Eucalyptus near Lake Ol' Bolossat in Nyandarua County, May 12, 2022. [Kipsang Joseph, Standard]

Did you know that a single eucalyptus tree consumes about 100 litres of water a day, even more than an elephant?

So you can calculate how much water is lost if you have one acre under these thirsty trees.

This is what contributes to declining water levels in rivers and streams, even in regions with abundant rainfall.

That is what happened in Kapchebangoror village, Cheptuiyet location, where springs have run dry and former swamplands are now suitable for farming.

This change occurred after residents cleared bushes for firewood and planted the water-intensive eucalyptus trees for income.

Ten years ago, Josephine Tanui a resident recalls fetching water from a spring that has since dried up.

"Indigenous trees surrounded the spring but over the years, they were replaced by eucalyptus trees which drained the underground water and cause the spring to dry up completely," Ms Tanui said.

Andrew Ngeno, another resident, notes that finding water during the rainy season is now a struggle.

Five years ago, Mr Ngeno convinced local authorities to implement measures addressing the village's water problems.

Now, regulations require non-indigenous trees to be planted at least 30 metres away from water bodies. Since 2009, the national government has banned planting of eucalyptus trees on riparian land and in water catchment areas due to the trees' connection to water shortages.

Eucalyptus trees planted close to a stream in Kipkoi, Bomet County. [Gilbert Mutai, Standard]

But Ngeno admits that enforcing these rules is hard. Villagers often ignore the laws and removing the trees by force is challenging. Every time his team cuts down one eucalyptus, three more sprout up in its place, he said.

Ngeno believes that the solution needs to come from the community itself. "A change of heart would be a win if they can work together to protect their water sources."

The sharp decline in water levels in Kericho County's rivers and streams prompted officials to ban the planting of eucalyptus trees near riparian land.

In 2020, former Kericho Governor Paul Chepkwony issued an executive order banning eucalyptus planting along river banks and water sources to reverse receding water levels.

Violators risk a jail term of at least one year.

"We want locals to understand that 30 metres of land from a riparian area is protected by the government. Even as we respect the right to land ownership, it must be utilised to the benefit of current and future generations," Prof Chepkwony said.

Unfortunately, progress has been slow, as most residents have not heeded the call despite witnessing adverse environmental effects.

Due to their fast-maturing nature and high demand for timber, residents prefer planting eucalyptus trees for profit.

The demand for wood fuel from learning institutions and tea factories - including those owned by the Kenya Tea Development Agency (KTDA) - has contributed to the increasing acreage of eucalyptus trees.

Multinational companies like James Finlay, Unilever, Sasini and Sotik Highlands have adopted solar power systems to reduce operational costs, including high fuel consumption.

However, the KTDA-run Momul Tea Factory has planted 357 acres of eucalyptus trees. Factory chairman Isaiah Langat says plans are underway to increase the acreage to over 600 acres as a long-term investment in wood fuel supply.

Eucalyptus tree harvesting at Kambiri in Shinyalu, November 5, 2021. [Benjmain Sakwa, Standard]

In January, the Council of Governors' Environment and Climate Change Committee prepared a Bill to replace eucalyptus trees with environmentally friendly indigenous trees in all 47 counties.

If enacted, the Bill, authored by committee chairman and Vihiga Governor Wilber Ottichilo, will mandate the removal of eucalyptus trees near riverbanks, wetlands, and land boundaries due to their contribution to environmental degradation.

Eucalyptus trees, native to Australia where they are also known as gum trees, have over 700 different species and are among the fastest-growing woody plants globally.

They serve as a food source for koalas and provide wood for making aboriginal wind instruments called didgeridoos.

They are one of the most widely used plantation forest trees, covering about 18 million hectares in 90 countries. The trees are a source of timber, fuel, cellulose, and medicinal and industrial oils, with researchers exploring their potential in biofuels.

In 2014, an international team of researchers unveiled the genetic blueprint of Eucalyptus grandis, identifying genes involved in critical biological processes controlling tree growth, wood formation, and flowering.

"The main interest is understanding how these trees grow so fast and how they are able to produce such large amounts of cellulose," Zander Myburg of the University of Pretoria's Forestry and Agricultural Biotechnology Institute said.

He added, "There's an interest in cellulose in the context of breaking the cellulose down into sugars, which can be fermented into biofuels. But really these trees are widely used industrially for cellulose-related products and timber, pulp and paper production."

According to Gerald Tuskan of the Oak Ridge National Laboratory and the US Department of Energy Joint Genome Institute, a comprehensive understanding of the genetic control of carbon allocation in woody plants is a crucial step toward developing future biomass crops.