3,000 Gallon Underground
Below-Ground Cistern
AED 3,200
3.20m × 2.30m × 2.20m · Soil load rated
Below Ground · Protected Storage
Water Stored Safe
Underground & Secure.
Buried GRP water tanks protect storage from sun, theft, and extreme heat. Below-ground cisterns for residential wells, commercial reserves, and rainwater harvesting across the UAE.
Soil pressure rated
Water-tight seals
3,000–15,000 gallon
Why Underground Storage
Below-Ground Protection & Stability
Buried tanks stay cool, stay hidden, and stay protected. No sun damage, no temperature swings, no visibility from street.
Natural Cooling
Soil acts as insulation. Underground water stays 15–20°C cooler than surface heat in summer.
Protected Storage
Shielded from UV, vandalism, and contamination. Water stays clean and uncontaminated below ground.
Consistent Temperature
Year-round thermal stability. Water doesn't freeze in winter or overheat in summer peak.
| Feature | Rooftop Tank | Underground Tank |
|---|---|---|
| Summer Water Temp (Ambient 50°C) | 40–45°C | 20–25°C |
| Winter Minimum Temperature | 5–8°C (risk of freeze) | 12–15°C (safe) |
| Daily Temp Fluctuation | 15–20°C | 2–4°C |
| UV Exposure | Direct sun all day | Zero UV damage |
| Theft Risk | Visible, accessible | Hidden from view |
| Algae Growth | Light promotes growth | No light = no algae |
| Installation Complexity | Simple crane placement | Excavation required |
| Typical Burial Depth | — | 1–3 meters |
Real Applications
Underground Tanks In Practice
Residential Homes
Home owners bury cisterns for groundwater storage or rainwater harvesting. Underground placement frees roof space and keeps water cool year-round.
Fire Reserve Storage
Civil Defence UAE requires fire suppression water. Underground tanks ensure water remains usable in winter and protected year-round.
Rainwater Harvesting
Underground cisterns collect roof runoff without evaporation loss. Buried tanks stay cooler and protected for year-round use during dry spells.
Commercial Facilities
Hotels, offices, and malls use underground reserves for backup water supply. Hidden storage doesn't interfere with building aesthetics.
Industrial Plants
Manufacturing facilities bury tanks for process water. Underground placement keeps supply temperature consistent for production needs.
Groundwater Wells
Underground tanks collect water from deep wells. Below-ground storage keeps borehole water clean and prevents evaporation during storage.
Burial & Installation
How Underground Tanks Are Installed
Pre-Installation Site Prep
1
Survey site. Locate underground services (pipes, cables, foundations).
2
Excavate pit to tank dimensions. Depth typically 1–3 meters depending on water table.
3
Check soil bearing capacity. Compact subgrade to prevent settling.
4
Lay sand base (100–150mm) for level support and drainage.
Tank Placement & Backfill
5
Lower GRP tank into pit (crane or manual for smaller sizes).
6
Connect inlet, outlet, and overflow pipes before backfilling.
7
Backfill around tank with suitable soil in 300mm lifts. Compact as you go.
8
Leave access hatch visible for maintenance and inspection.
Critical Factors
★
Groundwater level must be below tank bottom (or tank must be weighed down).
★
Soil type matters. Clay and sandy soil provide good support. Fill is less stable.
★
Tank must be pressure-tested before burial to ensure no leaks.
★
Access hatch and ventilation pipe must remain visible above ground.
Post-Installation Maintenance
A
Annual inspection. Check hatch seals, ventilation, and any signs of settling.
B
Clean filter screens and inlet strainers to prevent silt buildup.
C
Check overflow and drain lines for blockage. Clear as needed.
D
Pressure-test every 5 years to ensure seals are holding.
Technical Specs
Underground Tank Specifications
Materials & Construction
Walls
Reinforced GRP composite
Wall Thickness
4–6mm (extra strength)
Joints & Seals
Bonded + gasket seals
Access Hatch
Steel-framed, bolted cover
Connections
Threaded ports, corrosion-proof
Water Quality & Safety
Potable Water Safe
NSF/WRAS certified
Burial Standard
BS EN 13280
Pressure Test
1.5× working pressure
Max Operating Pressure
0.5–2.5 bar
Temperature Range
0°C to 60°C
Soil Load & Installation
Soil Load Rated
Up to 30 kPa bearing
Burial Depth
1–3 meters
Ground Clearance (Min)
0.5m above tank top
Groundwater Limit
Below tank bottom (or weighted)
Suitable Soils
Clay, sand, loam, gravel
Longevity & Durability
Design Lifespan
25–30 years
Standard Warranty
10 years
UV Exposure
Zero (protected underground)
Corrosion Risk
Very low (GRP is inert)
Maintenance Interval
Annual inspection
Pricing
Underground Tank Price List
Tank prices shown are ex-works. Excavation, installation, and backfill quoted based on site conditions and soil type.
5,000 Gallon Underground
Below-Ground Cistern
AED 5,100
5.20m × 2.50m × 2.50m · Soil load rated
8,000 Gallon Underground
Below-Ground Cistern
AED 7,600
7.00m × 2.20m × 2.20m · Soil load rated
10,000 Gallon Underground
Below-Ground Cistern
AED 10,200
7.50m × 2.80m × 2.80m · Soil load rated
15,000 Gallon Underground
Below-Ground Cistern
AED 15,800
10.00m × 2.50m × 2.50m · Soil load rated
Custom Size
Bespoke Underground Tank
Call
Any capacity · Site survey required for soil engineering
Note: Tank prices exclude excavation, installation, and site backfill. We provide free site survey and installation quote based on soil conditions and access.
Frequently Asked
Underground Tank FAQs
If groundwater is high, the tank floats upward. Our installer checks the water table before burial. If it's above safe level, we either deepen the excavation, or weight the tank with concrete ballast and anchor it to prevent floating.
Every underground tank has a bolted steel access hatch at ground level. We keep the hatch location marked. You can open it annually to inspect seals, clean inlet screens, and check for any silt or debris buildup. The hatch is large enough for a person to enter if needed for deep cleaning.
Not in normal conditions. Our underground GRP tanks are designed for soil loads up to 30 kPa bearing capacity. We properly compact soil in layers as we backfill. In poor soil or with inadequate compaction, settling can stress seams. That's why proper installation and annual hatch inspections are critical.
Concrete tanks are heavier and require thicker walls for durability. They last 20–25 years before needing recoating. GRP is lighter, corrosion-proof, and lasts 25–30 years without recoating. GRP tanks cost less upfront and are easier to install. Concrete is stronger in severe soil conditions but more expensive to replace.
Not recommended. While underground tanks handle soil loads, vehicles add dynamic stress. If you need vehicle access, we can install a reinforced concrete pad above the tank or place the tank deeper. Tell us during site survey if this is a concern.
Excavation and backfill depend on tank size and soil type. Small tanks (3,000 gallon): 3–5 days. Large tanks (15,000 gallon): 7–10 days. We coordinate with your excavation contractor. Once the pit is ready, the tank itself assembles quickly and is pressure-tested before backfilling.
Yes. Underground tanks are ideal for rainwater. They stay cool, protected from light (no algae), and prevent evaporation during dry months. You'll need inlet filtration and regular cleaning, but the underground location is perfect for long-term harvesting systems.