Rainwater harvesting has the potential to solve most of Africa's water shortages, according to a new study released on Monday.

"Africa is not water scarce. The rainfall contribution is more than adequate to meet the needs of the current population several times over," states the report compiled by the United Nations Environment Programme (UNEP) and the World Agroforestry Center (ICRAF).

The importance of rainwater harvesting and storage for drinking and agriculture lay in the fact that large capital investment was not required and only simple technology was involved, Achim Steiner, UNEP's Executive Director, said.

"As we look into what Africa can do to adapt to climate change ... rainwater harvesting is one of those steps that does not require billions of dollars, that does not require international conventions first - it is a technology, a management approach, to provide water resources at the community level," he said during the news conference to announce the findings of the study at the ongoing conference of the United Nations Framework Convention on Climate Change in Nairobi.

A pilot rainwater harvesting project in the Kisamese area of Kajiado District in southwestern Kenya has solved most the water problems experienced by the local Maasai community, Agnes Loikert, a community leader from the area, told reporters.

"Rainwater harvesting has helped women and children a lot," said Loikert, adding that women used to walk up to 10 km every day in search of water, leaving their school-going children unattended, before the mini-reservoirs [earth pans] to conserve rainwater were installed at Kisamese village. Women now had more time to engage in other economic activities, she added.

The Kisamese project has the capacity to store more than a million litres of water, some of which the community was using to irrigate small vegetable gardens, thus enhancing the community's food security.

"In the popular mind, Africa is seen as a dry continent," said Dennis Garrity, Director-General of ICRAF. "But overall, it actually has more water resources per capita than Europe. However, much of Africa's rain comes in bursts and is rapidly swept away or is never collected. The time has come to realise the great potential for greatly enhancing drinking water supplies and smallholder agriculture production by harvesting more of the rainwater when and where it falls," he said in a statement.

According to the study, Kenya, whose current population is estimated at about 33 million people, had enough rainfall to supply the water needs of six to seven times that number.

Ethiopia, where only a fifth of its estimated 77 million people is connected to the domestic water-supply system and an estimated 46 percent of the population experience frequent food shortages, has the potential rainwater harvesting capacity to meet the needs of more than 520 million people.

About a third of Africa is considered suitable for rainwater harvesting using 200mm of rainfall a year as the threshold, according to the study.

Ethiopia, for example, has rainwater harvesting potential of 11,800 cubic metres per person compared with annual renewable - river and groundwater - supplies of about 1,600 cubic metres.

Kenya has rainwater harvesting capacity of 12,300 cubic metres against its annual renewable water availability of just over 600 cubic metres. The country's capital, Nairobi, has the capacity to provide for the water needs of a population of 6-10 million, supplying each one with 60 litres a day if rainwater were efficiently harvested, the study noted.

The current population of Nairobi is estimated at 3 million, with only 21,000 people served by the city's existing water system.

With rainwater tapping, the Ugandan capital of Kampala, would be able to provide adequate drinking water for between 3.5 and 5.5 million people, each one receiving 60 cubic metres daily.

"Large-scale infrastructure can often bypass the needs of poor and dispersed populations," said Steiner. "Widely deployed rainwater harvesting can act as a buffer against drought events for these people while also significantly supplementing supplies in cities and areas connected to the water grid," he added, urging African governments and international aid donors to put more resources into rainwater harvesting projects on the continent.