Galvanised Steel Water Tanks, EPDM Liners and Covers for Irrigation Storage
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Introduction
A reliable water storage reservoir is the foundation of any serious irrigation system. Whether you are storing harvested rainwater, abstracting from a borehole or watercourse, or buffering a mains supply to meet peak irrigation demand, having adequate, well-protected water storage gives you control over your irrigation programme and independence from supply variability.
IrriSmart supplies a comprehensive range of galvanised steel water tank kits, EPDM liners, covers, and accessories — from compact header tanks to large farm reservoirs holding millions of litres. This guide covers the full range and helps you choose the right tank, liner, and cover combination for your application.
Galvanised Steel Tank Kits
Our galvanised steel water tanks are cold-water storage tanks manufactured from hot-dip galvanised steel panels, supplied in kit form for straightforward on-site assembly. They are available in a wide range of sizes, from under 2,000 litres to 4.5 million litres, making them suitable for everything from a small nursery header tank to a large farm irrigation reservoir.
Key Features
- Galvanised steel construction — hot-dip galvanising provides long-term corrosion resistance in outdoor agricultural environments
- Kit form supply — panels bolt together on site, requiring a minimum of two people and no specialist equipment. No crane required for most sizes.
- Wide size range — diameters from 1.83m (9ft) to 40.55m (133ft), standard heights from 0.81m to 5.35m
- Powder coating available — tanks can be powder coated to most RAL colours for aesthetic or identification purposes
- Installation service available — on request at additional cost, for operations that prefer a fully installed solution
- Typical delivery: 2 to 3 weeks
Available Tank Sizes
Tank sizes are specified by diameter and height in feet. The standard range available from IrriSmart covers:
- 9ft x 7ft 6in
- 12ft x 7ft 6in
- 15ft x 7ft 6in & 15ft x 10ft
- 18ft x 7ft 6in & 18ft x 10ft
- 21ft x 5ft, 21ft x 7ft 6in, & 21ft x 10ft
- 24ft x 7ft 6in & 24ft x 10ft
- 30ft x 10ft 30ft x 15ft
- 36ft x 7ft 6in
- 42ft x 10ft
- 48ft x 10ft
- With Many more available on request.
Tanks are supplied as the steel structure only — a liner is required separately to make the tank watertight (see below). Custom sizes and configurations are available — contact the IrriSmart team to discuss your specific requirements.
View Steel Tank Kits and pricing
EPDM Tank Liners
Galvanised steel tanks require a liner to make them watertight and to protect the water from contact with the steel. EPDM (ethylene propylene diene monomer) rubber is the preferred liner material for irrigation water storage, offering excellent flexibility, UV resistance, and long service life.
EPDM liners are safe for potable and irrigation water storage, resistant to UV degradation, and remain flexible across a wide temperature range — important for outdoor tanks that experience significant temperature variation between summer and winter.
0.75mm EPDM Liners
The 0.75mm liner is suitable for standard irrigation water storage applications where the tank is on a prepared, smooth base and the risk of puncture from sharp objects is low. Available in all sizes.
1mm EPDM Liners
The 1mm liner provides greater puncture resistance and durability, recommended for tanks in exposed locations, tanks storing water with higher chemical concentrations, or where a longer liner service life is required. Available in all sizes.
Liners can also be supplied in butyl rubber and PVC in thicknesses from 0.75mm to 2.00mm, in plain and nylon-reinforced varieties, for specific applications. Contact IrriSmart to discuss alternative liner materials for specialist requirements.
Liner Repair Kits
Even with careful installation and maintenance, liners can occasionally be punctured or develop small tears. The liner repair kit allows minor damage to be repaired on site without the need to drain and replace the entire liner. Available in two patch sizes:
- 230mm x 250mm repair kit — for small punctures and tears
- 230mm x 500mm repair kit — for larger damage areas
Keeping a repair kit on site is strongly recommended as part of your tank maintenance kit.
Tank Covers
Covering your water storage tank is important for several reasons: it prevents algae growth by excluding light, reduces evaporation losses, keeps out debris and wildlife, and protects the water quality from contamination. IrriSmart offers two cover types to suit different requirements.
Steel Covers (Galvanised Roof)
Galvanised steel roof covers provide the most robust protection for your tank, fully enclosing the water surface from rain, debris, wildlife, and light. Steel covers are the preferred option for permanent installations where long-term water quality protection is the priority, and for tanks storing water for sensitive crops or where water quality standards must be maintained.
Available in sizes from 12ft to 36ft diameter to match the tank range.
Anti-Algae Covers (Woven PP)
The woven polypropylene anti-algae cover is a cost-effective alternative to a full steel roof. It sits over the top of the tank and blocks sufficient light to prevent algae growth, while allowing rainwater to enter the tank — making it ideal for rainwater harvesting applications where you want to collect rainfall but prevent algae proliferation.
The woven PP construction is UV stabilised for long outdoor service life, lightweight for easy handling, and available in the full range of tank sizes from 9ft to 48ft diameter.
Anti-algae covers are particularly valuable during summer when warm temperatures and high light levels create ideal conditions for algae blooms. Algae in irrigation water blocks filters and drippers rapidly and can carry plant pathogens — prevention is far more cost-effective than treatment.
Tank Take-Offs
The tank take-off is the outlet fitting that connects the tank to your irrigation supply pipework. It passes through the tank wall (or base) and provides a flanged or threaded connection for the supply pipe. Available in four sizes to suit different flow rate requirements:
- 2 inch — suitable for smaller systems and header tanks
- 3 inch — for medium flow rate supply connections
- 4 inch — for larger systems with higher flow demand
- 6 inch — for high-capacity supply connections on large farm irrigation systems
The take-off size should be matched to your peak irrigation flow rate. As a guide, a 2 inch take-off is typically suitable for systems up to approximately 15 to 20 m³/hr; a 3 inch take-off for up to 40 m³/hr; and larger sizes for higher flow rates. Contact IrriSmart for help sizing the correct take-off for your system.
Choosing the Right Tank Size
Sizing your water storage correctly is one of the most important decisions in irrigation system design. Key factors to consider:
Peak Demand Buffer
Your tank needs to hold enough water to supply your peak daily irrigation demand, plus a buffer for days when your supply source (mains, borehole, or abstraction) cannot keep up with demand. A common design target is 1 to 2 days of peak irrigation demand as the minimum storage volume.
Abstraction and Refill Rate
If you are abstracting from a watercourse or borehole with a limited licence or pump capacity, your tank needs to be large enough to accumulate water during off-peak periods (overnight, weekends) to meet peak daytime irrigation demand.
Rainwater Harvesting
For rainwater harvesting, tank size is determined by the balance between roof or catchment area, annual rainfall distribution, and irrigation demand. Larger tanks provide greater resilience against dry spells but have higher capital cost.
Practical Considerations
- Ensure the tank location has adequate ground bearing capacity for the filled weight — water weighs 1 tonne per cubic metre
- Allow access around the tank for maintenance and liner inspection
- Consider the height of the tank relative to your pump inlet — a low water level in a tall tank can cause pump cavitation if the suction lift is excessive
- Plan the inlet, outlet, overflow, and access hatch positions before ordering
Installation Tips
- Prepare a level, compacted base — concrete or compacted hardcore with a sand blinding layer is ideal. An uneven base will stress the tank panels and liner.
- Lay the liner carefully, avoiding sharp folds at corners. Warm weather makes EPDM more pliable and easier to fit.
- Install the tank take-off before filling — it is much easier to fit with the tank empty
- Fill slowly initially to allow the liner to settle and conform to the tank shape
- Fit the cover before the tank is in full use to prevent algae establishment from the outset
Accessories and Water Quality Management
To maintain water quality in your storage tank throughout the irrigation season, consider:
- Float valves — for automatic level control when filling from a mains or borehole supply. Our Hansen float valves are ideal for tank level control.
- Level indicators — for at-a-glance monitoring of water reserves. The Hansen Level Alert provides a simple visual indication without electronic sensors.
- Filtration — install a filter on the tank outlet to protect your pump and irrigation system from debris. Our Amiad Filters range includes suction and inline options suitable for tank outlets.
- Water treatment — for tanks prone to algae or pathogen issues, consider periodic treatment with hydrogen peroxide. The HPNow GoGen onsite H2O2 generator provides a safe, chemical-free treatment option.
Conclusion
A well-designed water storage system gives you control over your irrigation programme, independence from supply variability, and the capacity to meet peak crop water demand reliably. IrriSmart's range of galvanised steel tank kits, EPDM liners, covers, and accessories provides everything you need to build a professional, long-lasting irrigation reservoir.
Browse the complete Steel Tanks, Liners and Covers range online, or contact the IrriSmart team for help sizing and specifying the right storage solution for your operation. With 20+ years of irrigation experience, we can support you from initial design through to a fully operational system.