Rainwater harvesting: cheap option but ignored

Mar 15, 2010

THE rains are back! But would it be surprising if you found someone carrying a jerrycan in search of water just after a heavy downpour? Some urban centres may even face a water crisis days after the wet season. <br>

By Sylvia Nankya

THE rains are back! But would it be surprising if you found someone carrying a jerrycan in search of water just after a heavy downpour? Some urban centres may even face a water crisis days after the wet season.

This happens because very few people look at rain water as a practical solution to water shortages.

Apart from the fact that harvesting water takes less time once the facilities are in place, it costs less than the services provided by National Water and Sewerage Corporation (NWSC).

Sarah Nalwoga, a resident of Kamwokya, says harvesting water does not make sense to her since she can access piped water at a kiosk near her home.

“I sometimes harvest water but it runs out soon and I still have to run to the kiosk,” Nalwoga adds.

Unlike Nalwoga, Nalongo Luswata, a resident of Ntinda, a Kampala suburb, is reaping from rainwater harvesting.

“I harvest water from all the buildings I have and fill my 10,000 litre tank,” she says.

“When there is a water shortage, I sell a 20-litre jerrycan at sh150. This is enough to feed my family. If we do not sell, this water can sustain us for three to four months,” Nalongo adds.

What you require
A home rainwater harvesting system usually requires:

A collection surface
Storage tank
A gutter which transports the water from the roof to the storage tank.

Because urban centres do not have any immediate alternatives to services provided by NWSC, one would think almost every dweller should take advantage of the rains.

NWSC, a utility parastatal owned by the Government, serves only 22 towns all over the country. The other towns get water from private suppliers.

But even these 22 centres are unreliable — sometimes they do not get adequate supply from the service provider which creates a need for alternatives.

The hilly parts of Kampala are often hit by water crises especially during the dry season when the Ggaba plant cannot pump enough water to meet the demand.

An official from NWSC says: “As the water reduces, the pressure in the pumps also reduces, making it difficult to push water to all the consumers.”

He notes that there is a lot of dirt at the water source. If the water is continuously pumped, there are more chances of supplying dirty water.

Are there any alternatives to piped water supply in urban centres during such times?

Florence Adongo, the commissioner for water quality management, says having another service provider in the same sector would be a contravention of the laws of Uganda.

“According to the 1995 NWSC statute; no other supplier is allowed to operate in an area where a water authority exists,” Adongo quotes.

The only option for any person not connected to the national water grid would be protected springs and rain water.

However, Adongo says it is becoming very unsafe to use rain water for human and livestock consumption in urban areas.

“With the increase in pollution, rain water in industrialised urban areas is acidic,” she adds.

Acid rain is linked to areas with many industries because of the fumes that go into the air.

Some of these fumes like sulphur dioxide are acidic. When it mixes with the rains, it forms sulphurous acid.

Adongo says it is best if the water collected is used on chores like gardening but not for consumption.

“Instead of using piped water for washing cars and cleaning, use the rain water because it subsidises the cost,” she advises.

Andrew, a farmer in Luwero, says he is always looking forward to the rainy season because it provides free water for his livestock and crops.

“I am setting up different water harvesting systems. I am tapping water from the roof into a tank, I have also constructed an underground lagoon for animal waste and I intend to use that to irrigate my garden,” he says.

“During the rainy season there is a lot of running water on the road. I am trying to set up a water reservoir to trap that water to irrigate my crops,” he adds.

Small towns elsewhere have technological options such as boreholes which may not be allowed in Kampala .

Adam Babaale, a principal economist with the local government says the Government would not encourage boreholes in large urban centres because there is a possibility that they would not provide safe water.

“In urban areas, we have sewerage systems, septic-tanks, homes which are a stand alone and you may find boreholes and sewerage systems in the same area. If the sewerage system drains in the soil then the water point gets contaminated,” Babaale adds.

Even without considering the possibility of contamination, one has to go through processes to drill a borehole.

“You have to get a no-objection letter from National Water informing us that they have failed to supply you with water,” says Jennifer Namuyangu, the state minister for water.

Benefits of rainwater harvesting Eases the strain on other water supply systems.

Ability to build or farm in areas with no other water supply.

Increased water security.

Lower water supply cost

Reduced soil erosion

Improved plant growth

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