Oleh Kovalchuk | Blog

When discussing irrigation, most farmers think first of pumping stations or irrigation machines. In practice, however, one of the costliest mistakes is often hidden underground—within the pipeline network.

It is this network that determines how much a farm will pay for electricity over the next 10–15 years, how reliably the system will operate, and whether fields will have to be excavated mid-season due to breakdowns.

In this post for the Variant Irrigation "Irrigation Practitioners Club" blog, we will discuss the pipeline network—a system component that directly impacts a farm's expenses over subsequent decades of operation. I will share practical approaches to selecting a pipeline system and explain where you absolutely should not cut corners.

A Pipe Is Not Just a Pipe

Over my years working with irrigation, I have become convinced that the pipeline network frequently dictates how economical the entire system will be to operate. Many view a pipe as a simple infrastructure element—bury it and forget it. In reality, however, this is exactly where you will find either future savings or constant financial leaks.

The pipeline network encompasses the entire piping system connecting the pumping station to the irrigation machines in the field. It is conventionally divided into two sections:

• the main pipeline—the primary pipe supplying water from the pumping station to the fields;
• distribution pipelines—smaller-diameter pipes delivering water directly to the machines.

In my view, one of the primary mistakes occurs when farmers construct irrigation systems and try to minimize upfront investments as much as possible without considering operations. Yet, the system is meant to run for decades, not just a single season.

Pipes I Recommend for Modern Irrigation

Personally, I recommend using pipes made from synthetic materials that are immune to corrosion and offer a predictable service life.

Polyethylene Pipes (PE)

Polyethylene is one of the most widespread options on the market. A major benefit is that these pipes are manufactured in Ukraine, and welded joints provide a highly reliable, durable system.

For projects with operational pressures up to 10 bar, I believe this is an excellent solution in terms of price-to-quality ratio.

However, if the system operates at higher pressures, the wall thickness increases substantially, which driving up the pipe's cost accordingly.

PVC Pipes

High-quality pressure PVC pipes are currently mostly imported. Their advantage lies in faster and cheaper installation because the pipes are lighter and feature bell-and-spigot joints with rubber gaskets.

However, there is a critical point that is often overlooked. If you fail to install concrete thrust blocks at turns, starting points, and dead ends of the pipeline, the pipe can simply "shoot out" of the socket under pressure. I have seen such incidents multiple times.

You must also consider constraints: these are typically limited to diameters up to 500 mm and pressures up to 16 bar. Due to imports and logistics, the final price often ends up higher than clients anticipate.

Fiberglass Pipes

Fiberglass is a great solution for large diameters. These pipes are also imported and require concrete thrust blocks, but at large diameters, they can be more cost-effective than polyethylene.

From practical experience, I can tell you that starting from a diameter of 630 mm and for pressure classes of 12 bar and above, fiberglass is frequently more economically attractive.

I generally do not recommend other materials for new systems or modernizations. In the long run, they are either more expensive or less reliable.

Where Farmers Lose the Most Money

Most frequently, it happens because of a desire to "save" on pipe diameter. At the procurement stage, it seems logical: a smaller diameter means a cheaper pipe. But once operations begin, all those savings quickly vanish into electricity bills.

I always select diameters to ensure that the required pressure is maintained at the furthest hydrant:

• 1.5 bar for center pivot machines;
• 2.5 bar for linear move machines.

If a pipe is too narrow, pressure losses spike dramatically. The pump begins operating under a heavier load, and the farm overpays for electricity during every single watering cycle. Over 10 years of operation, these overpayments can end up 2 to 4 times higher than the initial "savings" on the pipe.

Must-Have Features in a Pipeline System

In my experience, system reliability depends not only on the pipe itself but also on correct outfitting.

Pressure Relief Valve

I recommend installing a pressure relief valve at the beginning of the main pipeline. Its job is to vent water if pressure limits are exceeded, protecting the system from water hammer.

Air Release Valves

These must be installed:

• at high points along the pipeline;
• every 500–800 meters along the main line;
• at every hydrant within the distribution network.

Here I can share a practical solution that has proven itself well in operation: DN50 plastic valves have the exact same air venting orifice as DN100 metal valves, but they cost 5 to 7 times less.

Gate Valves and Outlets

A valve manhole with a gate valve is mandatory at the beginning of each distribution pipeline. This allows you to quickly isolate a specific section during repairs.

Drain valves must be placed at the lowest points of the system to evacuate water before winter. Otherwise, freezing temperatures can cause severe pipeline damage before the season even begins.

Why Proper Laying Depth Matters

I always emphasize that pipelines must be laid below the frost line for your specific region, plus the diameter of the pipe. This is another area where you should not cut corners, as issues typically do not manifest immediately, but rather after several seasons of operation.

Irrigation Is No Longer an Expense, But a Matter of Business Stability

Today, irrigation for many farms is no longer just a safeguard against drought. It is an instrument for stable production and predictable economics. And it is the pipeline network that determines how expensive running this system will be in the future.

I always advise looking beyond procurement or installation costs to evaluate the full operational economics of the system at least 10 years ahead. A properly designed pipeline network is a solution that allows you to save on operations for years and avoid critical issues during the watering season.

Oleh Kovalchuk, Head of the Irrigation Department for the "Prydniprovskyi" cluster at Kernel.

Responsible for 2,831 hectares of active irrigated land and a team of 43 qualified employees. Over 21 years of experience in irrigation operations.