Introduction: Estimating Borehole Costs in Tanzania
For anyone constructing residential or commercial properties in Tanzania, securing an independent and reliable water source is a critical preliminary step. Relying solely on municipal water (DAWASA/AUWSA) can be risky due to rationing. Under the category of Gharama za Ujenzi Tanzania (Construction Costs in Tanzania), drilling a deep water well (borehole) is a significant capital expenditure that requires careful planning.
Direct Cost Estimate: Generally, the cost of drilling a fully functional deep well (80m – 120m) in Tanzania ranges between TZS 7.5 Million ($3,000) and TZS 16 Million ($6,400). This variance depends heavily on the geological formation (coastal sand vs. inland rock), the drilling technology used, and the quality of the pump installed.
As a Senior Quantity Surveyor, I have prepared this detailed breakdown to help Diaspora investors, expatriates, and locals understand exactly where the money goes, ensuring you get value for money and avoid exploitation by middlemen ("Vishoka").
1. Preliminaries and Legal Permits
Before any heavy machinery touches the ground, technical and legal due diligence is mandatory. Ignoring these steps can lead to dry holes or government fines.
- Hydrogeological Survey: A qualified surveyor uses resistivometers to map underground aquifers. This scientific approach minimizes the risk of drilling a dry hole.
- Cost: TZS 300,000 – 500,000 ($120 - $200).
- Water Basin Permit: All water resources in Tanzania are managed by Basin Water Boards (e.g., Wami/Ruvu Basin). You must pay an application fee and a drilling fee.
- Estimated Fees: TZS 150,000 – 250,000 ($60 - $100).
2. Drilling Costs Breakdown
Drilling contractors in Tanzania typically charge per meter. This rate covers the rig operation, fuel, labor, and drill bits.
| Drilling Method | Application | Cost per Meter (TZS) |
|---|---|---|
| Mud Rotary Drilling | Used in sedimentary/soft formations (Dar es Salaam, Coastal Region). Uses bentonite clay to stabilize walls. | 70,000 - 90,000 ($28 - $36) |
| DTH (Down-The-Hole) Hammer | Used for hard rock formations (Dodoma, Arusha, Mwanza). Uses compressed air to fracture rock. | 90,000 - 150,000 ($36 - $60) |
QS Note: Always clarify if the "per meter" price includes casings. Usually, it is charged separately or as a "completed well" package.
3. Material Specifications and Costs
The longevity of your borehole depends on the quality of materials buried underground. Using substandard PVC casings is the leading cause of well collapse in Tanzania.
| Material Item | Unit | Approx. Qty (100m Well) | Unit Price (TZS) | Total (TZS) |
|---|---|---|---|---|
| UPVC Casings 6" (Class B/9) | Pcs (3m) | 34 | 45,000 | 1,530,000 |
| UPVC Screen Pipes (Slotted) | Pcs (3m) | 8 | 55,000 | 440,000 |
| Silica Gravel Pack | Tons | 4 | 120,000 | 480,000 |
| Surface Casing (Steel) | Pc | 1 | 150,000 | 150,000 |
| Cement & Sanitary Seal | LS | - | 100,000 | 100,000 |
| MATERIAL SUBTOTAL | ~2,700,000 |
4. Pump Installation and Plumbing
Once the hole is drilled and cased, you need to extract the water. The choice of pump depends on the Dynamic Head (depth + lift to tank) and the Yield (m3/hr).
- Submersible Pump: Leading brands in Tanzania include Grundfos, Dayliff, and Pedrollo. Avoid cheap generic brands as retrieving a failed pump from 100m deep is costly.
- Budget: TZS 850,000 - 1,500,000 ($340 - $600) for a 1.5HP unit.
- Riser Pipes (HDPE): High-density polyethylene pipes are preferred over steel GI pipes which rust.
- Cost: ~TZS 500,000 for 100m of Class 12 pipe.
- Submersible Cable: Waterproof electrical cable (4-core) is essential.
- Cost: TZS 800,000 for 100m (approx TZS 8,000/meter).
- Control Panel & Automation: Protects the pump from voltage fluctuations (common in Tanzania).
- Cost: ~TZS 350,000.
5. The Step-by-Step Construction Process
To verify you are getting what you pay for, monitor these stages:
- Mobilization: The rig arrives. Ensure access roads are clear. In rainy seasons, heavy rigs may get stuck, incurring recovery costs.
- Drilling: The noisy part. The operator monitors cutting samples to identify water-bearing layers (aquifers).
- Casing & Gravel Packing: Pipes are lowered. The space between the pipe and the earth is filled with gravel. This is crucial—it acts as a filter. If skipped, your water will always be muddy.
- Well Development: High-pressure air or water is injected to clear the mud and open up the aquifer veins. This should run until water is crystal clear.
- Pump Testing: A test pump is installed to determine the well's capacity. Do not skip this; it dictates which permanent pump you should buy.
- Lab Analysis: A sample is sent to government labs (e.g., Mkemia Mkuu) to test for fluoride, salinity, and bacteria.
6. Factors Affecting Your Budget
- Geography: Drilling in the rocky terrain of Mbezi Beach or Bunju is more expensive than the sandy soil of Kigamboni.
- Depth: Costs are linear. A 150m well costs significantly more than an 80m well due to extra drilling time, casings, cables, and pipes.
- Finishing: Constructing a steel tower (3m - 6m high) and installing 2,000L - 5,000L tanks (Simtank/Kiboko) adds roughly TZS 3 Million ($1,200) to the project.
7. Summary Budget Table (100m Deep Well)
| Cost Item | Estimated Cost (TZS) | Estimated Cost (USD) |
|---|---|---|
| Survey & Permits | 600,000 | $240 |
| Drilling (Labor & Rig) | 8,000,000 | $3,200 |
| Borehole Materials (Casings/Gravel) | 2,700,000 | $1,080 |
| Pump System (Pump, Cable, Pipes) | 2,500,000 | $1,000 |
| Testing & Lab | 200,000 | $80 |
| GRAND TOTAL | 14,000,000 | ~$5,600 |
Conclusion
Drilling a borehole in Tanzania is a complex engineering task, not just a hole in the ground. As a Quantity Surveyor, I advise clients to focus on the Total Lifecycle Cost. Saving TZS 500,000 on cheap casings today can cost you TZS 10,000,000 in repairs when the well collapses next year. Always sign a contract that specifies "Wet Hole" vs. "Dry Hole" payment terms to protect your investment.
Frequently Asked Questions (FAQs)
1. What happens if the driller finds no water?
This is called a "Dry Hole." Policies vary, but typically you still pay for mobilization and fuel/labor (about 50-60% of the total cost), but you do not pay for casings or the pump. This is why a hydrogeological survey is non-negotiable.
2. How long does the drilling process take?
In soft soil (Mud drilling), a 100m well can be completed in 3-4 days. In hard rock (Hammer drilling), it might take 2-5 days depending on the rock hardness. Pump installation takes an additional 1-2 days.
3. Can I use a Solar Pump instead of an Electric Pump?
Yes. Solar pumps are excellent for remote sites or to save on electricity bills. However, the upfront cost is higher (roughly double the price of an AC pump system), and they rely on sunshine, meaning you need larger storage tanks to last through the night/cloudy days.
4. Why is the price in Dar es Salaam different from Dodoma?
Dar es Salaam generally has soft sedimentary soil requiring Mud Rotary rigs and often requires casing the entire depth to prevent collapse. Dodoma has hard granite rock; while drilling is slower and requires expensive air compressors, the rock is stable, so sometimes less casing is needed, balancing the costs.
