Hope in Tapping Underground Water in Makueni
Residents of the County of Makueni have a reason to smile following promising results of a study fronted by Jomo Kenyatta University of Agriculture and Technology (JKUAT) that has revealed existence of sufficient reservoir of underground water that could be tapped to alleviate the acute water shortage in the County.
The study spearheaded by lead researcher, Stephen Kibe Nganga of JKUAT Department Civil, Construction and Environmental Engineering and titled Groundwater mapping, quality Assessment and Hydrogeophysical modelling in Makueni County, Eastern Kenya set to map out underground water potential zones, a project hoped to locate correct spots to guide the County and borehole prospectors to drill functioning wells.
Currently, incidences of abandoned dry boreholes at the County are widespread making the findings from the study handy, because of its potential to correct rampant practice of sinking unpredictable boreholes that fail to yield any water or dry up soon after commissioning.
Kibe and his team of four collaborators, Purity Kibetu, Prof. George Thumbu, Prof. George Okwadha and Prof. Maurice Nyadawa, drawn from JKUAT, Technical University of Kenya and Jaramogi Oginga Odinga University of Science and Technology respectively employed Remote sensing and Geographic Information technologies to generate the ground water potential map.
Launching the map in Makueni, County’s headquarters, Friday, August 26, 2016, at a day-long workshop attended by over 20 participants mainly water officers from the county, Nganga, summarised his findings on underground water potential zones under high, moderate and low yields categories.
High yield type of boreholes produce more than 4.2 cubic metres of water per hour with moderate and low level categories producing 3.15 and 2.1 metres cubic of water respectively. Nevertheless, the study found out that yield of the boreholes ranged between 0.1 to 24 metres cubic per hour with their depths extending from 22 to 182 metres.
The study established 39 percent of Makueni County represent the area with high ground water potential while 53 percent of the study area was classified as moderate, leaving the remaining eight percent area under low level underground water potential category.
To benefit from the project however, residents of Makueni have to wait for a longer time since the quality of the underground water according to the findings hardly passed the quality standards tests due to the presence of heavy metals mainly iron and its compounds.
‘The quality of water from these boreholes has been assessed based on known chemical and physical parameters that includes; heavy metals; iron, manganese, chlorides, and sulphates. Fluorides, nitrates, pH values, colour, turbidity, electrical conductivity were some of the physical parameters determined’ the workshop was informed.
To overcome the quality challenge Kibe and his team have developed a non-motorised system comprising of a raised platform made of locally available timber and plastic components to reduce heavy metals in underground water. Designed to increase contact time between air and water, in a water to air process, the system, fabricated and currently tested at JKUAT, has produced encouraging results, to the extent that the platform reduced excess Iron in water to acceptable World Health Organization standards.
Earlier, the researchers paid a courtesy visit to Prof. Kivutha Kibwana, the area Governor who assured the team of his support, saying water was a major obstacle to the County development goals. Accompanied by his deputy, Hon. Adelina Mwau, the law Professor submitted that resolving the problem of water in Makueni would be a game changer in the county’s advancement outlay.
By Ogeke Araka