Rain harvesting helps farmer reap cash from greenhouse

Necessity is the mother of invention and indeed it led Andrew Waweru to develop a rainwater harvesting system on his farm.
Fed up with frequent water shortages, Mr Waweru resolved to find an alternative source since the supply he was getting from the City Council of Nairobi was not enough.

And once he adopted greenhouse farming, Mr Waweru was sure that demand for water at his Miare Farm would go up significantly.
“The idea of gutters was not a new concept to me. I grew up seeing them, especially in government houses and so it was easier for me to adopt the model,” said the retired assistant police commissioner.

Eleven years down the line, Mr Waweru is a happy farmer. He has built more than three underground and five overhead tanks each holding more than 8,000 litres of water.

Won accolades

The underground tanks that measure 15 by 15 feet wide and 10 feet deep; 12 by 30 feet wide and 12 feet deep, are constructed using cement, concrete and wire mesh.

However he used more of cement than concrete for stability. He also put up breathers to ease pressure. “The breathers prevent the surface from getting wet and also protect the tank from bursting under pressure,” he says.

Mr Waweru collects rainwater from surface runoff with the help of a drainage that he built at his gate and gutters. The water drains through underground pipes to an underground storage tank.

Using an electric pump, the water is pumped up to overhead storage tanks, which supply the main house, servant quarter and the farm.
At Miare Farm no water goes to waste.

Grey water (dirty water used for washing in the house) and the one used to clean the cowshed is directed to another storage tank where it is recycled to irrigate Napier grass. The sewage system is also modified to recharge the ground water.

“We have put bricks that separate the water that comes through allowing it to sip through the ground,” said Waweru.

The concept has saved him 95 per cent in water bill.

He often has enough water for his three greenhouses, which require a lot of water, 28 dairy cattle, Napier grass and domestic use.

“We drink the water, it’s rain water,” says the farmer who has won accolades for the initiative.

Last year, President Kibaki honoured him with an award for small scale farmers at the Agricultural Society Show. He is also a recipient of certificate of recognition from Food Agriculture Organisation under the national small-scale farmer’s competition.

Although he acknowledges the attention he receives from the Ministry of Agriculture and farmers in the East African region, he says, that initially farming was not his passion. It only crossed his mind when he was preparing for retirement from the police force.

However, Mr Waweru says that he does not regret venturing into farming, which he says anyone could engage in for a living since the monetary reward is huge.

Rainwater harvesting is the most effective way to end perennial water shortages experienced in the country. 

It is an easy and cheap method that can be implemented by greenhouse farmers who require a lot of water to irrigate their farms or any household for domestic use.

Erratic supply

“It is a simple and low-cost water supply technique that can easily be used by every household and thus reduce water and sanitation challenges experienced in Kenya,” said Mr Andrew Njogu, the principal meteorologist at the Meteorological Department.

If harvested and stored well, rainwater can be able to save households up to 60 per cent of water needed for domestic use since farmers need not to depend on treated water supplied by local authorities or companies. It could also complement tap water, whose erratic supply makes it unreliable for farming.

Although some greenhouse farmers prefer to use borehole water, rainfall is the best since it is eco-friendly.

However, farmers are yet to fully exploit the high rainfall received during the wet season.

According to the UN, Kenya ranks 21 among countries with worst portable water access in the world indicating the depth of water insufficiency in the country. Schools are worst hit with 70 per cent without tap water supply.

To alleviate the shortage of water, companies and stakeholders have come out to support communities to take advantage of the heavy rain expected this season. 

Coca Cola Company, for instance, convened a two-day symposium at the National Museums of Kenya, Nairobi, last week to encourage water harvesting practice in Kenya. 

The company has committed $30million for water projects in the next five years and would work with relevant government ministries to implement it.

“We have initiated discussions with the Ministry of Education so that they can help us identify schools where we can set up model rainwater harvesting centres,” said Norah Odwesso public affairs and communications director at Coca-Cola Central, West and East Africa.

“We appeal to like-minded entities to join us and support setting up model schools in every county in Kenya. This is not a goal we can achieve on our own.”

Prof Bancy Mati, the director of Water Research and Resource Centre at Jomo Kenyatta University of Agriculture and Technology, who attended the session, said that at harvesting at least 15 per cent of rainwater annually could see water secure Kenya.

The National Museum of Kenya is another institution that has adopted rain water harvesting model.

The institution has three underground water tanks and uses it to water its botanical garden, among other needs.

The Meteorological Department has predicted heavy rains this year and with good water harvesting strategies and storage, the rainwater would be useful in irrigating farms during the dry season.

esituma@ke.nationmedia.com