An interesting scenario is emerging as scientists clash over the gloomy projections of the water situation in the country.

The Water Management Programme argues that Kenya has enough water to support up to seven times its current population, disputing climate change experts' predictions.

Mr Maimbo Malesu, the regional coordinator of the programme, which works under International Centre for Research on Agroforestry (Icraf), argues that projections by the climate change experts are mathematically wrong, as they do not take into consideration all the available volumes of water.

According to findings of a new study by Water Management Programme, what is required is only change of policy to embrace rainwater harvesting.

Mr Malesu dismisses the gloomy picture of future that is touted by climate change experts, saying: "Despite accounting for only a third of the global water capacity, blue water, which is made up of conventional sources of renewable surface and ground water, is all that is usually considered during planning."

An important resource

The rest of the water - called green water - he explains, goes to waste and is taken up by plants. "It is the green water, which when exploited, can make a country rich."

Rainwater is an important resource that most of the time is left to go to waste. Apart from stemming the perennial water shortage, rain water harvesting holds the promise of reducing incidences of floods.

Water is an emotive issue in Kenya and has been at the centre of conflicts in the arid and semi-arid areas. Scarcity of the resource has been known to fuel tension in some parts.

Slum dwellers in most parts of the country go for days without the commodity, but when they get it, are ripped off by water vendors. Lack of infrastructure, occasioned by the poor planning in slums, has been blamed for this.

In areas with sufficient rainfall, runoff develops into floods that unleash havoc. Residents of Budalang'i, Nyando and other regions that are routinely hit by floods, have vivid memories of their experiences with a mass of untamed water.

But the hostility arising from lack of water and the inconveniences of floods could soon be history, if policy makers heed the findings of this new study.

The findings, contained in a report titled Mapping the potential of rainwater harvesting technologies in Africa, recommend investment in rainwater harvesting technologies.

"Scarcity of water in Kenya and the rest of Africa has nothing to do with lack of water, but rather lack of investment in appropriate technologies," Mr Malesu says.

Rainwater harvesting involves capturing rainwater and directing it into reservoirs, where it is stored for later use. Rainwater can be tapped from either roof tops or the ground and stored in ponds, earthen dams and cisterns.

The stored water can not only be used for agriculture and domestic purposes, but also for environmental eco-tourism and industrial purposes.

Rainwater harvesting is an ancient means of conservation in parts of Africa and Asia.

Apart from designing reservoirs for storage, he recommends, water saving technologies such as drip irrigation and conservation agriculture.

Conservation agriculture includes planting different crops that reduce loss of soil by erosion and evaporation of moisture. Rainwater can also be harvested off the farm and directed into the area with crops using channels.

Mr Malesu says that reservoirs, which should be steep-sloped to impede thriving of mosquito larvae, could also be used in flood-prone areas for irrigation and livestock management.

To sustain forests

According to the study, more than 10 per cent of Kenya receives above 400mm of rainfall.

This, Mr Malesu argues, is a lot of water, which if harvested and stored, can supply water to dry areas such as North Eastern Province with sufficient water.

However, he says, not all the water can be harvested for domestic use as over a third of rainfall is needed to sustain forests, grasslands and healthy river flows.

Rain water harvesting, he added, is an efficient coping strategy against climate change, which experts predict may increase water scarcity in Africa where a large proportion of inhabitants lack access to the resource.

The chairperson of the Water Services Regulatory Board, Ms Jane Njagi, concurs that rain water harvesting is a viable option since Kakamega, Kisii, Kericho and several other parts are endowed with sufficient rainfall.

"If all this water was harvested and stored, the country would make great strides towards provision of safe clean drinking water," she adds.

Moreover, if harvested hygienically, rainwater does not need additional purification as it is in a natural form.

Apart from the traditional water reservoirs, even sand is usable.

In fact, experts say that more water can be extracted from sandy beds compared to riverbeds with fine textured sand. Sand dams are also a common water storage facility in Ukambani and other parts of Eastern Province.

Apart from conserving water, sand dams also help in rehabilitation of gullies and provide a base for construction of riverbed crossing.

In addition to this, the Water Resources Management Authority is also involved in an initiative to promote rainwater harvesting beyond the traditional roof catchments.

Ms Margaret Abira, the regional manager of the authority's Lake Victoria South catchment area, says that the initiative, dubbed green-blue water initiative, encourages soil and water conservation.

"The initiative is promoting practices that encourage soil and water conservation on farms," she adds.

The Inter-governmental Panel on Climate Change, an international body established by the World Meteorological Organisation and Unep, estimates that by 2020, up to 250 million people in Africa will be at risk of water stress, a figure that is expected to double three decades later.