Water Storage for Agribusiness and Irrigation
How to size large-volume water reserves for irrigation, spraying and livestock with bolted steel tanks: advantages, data and a comparison table.
Agribusiness needs to store water in large, reliable volumes for three critical uses: irrigation, spray water (for crop protection mixes) and livestock watering. In the 500 to 20,000+ m³ range, the most efficient solution is the bolted steel tank built to AWWA D103: it is erected in weeks rather than months, delivers large reserves at a low cost per cubic meter, and can be relocated if the operation moves. This article explains how to size that reserve and what the grower gains over an earthen pond or concrete.
The sector challenge: variable inflow, concentrated demand
On a farm, water rarely arrives exactly when it is needed. A well or river intake delivers a fairly constant flow, but irrigation and spraying demand is concentrated into a few hours and short weather windows. Without a buffer reserve, the grower loses the application window or oversizes the pumping system.
Three conditions typical of Latin American agribusiness add to this:
- Seasonality: the campaign concentrates consumption; off-season the tank can serve other uses.
- Distance from the grid: many farms rely on a deep well or surface water, with no public network backup.
- Water quality: water with iron, sediment or some chemical aggressiveness demands an internal coating that will not degrade.
In Paraguay, any surface or aquifer abstraction falls under Law 3239/07 on Water Resources and, depending on scale, under Law 294/93 on Environmental Impact Assessment. It is worth verifying the water-use permit and environmental license with MADES before finalizing the project.
The Tech Tank solution: turnkey large-volume reserve
Tech Tank builds farm water reserves with bolted steel tanks in different coatings, sized to the use:
- Glass-fused-to-steel (GFS) tank, with enamel fused per ISO 28765: the first choice for water with iron, salts or abrasive sediment, because the glass does not corrode and never needs repainting.
- Epoxy tank: a lower-cost alternative for good-quality water.
- Galvanized tank: rugged, low-cost reserves for irrigation and watering.
Delivery is turnkey: sizing engineering, foundation, on-site bolted assembly and commissioning. Because it is bolted rather than welded, the tank goes up in a few weeks and, if needed, can be dismantled and relocated to another plot without losing the investment. To choose capacity, coating and accessories, see our guide on how to size a water storage tank.
How to size the reserve
The starting point is the daily peak demand per hectare and the number of days of autonomy you want to cover. A rule-of-thumb method:
- Estimate the required irrigation depth (mm/day) and multiply by the area: 1 mm over 1 ha equals 10 m³.
- Set the autonomy (days the reserve must cover without recharge, typically 1 to 3 days).
- Add the spray water demand and livestock watering if they share the reserve.
- Add a safety margin of 10-20% for evaporation and peaks.
Illustrative example: a center pivot irrigating 50 ha at a peak depth of 6 mm/day demands on the order of 3,000 m³/day. With 1 day of autonomy and a 15% margin, the reserve is around 3,450 m³: a bolted tank of that size is erected in weeks and occupies far less land than an equivalent earthen pond.
Advantages over earthen ponds and concrete
An excavated pond is cheap to dig but loses water to infiltration and evaporation, picks up sediment, and is not suitable for spray water, which needs to be clean. Concrete is durable but slow and expensive to build. Bolted steel offers a winning middle ground for farming:
| Criterion | Bolted steel (GFS/epoxy) | Earthen pond | Concrete |
|---|---|---|---|
| Construction time | Weeks | Days (excavation) | Months |
| Infiltration/evaporation losses | None (closed) | High | None |
| Suitable for spray water | High (clean water) | Low | High |
| Cost per m³ | Low-medium | Very low | High |
| Relocatable | Yes | No | No |
| Typical service life | 30-50 years (GFS) | Variable | 40+ years |
Typical parameters by use
| Use | Indicative demand | Suggested coating | Typical autonomy |
|---|---|---|---|
| Pivot/drip irrigation | 4-8 mm/day per ha | GFS or epoxy | 1-3 days |
| Spray water | 50-200 L/ha per application | GFS (clean water) | Per campaign |
| Livestock watering | 40-100 L/head/day | Galvanized or epoxy | 1-2 days |
These ranges are indicative and depend on crop, climate, irrigation system and water quality; final sizing is done per project.
If you are evaluating a reserve for your farm, the Tech Tank team can calculate capacity, coating and foundation and deliver the system turnkey. Request a technical assessment with your area and available flow data.
Frequently Asked Questions
What tank capacity do I need for irrigation?
It depends on the irrigation depth (mm/day), the area and the days of autonomy. As a reference, 1 mm over 1 ha is 10 m³; a 50 ha pivot at a peak depth of 6 mm/day with 1 day of autonomy needs on the order of 3,000-3,500 m³. The exact figure is calculated per project.
Can I use the same tank for irrigation and spraying?
Yes, as long as the water stays clean. Spraying needs sediment-free water to avoid clogging nozzles or degrading the mix, so a closed tank with a GFS or epoxy coating is preferable to an open pond.
Does a bolted steel tank handle water with iron or salts?
Yes. For aggressive water or water with iron and sediment, the glass-fused-to-steel coating (per ISO 28765) is the best option, because the fused glass does not corrode and needs no periodic repainting.
Can it be relocated if I change fields?
Yes. Being bolted rather than welded, the tank can be dismantled and reassembled on another plot, preserving the investment. That is an advantage over concrete or an earthen pond, which are fixed in place.
Do I need an environmental permit in Paraguay?
Water abstraction is regulated by Law 3239/07 on Water Resources and, depending on scale, by Law 294/93 on Environmental Impact Assessment. Verify the water-use permit and environmental license with MADES before executing the works.