Machakos County is home to about 1.42 million people, according to the 2019 census by the Kenya National Bureau of Statistics (KNBS). It covers 6,043 square kilometres of hills, plateaus and dry plains, from Kangundo and Matungulu in the north to Mavoko, Machakos Town, Kathiani, Mwala and Yatta.
Most of the county is semi arid. Rain is short and unreliable, and piped supply does not reach many homes and farms. That is why borehole drilling in Machakos is now one of the best long term investments a landowner can make.
But Machakos is also one of the harder places in Kenya to drill. The rocks are old and hard, water sits in cracks rather than in big layers, and yields vary a lot from one plot to the next. This guide explains what to expect, so you can plan your borehole with clear eyes.
Machakos Has a Real Water Problem
Machakos sits in the dry lands east of Nairobi. Rivers like the Athi and Thwake carry water through the county, but much of the land between them stays dry for months.
- Many villages rely on shallow wells, sand dams and water vendors in the dry season.
- Fast growing towns like Athi River, Syokimau, Mlolongo and Machakos Town outpace piped supply.
- Farmers in Mwala, Yatta and Kathiani lose crops when the short rains fail.
A borehole gives you water that does not depend on rain or on the county supply. To see how quickly it pays back, try our borehole savings calculator.
Understanding Machakos Geology
Most of Machakos sits on very old basement rock. These are hard gneisses and schists that formed hundreds of millions of years ago. They hold almost no water in the solid rock itself.
Instead, groundwater collects in two places:
- The weathered zone. The top layer of rock that has broken down over time. It can hold useful water when it is thick.
- Fractures and fault lines. Cracks deep in the rock where water flows. Hitting a good fracture is the key to a strong borehole.
The British Geological Survey hydrogeology summary for Kenya quotes an average yield of about 4.4 cubic metres per hour for boreholes in this type of basement rock. It rates these aquifers as low to moderate in productivity. In plain words, water is there, but you must find the right spot.
Parts of the county also have volcanic rocks, such as the plains around Athi River and the Yatta plateau. These behave differently, and water quality can change too.
What Real Data From Machakos Shows
A hydrogeological study for the Mitaboni area (Miumbuni and Misuuni) looked at 11 boreholes within about 5 kilometres. The study found:
| Measure | Range | Average |
|---|---|---|
| Borehole depth | 70 to 135 m | 95 m |
| Yield | 1.5 to 11.3 m³/hr | 4.3 m³/hr |
| Rest water level | 1.2 to 45 m | 21.5 m |
The same study warned that most of the plains had very poor groundwater potential, and that several boreholes there were dry or weak. The better results came from weathered and fractured zones along fault lines.
Depth can also be much greater in the hills. A recent hydrogeological survey we handled near Mua, in Machakos Central, recommended drilling to 320 metres, with an expected yield of 1 to 4 cubic metres per hour. Every site is different, which is why the survey matters so much here.
Area by Area: What to Expect
| Area | Main ground type | What to watch for |
|---|---|---|
| Mavoko, Athi River, Syokimau | Volcanic plains near Nairobi | Can be deep. Fluoride and salinity are common, so test the water. |
| Machakos Town, Mua, Kathiani | Hard basement rock and hills | Deep drilling is often needed to hit fractures. A good survey is vital. |
| Kangundo, Matungulu, Tala | Basement rock with weathered zones | Yields vary from plot to plot. Siting makes the difference. |
| Mwala, Masii, Mitaboni | Basement rock and tuff plains | Plains can be poor. Aim for fault lines and valleys. |
| Yatta, Matuu, Masinga | Volcanic plateau and basement rock | Water quality and depth vary. Test pumping is essential. |
Treat this table as a guide only. Your actual depth and yield come from a survey on your own land.
Why the Survey Matters Even More in Machakos
In soft sediments you can often find water almost anywhere. In Machakos you cannot. The survey uses electrical readings to find weathered zones and fractures before you spend money on drilling. Read more in our guide to hydrogeological surveys in Kenya.
- It tells you the best point to drill on your land.
- It gives a recommended depth, so you can budget properly.
- It is required for your permit application.
If you are still choosing land, our guide on surveying before you buy land explains how to check for water first.
Water Quality in Machakos
Basement rock water is often hard. Some boreholes are slightly salty, and the plains near Athi River can have high fluoride, like much of the Nairobi area.
The World Health Organization sets the fluoride guideline for drinking water at 1.5 mg per litre. Always run a full lab test before you drink borehole water. Our guide to 7 essential water tests explains what to check, and our salinity guide covers salty water.
Permits for Machakos Boreholes
| Permit | Authority |
|---|---|
| Authorisation to drill and later a water permit | Water Resources Authority (WRA) |
| Environmental licence | NEMA |
| County approval | Machakos County Government |
We handle these applications for our clients. See our full 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: usually air drilling with a down the hole hammer in hard rock.
- Casing and gravel pack: to keep the hole open and the water clean.
- Test pumping: 24 to 72 hours to measure safe yield. See our test pumping service.
- Pump and tank: sized to the test results. See pump installation.
Solar is a strong choice in Machakos, with plenty of sunshine all year. Our solar borehole pump systems remove monthly power bills.
How Much Does a Borehole Cost in Machakos?
Cost depends mostly on depth, and depth in Machakos ranges widely. Survey, permits, drilling, casing, test pumping and the pump all add up. Use our borehole cost calculator for a first estimate, then ask us for a quote based on your survey.
Frequently Asked Questions
How deep are boreholes in Machakos?
It varies a lot. Studies in the Mitaboni area found boreholes of 70 to 135 metres, while hilly areas such as Mua can need 300 metres or more. Your survey gives the recommended depth for your plot.
Is there water everywhere in Machakos?
No. Some plains have very poor groundwater. That is why siting by a qualified hydrogeologist is so important here.
Is Machakos borehole water safe to drink?
Often yes after testing, but some areas have hard, salty or high fluoride water. Always test before drinking, and treat the water if needed.
How long does drilling take?
Drilling itself usually takes a few days. The full project, including survey and permits, usually takes several weeks.
Ready to Drill Your Borehole in Machakos?
Bonvic Drilling has worked across Kenya since 2010 and delivered over 700 boreholes. We survey, drill, test, equip and maintain boreholes in every part of Machakos. Contact us, or send your location on WhatsApp.
