Kenya Lake System in the Great Rift Valley

Small irrigation dams have been constructed on rivers flowing into the lakes and river flows have reduced markedly (IUCN, 2012). At Lake Elementaita there was little water flowing into the lake at the time of the last management plan development because ‘farmers use most of the water for irrigation upstream' (GLECA, 2010). A recent example is the Mereroni-Mbaruk Wetland which is being destroyed by farmers (WRA, 2024). These are common occurrences throughout the region and the Water Resources Authority (WRA) lacks capacity to effectively manage water abstraction licensing and compliance to ensure downstream users are not affected.

Lake Elementaita has geothermal activity and receives baseline water underground from Lake Naivasha, a fresh water lake (outside the site) fed mainly by the Aberdare Mountain ecosystem. Naivasha's own lake water level has been critically lowered in recent years due to abstractions of water for agriculture, a situation likely to be exacerbated by the construction of a dam on the Malewa River, some of whose water may be transferred out of the basin (LNRA, 2019). On the other hand, since 2020 Lake Naivasha's level has also risen to levels last seen in the early 1900s.

Given the rate of human population increase and intensification of land use in the Rift Valley catchments, the trend of increasing water abstraction will accelerate and continue to impact medium and low flows. The Rift Valley Basin population is forecast to increase 53% by 2030 (WRA, 2020). And the changing land usage coupled with an increasing rainfall trend is leading to larger floods and lake flooding (Avery, 2020). The Rift Valley lakes of Kenya have reached levels last witnessed in the early 1900s. Lesser Flamingos from 1990 to 2014 numbered roughly a million birds, but since 2014 that number reduced drastically to only 200,000 birds (NFIT, 2025b). This drop in bird numbers is associated with rising lake levels (ibid).

Lake Bogoria's water level has risen close to the high levels of the early 1900s which is close to the point where the lake would spill into the Lake Baringo basin, this being the physical limit beyond which the lake level cannot rise. There have been local concerns that Lake Bogoria's saline waters will spill overland and contaminate Lake Baringo's fresh water.

Lake Nakuru's limnological conditions have been altered by pollution and dilution, and this has caused flamingos to desert the lake, which in turn reduces tourism numbers (RVWSB, 2018). Fish from the lake are subjected to pollution levels such that today the fish are reported unfit for human consumption (Nation epaper, 2025). Lake Bogoria's saline waters are likewise diluted leading to reduction in phytoplankton that flamingos depend upon (Byrne et al., 2024a & 2024b). All the lakes have reached high water levels with access roads, buildings and terrestrial ecological habitat inundated (Avery, 2020; Kiogora et al., 2021), which deters tourism. These changes are affecting the OUV but the lake water levels are a consequence of climate and catchment land use changes beyond the site, pollution can be controlled, and the ecologies will adapt.

The Lake Nakuru hydrology is complicated and it is believed that there has been increased seepage from the lake underground to recharge aquifers to compensate water pumped from boreholes near the lake, and also to compensate decreased groundwater recharge arising from deforestation (RVWSB, 2018). On the other hand, Lake Nakuru lies on a seepage path flowing from Lake Naivasha via Lakes Elementaita, Nakuru, Bogoria and into Lake Baringo (Kiogora et al., 2021). This underground seepage will increase with rising lake levels and contributes to replenishing aquifers. Plus, catchment deforestation and increasing land use pressures mean the runoff volumes reaching the lakes are increasing, as is the stormwater runoff into Lake Nakuru from its expanding neighbouring city. In addition, water supply to the expanding city will be increased by water imported from outside the catchment which will generate wastewater which adds to discharges to the lake.

The challenges facing the site were exacerbated by the collapse of tourism revenue due to the Covid-19 pandemic (since March 2020). Tourism in Kenya has since recovered in 2023 and 2024, but the high lake levels in Nakuru that have inundated beyond the park boundary persist (Birkett, 2025), and are forecast to continue to rise (Kiogora et al., 2021).

There has been concern about the growth of Solanum incanum in the grazing areas for the large mammals within Lake Nakuru National Park (LBNR Committee, 2007). The presence of this plant is often associated with degradation. A later Kenya Wildlife Service (KWS) workshop presentation added Datura stramonium and Lantana camara amongst invasive plants that are reducing grazing / browsing areas for wildlife (KWS/NMK, 2020).

A notable invasive plant that invades grasslands is Prosopis juliflora, seen throughout Kenya's Rift Valley, and proliferating in the region of Lake Bogoria (LBNR 2019; NFIT 2025d ). The plant is robust and thorny and invades grasslands and wetlands and displaces the indigenous vegetation.

Though invasive plants may affect the integrity of the site, it is noteworthy that new species may in some cases be beneficial as observed with the introduction of the cichlid grahami in Lake Nakuru in about 1960, that changed the ecology and trophic dynamics of the lake (Vareshi, 1979). Prior to this introduction there were no fish in Lake Nakuru, and its introduction extended the food chain and has since supported a diversity of piscivorous birds, the dominant fish-eating bird being Great White Pelicans that breed at nearby Lake Elementaita (Vareshi, 1979; KWS, 2003). A past media post reported a study citing a total of four new tilapia species present in Lake Nakuru (The County Look, 2020; Kiogora et al., 2021). A very recent report refers to the "accidental introduction of Nile Perch" (NFIT, 2025d). Fishing Lake Nakuru has become a livelihood carried out by nearby communities, leading to controversy and conflict with the authorities as fishing the lake is illegal (Nation epaper 2025a). Past reports have declared the fish "unfit for human consumption" and "poisonous" (Nation epaper 2024).

Lake Nakuru borders Nakuru municipality whose population continues to expand. A recent study report determined that Lake Nakuru's water level is likely to continue to rise potentially expanding its water surface area 20.6% by 2031 covering an area 82 sq km (compared to 68 sq km in 2010) (Kiogora et al., 2021). The current lake level has flooded communities beyond the park border and recommendations have been made to re-possess low-lying land and compensate those communities through extending the park boundary and creating a buffer zone (Kiogora et al., 2021). The urban pressures have included fires being started within the Lake Nakuru park by people, including recently due to civil unrest (Nation, 2025).

Lake Elementaita borders the Soysambu Conservancy, which is a rural agricultural area not far from the growing Nakuru municipality and Gilgil township. There are housing developments both in parts of the former Ututu conservation area to the south as well as along the eastern side of the lake, thereby pressurising the lake's critical buffer zone. The previously contiguous Ututu conservation area no longer exists, as it has been sub-divided into small plots and sold off (State Party of Kenya, 2019), thereby altering the land usage within the designated Ramsar site, and reducing the area available for conservation. The wildlife corridor concept from Lake Elementeita to Lake Naivasha through Ututu Conservancy has since been suspended as that area is now increasingly heavily settled with people and the proposed corridor is deemed by the State Party as "not adding value to the OUV of the property" (State Party of Kenya, 2024).

There are commercial developments in close proximity to Lake Elementeita including the drilling of geothermal exploratory wells to the south (NEMA, 2020), and the construction of a carbon capture facility less than one kilometre from the lake (NEMA, 2024). The geothermal concession area to the south encroaches into the Ramsar site and extends to within 600 metres of the Lake Elementeita shoreline (NEMA, 2020). The nearest ongoing exploratory geothermal drill site is 9 km to the south of Lake Elementeita.

In contrast, Lake Bogoria is located in rural surroundings in Baringo County and hence is not vulnerable to urbanisation and commercial developments other than tourism and agriculture. Baringo County is proud of its natural heritage and biodiversity hotspots "that support the livelihoods of thousands" (KWS, 2025). The County recently celebrated World Wildlife Day at Lake Bogoria with the Director General of KWS as a guest (KWS, 2025). The habitat degradation, human wildlife conflict, and climate change are acknowledged, but the County is active and supportive in creating conservancies and improving tourism facilities.

The lesser flamingos and other birds move great distances between the ten ‘flamingo lakes’ of the Rift Valley, and beyond, so are vulnerable to ecological changes or pollution of any of the other lakes within the food chain. There has long been trona mining and a major soda ash factory on Lake Magadi near the Tanzanian border, and a similar development has been mooted for Lake Natron to the south in Tanzania, which serves, critically, as the main breeding site for lesser flamingos. There are also plans for a cascade of three hydropower dams and associated irrigation developments on the Ewaso Ngiro South river in Kenya, this being the main freshwater feed to Lake Natron via its associated Shompole swamp at the northern end of the lake within Kenya. There are numerous wetlands fringing the shores of Lake Natron under anthropogenic pressure, and important susceptible wetland habitats elsewhere within the Rift Valley that are utilised by migrating birds. These include the Suguta valley and Lake Logipi, small ponds at the south end of Lake Turkana, a small soda lake and two other fresher lakes on Central Island within the endangered Lake Turkana National Park World Heritage Site, and the Kerio, Turkwel and Omo river deltas feeding into Lake Turkana. Riparian swamps on the rivers flowing into the Soysambu Conservancy have been illegally destroyed for agriculture in recent years (IUCN Consultation, 2020; WRA, 2023), thereby exacerbating the sediment runoff into that lake. Typha swamps in the vicinity and north of Lake Bogoria have similarly been reduced to dry bare areas in recent years through persistent grazing and browsing by livestock (IUCN Consultation, 2020). The rising lake levels have throughout led to loss of terrestrial habit through inundation and the river inflows have diluted the saline waters of soda lakes with unknown adverse effects on the food chain of the water birds (Byrne et al., 2024a & 2024b). And the impacts of regulation of river flows into Lake Turkana and nutrient capture by the huge Gibe III and IV hydropower dam reservoirs were glossed over by environmental impact assessments (Avery, 2012 & 2018). Recent independent studies have reported diminished diversity in the Omo delta zone on Lake Turkana as a result of the dams (Zen et al., 2023). Rift valley lakes in Ethiopia are undergoing changes relating to human activities too (CGIAR, 2024).

Tourism was curtailed by Covid-19 and in the case of Lakes Nakuru and Bogoria is seriously impacted by the submergence of park infrastructure due to rising lake levels. Lake Nakuru National Park has in the past attracted up to 340,000 visitors annually, albeit with reductions in recent years, and this had been creating some pressures related to off-road driving, over-crowding, littering and waste management challenges for the park authorities. Lake Nakuru is one of KWS's flagship tourism destinations. At present, tourism exerts little pressure on either of the other two lakes, and is a force for their conservation (BirdLife, 2017c). However, littering of the hot springs and campsites in Lake Bogoria had been a problem in the past that significantly detracted from the tourism experience, as well as being a hazard to wildlife. Off-road driving is not allowed in national parks. Kenya has taken stern measures to limit plastic usage, and plastic water bottles are no longer allowed in national parks.

Small-scale extraction of soda and sand on the eastern shores of Lake Elementeita is not a major threat, but an expansion of these operations could have a significant impact on the site (BirdLife, 2017c).
A geothermal development concession to the south of Lake Elementeita has been granted to a private developer. An ESIA for drilling exploratory wells within this concession area was presented to the National Environment Management Authority (NEMA, 2020). The northern boundary of the concession area reaches within 600 metres of the southern shore of Lake Elementeita and the concession area includes southern parts of the Ramsar site. The exploratory drilling project is ongoing and currently entails drilling deep exploratory wells some 9 km distance from the lake. The ESIA states the risks include "contamination of underground and surface water bodies" (NEMA, 2020, p.107) and "sustainable abstraction from the lake" (ibid. p.49). There is also a recently launched Direct Air Capture (DAC) project within the above geothermal concession area, whose project site is only 1km from the lake. This project entails drilling into underground basaltic aquifers to store carbon (NEMA, 2024). The negative impacts are stated to be "potential air and noise pollution during construction, risk of water contamination and soil erosion, disruption to local biodiversity, and aesthetic changes to the landscape (NEMA, 2024, p.iv).
In January 2025, Nature Kenya issued comments on the DAC EIA Study Report and recommended rejection of the proposed carbon capture project location as it is too close to the lake (Nature Kenya, 2025). The targeted underground basaltic aquifers are likely part of the aquifer system that sustains the lake's springs, and hence the potential impact of the geothermal and carbon capture project should be addressed by experts.

Pollution of the lakes’ waters affects inflows from the growing agricultural and industrial town of Nakuru (population of 390,000 in 2020, predicted to increase to over 800,000 by 2045 (medium growth rate) (RVWSB, 2018). Though the municipality has existing wastewater treatment facilities, these are too close to the lake and the treatment of wastewater entering the lake has been inadequate (BirdLife, 2017a). This is being rectified by the Lake Nakuru Biodiversity Conservation Project (CRVWWDA, 2023). In the wider catchments, intensification of agriculture and increased use of fertilisers may be increasing the nutrient load of inflowing waters and could lead to eutrophication. A further challenge is the siltation arising from the soil being washed into the lake from the deforested and degraded catchment areas.

Lake Nakuru has long been impacted by poorly treated wastewater runoff into the lake, a situation that will be exacerbated by the increase in water supply brought into the town from Itare dam, with the wastewater volumes doubling by the year 2045. In addition to increased pollution risks, with the increased volumes of wastewater being discharged to the lake, lake levels would rise appreciably (RVWSB, 2018).

Increasing urbanisation is increasing the stormwater runoff into the lake, and this is compounding the impacts of increasing wastewater discharges. In addition, due to poor waste management within the town (RVWSB, 2018), the stormwater drains are often used to dump a range of wastes including garbage, plastics, sullage and oils, which are then carried by stormwater untreated to the lake, to the detriment of the lake ecology and wildlife (RVWSB, 2018). Whereas the current Lake Nakuru Biodiversity Conservation Project is addressing sewerage and sewage treatment improvements, stormwater is not a component amongst new works recently tendered.

Plans are being implemented in Nakuru municipality to improve both stormwater management, sewerage reticulation, sewage treatment and final disposal of effluent (RVWSB, 2018; CRVWWDA, 2023). Under current plans, raw sewage is planned to be transferred through pumping from Kaloleni Treatment Works to the new Njoro Wastewater Treatment Works. These are further from the lake, but still within the catchment draining into Lake Nakuru (CRVWWDA, 2023; 2024).

Only 21% of water consumers within the former Nakuru city were connected to sewers (RVWSB, 2018). The performance in maintaining the sewage pumping and treatment facilities was poor with biochemical oxygen demand (BOD; or simply the 'food' for the biomass) loadings in the final sewage treatment ponds that were almost 10-times the allowable limit for safe release to Lake Nakuru (RVWSB, 2018). Later water quality sampling in the Lake Nakuru sewage treatment ponds identified the presence of cyanotoxins which if ingested by wildlife through drinking can be fatal (LNRA, 2019). Difficulties have been compounded by submergence of the grass plots and rock filters of the existing Kaloleni sewage treatment works due to the high lake levels.

The Kisumu-Lessos-Olkaria high-voltage power transmission line has been built on the southern edge of Lake Elementeita. The project proponent is KETRACO (Kenya Electricity Transmission Company). The alignment passes very close to the southern lake shore and thereafter west through the Soysambu Conservancy. The structures are unsightly, and they create a physical barrier spanning across bird flight paths, in this case within 500 metres of the southern shore of Lake Elementeita. The pylons are 50 metres tall, and the physical hazard to birds in flight is considerable. There was a media outcry (Mangat, 2019a; 2019b), including reference to a letter from WH Committee to Kenya's permanent delegate to UNESCO whose contents were published by the media and online (WHC, 2019; cited by Mangat, 2019b).

There was conflicting information that required clarification as follows:

1. In Kenya’s earlier state of conservation report (Kenya, 2020), it states that an EIA license for the transmission line had been issued to KPLC (Kenya Power Lighting Co.) on 6th Sept 2019, whereas the license attached by the State Party was actually issued nine years earlier on 6th Sept 2010, and was only valid for 24 months. Compounding matters, that license was transferred to KETRACO by NEMA with effect from 24th Aug 2015, although its validity had already expired three years earlier, which meant the EIA exercise needed revision in order to capture changed circumstances.

2. The Executive Summary of Kenya’s report (Kenya, 2020) stated that a joint KETRACO/KWS assessment was undertaken in June 2019 to ascertain impacts and included mitigation measures to guard the OUV of the lake, and that these have been factored into re-designing the powerline routing. However, there has been no re-routing. The transmission line has been built following the same alignment (through the Ramsar site) to which stakeholders had objected.

3. The same Executive Summary of Kenya's report (Kenya, 2020) used the explanation that "flamingo / pelican migration is between Lakes Elementeita and Nakuru and not any other route" to justify the alignment between Lakes Naivasha and Elementeita. This is factually incorrect, as flamingos and pelicans and other birds fly both up and down the Rift Valley including south to Lake Naivasha and beyond to Lakes Magadi, Natron, and Manyara in Tanzania. The joint KETRACO-KWS rapid assessment dated June 2019, which was annexed to the State Party report even stated that "the line will pass across bird migratory routes or paths" (KWS/KETRACO, 2019). The joint assessment concluded that "the proposed transmission line should avoid bird migratory routes or paths" and further stated "There is need to engage bird experts (ornithologists e.g. from Nature Kenya[…])" (KWS/KETRACO, 2019).

4. Kenya’s state of conservation report did not mention that Nature Kenya was thereafter consulted as recommended by the joint assessment, and that in their letter dated 5th August 2019, Nature Kenya urged NEMA to "please stop the transmission line through Lake Elementeita and Soysambu" as the line "is a huge danger to birds and fails to meet avian safety standards" (Nature Kenya, 2019a). Meetings were then convened between Nature Kenya and KETRACO at which the unacceptability of the transmission line alignment was repeated, and it was resolved that a joint team Nature Kenya / KETRACO would undertake a study, the results and recommendations of which would inform subsequent decision making. These resolutions were confirmed by letter to KETRACO copied to a long list of leading government officials and JICA, UNESCO, and KWS (Nature Kenya, 2019b). The outcome has never been reported, and the precedent to disregard the due process is unfortunate.

The alignment is inappropriate as it is contrary to guidelines that sensibly state that "powerline routing should avoid large wetlands and other sensitive bird habitats, important migratory routes or protected areas designated for species of conservation concern" (Bernadino, 2018).

Note that the state of conservation report for 2023 merely states the power line passes "5 kilometres away from the Lake Elementeita" (State Party of Kenya, 2024). However, reference to Google Earth shows that the line passes less than 800 metres from the lake and cuts right across the bird flight path to Lake Naivasha.

The discussions concerning raptor deaths due to powerlines are an escalating concern as more powerlines are constructed. The Peregrine Fund is at the forefront leading discussions with Soysambu Conservancy, Kenya Power and Lighting Company (KPLC), KETRACO, Rural Electrification and Renewable Energy Corporation, National Museums of Kenya, KWS, WRTI (Peregine Fund, 2024 & 2025). Declines in raptor populations are a major concern and protected areas are increasingly important to their survival (Ogada et al. 2022). Hence enhanced protection of these areas is vital, and any encroachment must surely be avoided. Whereas poisoning used to be the main cause of bird casualties, today it is electrocution, and in the case of low powerlines, large mammals such as giraffe are also electrocuted.