Water Resources in Kenya: Managing Scarcity, River Basins, and the Path to Water Security

Kenya is classified as a water-scarce country, with per capita freshwater availability of just 586 cubic metres annually — well below the 1,000 cubic metre threshold that defines absolute water scarcity. With this figure projected to drop to 475 cubic metres by 2030 and as low as 293 cubic metres by 2050 due to population growth and climate change, water security represents one of Kenya's most pressing development challenges. Understanding the country's water resources, distribution challenges, and ongoing infrastructure investments is critical for anyone interested in Kenya's future.

Kenya's Major River Basins and Water Distribution

Kenya's water resources are distributed across five major drainage basins, each with vastly different endowments. The Lake Victoria Basin in western Kenya is the most productive, accounting for 59 per cent of surface water and 54 per cent of total renewable freshwater. The Tana River Basin, Kenya's longest river system at over 1,000 kilometres, supplies 19 per cent of freshwater resources and includes the Thika River, which is a key water source for Nairobi.

The Athi River Basin serves the greater Nairobi and Mombasa metropolitan areas but has the lowest water availability among the five basins. The Ewaso Ng'iro North Basin drains the semi-arid northern rangelands, while the Rift Valley Basin includes several saline lakes with limited freshwater utility. Only the Tana and Lake Victoria Basins have surplus water resources — the other three face chronic deficits, creating severe regional disparities in water access.

Groundwater provides a critical supplementary source, particularly in arid and semi-arid lands where surface water is scarce. However, groundwater levels are declining at alarming rates — in Isiolo County, levels fell by 3.8 metres between January 2023 and December 2024, the steepest annual decline on record. In arid counties, per capita water availability ranges between just 100 and 300 cubic metres per person.

Water Access and Supply Challenges

Access to clean, safe water remains uneven across Kenya. Urban areas have significantly better coverage than rural regions, but even cities like Nairobi experience frequent water rationing due to demand outstripping supply. The Water Services Regulatory Board (WASREB) monitors access levels nationwide and regulates the 88 water service providers (WSPs) operating under county governments.

One of the sector's most significant challenges is non-revenue water, which stands at 43 per cent — meaning nearly half of all treated water is lost through leaking pipes, illegal connections, and metering inaccuracies before reaching paying customers. The government has set an ambitious target to reduce this to 15 per cent by 2030, but achieving this will require massive investment in infrastructure rehabilitation and smart metering technology.

Agriculture is the largest water consumer, accounting for approximately 70 per cent of total freshwater withdrawals. Total water stress is high, with withdrawals amounting to 33 per cent of the total renewable resource endowment. Climate change is intensifying this stress — the Kenya Meteorological Department's January 2025 forecast predicted below-average rainfall for the March–May long rains, which would mark an unprecedented stretch of failed seasons.

Major Dam and Infrastructure Projects

The Kenyan government is investing heavily in water storage infrastructure to address supply gaps. The Ministry of Water, Sanitation and Irrigation has completed feasibility studies and environmental impact assessments for 34 dams, with 67 dam concept notes submitted for development. The government's target is to build 4,000 dams to enhance water security for domestic, irrigation, industrial, and hydropower purposes.

The Mwache Multi-Purpose Dam in Kwale County, at 65 per cent completion as of December 2025, is designed to enhance water supply for Mombasa and Kwale counties, support irrigation, and mitigate flooding. The Kenya Water Security and Climate Resilience Project (KWSCRP), supported by the World Bank, continues to fund critical water infrastructure improvements across the country.

Other significant projects include the Thwake Multi-Purpose Dam in Makueni County, designed to supply water to Makueni, Kitui, and parts of Machakos counties, and various urban water supply expansion projects in Nairobi, Mombasa, Kisumu, and secondary towns under county water service providers.

Irrigation and Agricultural Water Use

In March 2025, the State Department of Irrigation launched the National Irrigation Investment Plan (NISIP), which outlines five pathways for revitalising national irrigation schemes and expanding farmer-led irrigation projects. Kenya's irrigated area remains small relative to its potential — approximately 200,000 hectares are under irrigation against a potential of 1.3 million hectares.

Major irrigation schemes include the Mwea Irrigation Scheme in Kirinyaga County (Kenya's largest rice-producing area), the Bura and Hola schemes along the Tana River, and the Galana-Kulalu Food Security Project in Kilifi and Tana River counties. Expanding irrigation is central to Kenya's food security strategy, particularly as climate variability makes rain-fed agriculture increasingly unreliable.

Water Policy and Governance

Kenya's water sector is governed by the Water Act 2016, which devolved water service delivery to county governments while maintaining national oversight of water resource management. The Water Resources Authority (WRA) manages water resources at the basin level, while WASREB regulates water service providers. County governments are responsible for providing water and sanitation services through licensed WSPs.

Article 43(d) of the 2010 Constitution guarantees every person the right to clean and safe water in adequate quantities, making water a constitutional right. The National Water and Sanitation Strategy sets targets for achieving universal access to safely managed water and sanitation services in line with Sustainable Development Goal 6.

Conservation and the Path Forward

Addressing Kenya's water crisis requires a multi-pronged approach: protecting and rehabilitating water catchment areas (particularly the Mau Forest Complex, Mt. Kenya, and the Aberdare Ranges), investing in water harvesting and storage infrastructure, reducing non-revenue water losses, expanding irrigation sustainably, and promoting water-efficient technologies in agriculture and industry. With climate change accelerating water stress and population growth increasing demand, achieving water security will be one of Kenya's defining challenges in the coming decades.