Low cost underground tanks feed livestock and crops

Extension officers working with farmers in Bulanda area of Western Kenya are channeling water from the surface of large rocks that are a common phenomenon in the area into small underground tanks which has assisted them irrigate their farms and feed their livestock at a time when water supply or lack of it has stood in the way of farmers' high yields.

This comes as government heightens its call for water harvesting techniques which it says remains the only affordable and long term solution to the perennial water shortage and drought that has beset the country. The extension officers look for rock outcroppings that are relatively large and flat, and which are nearw a steep incline that would allow water to easily run off to a collection point. Lines of bricks or stones are then built to direct the water downwards. This directs the rainwater runoff into the tank and helps to speed up the water collection.

Two underground tanks have already been built using contributions from members of farmer groups in the area. The tanks are made of chicken wire mesh and cement, and are oval in shape. They are about two and a half metres long, two and a half metres wide, and from four and one half to six metres deep and are lined with plastic sheets with their floor and walls should be cemented.

The water channel walls are made of bricks with cement applied to them to protect them from wearing out from contact with water, with the top being covered with wood and iron sheets to protect the water from contamination by foreign matters. “For the six months we have been doing this, we have seen tremendous improvement especially in the farming of horticultural produces in the area which traditionally was missing.

This has meant that, since fresh produce are not produced here, the demand is high which is seeing farmers in the area pocket a lot,”said Agatha Nelima, an extension officer working with the farmers. Indeed the price of a kilo of carrots which is usually shipped from neighbouring district is now going for Sh120, which has lifted the fortunes of the farmers.

The extension officer also hails the rock channeled water as highly nutritious to crops. According to Nelima minerals from the rocks are captured in the water and ultimately used by plants. “Water from rock outcroppings will also improve soil conditions, since more rock particles will be broken down and made available for plant growth,”she added.

A small tank that holds about 1000 litres is enough to irrigate at least an acre of land and can last for upto three months. “We have a lot of underground water to tap into but the problem is availability of tanks. We want to marshal funds so that we can ensure that at least each farmer has a small tank connected to their farms because right now we are only sharing the tanks among ourselves,”says Athanus Murumba one of the farmers in the project who is actively into spinach and tomato farming and who has found a huge market in local supermarkets and schools in the area.

The farmers have now set a target to have the over 60 members own an underground tank by end of the year. There has been numerous reports actively campaigning for retail water harvesting methods like the rock water harvesting as the only way out of food insecurity in Kenya and Africa. According to the United Nations Environmental Programme, across Africa the ongoing water crisis has been exacerbated by the low investment in water projects, even where water resources are plentiful. A UNEP report in November 2006 showed Kenya wouldn’t even rank as water stressed if rain water harvesting became commonplace.

Nairobi, alone, could support six to ten million people with 60 litres a day if rain water harvesting techniques were implemented, reported the organisation, with the supply potential of the city running at 460,000 cubic metres - but only 50 per cent of that currently reaching consumers.