To beat rationing, why not sink a borehole?

What you need to know:

  • While still at the planning stage, you are have  to notify the local water service provider that you intend to sink a borehole within its jurisdiction. The provider will then grant you approval on condition that, in case of future water shortages, you will be obliged to supply water to your neighbours, with the service provider reimbursing you at a reasonable rate.
  • Once the drillers strike water, a test pumping is done to determine the amount of water that can be discharged from the borehole within a given period. This is to gauge the number of households that the water can serve sufficiently.

The need to ration water during dry spells calls into question the over-reliance on tap water provided by local water authorities  in most urban areas in the country. Consequently, developers and estate planners are turning to  alternative  water sources such as boreholes.

“Boreholes have become vital in many residential developments in urban areas, where they serve as a major selling point for estate developers looking for home buyers. Individual home owners have also gone a step further to sink boreholes in their compounds in order to reduce water bills and ensure constant water supply,” notes Mr Humphrey Ngeruro Kiogothe, a water engineer and MD of Eco-world Construction Ltd, a company that specialises in water works.

While sinking a borehole might be costly, is  worthwhile because a borehole can serve generations.

Mr Kiogothe notes that the process  relies  heavily on selecting a competent drilling company.

“A proficient drilling company should have in its team professionals such as a ground surveyor, a hydrogeologist, an environmental expert, a drillerand most importantly, a water-engineer to oversee the entire project. It can be frustrating to hire a driller, only to fail to hit water,” says Mr Kiogothe.

The initial phase requires a hydrogeological study, where  a hydrogeologist (an expert in water that occurs below the earth surface), together with the water engineer,  go around your property and determine the best location to sink the borehole.

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They  then perform tests to determine the nature of the rocks underground and approximate the distance to be drilled before striking water.

If they find that sinking a borehole on your land is viable, the hydrogeologist will prepare a detailed report and  submit it to the Water Resources Management Authority (WRMA). If satisfied, WRMA will issue a water abstraction permit.

While still at the planning stage, you are have  to notify the local water service provider that you intend to sink a borehole within its jurisdiction. The provider will then grant you approval on condition that, in case of future water shortages, you will be obliged to supply water to your neighbours, with the service provider reimbursing you at a reasonable rate. Mr Kiogothe observes that some people even go a step further and lay pipes from their boreholes to their neighbours’ premises. They can then provide water to their neighbours at a fee.

Before the drilling begins, an Environmental Impact Assessment (EIA) has to be prepared and submitted to the National Environment Management Authority (Nema). This, Mr Kiogothe says, should be done by a registered lead environmental expert attached to Nema.

“Drilling companies usually base their costs on how deep they have to drill before they strike water, charging their clients for every metre their machines sink into the ground,” says Mr Kiogothe, adding that since water tables vary from place to place, people living  in areas that receive heavy rainfall throughout  the year will be charged less for sinking boreholes thanks to elevated water tables.

The final drilling cost is greatly determined by the type of rocks the area.

The energy used depends on  on the hardness of the underlying rocks in the area, so if they are hard, more energy is used.

Once the drillers strike water, a test pumping is done to determine the amount of water that can be discharged from the borehole within a given period. This is to gauge the number of households that the water can serve sufficiently. The results of the test pumping are used to decide on the size, and hence the cost, of the pump that will be used to draw out the water.

“Once they have  sunk a borehole, many drilling companies do not bother checking on the quality of the water to ensure that it is safe for human consumption,” reveals Mr Kiogothe.

However, it is advisable to submit a sample of the water to a government laboratory for analysis for fluoride and other dissolved minerals whose presence in large quantities can be harmful to health, he adds.