Borehole depths in Kibwezi, Makueni County, typically range from 80 to 200 meters, depending on local geology, aquifer location, and project needs.
Typical Depth Range
Most boreholes in Kibwezi and surrounding Makueni areas target aquifers between 80-150 meters deep to ensure reliable yields in semi-arid conditions. Shallower boreholes around 120 meters have been documented in projects like Kikumbulyu, while deeper ones up to 200 meters penetrate stronger aquifers such as A7/B2 in Mbui-Nzau sub-location. Depths vary by site-specific hydrogeological surveys, which account for hard rock layers common in the region.
Factors Influencing Depth
Geological formations in Kibwezi often require drilling through basalt and fractured basement rocks, pushing depths beyond 100 meters for sustainable water strikes. Hydro-geological surveys determine optimal depth based on expected yield, with yields improving in deeper aquifers for domestic, irrigation, or community use. County projects, like those in Katangini or Ngai Ndethya, confirm this range supports 25 cubic meters per hour or more.
Project Examples
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Katangini borehole (Kalawa Ward): Depth not specified, but part of SIVAP initiative yielding 25 m³/hour.
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Mbui-Nzau (Kibwezi West): Targeted 200m for full aquifer penetration.
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Kikumbulyu: Planned at 120 meters.
Raeli Hydro uses surveys to recommend precise depths, ensuring cost-effective drilling from KES 3,000-5,000 per meter.