The moment the drill rig completes the borehole is not the moment you have running water. It is, however, the moment the second phase of the project begins — and for many property owners, this phase is less well understood than the drilling itself.
Drilling creates the hole. Everything that comes after drilling turns that hole into a functioning water supply. The steps between drill completion and water flowing from a tap include borehole development, yield testing, pump selection and installation, rising main and wellhead construction, overhead tank installation, surface reticulation pipework, pump control panel wiring, and system commissioning. Each step depends on the one before it.
This guide walks through every step in sequence — what happens, why it matters, and what you should expect at each stage of the process.
Drilling Is Just the First Step
A completed borehole at the end of drilling is a hole in the ground. It has a casing (steel or PVC) installed through the unstable upper section to prevent collapse, and it has penetrated the water-bearing formation that was targeted. Water will have entered the borehole from the aquifer fractures intersected during drilling, and in most cases a column of water is now sitting in the lower section of the casing.
But this raw borehole is not yet a water supply. The water in it is mixed with drilling fines — rock particles, clay, and dust produced by the percussion drilling process. The borehole walls in the water-bearing zone need to be developed (cleaned and opened up) before a permanent pump can be installed. The yield of the borehole — how much water it can sustainably produce — needs to be measured, because the pump must be selected to match that yield precisely. Only once yield is known can the right pump be specified, ordered, and installed.
The sequence is non-negotiable. Installing a pump before development and yield testing wastes one of the most significant components in the system on an undeveloped borehole.
Borehole Development
Borehole development is the process of cleaning the borehole and improving its connection to the surrounding aquifer. During rotary percussion drilling, fine rock particles and clay are circulated out of the hole by compressed air — but not all of them leave. Fines accumulate around the borehole wall and in the fractures that constitute the aquifer. If left in place, they reduce the flow of water into the borehole and cause a submersible pump to draw fine sand, which damages the pump's impellers and shortens its life significantly.
Development uses one of two primary techniques: airlifting or jetting. In airlifting, compressed air is injected into the borehole through a tube to create a vigorous surging action in the water column — this breaks up sediment deposits and lifts fines to the surface. Jetting uses a high-pressure water jet directed at the casing perforations and aquifer zone to flush fines outward. The borehole is considered developed when the water coming to the surface is consistently clear, with no visible sediment load. Development may take a few hours to a full day depending on the formation.
Yield Testing
Yield testing determines how much water the borehole can sustainably produce — the key number that drives every subsequent decision about pump selection, tank sizing, and daily water budget.
A basic yield test uses an airlift pump or a test pump to pump the borehole at a known rate while measuring the water level inside the casing at regular intervals. The test continues until the water level stabilises (reaches a dynamic equilibrium) at a constant pumping rate, or until the water level drops to a minimum safe pumping depth. The stabilised pumping rate at the stabilised water level is the sustainable yield of the borehole.
The yield result determines the pump model: a pump rated above the borehole's sustainable yield will eventually pump the borehole dry, causing pump damage and aquifer stress. A pump significantly under-rated for the yield wastes the borehole's potential. The yield test is also when the rest water level (the natural standing water level before pumping) and the dynamic water level (the stabilised level during pumping) are recorded — these figures are critical for calculating the correct pump installation depth.
Pump Selection and Installation
With yield data in hand, the correct submersible pump can be specified. The pump selection is driven by three primary parameters: the yield (the pump must not exceed what the aquifer can sustain), the total dynamic head (the vertical distance from pump to surface, plus friction losses in the rising main, plus any additional pressure required at the delivery point), and the daily demand (the volume of water the property requires per day).
The pump is lowered into the borehole on the rising main, which is assembled in sections as it is lowered. The pump installation depth is set so that the pump inlet sits below the dynamic water level recorded during yield testing — typically at least 2–3 metres below the stabilised pumping level, to provide a buffer against water level fluctuations. The pump's power cable is taped to the rising main at regular intervals to prevent it from hanging free inside the casing and becoming abraded or tangled.
Rising Main and Wellhead
The rising main — the pressure pipe that connects the pump to the surface — is assembled as the pump is lowered. At the surface, the rising main exits the borehole casing through a sealed wellhead. The wellhead is a critical component: it seals the top of the casing against surface water ingress, supports the weight of the pump and rising main, and provides the connection point for the surface pipework.
A properly constructed wellhead includes a non-return valve immediately above the pump to prevent back-draining when the pump stops, a gate valve for isolation, and a pressure gauge connection. The wellhead is concreted into a small apron around the casing top to direct surface runoff away from the borehole and to prevent the casing from moving under the weight of the rising main.
Overhead Tank Installation
An overhead storage tank is the buffer between the intermittent operation of the borehole pump and the continuous demand for water on the property. The pump fills the tank when it runs; the tank supplies the property between pump cycles. Without a storage tank, the pump would need to start every time a tap is opened — a punishing duty cycle that shortens pump life significantly.
Tank sizing is based on daily demand and the pump's fill rate. A tank sized at one to two days' consumption provides a useful buffer against pump downtime for maintenance or minor faults. The tank must be elevated — either on a tower structure, a raised platform, or the roof of a suitable building — to generate gravity-fed pressure to the property below, or to serve as a low-pressure reservoir for a downstream booster pump. A float valve in the tank inlet and a float switch for pump control are installed as standard. An overflow pipe is fitted so that a stuck-open float valve does not cause the tank to overspill onto the structure below.
Reticulation
Reticulation is the pipework that carries water from the storage tank to every point of use on the property — internal plumbing, garden taps, irrigation zones, and any industrial or agricultural end-use points. See our detailed borehole reticulation guide for a full breakdown of pipe materials, pressure management, municipal bypass valves, and irrigation zone design.
At this stage, if the property has an existing municipal connection, the changeover arrangement between borehole and municipal supply is also installed — with non-return valves on each supply line and clearly labelled isolation valves to prevent cross-connection between the two sources.
Pump Control Panel
The pump control panel is the brain of the borehole water supply system. It houses the motor starter or variable speed drive, the dry-run protection relay (which shuts the pump down if it runs without water), the overcurrent protection, and the wiring connections for the float switch in the overhead tank and the flow switch in the rising main.
The panel is mounted in a weatherproof enclosure at a convenient point near the borehole or at the main electrical distribution board of the property. Wiring from the panel to the submersible pump runs down the inside of the borehole on the pump cable, which was taped to the rising main during installation. The float switch cable from the overhead tank runs to the panel through a surface conduit.
Once wired and commissioned, the panel operates the pump automatically: the pump starts when the tank level drops to the lower float switch position, and stops when the tank is full. The dry-run protection monitors the pump's electrical current draw continuously — a sudden drop in current (indicating no water load on the pump) triggers an immediate shutdown and an alarm condition. For solar-powered systems, an MPPT solar controller replaces the conventional motor starter and manages power from the solar array to the pump.
Handover and System Check
The final step before the system is handed over to the property owner is a full commissioning check. The technician runs the pump from a cold start, confirms flow at the wellhead pressure gauge, checks that water reaches the tank without leaks in the surface line, verifies that the float switch shuts the pump down correctly when the tank reaches full level, and confirms that the dry-run protection circuit responds correctly to a simulated dry-run condition.
All valves are checked for full closure and full opening, the reticulation is pressurised and checked for leaks, and if a municipal bypass is fitted, the changeover is tested in both positions. The property owner is walked through the system — the location and function of each valve, how to operate the manual override on the control panel, what the alarm condition looks and sounds like, and what to do if the system stops unexpectedly.
Everest Drilling provides a handover document recording the borehole depth, pump installation depth, yield test results, pump model and serial number, and the settings of the control panel — all the information needed for future service and maintenance.
Long-Term Maintenance: What Your Borehole Needs After Installation
A borehole system that is properly installed and correctly operated is a long-lived asset. Submersible pumps in clean, non-corrosive borehole water commonly run for five to ten years before major service is required. The borehole itself — the casing and the aquifer it draws from — is essentially permanent if not overpumped.
Ongoing maintenance is not onerous, but it is important. An annual inspection is recommended as a minimum, covering:
- Pump performance check: Measuring current draw and flow rate against the baseline figures recorded at installation. A decline in flow at constant current indicates pump wear or a partially blocked rising main. An increase in current at constant flow indicates increasing resistance — check for a blocked filter or partially closed valve.
- Wellhead inspection: Check that the wellhead seal is intact, that the casing cap is secure, and that the apron around the casing is undamaged. Surface water must not be able to enter the borehole casing.
- Control panel inspection: Check for corrosion on terminals, verify that the dry-run protection setting has not drifted, and confirm that the float switch operation is correct. Clean the panel enclosure of dust and insects.
- Filter cleaning: Clean or replace sediment filter elements in the reticulation system. Frequency depends on sand load — in boreholes that produce water with fine sand, filters may need cleaning monthly. In clean boreholes, annual cleaning is typically adequate.
- Reticulation check: Walk the pipework for any signs of leakage, joint failure, or UV degradation of exposed pipe sections.
Do not wait for a failure. A pump that is showing declining performance during an annual check can be addressed with maintenance before it fails. A pump that fails without warning — particularly on a farm or at a property with no municipal backup — leaves the property without water. Scheduled annual inspection is far less disruptive and less expensive than emergency pump extraction and replacement.
For properties without in-house maintenance capability, Everest Drilling offers annual service contracts that include all the inspection items listed above, plus pump extraction and re-installation for servicing on a fixed-term schedule.
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From Drilling to Running Water — We Handle It All
Everest Drilling manages the complete post-drilling process: development, yield testing, pump, tank, reticulation, and control panel. One team, one project, one point of contact. Contact us for a project-specific quotation.