All you need is love... and water

Yet water is a resource in dwindling supply. Dams like this one – Ndakaini Dam, which supplies 80 percent of Nairobi’s water – have been hit by drought. Protecting water supplies is more important than ever. But water management is becoming more complicated, with different consumers competing for less water. From flower farms and smallholder farmers, to the largest electricity supplier in the country and the average Nairobi user, each drop is in demand. Costs could spiral if action isn’t taken.

These gullies are caused by wind and water, as eroded soils are washed away. CIAT’s research in the Tana River watershed aims to protect these landscapes, while generating income for the communities living there. “Our research guides management options tailored to specific areas of the watershed, which protect the environment, boost agricultural productivity and lower the cost of delivering clean water,” said Fred Kizito, Senior Soil Scientist at CIAT.

CIAT’s Jane Gicheha collects data from different parts of the watershed, measuring soil erosion. As an environmental engineer, she says: “Very few people know that for many, farming is the only way out of poverty,” she says. “I have a passion for working in soils research, because agriculture is the backbone of the economy and our soils are life – it’s the basis of food production.”

The upper part of the Tana River watershed is a green carpet of tea plantations, giving way to the coffee plantations in the lower part of the watershed. The changing nature of land use on the steep slopes of the watershed is influenced by many factors, including rising or falling demand for tea or coffee; new roads built and conservation areas. But these changes cause soil loss and erosion. Exacerbated by extreme weather like flooding and drought, soil washes down the slopes, clogging up the Tana River.

When the Tana River is running low, that’s bad news for urban users. Soil erosion also affects big business, like The Nairobi Water and Sewage company pictured here – Nairobi’s largest water supplier. KenGen, Kenya’s biggest electricity supplier, is also affected. Reduced water flow for hydropower generation means switching to expensive thermal alternatives, increasing the tab by around a third for consumers.

Rachel Njeri is a farmer who works with Jane, collecting soil run-off information on her farm to check how effective measures – like planting grass strips on sloping land – prevent soil erosion. Jane is among a group of researchers working to improve the flow of water in the Tana River by advising which agricultural management practices farmers like Rachel can use to reduce soil erosion and even boost harvests. “When I planted the Napier grass, the water was trapped. Now more soils stay at the top of the farm,” said Rachel.

Jane also works with partners like the Water Resources Management Authority of Kenya (WRMA), to measure soil sedimentation along the river course. The information is used to make digital maps, showing which areas of the watershed are most vulnerable to soil erosion, and presented to the Nairobi Water Fund. The first water fund for Africa, coordinated by The Nature Conservancy, it works by uniting water users along the watershed – like Coca Cola – leveraging big businesses to finance protection measures carried out by uses upstream – farmers like Rachel.

Priscilla Ngacha, from the Green Belt Movement, enjoys fruit from trees planted by her team of “Green Rangers” – community farmers recruited to plant trees and protect the upper part of the watershed. “When I first came to this upper part of the catchment, I found very few trees,” said Ngacha. “That’s changing now, as our Green Rangers give farmers the financial and technical incentive to improve soil management.”

A two-year pilot phase, enabling 5,000 farmers to adopt conservation measures, has already translated into big benefits – for the whole ecosystem and for investors. KenGen has estimated savings of US$6 million in avoided interruption and increased water yield. So if your Valentine’s rose came from Kenya, have a heart for all the people who manage the watershed, so that both farmers and flowers can thrive.