Rwanda: Waste and climate change among the causes of water pollution

The quality of water in Rwanda is at risk due to human waste, industrial activities, agriculture, and climate change, which leads to heavy rainfall and disasters that affect water sources.

A 2019 study conducted by Valentine Mukanyandwi and her team examined water quality in Rwanda. It revealed that much of the water is contaminated because of population growth, industrialization and urban expansion, poor waste management, heavy rainfall, Rwanda’s mountainous terrain, and climate change.

Climate change contributes to water pollution in several important ways

Heavy rainfall and flooding

Climate change causes more intense and unpredictable rainfall, leading to flooding; floods wash pollutants such as fertilizers, pesticides, sewage, oil, and industrial waste into rivers, lakes, and groundwater; this increases chemical and biological contamination in water sources.

Rising temperatures

Higher temperatures make water bodies warmer, which encourages the growth of harmful bacteria and algae (like toxic algal blooms); warm water also holds less oxygen, harming aquatic life and disrupting ecosystems.

Droughts and dry periods

Long dry seasons cause pollutants to accumulate on the ground (from farming, vehicles, and industry); when rain finally falls, it flushes all those pollutants into rivers and lakes at once, causing sudden pollution spikes.

Sea level rise

Melting ice and thermal expansion cause sea levels to rise, allowing saltwater to enter freshwater systems (like wells and rivers near coasts); this process, called saltwater intrusion, makes water too salty to drink or use for farming.

Acid rain

Climate change is linked with increased air pollution from burning fossil fuels; this pollution can cause acid rain, which lowers the pH of lakes and rivers, harming fish, plants, and microorganisms.

Climate change increases extreme weather events (floods, droughts, heat), which leads to more pollutants entering water and greater stress on water ecosystems  ultimately making clean water harder to find and maintain.

Other causes of pollution include poor waste management and the use of shared latrines and dirty drainage systems, both in urban and rural areas, as shown in a 2017 study by Aboniyo J. and colleagues.

According to the researchers, “Water quality in Rwanda is threatened by human waste, industrial activities, agriculture, and climate change, which causes heavy rainfall and disasters that impact water sources.”

In 2011, researchers from the University of Rwanda showed that untreated water often contains high levels of harmful substances such as iron, manganese, copper, and zinc, making it unsafe for drinking.

Israel Dufatanye from the Rwanda Environment Management Authority (REMA) also mentioned other often-overlooked pollutants, such as residues from hair products, used motor oil, open defecation, and wastewater from homes and businesses.

In 2019, the Rwanda Water and Forestry Authority reported that human activities such as soil erosion caused by agriculture, mining, and the use of pesticides significantly contribute to water pollution.

Urbanization and Water Pollution Challenges

The 2019 report by the Rwanda Water and Forestry Authority indicated that, although the government has put in place measures to manage wastewater especially in Kigali pollution persists due to rapid urbanization. The report noted that as cities, particularly Kigali, expand rapidly, pollutants from industries, institutions, and households continue to threaten the quality of both surface and groundwater.

Health Impacts

A pollution exposes people to health risks. A study conducted by Omara Timothy and colleagues revealed that heavy metals in water can cause cancers, kidney failure, liver damage, heart diseases, and even death.
A 2011 study from the University of Rwanda also found that during the rainy season, microbes from human and animal feces can enter rivers, lakes, and groundwater, posing risks to those who consume untreated water.

Reducing Water Pollution

Research shows that water contamination comes from both natural and human sources. To combat pollution caused by human activities, researchers recommend actions such as avoiding the discharge of oils, paints, and pesticides into water sources, limiting pesticide use, and preventing open defecation.

Rwanda’s Environmental Law

The 2018 Environmental Law of Rwanda enforces the conservation of water. Article 12 states that water resources must be protected from all sources of pollution. Article 37 mandates the government to promote hygiene through public toilets, strict waste management measures, and water quality standards for rivers, lakes, and wetlands.
Article 42 identifies and prohibits 16 polluting activities, including dumping waste into rivers or wetlands, raising livestock near water sources, and building in restricted areas around lakes and rivers.
Violations result in fines ranging from 10,000 to 5 million Rwandan francs, depending on the offense.