Lake Naivasha in southern-central Kenya is famed for its flower farms, fisheries and diverse wildlife, including buffalos, hippos and Eurasian migratory birds. The main inflow into the lake is from the Malewa river on the northern shores. At the river mouth, there is a wetland which once spanned 1,350 hectares. Twenty years ago, flooding gouged out the Malewa riverbed so deep that seasonal overflow stopped, and the wetland diminished to 450 hectares.
The original wetland functioned like a natural water treatment plant capturing sediments, organic matter and nutrients before they entered the lake, improving water quality and keeping fish populations healthy. Better water quality also reduced the cost of water treatment for the municipal water supply and commercial farms around the lake.
The wetland itself created macro- and micro-habitats for birds, fish spawning and for larger mammals. Papyrus shading the shallows helped reduce evaporation from the main lake, increasing the water available for wildlife and human livelihoods. But, as the wetlands have diminished, up-stream deforestation is leading to siltation of the main lake.
A nature-based solution
Wetlands are widely seen as a nature-based solution – locally appropriate actions that address challenges such as climate change and provide biodiversity benefits by protecting, managing and restoring ecosystems.
Inland wetlands reduce floods and relieve droughts. Their flood plains, rivers, lakes and swamps function like sponges, absorbing and storing excess rainfall. During dry seasons, wetlands release stored water, to prevent droughts and minimize water shortages. They are also known as carbon sinks – as they capture large amounts of carbon dioxide from the atmosphere.
As part of its work on Sustainable Development Goal 6, the United Nations Environment Programme (UNEP) is monitoring the extent of wetlands and the pressures they are under. UNEP’s Freshwater Ecosystems Explorer provides accurate, up-to-date, high-resolution geospatial data based on earth-observations, depicting the extent of freshwater ecosystems change over time.
Hippos in Lake Naivasha. Photo: Joakim Harlin, UNEPç
A financing challenge
In 2009, Marula Estates, a private estate located on part of the original wetland in the Naivasha area funded a pilot project to restore around 10 per cent of the ecosystem. This involved, among others, creating a roosting area for migratory birds and re-establishing the former papyrus ecosystem.
The pilot was a proof-of-concept of “artificially” restoring wetlands – it helped rehabilitate 140 hectares and greatly improved the area’s biodiversity.
Local stakeholders see a viable future in conserving the wetland and its wildlife, but expanding it to its original size will require a financing plan that engages not only the landowners but also local government, ministries, the tourism industry, fisheries, and agricultural and urban water users.
UNEP is exploring financial solutions to restore the wetland but accessing public and private funding for restoration has been challenging.
“Private investors like to see a 15-20 per cent return on the capital invested over about 10 years, which is impossible for nature-based solutions with environmental benefits for a large group of stakeholders,” says Joakim Harlin, head of UNEP’s Freshwater Unit.
“Providing global and public funds for nature-based solutions that may also benefit private asset holders can be controversial. If private landowners are to be encouraged to engage with ecosystem restoration then funding mechanisms need to be found to assist them,” he adds.
“Nature-based solutions are key to stepping up conservation efforts, building efficient climate resilience, and improving the livelihoods of poor communities across Africa. The private sector should be actively engaged and supported by African governments through sound policies and innovative funding mechanisms,” says Juliette Biao, Director of UNEP’s Africa Office.
There is growing recognition of the value of nature-based solutions. UNEP’s Adaptation Gap Report 2020 finds that since 2006, multilateral funds serving the Paris Agreement have backed around 400 climate adaptation projects in developing countries, half of which started after 2015. The majority focus on agriculture and water, with drought, rainfall variability, flooding and coastal impacts.