarers and pearl divers who are “historically and socially indebted to the seas” (EDA 2024).

Bottom line: Water subsidies to Emirati citizens deepen social inequalities and hinder collective water conservation efforts.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

40% of Chile’s water at risk?

Thadine writes*

Chile has been identified as one of the twenty-five countries most impacted by climate change. The country has been experiencing its longest and most severe drought in recorded history, possibly the worst in a millennium. Apart from the drought, several other climate-related events have further exacerbated water availability and quality issues. These include mudslides, increased turbidity, extended supply cuts due to pollution, and sewage discharge into lakes during periods of heavy rainfall.
By the end of 2021, more than half of the population (around 8,5 million people) lived in areas suffering from severe water scarcity. It is expected that the water availability in northern and central Chile will be halved by 2060.
Santiago de Chile, the capital and largest city, has 7 million inhabitants, of which 90% get their water supply and sanitation from the private company Aguas Andinas. Article 5 of Chile’s 1981 Water Code (“Código de Aguas”) says that water is public property. The Water Code was implemented under the military regime led by General Pinochet. This document, following the principles of neoliberalism, resulted in a “law which introduced a system of private water rights that could be traded in free markets with almost no government regulation.” A significant challenge facing markets for Water Use Rights (WURs) is finding a balance between optimal water usage and the long-term health of rivers and aquifers.
The Maipo river and its basin are responsible for 85% of the total water production for Santiago. Hydroelectricity, copper production, tourism, recreational activities and agriculture also consume the water provided by the Maipo River basin. However, the Maipo river is severely affected by the changing climate and ongoing over-extraction. Extreme weather has increased erosion and thus worsened turbidity in the Maipo. Climate change could reduce annual flow in the Maipo by 10% to 40%, which could lead to a crisis for users.
Maipo River Basin and water users

To mitigate and adapt to these challenges, the Superintendence of Sanitary Services (Superintendencía de Servicios Santiarios – SISS) – Chile’s urban water utilities regulator –initiated a participatory process in 2017, involving over 700 participants from various sectors and regions. This collaboration resulted in the 2030 Water and Sanitation Agenda, a comprehensive plan that identifies challenges, solutions, and a roadmap for addressing the country’s water issues over the next decade.

Bottom line: Santiago’s water supply is threatened by climate change, over-extraction, and extreme weather.

* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Athenians fight for public water

Clea writes*

The water supply system in the Attica region dates to the 5th century BC. Until the beginning of the 19th century, the water system was small-scale, but they Athens’ water management expanded to adapt to droughts, urbanization and population.

The Marathon reservoir with its dam and its aqueduct were the first main constructions, finished in 1931. Then, three other reservoirs (Yliki, Mornos and Evinos) with their related aqueducts were built to meet the capital’s demands. The water supply system covers 4000 square kilometers (G.-Fivos Sargentis et al. 2019).

In recent decades Athens faced new challenges including rising temperatures and financial restrictions.  Greece faced a massive economic crisis from 2008 onwards, and the Greek state received major loans in 2010, 2012 and 2015 from the European Commission, the European Central Bank and the International Monetary Fund (the “Troika” ). The Troika required the creation of the Hellenic Republic Asset Fund, which would privatize state assets, such as EYDAP — the Athens Water and Sewage Company  (Pempetzoglou and Patergiannaki, 2017).

Greek citizens protested privatizations as a threat to the quality and price of water services. In Athens, “SOStonero” and “Save Greek Water” joined the European movement “Right2Water” to defend water as a common good.

The Council of State decided in 2014 that privatization was unconstitutional, so water utilities should stay under state control (European Water Movement). But Greece must still follow the Troika’s austerity measures, so 49% of EYDAP was privatized with the other 51% held by the Hellenic Corporation of Assets and Participation (HCAP), a state-owned fund (Shareholders composition Eydap, 2022). Activists think that the state is trying to privatize EYDAP despite the state’s majority share (Tasos Kokkinidis, 2023).

Bottom line: The 2008 financial crisis forced the Greek state to (partially) privatize Athens’ water company, which triggered resistance by citizens afraid of higher prices and outsider control.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂