Nakuru County is home to about 2.16 million people, according to the 2019 census by the Kenya National Bureau of Statistics (KNBS). It stretches across the Rift Valley, from Naivasha, Gilgil and Nakuru City to Njoro, Molo, Kuresoi, Rongai, Bahati and Subukia.
Nakuru is growing fast, and water has not kept up. The county itself describes Nakuru as water scarce and dependent on groundwater. That makes borehole drilling in Nakuru one of the most valuable investments for homes, farms, schools, hotels and flower farms.
But Nakuru has one big issue you must plan for from day one: fluoride. This guide explains the geology, the depths to expect, the fluoride risk and how to get safe water.
Nakuru’s Water Gap
In 2025 the county reported a daily water deficit of about 75,000 cubic metres, and said only 62.3 percent of residents had access to clean, safe drinking water, as reported by The Standard. The county bought its own drilling rig able to reach 450 metres, and plans dozens more public boreholes.
For private landowners, waiting for public supply is not a plan. A private borehole gives you control over your own water.
Understanding Nakuru Geology
Nakuru sits inside the Rift Valley, so most of the ground is volcanic. Lava flows, ash and tuffs from old volcanoes like Menengai and Longonot fill the valley.
- Water is often plentiful. Volcanic rocks can hold good water in fractures and between lava layers.
- Depths can be large. On higher ground the water table can sit far below the surface.
- Some formations are loose. Soft ash and pumice can collapse during drilling and need careful casing.
The British Geological Survey notes that boreholes in the Kabatini aquifer that supplies Nakuru are typically drilled to about 150 metres, and that volcanic aquifers in Kenya give an average of about 7.5 cubic metres per hour.
From our own work in the Molo and Kuresoi area, we have drilled past 200 metres, and as deep as 301 metres, through loose volcanic material. In those formations, drilling method, full casing and gravel packing make a big difference to how clean the water runs. Read more about why gravel matters.
The Fluoride Problem in Nakuru
Fluoride is the single biggest water quality issue in the county. A county study of 15 boreholes in Naivasha found fluoride of 2.15 to 6.5 mg per litre, and most private boreholes there exceed the safe limit, according to the Kenya News Agency. The World Health Organization guideline is 1.5 mg per litre.
The same report names Naivasha, Njoro, Nakuru Town West, Gilgil, Nakuru East and Bahati as areas with high fluoride. Too much fluoride over many years stains teeth (dental fluorosis) and can damage bones.
This does not mean you should not drill. It means you should:
- Test the water at a certified lab before drinking. See our guide to 7 essential water tests.
- Use the water freely for washing, cleaning, livestock and most irrigation.
- Fit a defluoridation or reverse osmosis system for drinking and cooking water where levels are high.
We design treatment systems based on your lab results. Our water quality results interpreter can help you read a report you already have.
Area by Area: What to Expect
| Area | Ground type | What to watch for |
|---|---|---|
| Nakuru City, Bahati, Lanet | Volcanic rocks around Menengai | Moderate to deep drilling. Fluoride testing is essential. |
| Naivasha, Maai Mahiu, Longonot | Volcanic ash and lava near the lake | Water is often available, but fluoride is high in many boreholes. |
| Gilgil | Volcanic plains | High fluoride reported. Plan for treatment. |
| Njoro, Rongai | Volcanic soils and tuffs | Fluoride reported. Depth varies with altitude. |
| Molo, Kuresoi, Elburgon | Highland volcanic soils, sometimes loose | Can be deep, past 200 m. Loose ground needs careful casing. |
| Subukia, Solai | Volcanic and escarpment ground | Depth and yield vary. A survey is key. |
Treat this table as a guide only. Your survey gives the real depth and yield for your land.
Why a Survey Comes First
A hydrogeological survey reads the ground before drilling. It shows where water bearing layers are and how deep to go. It is also required for your permit. Learn more in our guide to hydrogeological surveys.
Permits for Nakuru Boreholes
| Permit | Authority |
|---|---|
| Authorisation to drill and later a water permit | Water Resources Authority (WRA) |
| Environmental licence | NEMA |
| County approval | Nakuru County Government |
We handle these for you. See our guide to borehole permits in Kenya.
The Drilling Process Step by Step
- Survey: find the best point and depth.
- Permits: WRA, NEMA and county approvals.
- Drilling: method chosen to suit hard lava or loose ash.
- Casing and gravel pack: critical in loose formations.
- Test pumping: 24 to 72 hours to measure safe yield. See our test pumping service.
- Water test and treatment: especially for fluoride.
- Pump and tank: sized to the test results. See pump installation or our solar pump systems.
How Much Does a Borehole Cost in Nakuru?
Depth is the biggest factor, followed by casing, the pump and any treatment system. Use our borehole cost calculator for a first estimate, and ask us for a quote based on your survey.
Frequently Asked Questions
How deep are boreholes in Nakuru?
Many are drilled to around 150 metres, but highland areas like Molo and Kuresoi can need 200 to 300 metres or more. Your survey gives the recommended depth.
Is Nakuru borehole water safe to drink?
Not always. Many areas have fluoride above the WHO guideline of 1.5 mg per litre. Test first, and treat drinking water where needed.
Can fluoride be removed?
Yes. Reverse osmosis and defluoridation filters can bring levels down to safe limits for drinking and cooking water.
My borehole water is dirty. What can I do?
Loose volcanic ground can push fine material into a borehole. Flushing and repairs often help. See our maintenance and repair service.
Ready to Drill Your Borehole in Nakuru?
Bonvic Drilling has worked across Kenya since 2010 and delivered over 700 boreholes, including in Nakuru County. We survey, drill, test, treat, equip and maintain. Contact us or send your location on WhatsApp.
