Groundwater Supplies On Kenya’s Coast Must Be Managed for People and Industry

Diani Beach, Kenya. Dan Rata/Shutterstock

By Nuria Ferrer Ramos

Industry is growing along Kenya’s coast, and some of these companies – such as mining and agricultural companies – are water intensive. To meet their demand, most industries are turning to groundwater.

Groundwater is a natural resource that exists beneath the earth’s surface in soil pore spaces and in the fractures of rock formations. It can be stored in, or move through, aquifers: a body of permeable rock – like gravel or sand.

Groundwater has many intrinsic advantages: it can be developed quickly (and at a relatively low cost), it’s easy to find, it’s drought resilient and can meet water needs on demand. This has made it a crucial component in rural water supply, and for industry.

The problem is, even though Kenya has policies, laws, and institutions that are specifically dedicated to managing groundwater, in practice, groundwater is treated as a common pool resource, belonging to whoever owns the land overlying the aquifer. The majority of water users ignore the potential long-term consequences of unregulated use.

This is what’s happening in Kwale county, on the southern coast of Kenya. Over half a billion US dollars in capital investment has been made in two water-reliant industries in Kwale: heavy sands mining and commercial sugarcane. In addition to this Kwale also hosts significant tourism.

Because aquifers in Kenya are not always properly managed, my colleagues and I wanted to know how increased abstraction of groundwater by industries could affect local communities that use groundwater as their main water supply.

We found that, at the moment, the new industries are not affecting the water supply for local communities. What is affecting the community wells are long drought periods, such as the last drought which lasted from 2016 to early 2017. The consequences of dry wells are that people have to walk further to get water, and water becomes more expensive to buy.

For industry, understanding investor risk and liability for groundwater sustainability would seem prudent, if not a legal obligation, before major abstraction starts.

Our research shows that groundwater resources can be significant and resilient to unpredictable but recurrent drought events, if understood and managed properly.

Sustainable use?

We focused our study on the Msambweni aquifer, located on the coast of Kwale county in Kenya. This aquifer system is composed of a shallow aquifer (about 25 metres thick) and a deep aquifer below this shallow aquifer (about 350 metres thick).

The shallow aquifer is recharged by rain through the ground surface and the deep aquifer is recharged by water that flows underground from the Shimba Hills.

The shallow aquifer is mainly exploited by the local rural communities and the hotels located near the coastline. The deep aquifer is exploited by the mining and sugar operations.

The communities rely heavily on shallow groundwater, which they get from wells or by using a handpump in a borehole, because they don’t have piped water, and water from the two main rivers in the area is not considered safe to drink. Also, in the 1980s, the Swedish International Development Agency installed hundreds of handpumps at boreholes in Kwale county.

Industries now also rely on groundwater. But they use new boreholes, equipped with electrical pumps, that reach the deep aquifer. These have higher abstraction rates than traditional dug wells or shallow boreholes equipped with handpumps.

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