Month: March 2022

Flore writes*

My case-study is not about a “city” but six communities located in the lower Ouémé Valley in South Benin. These communities are Cotonou (the capital of Benin), Abomey-Calavi, Porto-Novo, Sèmè-Podji, Sô-Ava and Zê. The water scarcity in these six communities is very interesting to study in so far as it leads to a lot of ecological and socio-economic issues for the nature and the inhabitants of the region.

According to the home page of the Réseau International des Organismes de Bassin, the watershed of the six communities is the Ouémé watershed, which represents 40% of the Beninese national territory and their largest source of water is the Nokoué Lake, the biggest lake of the country.

According to a video made by the International Cooperation Agency of the Association of the Dutch Municipalities (“VNG International”), the effects of climate change on water in the lower Ouémé Valley are very problematic for the region’s wildlife and the livelihoods of its inhabitants.

The Ouémé Delta is no stranger to seasonal rainfall and floods. Yet, since climate change started, seasonal rainfall and floods have became more extreme and unpredictable. The unpredictability of the flood affects the reproduction of fish, hinders recessional agriculture and leads to the destruction of off-season crops. Moreover, the floods impede water transportation and damage access roads.

According to VNG International’s video, pollution makes these problems worse. In fact, because waste management in the country is bad, Beninese people throw their waste in the nature which has consequences on the many channels created for the evacuation of water that get filled with waste and garbage. This phenomenon leads to obstructions in the drainage system of the region causing more floods and raising health risks due to polluted drinking water.

One of the more interesting problems caused by water scarcity relates to the water hyacinth. According to the page dedicated to the existing ecosystems in the region of the official website of the Nokoué Lake, the water hyacinth fills rivers so densely that boats can barely pass. Yet, this invasive plant has the potential to become a valuable source of fiber or organic fertilizer. Removal of the hyacinth also unclogs the rivers, benefitting water transportation and fishing.

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

Evi writes*

Australia is the driest continent on this planet (after Antarctica), which means that people there are used to droughts. Still, nobody was prepared for the 1997-2009 Millennium Drought. “The Big Dry”, as this disaster was appropriately called, was the worst drought South-East Australia experienced in 125 years.

The region most affected by the drought was the Murray-Darling River Basin. This area spans four states and usually provides 75% of Australia’s water, 40% of Australia’s agricultural produce and is home to nearly 2 million people. In addition, it contributes to the water supply of Adelaide (population of 1.4 million). The Big Dry showed the Murray-Darling River Basin’s vulnerability to droughts and exposed flaws in water management in the basin.

Most researchers agree that the Big Dry was probably caused by El Niño, but the human influences must also be considered. High water use meant water levels were well below natural averages before the drought started. Therefore, changing the way the water is distributed in the basin could be an important factor in managing future droughts.

During the Big Dry, more than A$2 billion (€1.3 billion) was spent on expensive engineering projects. These projects focused on saving Adelaide and rural areas at the end of the water system from soil acidification.

However, acidification was a clear symptom of the drought, so focusing on the things that actually caused the drought, like water allocation, probably would have saved the government quite some money. For example, research showed that increasing the amount of water allocated to the environment at the end of system, particularly during dry spells, could achieve greater environmental benefits at lower costs.

Of course, the politicians only wanted to help the big cities and the agricultural sector by providing as much fresh water as possible. However, taking this water from the environment exposed the water supply to acidification, which further endangered people’s water supply.

Bottom line: Saving water for the environment during a drought protects the water supply.

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

Merel writes*

Bonaire is known for its waters: thousands of tourists come here every year for the beautiful diving and snorkeling opportunities, wave and windsurfing, and for the flamingos at the brackish Goto Lake. However, this “special” municipality of the Netherlands has virtually no fresh water supply. There is no fresh surface water, barely any rain, and few freshwater wells (van der Geest & Slijkerman 2019). At the same time, Bonaire is experiencing increasing demand due to mass tourism and population growth, and a decreasing supply due to climate change and sea-level rise, leading to saltwater intrusion (Verweij et al. 2020). All drinking water for Bonaire’s 20,000 inhabitants and 159,000 annual tourists comes from desalination plants (WEB).

While desalinated water offers many advantages such as a seemingly unlimited supply of good quality drinking water, there are three major drawbacks to this method of drinking water production: costs, greenhouse gas emissions and local pollution.

Even with the subsidies of the Dutch government, drinking water in Bonaire costs €3.30 per m3; the average price in the Netherlands is 60 percent lower, at €1.20 per m3 (WEB; NIBUD). This is undesirable as there is a relatively high poverty rate in Bonaire. The median income on Bonaire is €4,500 lower than in the rest of the Netherlands (CBS 2021a; CBS 2021b). Desalinated water is expensive due to the high fossil fuel consumption which brings us to the next disadvantage, greenhouse gas emissions. The plant is energy-intensive and emits greenhouse gasses (GHG), which further contributes to global warming and thus sea-level rise, one of the biggest threats to livelihoods in Bonaire (Lattemann & Höpner 2008). On top of the GHG emissions, there are other key environmental concerns. The chemicals generally used in this process can impair the marine environment when brine is dumped into the sea (Lattemann & Höpner 2008). Furthermore, brine is hypersaline and warmer, which further disturb marine life (DCBD 2011). The coral reefs in close proximity of the plant on Bonaire had a higher mortality rate, higher sand cover, and lower hard, soft, and fire coral cover compared to control sites (DCBD 2011). With most of the economy depending on tourism, the destruction of coral reefs is a highly unwelcome side-effect of the water provision.

While the plant has several negative impacts, it is currently the only option to ensure a steady freshwater supply in Bonaire. To end on a more positive note, in September 2021, an advanced reverse-osmosis plant was opened. The plant, which will eventually meet 100% of the drinking water demand, does not use chemicals, is more energy-efficient, and does not dump warmer water back into the environment (WEB). While the exact environmental impacts of this plant still have yet to be determined, it is a hopeful step towards a more environmentally-friendly future.

Bottom Line: Desalination has many disadvantages, it is expensive, energy-intensive, and environmentally unfriendly, however, it is currently the only option to meet the freshwater demand on Bonaire.

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

Leane writes*

Bangalore, the capital of the South Indian State of Karnataka, is nicknamed “India’s Silicon Valley” for being the country’s  biggest technological hub. The city, the third biggest in India, is experiencing severe water shortages due to the rising demand for irrigation, industrial activities, and human consumption.

Bangalore gets most of its water from the Cauvery River and from groundwater, which are both supplied and regulated by the Bangalore Water Supply and Sewerage Board (BWSSB) through pumps and borewells. While newly constructed settlements tend to have their own borewells, rainwater harvesting facilities, and sewage treatment plants (STPs), individual houses and the city’s periphery rely on the weekly delivery of water by tanker trucks. The BWSSB has been accused of supplying and regulating the city’s water very poorly, leading to the emergence of water mafias and illegal sewage dumping due to the shortage of STPs in the city.

Bellandur Lake formerly supplied water for irrigation and households from  18 surrounding villages.  Now it is covered in a layer of toxic foam that catches fire under high temperatures. Bellandur is one of the biggest lakes in Bangalore, but also one of the most polluted. Indeed, around 40% of Bangalore’s untreated sewage and waste from upstream industries flow into the lake. Accumulating chlorides, phosphates and nitrates raise alkalinity levels to a pH of around 8. In a balanced ecosystem, pH levels range from 5.5 to 8.5, so Bellandur is barely “safe”. Alongside liquid waste, solid waste from garbage and construction debris is also being dumped in the lake, releasing traces of methane and petrol, which burn under high temperatures.

In total, around 300 million cubic meters of sewage is dumped every day in the lake, causing extreme pressures on the lake’s ecosystem, surrounding environment and neighboring habitants. The accumulation of liquid and solid waste creates a layer of white, highly toxic foam on the surface of the lake, which in contact with skin, can cause severe irritations and respiratory problems. Fires on the lake are becoming more and more frequent, sometimes lasting up to 30 hours, which is alarming not only for the city but also for rapidly  urbanizing cities whose lakes may also become “artificial reservoirs of sewage and industrial waste.”

The bigger picture of this occurrence is that of Bangalore’s extremely poor water management. While the surrounding citizens and construction facilities contribute to the lake’s pollution, the main actor responsible for the state of Bellandur lake today is BWSSB, for its failure to treat the city’s sewage, which only leads to one question: If BWSSB is incapable of preserving a single lake, how can it manage the water supply and sewage treatment of 13 million people?

Bottom Line: Bangalore’s rapid economic and demographic growth has made it the “Silicon Valley of India,” but urbanization and poor sewage management has converted Bellandur Lake from an extinguisher of fires to the source of fuel for fires.

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

Harriet writes*

The Nakivubo Channel is a waste-and stormwater channel located in Kampala, Uganda. The open channel traverses the highly populated Makere Kivulu slum, three markets, and an industrial area before it discharges into Murchison Bay, Lake Victoria which provides drinking water to the people living in Kampala and is important for fish production. Before it discharges into the Lake, the channel feeds the Nakivubo Wetlands which are cultivated for yams and sugarcane.

Only an estimated 10% of the population of Kampala is served by the sewer system and about 54 % is either treated on-site or contained, leaving 46% which is released untreated (International Water Association 2017). The Channel flows through the Makere Kivulu Slum, which has a low water table, meaning that pit latrines are often built up instead of dug down and emptied into the channel untreated when full (Fuhrimann et al. 2015). Heavy metals and chemicals find their way into the channel through discharge from the industrial area. The Nakivubo Channel is the source of approximately 75% of the nitrogen and 85% of phosphorus nutrient load discharged daily into Murchison Bay.

The pollution of the Nakivubo channel poses a threat to the public health and economy in the area. In a process known as eutrophication, the increased influx of nutrient load has caused significant algal blooms which result in low oxygen levels in the water. Low oxygen levels are harmful to aquatic organisms in the bay and have resulted in fish-die offs, which not only signify disruptions of the aquatic ecosystem but also impacts on local fishermen. Informal communities at low altitudes also face the threat of flooding during the rainy season which exposes them to raw wastewater which carries the risk of a multitude of health consequences as well as the danger of Cholera and Typhoid Fever outbreaks (Fuhrimann et al. 2015). Furthermore, the increased pollution and algae causing blockages in water treatment plants located in the bay makes the water treatment process more costly as evidenced by the fact that water treatments costs have tripled in the last 10 years.

The heavy metals discharged into the channel find their way into the agricultural goods grown in the area. A study found elevated concentrations of heavy metals such as lead in yams grown in the wetlands. The heavy metals pose a health risk as increased levels can cause damage to organs and cells in humans and animals.

Bottom Line: Pollution of the Nakivubo Channel not only poses a threat to the ecosystem of Murchison Bay, Lake Victoria. But also poses a threat to humans as it endangers the water supply of Kampala and the health and livelihood of people living around the Channel.

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

Marta writes*

The city of heavy rains. The city that regularly floods. The city that is sinking around 50 cm every year. The city where thousands of litres of water are wasted every second. And finally, the city with one of the largest water-scarcity problems in the world. A paradox? No, this is everyday life in Mexico City, home to more than 20 million people.

Among the variety of issues with water supply, services, infrastructure and management, let me focus on what makes this area so unique. Namely, the seemingly ridiculous combination of too much and too little water existing on daily basis in the life of millions of citizens of Mexico City.

The main source of water for Mexico City is the underground aquifer, which provides more that 70% of the water. But… it is depleting. With the amount of water that is taken out of it, nature cannot keep up to recharge it. Therefore, there is less and less supply every single year. You were wondering how is it possible that a city is sinking? This is exactly why. With the water under it being gradually overexploited and the concrete covering such a huge area ­- so the rainwater does not seep through it – the level of the ground is declining. What is more, it is happening to such an extent that the buildings are already uneven and 14 large steps had to be added at the base of the most famous column, the Angel of Independence, because the area around it sank so much over the decades.

So, the water scarcity… how do people get their water if not through the aquifer? Is there any other option? Well, yes – the city also pipes 30% of its water from 150km away. However, the question remains – how effective is that? And here Mexico City faces another major issue, namely, its outdated infrastructure. The water system has many flaws and this leads to the loss of 1000 litres of water lost every single second. All because of leakages that are so numerous that repairing them is more or less impossible.

Nevertheless, through connecting some dots from the previous sections, we could see the silver lining. What if there was another source of water, thanks to which the aquifer would not be exploited in such a scale and the sinking of the city would be slowed down? Couldn’t the “problematic” rains also become a saviour for Mexico City’s citizens? The company IslaUrbana decided to take advantage of the water which is literally coming down from the sky and capture it to the cisterns installed on the roofs of households. So far, they have installed 21,800 systems, which benefited 131,000 users through harvesting 870M litres per year, and these systems will help for years to come.

Bottom Line: Mexico City simultaneously suffers from overexploitation of its main aquifer, sinking land, and heavy rains. Rainwater harvesting can help reduce its water crisis.

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

Nóra writes*

Budapest, the Hungarian capital, is widely known as ‘the city of waters’ with its numerous thermal springs, spas and baths. The Celts who first settled there named it Ak-ink, while the Romans called it Aquincum — both names mean ‘abundant water’. Budapest’s ‘artery’, the River Danube, flows through the city supplying the entire population with drinking water. Undoubtedly, Budapest and water scarcity rarely appear in the same sentence. Nevertheless, the city has its fair share of water-related issues if not concerning scarcity, then pollution and infrastructural failures.

It has been long recognized that human activity has adverse impacts on the environment and to limit these to the minimum, a strict environmental protection policy is needed. Therefore, it may come as a surprise that Hungary does not have a designated environmental ministry (OECD 2018). This is especially concerning since not only is the whole capital reliant on the Danube for drinking water, but also the country itself as it is located in its entirety in the Danube Drainage Basin along with 17 other countries. Consequently, environmental problems occurring in Budapest simultaneously create transboundary issues. Furthermore, the river discharges into the Black Sea which exacerbates the pollution’s potential severity (Water Quality Governance, 2015).

Unfortunately, Budapest is no stranger to water pollution. During the 1960s, the water pollution was so severe that the Hungarian cotton industry could not produce white clothing, and at the Csepel paper mill, the white paper got discoloured (Pulay and Péntek, 2008). Since then the situation has significantly improved, but there is more work needed. In 2018, almost 56% of drinking water supply systems have been categorized as ‘mostly risky’ and 30% as ‘risky’ — see figure below (Századvég, 2018). Many attribute the poor quality of drinking water to the ageing infrastructure and degrading assets caused by the lack of replacement and refurbishment investments (World Bank Group, 2015).

Furthermore, technical obsolescence accelerates the number of errors associated with water systems. Between 2008-2018, the number of reported failures doubled because 45% of the system is older than its planned lifespan. (Századvég, 2018). With respect to the sewage system, malfunctions increased by 41% between 2012-2017 and it is estimated that 8% of the network poses a substantial risk. (Századvég, 2018).

Where is the root of the issue?

Despite the fact that between 2007 and 2020, Hungary received a €3.7-billion in financial support from the EU to improve its water system, the main issue seems to be a lack of money, as the sector is running a 37-billion-HUF (about €100 million) deficit (Kis and Ungvári, 2019).

Water and wastewater charges have not changed since 2013 due to the Water Utility Service Act freezing prizes and the 2013 utility cost reduction decreasing charges by 10%. (Kis and Ungvári, 2019). As a result, right now, charges do not cover the costs and in the current state of operation, it is greatly feared that without interference, the sector will reach its limits.

Bottom Line: Budapest’s major issues concerning water pollution and infrastructural failure can be traced back to financial mismanagement. To maintain the system, both economic and political tools have to be utilized. Firstly, the establishment of an environmental ministry responsible for the mitigation of water pollution of the Danube. Secondly, correct water pricing is necessary to ensure the maintenance and renewal of the drinking and wastewater utilities.

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