Space is limited on many UAE properties, but reliable water storage remains essential for villas, residential buildings and commercial facilities. An underground water tank UAE property owners choose can provide sufficient storage without occupying valuable garden, parking or rooftop space. It also helps protect stored water from direct sunlight and extreme outdoor temperatures.
Choosing the right tank involves more than selecting a capacity. Material, groundwater conditions, soil stability, surface loads and installation quality all affect performance and durability. This guide explains the different tank types, how to choose the right size, installation requirements, maintenance practices and the factors that influence costs in the UAE.
Need an underground water tank for your property? Contact Polycom for a suitable storage solution and a free quote.
What Is an Underground Water Tank?
Underground Water Tank is the water tank that is installed under the ground level for storage purposes for domestic, commercial, or industrial use. It may be used for storing potable water for household use or water for irrigation, cleaning and other non-potable uses, depending on the design.
How It Works
The water enters the tank via an inlet pipe and is stored until it is needed. A transfer pump/booster pump is used to pump water into the building’s plumbing system when necessary. Safe operation and easy maintenance are provided by an appropriate outlet, overflow and vent lines and an accessible manhole cover.
In the case of newer underground tanks, the material is polyethylene and often the tank is seamless, meaning that there are no joints in the tank body and is created using a technique called seamless rotational moulding that produces a durable, leak-resistant tank. The tank, however, should be engineered with the specific application of being buried in the ground; regular above-ground tanks might not be able to support the pressure of the surrounding soil.
Where Underground Tanks Are Used
Typical uses include villas, apartment buildings, hotels, commercial buildings, factories, landscaping and agricultural buildings. It is especially useful to have a tank beneath the house for the villas if they require room for parking or gardens or for recreational use.
Underground Water Tank Types: Polyethylene vs GRP vs Concrete
Selecting the right material depends on the required storage capacity, installation conditions, budget and maintenance expectations.
Underground Polyethylene Tanks
Underground polyethylene tanks are manufactured from durable plastic and are available in different capacities and configurations. Quality underground plastic tanks designed for burial can offer corrosion resistance, relatively low weight and straightforward transportation.
If the tank is approved for potable water storage and meets applicable requirements, food-grade polyethylene is suitable for potable water storage. They can be made with seamless rotational moulding processes, which also minimize the chances of leakage at body joints.
But not all plastic tanks will work underground. The purchaser is responsible for verifying that the product is designed for burial including the indicated backfill procedure, groundwater conditions and loads on the surface.
Explore Polycom’s polyethylene underground water tank solutions to understand the available options.
GRP Underground Tanks
Glass-reinforced plastic (GRP) tanks are made by mixing resin with reinforcing glass fibres. These can be produced in larger capacities and in modular sizes to suit selected commercial and industrial applications.
The structural design, installation support and external pressure protection of the GRP system are needed. Verify from the manufacturer the suitability of a specific model to be used for direct burial.
Concrete Tanks
For large capacity storage and projects that demand great structural strength, concrete tanks are typically used. They can be built or fabricated off-site (precast) to suit project requirements.
However, waterproofing and crack control and structural engineering are necessary for concrete tanks. Installation may require more time for construction, may require more heavy equipment including civil works.
Comparison Table
Feature | Polyethylene | GRP | Concrete |
Weight | Relatively light | Relatively light | Heavy |
Corrosion resistance | Generally high | Generally high | Depends on concrete quality and protection |
Installation | Often quicker | Depends on system design | Usually more construction-intensive |
Capacity | Model-dependent | Often available in large configurations | Suitable for large capacities |
Maintenance | Generally straightforward | Requires inspection | Requires inspection for cracks and leakage |
Key consideration | Burial suitability | Structural design | Waterproofing and structural integrity |
The best choice depends on the site and application rather than material alone.
How to Choose the Right Capacity
The right selection of water storage capacity ensures the avoidance of water shortage and unnecessary installation costs. Take into account the number of people using this, how much water they use each day, availability of supply, and space for installation.
Villas
If it’s a residential property, estimate the daily water usage and calculate the number of days of water backup that is needed. One family of four might require a different size as compared to a family of ten in a bigger villa with a garden, swimming pool or other household needs.
One example is that if a household consumes 150 litres per person per day, four people will consume about 600 litres per day. Assuming no other consumption, no reserve or no disruptions in supply, it would take three days of storage to be 1,800 litres.
This is only an initial calculation. Consumption is variable and the final capacity should be based on local supply/demand and household needs.
Other factors to take into account when choosing an underground tank for a villa are the space available for excavation, the depth of the ground water and access for installation and ongoing maintenance.
Buildings and Industrial Sites
Typically a more detailed demand assessment is required for apartment complexes, hotels and industrial facilities. Capacity can be greatly affected by occupancy, operating hours, production processes, fire-safety requirements and peak consumption.
The storage needs should be determined by engineers following the relevant building codes and project specifications. Separate tanks may be necessary for potable water, process water and fire-water reserves.
Underground Water Tank Installation Process
Correct buried water tank installation is essential to prevent deformation, leakage and premature failure. Always follow the tank manufacturer’s installation instructions and obtain engineering advice where site conditions require it.
Excavation and Base Preparation
The installation team first evaluates the underground utilities, soil conditions, and groundwater levels and safety for digging. Excavation should be sufficient to allow for foundation and cover, and for adequate clearance around the tank.
A stable level base is then prepared, following manufacturer’s instructions. This could include either compacted granular material or a concrete base that has been specially engineered to the site.
Sharp stones and uneven support that might result in concentrated loads should be avoided from the tank.
Placement and Backfilling
The tank is carefully lowered using appropriate lifting gear. Must be properly aligned and checked prior to re-filling of surrounding space.
Backfilling material, sequence of placement and compaction should be in accord with the manufacturer’s requirements. Too high a compaction pressure or the wrong material can cause damage to the tank.
Tanks with some designs need to be filled with water during backfilling to counteract the internal and external pressures. This procedure must only be followed when specified by the manufacturer.
The installation must also consider the depth to be buried, the ground water conditions and the expected loading on the surface.
Pump and Piping Connection
Once installed, the installer makes the inlet, outlet, overflow and vent lines connections. A float switch may be used to supervise the operation of a pump or give a low water indication and high water indication, and a transfer pump can be used to pump the stored water to the destination.
The correct sizing of the pump for the flow rate and delivery head should be used. Electrical components should be installed in a safe manner, properly shielded from moisture.
The right fit of the manhole cover allows access for inspection and cleaning and helps to prevent unauthorised access and contamination. Installer should check connections, test pump, and test tank filling and draining prior to system commissioning.
Soil, Groundwater and Load Considerations
Underground conditions are particularly important in the UAE, where sites can differ in soil composition, groundwater levels and construction requirements.
High Groundwater and Buoyancy
Can an underground tank be installed in high groundwater areas? Yes, but the tank and installation system must be specifically designed for those conditions.
If the tank is empty and the groundwater rises around the tank, buoyancy can cause the tank to be pushed up or damage it. This risk is even more pronounced in light weight underground polyethylene tanks.
An anchoring system of some type, a reinforced concrete slab or other acceptable system may be necessary depending on the site. Excessive groundwater might also need to be controlled during excavation.
Before work is done, the buoyancy, groundwater pressure and manufacturer’s installation limits should be evaluated by a qualified engineer.
Soil Type and Surface Load
Clay, loose sand, rocky ground and poorly compacted fill behave differently under pressure. The soil type affects excavation stability, drainage, foundation design and the pressure acting on the tank walls.
Surface load is equally important. A tank beneath a garden may face different loading conditions from one beneath a driveway or parking area. Vehicle traffic must never be allowed over a tank unless its design and the complete installation system are approved for that load.
Underground Water Tank Maintenance Tips
Regular maintenance protects water quality and helps identify problems before they become expensive repairs.
- Clean the tank periodically: Inspect and clean it according to water quality, usage and local requirements. Annual inspection is a useful starting point, but cleaning frequency should reflect actual conditions.
- Check for sediment: Remove accumulated sediment and inspect for unusual colour, odour or visible contamination.
- Inspect the cover: Ensure the manhole cover fits securely and prevents dirt, insects and debris from entering.
- Check pipes and pumps: Look for leaks, damaged connections, unusual pump noise and changes in water pressure.
- Test float switches: Confirm that automatic pump controls and water-level indicators operate correctly.
- Inspect overflow and vent lines: Keep them unobstructed and protected against contamination.
- Maintain potable water hygiene: Use suitable disinfection and cleaning procedures when required, particularly after repairs or suspected contamination.
Never enter an underground tank without appropriate confined-space safety procedures. Inspection and cleaning should be handled by trained personnel.
How to Choose an Underground Water Tank Supplier
A reliable supplier should offer more than a tank at a competitive price. Before purchasing, consider the following factors:
- Burial suitability: Confirm that the specific model is designed for underground installation.
- Material quality: Ask about material specifications, potable-water certification where applicable, and manufacturing standards.
- Capacity options: Choose a supplier with options suited to residential, commercial and industrial requirements.
- Installation guidance: Check whether technical documentation covers excavation, base preparation, backfilling and groundwater conditions.
- Warranty and support: Review warranty terms, exclusions and after-sales service.
- Transparent pricing: Request an itemised quotation covering the tank, delivery, excavation, installation and accessories.
Polycom offers water storage solutions for different applications. Compare the polyethylene underground water tank range with vertical water tanks and horizontal water tanks to identify a suitable option for your property.
FAQ
A quality underground plastic tank can last for many years, depending on its material, design, installation and maintenance. Actual service life varies by model and site conditions, so check the manufacturer’s warranty and expected lifespan.
Burial depth depends on the tank design, soil conditions, required cover and surface loads. Follow the manufacturer’s specifications and applicable engineering requirements rather than using a universal depth.
Yes, provided the tank and installation are designed for the groundwater conditions. Buoyancy calculations and engineered anchoring may be necessary to prevent the tank from floating or shifting.
Yes, if it is manufactured from suitable food-grade material, certified or approved for potable water where required, and installed and maintained to prevent contamination.
Estimate daily consumption, the number of occupants and the number of days of backup storage required. Consider additional garden and household needs before selecting a capacity.
The underground tank price UAE buyers pay depends on capacity, material, design, delivery, excavation, groundwater protection and installation. Request a quotation based on your specific site and requirements.
Get a Quote for an Underground Water Tank in UAE
The right underground water storage UAE solution combines suitable capacity, durable materials, correct installation and reliable maintenance. Whether you need storage for a private villa, a residential building or a commercial facility, assessing the site before purchasing helps avoid costly installation problems.
Contact Polycom to discuss your requirements, compare available tank options and receive a tailored quotation.
Get a free quote today through Polycom’s phone or WhatsApp contact options.
