KENDO: Climate change a risk to groundwater

Water Resource Authority, whose mandate includes controlling water exploration and use, is yet to respond to the growing challenge of dry boreholes. The silence worries, particularly in the age of climate change.

WRA also collects, collates and disseminates information on water. The information is critical for water allocation, water resources investment decisions, and modelling to establish a better understanding of the impact of climate change.

The authority issues site-specific permits before drilling boreholes. The authority also sets discharge threshold for investment in water wells.

WRA is yet to respond to SoS over the challenge of dry boreholes in the water-starved community of Midwest Karachuonyo. But some water experts and consumers, however, have noticed the challenge.

The challenge, Engineer Peter Mangiti says, is not confined to a location. Hydrogeology isn't an exact science even though its practitioners expect observers to believe in its exactitude.

The challenge may not be technology of water exploration. David Ayete, a referred hydro-physical surveyor with a practice spanning 30 years and 98 per cent success, says:

"The machines we use have been proven for many years and indeed boreholes drilled by the Lake Basin Development Authority since the 1980s used these machines. The boreholes dot the entire Lake Victoria region. The area may be located in a branch of Rift Valley commonly known as the Kavirodian rift where groundwater prospects may be low or deep."

The common water aquifer-detecting technology, which local hydro-physical surveyors use, is imported from India and Sweden.

Midwest Karachuonyo case study should interest geologists first before hydrological-surveyors gamble with the possibilities of hitting productive aquifers.

Mangiti, a civil engineer with a major in groundwater hydraulics, says, "However deep you drill, if there is no groundwater, you won’t find any. Hydrogeology isn’t an exact science. There are many hydrological and earth property variables that are determined through solution of partial differential equations, again with many assumptions."

'Earth property variables ... partial differential equations'? Those are loaded engineerese. Everyone reading this needs water to meet household or agricultural needs.

Because the endangered precious life-supporting liquid is a common good, consumers need information to appreciate the danger to water exploration and conservation.

Surrender, in the face of dry boreholes, is not an option in the search for water. There are operational boreholes about four kilometres from the dry boreholes of Midwest Karachuonyo.

One has been operational from 2018, serving a primary school and a community of 400 households. The major host is a boarding secondary school, with 1,500 students. Otaro Secondary School, Otaro Primary School and community have not lacked water since 2018.

"Precisely my point ... groundwater is not like a lake or any other water mass. Occurrence in viable quantities is random, governed by rock and soil formation conditions. The situation you are describing points to lens aquifer conditions and therefore the current productive boreholes are likely to dry up in the near future, unless there is a rock fissure that connects to the lake and therefore providing steady recharge.

"Let geologists do a detailed study of the rock formation before the hydrogeologists confirm drilling sites."

Prof George Krhoda, a hydrologist/water scientist at the University of Nairobi, is interested in the phenomenon. He plans to visit the sites of dry boreholes next month. One hopes the visit could trigger a special study by the relevant department of the University of Nairobi.