Irrigation Start-up Best Practices - Expert Recommendations
Spring is near, which means it’s almost time to start thinking about charging up your irrigation system. The colder winter months can take a heavy toll on an irrigation system. It’s critical to perform routine start-up maintenance of your system components before the heavy watering season begins. De-winterizing your irrigation in the spring is just as important as winterizing! Whether you’re running a commercial, agricultural, golf, or residential irrigation system, the efficiency and performance depends on starting up your system with care. Protect your irrigation investment by following these expert recommendations.
When to Start Up Your Irrigation System
Timing your irrigation start-up can be a gamble. If you open it up too soon, you run the risk of freezing the pipes you worked so hard to protect over the winter. This is an expensive mistake. If you wait too long, however, you shorten the window of time available to address any repairs or replacements your system requires for the start of a new season, putting your landscape at risk.
Many experts recommend waiting until the first full week without any freezing temperatures. Depending on your geography, this could fall anywhere within a wide spectrum of March through May. A general rule of thumb is to wait until nighttime temperatures remain above 0 degrees Celsius, and that the soil has achieved thawing to a depth of at least 12 inches. It is generally safer to turn on a system with a backflow preventer earlier than a system that utilizes pumps, as the latter is more susceptible to harm from an unexpected freeze.
Commercial Start-Up
Irrigation system design in a commercial system is quite similar to that of a residential system, just on a larger scale. In a commercial setting, landscape appearance is critical to attracting customers, and employees may be anxious to “just turn on the valve”. A professional landscape contractor will slowly open all supply valves and pressurize the water main pipes. It is critical to counsel commercial property owners to schedule their spring irrigation start-up prior to landscaping and installing plants. This will help guarantee that new plants will receive water immediately following install.
If the commercial system is connected to a Booster Pump, the pump will also require priming, which occurs when the water gets turned on. If contractors removed flow meters during winterization, they will require re-installation prior to priming. Refer to IRRIGATION START-UP PROCEDURES for more detailed commercial irrigation start-up tips.
Agriculture Start-Up
Layout
Most agricultural irrigation systems utilize a pump. A well pump may supply a drip system, or suction led pump may draw from a surface reservoir. Downstream of the pump, fertilizer injection tanks and filtration may precede the control valves. At each of these intersections are valves that must turn on slowly and sequentially, starting closest to the source. Essentially, you perform in reverse what you drained in the fall. The final stop in the agricultural irrigation system is the Emission Device, whether drip or some type of the the many kinds of sprinklers.
Drip Irrigation set-up
The biggest battle with starting up a drip irrigation system is debris in the system. This is why the flushing process during winterization was so critical. The underground pipe from the control valves is connected to the main line, where a series of control valves lead to multiple zones. Drip lines may be above the soil or buried very shallow.
For a vegetable crop that is annually harvested and requires working of the soil, growers typically utilize a thin disposable drip tape. Consequently, this system is built up every year before planting. This involves laying down plastic mulch above a drip line. Drip tape feeds off reels beneath the plastic. The plastic simultaneously holds the moisture around the drip system and suppresses weed growth. Row breaks perpendicular to rows, are reserved for supply tubing. Hoses get dug in and connected to the drip tubing with fittings. Supply lines are limited by pressure, so the field design must take water pressure into account, and zones must be partitioned accordingly.
Drip Irrigation Protection
When it’s time to plant a crop into the plastic mulch, the grower must take care not to poke a hole into the drip tape. To make things easier, growers often offset drip tape from the middle to avoid chances of puncture with planting. Alternatively, in an orchard, longer-lasting drip lines are in place, requiring thicker tubing to ensure longevity. A supply line on one end connects to rows of drip tubing, each could be fitted with an individual valve. Tubing may be subsurface or aboveground tied to a truss wire. Because this system does not require annual set-up, the tubing is thicker and lasts 5-10 years before requiring replacement.
Valve access
Some irrigation systems will have a supply hose on both ends of the crop rows. This orientation helps with the design process to ensure uniform irrigation. However, this design also requires valves to be paired with each supply hose to enable draining and flushing. Before spring start-up, there is likely to be some debris that has settled in the system over the winter that needs flushing out. Ideally, this debris will flush out when the system is turned on, but the crew must be astute to ensure that no drip openings are clogged.
Most drip systems will have air vents connected to valves if they are laid subsurface. Valves may be manual or wired to a controller. These valves will need to be opened up to alleviate built up air. Pressure-reducing valves within a drip-system may help moderate pressure to 20 pounds to avoid rupture.
While drip tapelines may have their own individual valves, others may not, and require the user to cut the end and then reseal following a good flush.
The pivot rotates around a fixed point and is typically supplied by an underground pipe. The most critical step to starting up this system is ensuring that the connection to the underground pipe is secured, and valves are open in order to turn the pump on to feed through the system.
Many growers will conduct a “dry run” before running water through it, running one pass to ensure everything is working electrically. This also creates an established wheel track, keeping the towers from expanding the pivot too far once water is running through the system and the soil becomes muddy or wet. Running water through the system, similar to the drip, will ensure no debris is stuck and clogging the nozzles. Many of the newer style nozzles have a setting orientation that allows flushing to remove debris.
A Bauer Traveller is a mobile irrigation system, which is essentially a hose on a reel. The hose needs to be connected to a supply source, and the cart gets pulled out and set at the retraction speed. Smart growers will do a test run prior to irrigation to ensure seals, belts, and other parts are in working order. Make sure the battery that regulates the controller is charged and the tires have air. A visual inspection goes a long way to detecting tears, leaks, or predator problems. Early detection of problems helps avoid costly repairs during the growing season and prevents putting crops at risk of desiccation due to mid-season irrigation repair.
Golf Course Start-Up
Avoidable problems
Like commercial and agricultural systems, golf course underground irrigation systems require a place for air to escape. In the absence of open-air vents, open pipes, or open sprinklers, air can build up and rupture pipes. With their broad coverage and varied elevation, pipe rupture is the biggest threat facing golf course irrigation systems. It is critical to pressurize the lower half of the system prior to pressurizing the upper half. A single course might have upwards of eight air relief valves, which requires the user to be methodical when starting up in spring.
Electric maintenance
Unlike the typical commercial or agricultural system, golf course irrigation systems contain many electrical components that also require testing to ensure there are no wire breaks that occurred over the winter. Fuses, controllers, and solid-state satellites are all part of the average golf course system. Familiarize yourself with the use of a voltmeter, which will allow you to troubleshoot fuses and other electrical system components.
Keep appropriate replacement parts
With an area as large as a golf course, it’s possible that you may require a replacement part for your irrigation system at some point during start-up. To facilitate a smooth transition to spring, have the necessary replacement parts in stock to help minimize delays. It is useful to create an inventory of replacement parts to help you anticipate any replacement needs. Contact our Vanden Bussche golf team and we can assist you in getting set up with the appropriate list of products that would be required for simple repairs or replacement.
Residential Start-Up
Landscape contractors serving homeowners often have the responsibility of starting up a residential irrigation system. While irrigation systems may look different, they all are installed according to the same principles. If you are a landscape contractor, it’s important that you visually inspect valve boxes for rodent nests and damage. Crack the water source valve very slowly to begin charging the system. Next, charge the backflow device, slowly opening its valve. Open the control valve to charge the system. Activate the individual zones using your controller. After pressurizing the system, walk past each station and inspect for leaks, clogged sprinkler heads, and proper coverage. Lastly, you will program the irrigation controller for optimal watering settings. If there’s a water irrigation meter connected to the system, it’s worthwhile to take a picture of the meter readout to document how many gallons the system is starting out at for the season.
An irrigation system is a sizable investment, but proper start-up care of your irrigation system will ensure that it will continue to serve you all summer long. If you encounter any challenges as you start up your system, contact our sales and service team at Vanden Bussche Irrigation, or head over to your nearest Vanden Bussche location. We will connect you with an irrigation professional to keep you on track for a successful irrigation season!
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