Water and climate change: The challenge


Water and climate change are closely linked. Water scarcity is a challenge affecting many regions of the world. It refers to the lack of access to fresh water sources to meet the basic needs of the population.This shortage is exacerbated by climate change as precipitation patterns are modified, evaporation increases, and extreme events, such as prolonged droughts, are triggered.

In addition to climate change there are other factors that make water scarcity a problem in the medium and long term: population growth, inefficient water consumption, water pollution by industrial waste, pesticides or fertilizers.

The impact of water scarcity

Water and climate change are having a significant impact on society, the economy and the environment. Some of the most notable impacts are:

  1. Lack of access to drinking water and adequate sanitation can lead to water-borne diseases such as diarrhea, cholera and typhoid. These diseases can have serious health effects and cause death, especially among the most vulnerable groups, such as children and old people.
  2. Lack of water for irrigation reduces agricultural productivity, which can lead to reduced crop yields and crop losses. This in turn can increase food prices and create food insecurity in affected communities.
  3. Reduced water flows and overexploitation of water resources can affect aquatic ecosystems such as rivers, lakes and wetlands. Reduced water levels and pollution can damage biodiversity, cause loss of aquatic habitats and adversely affect water-dependent species.
  4. Limit industrial and tourism development, and generate additional costs for water purification and water supply in affected areas.
  5. Water scarcity can generate tensions and conflicts between different water users, such as farmers, industries and local communities. Competition for limited water resources can trigger social, political and even armed conflicts in some regions.
  6. It can also lead to population migration to areas with access to water, which can generate additional pressure in those areas.

Here are some examples of challenges related to water and climate change.

Water pollution in the Magdalena river in Colombia

The Magdalena River is a river that represents 24% of the territory of Colombia. It travels the country from south to north, along about 1540 km, between the Central and Eastern mountain ranges of the Colombian Andes. It empties into the Caribbean Sea with almost 1000 navigable km and crosses 11 departments of the country in which 80% of the Colombian population lives.

In its route there are at least 700 municipalities that are pouring their wastewater directly. In addition, there is a phenomenon of illegal mining and other types of extractions close to the river´s edge.

The river presents high levels of pollutants, as a consequence of several factors: wastewater, industrial waste, direct discharges from clinics, car washes, etc. The environmental impact gets worse as municipalities grow.

This catastrophe is widely known thanks to the efforts of some universities that seek to make the problem visible. In 2019, a meeting took place along the Magdalena River, led by researcher Luis Carlos Moreno Gutiérrez of the Universidad del Atlántico. They announced that 80% of the municipalities that discharge their water to the river do not have wastewater treatment systems or plants (PTAR).

As a result of his research, the professor explained that among the other 20% of municipalities that have PTAR, 60% present technical issues in the management of water that goes to the river.

Another problem is the dumping of metals. In November 2022, the municipality of Santa Rosa del Sur, in the department of Bolívar, went on alert after the fall of cyanide bins into the river. This event led to the closure of water concessions in the area while the risk was reduced.

This was not the first time such an accident had occurred. Already in 2008, there was another spill of the ferry La Paula, where a truck carrying 96 bins of cyanide fell. Each of these had 50 kg. and sank in the Magdalena River, although 94 were recovered.

Cyanide began to move strongly in the mines of southern Bolivar in the late 1980s, to wash the veins and remove gold in large quantities. Dropped bins were only a small part of the large quantities used by the about 250 mines in departments such as Santander, Boyacá, Cesar, Antioquia and Bolívar, mainly.

Water scarcity generates poverty in Chile

A good example of water scarcity and climate change can be found in Chile. According to the Amulén foundation, more than 300,000 houses in the rural sector still do not have the infrastructure to supply themselves with drinking water.

They source water from rivers, springs, wellsprings, and this situation affects these families in different dimensions: economic, health, education and gender equity.The World Health Organization (WHO) calculates the impact of lack of access to drinking water:

  • For every dollar invested in drinking water supply infrastructure there is a saving in health between 3 and 34 dollars.
  • Considering education, children spend long hours transporting this basic resource instead of attending school.
  • Gender equity is affected, as women often take the responsibility of bringing water for their communities, after endless tours in search of wellsprings or rivers.
  • Therefore, without access to drinking water, there is no development and no way out of poverty.

47.2% of the rural population in Chile does not have a formal supply of drinking water: 58.8% is supplied from wellsprings, 25.8% is supplied by rivers, estuaries, canals or streams. The remaining 15.4% is supplied by water tankers.The rural population with not formal drinking water supply is mainly concentrated in the southern of the country. The regions that have a greater proportion of rural population with informal sources are La Araucanía (71%), Biobío (68%), Los Lagos (64%) and Los Ríos (62%).

Many concentrated and semi-concentrated villages are supplied by traditional rural drinking water systems (APR). This program, which began in 1960, has been successful in providing rural drinking water infrastructure. The supply of the rural population with rural drinking water increased from 6% in 1960 to 53% in 2018, serving 1,787,916 beneficiaries. This progress has led to major public health consequences and overcoming poverty.

Expanding the programme presents new challenges given the dispersion of the population. An example of these regions is La Araucanía, with lower population density, where water supply will require innovative solutions, since traditional systems are not viable at a reasonable cost.

Over time, APRs have experienced disruptions in the water supply, affecting approximately 350,000 people. The vast majority of these are unscheduled outages, mainly due to operational reasons, both for maintenance, internal management and external reasons, such as power outages.

In five regions, unscheduled cuts were found in more than 40% of the PRAs: Valparaíso (60%), Tarapacá (51%), Arica-Parinacota (46%), Antofagasta (40%) and Atacama (40%).In addition to this, the forecast for water availability following the climate change poses significant challenges to drinking water supply in Chile for the future.

An example of solution to the lack of water

Fog catchers represent a very interesting solution to capture water in some regions such Atacama in Chile, one of the driest places in the world.

In this region, the average rainfall is less than 0.1 mm per year and in many regions it has not rained for decades. Although rain is scarce, the clouds are full of water. That fog is formed on the Chilean coast and then moves to the interior in the form of cloud banks. Locals call this fog "camanchaca"

In 1956, during a particularly severe drought, the scientist Carlos Espinosa Arancibia, had an idea during some experiments in the mountains near Antofagasta: A net with small openings of about 1 mm to capture the small drops of water from the mist.

The droplets accumulate in the net, form larger droplets and fall from the net into a gutter below. From there, the water is sent through a pipe to containers at the base of the mountains.

This same system is used in the hills surrounding the city of Peña Blanca, where there are six large nets. According to Nicolás Schneider, technical advisor, these devices have succeeded to address desertification in the region. There are now 100 hectares covered with plants and they also consider providing water from fog catchers in the near future to local families.

In the center of the community there is also a small building that uses the same water: the city’s craft brewery. " Atrapaniebla" is a small company. It produces about 24,000 liters per year. Its owner, Miguel Carcuro, is proud. " Camanchaca water is of excellent quality and gives the beer a very special flavor," he explains.