Tackling the root causes of water hyacinth in Lake Victoria

It continues to flourish primarily because of human activities.

In Summary

•Homa Bay’s sewage treatment works produces a very poor quality final effluent that is discharged directly into the lake. 

•Overstocking of livestock has also been increasing, resulting in overgrazing and subsequent soil erosion

Fishermen manoeuvre through water hyacinth.
Fishermen manoeuvre through water hyacinth.

Lake Victoria is one of Kenya’s most important water resources. It accounts for about 96 per cent of the country’s total fish production, and is a source of food, energy, water for domestic and industrial use, shelter and transportation.

More than 10 million people, representing approximately 25 per cent of Kenya’s population, derive their livelihoods from within the Lake Basin Region. As such, Lake Victoria has the potential to be an excellent blue economic resource.

Despite the economic and social value of Lake Victoria, it is increasingly under pressure from a variety of interlinked human activities and has become a repository for industrial, domestic and agricultural wastes.

Water hyacinth has invaded Lake Victoria and covers vast swathes of its surface. Due to its potential to rapidly reproduce and spread, the weed has inhibited activities such as fishing and transportation in the lake.

Additionally, its dense mats create a microhabitat for vectors of disease thereby affecting human health. The reduction in fish catch and increase in diseases detrimentally impact the livelihoods of individuals dependent on the lake and has serious consequences for communities living in the Basin Frontier counties of Migori, Homa Bay, Kisumu, Siaya and Busia.

Despite various efforts to remove the weed, water hyacinth continues to flourish primarily because of human activities. Towns have continued to mushroom along the lakeshore and adjacent catchment areas as people move there in search of livelihoods especially from the fishing industry.

To sustain these urban centres, land has been cleared for agricultural use and industrial development, while wetlands that are supposed to act as pollution buffers, have been converted into settlement areas. While towns in the Lake Victoria Basin have continued to experience burgeoning population growth, the physical infrastructure, such as sewer lines, have not been improved to meet the demand.

For example, Homa Bay’s sewage treatment works, constructed in 1982, has a design capacity of 750 m3 per day, but the current daily raw wastewater flow is in excess of 2,000 m3 per day. Consequently, the treatment works produce a very poor quality final effluent that is discharged directly into the lake.

The situation in Kisumu is no better, with the Kisumu Water and Sewerage Company causing high levels of pollution by discharging treated effluent directly into the Kibos and Kisat rivers. Additionally, urban surface runoff carrying oils and other municipal waste contaminate the lake’s water.

Intensive use of agrochemicals, in the form of fertilizers and pesticides applied to boost farm yields, has caused a high flow of nutrients into the lake. High levels of nutrients cause eutrophication, a condition which causes excessive growth of aquatic weeds such as water hyacinth, and oxygen-depletion in the bottom waters, contributing to fish kills and loss of habitat.

Overstocking of livestock has also been increasing, resulting in overgrazing and subsequent soil erosion. Furthermore, the draining of wetlands for additional arable land, as well as cultivation on river banks and adjacent slopes, have resulted in high levels of sedimentation in the lake.

This increase in sedimentation and the degradation of wetlands has rendered wetlands incapable of buffering pollution and sediments from the catchment. Consequently, agricultural, municipal and industrial wastes freely enter the lake.

There has been a growing public outcry, especially in Kisumu, because of industries in the area pumping raw effluent directly into streams and thereby threatening the lives of thousands of people dependent on that water for domestic use. Breweries, tanning, fish processing, agro-processing and abattoirs are key pollution sources in the Lake Victoria catchment.

Major rivers draining into the lake traverse through industrial and agricultural zones and thus transport industrial and agricultural pollutants into the lake, creating a fertile ground for the proliferation of water hyacinth. Non-implementation and monitoring of pollution regulations by the relevant authorities exacerbates the problem.

Lake Victoria Basin area is concentrated with poor populations who are dependent on natural resources for their livelihoods. These communities exert considerable pressure on the lake and adjacent land and forests.

Amb John Kakonge
Amb John Kakonge

To meet their food demands, unsustainable farming practices are employed, leading to soil erosion, sedimentation of waterways and destruction of wetlands. Furthermore, poor sanitation conditions and over-dependence on wood fuel have led to pollution and sedimentation of the lake.

There is an acute shortage of manpower, from extension officers to train farmers on best farming practices, to environmental conservation practitioners to monitor polluters and conduct environmental impact assessments (EIAs). The situation is worsened by incapacity in terms of regulations, facilities, funding and institutions.

Such capacity gaps have only propelled unscrupulous individuals and industries to pollute with impunity. For sustainable environmental management of the Lake Victoria Basin, construction, and or dedication, of institutions that can offer training for the various persons required to oversee environmental quality is essential.

The lake is a shared resource amongst the catchment communities, thus the challenges threatening its sustainability should also be shared amongst those communities.

This calls for a well-coordinated approach in dealing with all environmental problems, including the water hyacinth challenge in the lake. Such an approach will bring together all government authorities tasked with environmental management, water quality regulation, international donors, county governments and the national government under one umbrella, with the aim of pursuing a two-prong approach: physically eradicating the weed from the lake and reducing the causes of the reproduction and spread of water hyacinth.

As envisaged in Vision 2030, Kenya seeks to benefit from the blue economy potential of activities such as water-based tourism and fishing in Lake Victoria. However, to achieve this, a holistic approach is required to combat poor water quality in the lake and to deal with the invasive water hyacinth.

The polluter pays principle is a practice whereby those producing pollution are made to bear the costs of managing it to prevent environmental damage. Learning from China’s example, Kenya could conduct a survey of polluters to assist the national environmental watchdog, NEMA, in enforcing the principle.

Proper adoption and enforcement of the polluter pays principle will result in a reduction of industrial effluents being discharged into rivers draining into Lake Victoria, thus cutting down nutrient sources for water hyacinth.

Pollution and sedimentation emanating from agriculture has been recognized as one of the major causes of deteriorating water quality in the lake. Increased sediments in the lake make it shallower and thus more conducive for the growth of water hyacinth.

Lake Basin counties should employ extension staff to train farmers on best farming practices to prevent soil erosion, and also to help farmers adopt better conservancy activities. For example, conservation agencies in the Lake Naivasha communities, involved farmers in a drive to protect the lake. Farmers planted Napier grass, fruit trees and cock’s-foot grass on their slopping farms, which reduced the amount of soil washing into rivers.

The majority of communities, especially most farmers, are not aware of the effects of their land use practices on the lake and consequently they continue to pollute it. To change this scenario, information dissemination is needed on the impacts of improper land use activities on water pollution and sedimentation and the resulting proliferation of water hyacinth.

Communities are greatly influenced by politicians. If politicians take the lead role in supporting programmes that address environmental challenges, catchment communities are likely to follow. Recognizing that Lake Victoria is important to the blue economy, the government must introduce legislation and endorse projects that seek to conserve the waters and adjacent land around the lake.

For example, the Kenya government has invested Kshs 3 billion for work that will see a facelift to the Kisumu port, dredging of a harbour and the clearing of water hyacinth. Such strong political support and will should steer the water hyacinth eradication project to fruition.

The nature of the water quality, and associated water hyacinth problem, necessitates sustained and long-term financing if the weed is to be completely eradicated. Such a programme will only succeed with multiple sources of funding from all three Lake Victoria national governments, international donors and partners.

Additional finances are required to train agricultural extension staff and staff in water regulatory bodies to build their capacity to deliver quality services. This will enhance timely and effective monitoring and enforcement of water quality regulations and hence curb excessive industrial and agricultural pollution.

Overall, Lake Victoria is Kenya’s largest freshwater body and more than a quarter of the country’s population is directly dependent on it for their livelihoods. To eradicate, or at least control, water hyacinth on the Kenyan side of Lake Victoria, there is an urgent need for the Lake Basin counties to implement an effective integrated Lake Basin management approach which addresses both the causes of water hyacinth spread and the actual removal of the weed.

By addressing catchment activities that cause sedimentation and pollution, while increasing capacity in agricultural extension and enforcement of environmental regulations, we have the potential to control, and possibly eradicate, the weed once and for all.

Ambassador Kakonge is the president of the Association of the Former International Civil Servants of the United Nations and other international organisations.