Kenya loses Sh12 billion to wastewater annually

Kenya’s agriculture, fisheries and health sectors incur Sh12 billion losses every year resulting from poorly treated wastewater.

A new report launched on March 12, 2025, during the Word Ocean Summit in Japan revealed that only 11 per cent of wastewater in Kenya undergoes adequate treatment.

The report documented the consequences of improperly treated wastewater as it enters rivers, oceans, and drinking water supplies.

With only 16 per cent of Kenya’s population connected to a sewer system, the report reveals that the health sector is the hardest hit by contaminated waterways which exposes over 15 million people a year to contaminated drinking water. This costs the sector Sh8 billion annually. The amount is equated to hospitalisations and medical bills accumulating as a result of waterborne diseases.

Chief Economist of the Sustainable Development Practice Group at the World Bank, Richard Damania noted that inadequate sewage systems are leaving populations sick and starving, all the while costing the economy billions.

 “It is no new revelation that untreated wastewater has serious consequences, but it is not often thought of as an economic burden, nor as a burden on health systems, but as an environmental problem," he said.

The report noted that while most cases are mild, some can be life-threatening, causing hospitalisations that further strain healthcare systems, incomes and economies.

Documented waterborne diseases associated with poor wastewater treatment included diarrhea, where Kenya was leading among the surveyed countries.

The study found that contaminated water used for irrigation is severely reducing crop yields, fisheries are also collapsing due to polluted rivers and coastal waters.  

Agriculture and fisheries sectors lose Sh12 billion per year as a result of untreated water resulting in decreased yields of crops such as sugarcane, maize, and potatoes.

As per the statistics, maize bears the biggest burden of wastewater where farmers incur losses of up to Sh5 billion, while sugarcane farmers incur Sh2 billion and potato losses standing at Sh3 billion annually.

The report was launched by ocean health initiative Back to Blue, and the Ocean Sewage Alliance, where they calculated the devastating cost of inaction in wastewater management across five low, middle and high-income countries.

Kenya suffered the greatest fisheries losses among surveyed countries, including Brazil, India, Kenya, the Philippines, and the UK.

Of the countries surveyed, Kenya had extreme cases of untreated or inadequately treated wastewater released into the environment, which resulted in a major source of pollution and disease.

The report called on governments to invest in wastewater infrastructure to save money and lives.