There is something called a 'dry borehole' in the parlance of drillers of underground water. The crisis should attract the curiosity of seismologists, climatologists, geologists, and hydro-physical surveyors.
One dry borehole is bad enough; two is a crisis. Four aborted attempts should attract hydro-geological curiosity, and the attention of the Water Resource Management Authority.
Curiosity is key to invention. It should also be the basis of further research into the effects of climate change.
The challenge of serial dry boreholes was raised early this year by experts, including Prof George Kroda of the University of Nairobi, Geologists Without Borders and Engineers Without Borders.
The Kenya case study was also shared with experts from the University of Hasselt, Belgium, Fresh Water School, the University of Wisconsin Milwaukee, US, and Students for Energy in Africa, which is linked to Flemish Colleges.
Water experts at the University of Wageningen, The Netherlands, are also appraised of the threat to underground water regimes in this part of Homa Bay county.
A Flemish newspaper in Belgium, Het Belang van Limburg, covered the dry borehole in its April 21 edition. There are four such boreholes in water-starved Kojwang' in West Karachuonyo.
The Flemish newspaper got interested because engineering students from the University of Hasselt participated in the search for water for Ndhole Primary School in West Karachuonyo.
The Belgian students stayed in Kanjira village for 90 days, for their post-graduate value-addition research. The study would have given 800 households clean water, from a solarised borehole in May. The expectation fell apart after a well developer hit dry boreholes four times in two schools.
A published author in underground water regimes did hydro-physical surveys. The surveyor, David Ayete, has referrals and a practice spanning 30 years, and 98 per cent success.
Doubts about the accuracy of the science of the underground water aquifers did not arise. Sparr Drilling, a well developer with referrals across East Africa, arrived on the site on March 23. Drilling, pump-testing, and well development would take seven days.
The driller would then move to Kanyamfwa Secondary School, two kilometres from Ndhole.
Another survey was recommended. There were indications the second site would yield more cubic metres of water. But the signs diminished as the wells got deeper.
Aquifers were found to have dried up. Two other boreholes – 250m and 225m – have low yields, far below recommended recharge for pumping.
A driller-recommended geologist, with national referrals, surveyed the site of the fourth borehole. He consulted widely with his peers. The driller returned in August for another try, which yielded a fourth dry borehole.
Ayete says: "I have surveyed sites in Karachuonyo having similar data. We had successful drilling. We are baffled these wells are not successful, even after repeat surveys. Any geologist would recommend drilling after reviewing the data. During the re-surveys, I consulted widely. My colleagues concurred with the findings."
The geologist says of the fourth dry borehole: "The drilling encountered a moist and fractured section at depths between 130m to 200m, which appear to be the aquifer zone of the borehole. The recharge is however slow due to the carbonaceous clogs in fractures and underlying rocks.
The rocks of Kanyamfwa area are rich in carbonate minerals and hence termed carbonatite complex. The carbonate-rich magma might have been mixed with organic sediments generating the carbonate rocks.
"The aquiferous zone of the drilled borehole should be hydrofractured to increase the permeability and transmissivity of underground water."
Hydrofracturing is a well development process that involves injecting high-pressure water via the well into the bedrock formation.
"The borehole could still be left to recharge itself, however, this would take a long time and low yield."
