Steps to Audit Arkansas Irrigation Efficiency Before Peak Season

Why a pre-season irrigation audit matters in Arkansas

Irrigation is the single largest controllable use of water on many Arkansas farms and landscapes. Peak water demand in Arkansas generally occurs in late spring through summer, when high temperatures and crop water needs coincide with lower rainfall. Conducting a focused irrigation efficiency audit before peak season reduces waste, protects yields, lowers energy costs, and ensures compliance with any local water use requirements.
A good audit identifies system losses, mismatches between application and crop needs, and opportunities to upgrade controls or hardware for greater efficiency. This article walks through a methodical, practical audit tailored to Arkansas conditions, covering field tests, pump and distribution checks, controller and scheduling adjustments, record keeping, and prioritized corrective actions.

Prepare: gather information and plan the audit

Begin with preparation. A thorough audit saves time and produces better recommendations when you bring the right data and people together.

Collect system documentation: as-built pipe and lateral maps, sprinkler and emitter types and spacing, pump curves, and controller model and program files.
Assemble recent records: water meter logs, energy bills during irrigation months, crop rotation and planting dates, recent rainfall records, and soil test results if available.
Identify stakeholders: farm manager, irrigation technician, landowner, and a licensed pump or irrigation contractor if complex repairs or system redesign may be required.
Schedule timing: plan the audit for a typical irrigation day before peak season arrival, ideally when the system is already running or can be started for tests.

Step 1 — Visual inspection of the whole system

Conduct a systematic walk-through. Arkansas systems range from center pivots and traveling guns in row crops to gated pipe and siphon systems in rice production, and micro-irrigation for vegetables and nurseries. Visual inspection flags obvious problems quickly.

Check for visible leaks on mains, laterals, valves, and hydrants.
Inspect sprinkler heads and emitters for clogging, damage, or misalignment.
Verify valve boxes are accessible, lids intact, and valve stems move freely.
Look for signs of pressure fluctuation: water hammer, surging, or noisy pumps.
Note any vegetation or soil erosion that indicates over-application or lateral seepage.

Record location, severity, and photos (if available) for each issue. Prioritize safety: shut down individual sections before accessing pressurized components.

Step 2 — Measure flow and pressure

Accurate flow and pressure measurements are fundamental to diagnosing efficiency problems.

Measure system flow at a calibrated flow meter or using a pitot tube or portable flow meter at the main line. Record flow in gallons per minute (gpm) or cubic feet per second (cfs).
Measure static pressure and operating pressure at representative points using a reliable pressure gauge. Note pressures at the pump discharge, at field valves, and at the sprinkler head riser when the system runs.
Compare measured flow and pressure to pump curve specifications and design operating points. Large deviations indicate pump wear, clogged intake screens, or pipeline obstruction.

Guideline numbers: many lateral-driven sprinkler heads perform best between 30 and 60 psi; center pivot systems vary widely by design but should run within manufacturer-specified pressure ranges. Pressure variations greater than +/- 10 percent across a system warrant corrective action.

Step 3 — Evaluate distribution uniformity (DU)

Distribution uniformity is the single most important field metric for irrigation effectiveness. DU measures how evenly water is applied across a field.

Perform a catch-can test or grid-based catch can layout for sprinklers: place identical containers in a representative pattern across a full irrigation pass, run a timed irrigation cycle, and measure collected volumes.
Calculate low-quarter distribution uniformity (DUlq): average of the lowest quarter of catch cans divided by the overall average. DUlq is commonly used for decision-making.
For micro-irrigation, use emitter flow tests and lateral pressure tests to identify clogged or underperforming emitters.

Target DU values: aim for DUlq of 0.75 (75 percent) or better for sprinkler systems. Lower DU indicates overwatering in some zones to ensure minimums in dry spots–this increases water use and reduces yield potential where moisture is excessive.

Step 4 — Inspect and test pumps and motors

Pumps and motors are often overlooked until failure. Pre-season checks improve reliability and reveal inefficiencies.

Verify pump suction is clear of debris and intake screens are intact.
Check belts, couplings, and bearings for wear. Tighten or replace as needed.
Record pump operating point (flow and head) and compare to pump curve. Operating far from the best efficiency point reduces pump efficiency and increases energy use.
Review motor electrical characteristics: amperage draw, voltage, and power factor. Compare to nameplate values.
For systems with VFDs (variable frequency drives), confirm settings match intended ramping, pressure control, and frequency limits.

Practical thresholds: if pump efficiency is below 70 percent of nameplate best efficiency, consider rebuilding or replacing. Energy cost savings often justify upgrades, especially on systems that run many hours per season.

Step 5 — Check valves, filters, and emitters

Small components cause big inefficiencies if ignored.

Clean or replace clogged filters and strainers. Record differential pressure across filters to assess clogging rate.
Test pressure regulating valves for consistency under flow. Malfunctioning PRVs cause uneven application.
Inspect and test check valves and anti-siphon devices to prevent backflow and contamination.
For drip systems, flush laterals, check emitter flows, and perform acid or chemical treatments if mineral buildup is present.

Replace damaged sprinklers, worn nozzles, and cracked emitters. Standardizing nozzle types and sizes simplifies maintenance and improves uniformity.

Step 6 — Review scheduling and control strategies

An efficient system without efficient scheduling still wastes water.

Compare applied irrigation depth to crop evapotranspiration (ETc) estimates and soil water holding capacity. Adjust irrigation set times to replace only the net ET loss between irrigations.
Use soil moisture sensors or tensiometers at representative locations and depths to trigger irrigations based on root zone moisture rather than fixed schedules.
Configure controllers for multiple program zones to reflect different crop stages, soil types, and slopes.
Incorporate local weather adjustments: reduce or skip runs after significant rainfall and increase frequency during heat waves. For Arkansas, be mindful of rapid ET increases in July and August.
For center pivots, verify pivot speed and nozzle package match crop water needs and desired application depth to avoid over-application.

Step 7 — Legal, environmental, and crop-specific considerations

Arkansas has diverse irrigation contexts–surface water withdrawals, groundwater wells, and public irrigation districts. Be aware of allocations, reporting requirements, and water quality concerns.

Confirm any required permits or reporting obligations are current before peak season.
For rice and other managed-flood systems, optimize flood durations and tailwater recovery to reduce losses.
Avoid irrigating during high runoff risk (heavy rains, compacted soils) to prevent nutrient and sediment export.
Keep a buffer from ditches and streams to protect water quality and follow any local conservation district recommendations.

Prioritize corrective actions and create a repair plan

After auditing, categorize findings into urgent, near-term, and long-term actions.

Urgent: leaks, failed pump or motor, blocked intakes, or safety hazards that prevent reliable operation.
Near-term: low distribution uniformity zones, failing pressure regulators, or worn sprinklers–these should be corrected before peak demand arrives.
Long-term: system redesign, major pump replacement, or conversion to precision irrigation (drip, variable rate) that require capital planning.

Assign cost estimates, labor needs, and a timeline. Use energy and water savings estimates to calculate simple payback for upgrades.

Practical takeaways and quick checklist

Below is a concise pre-season checklist you can use in the field.

Walk the system and document leaks and visible damage.
Measure mainline flow and pressures; compare to design values.
Run a catch-can or emitter flow test to calculate distribution uniformity.
Inspect and test pump, motor, and VFD settings; record operating point.
Clean and test filters, strainers, and emitters; replace worn nozzles.
Verify controllers, programs, and soil moisture sensors; update seasonal schedules.
Check permits, reporting obligations, and surface water return flows or tailwater recycling systems.
Prioritize fixes and prepare a repair and/or upgrade budget.

Conclusion: make the audit routine and data-driven

An irrigation audit before Arkansas peak season is an investment that pays back in water saved, energy reduced, and improved crop outcomes. The most effective programs combine practical field tests (flow, pressure, DU), routine hardware maintenance (pumps, filters, valves), and smarter scheduling driven by soil moisture and ET.
Make audits a recurring step in your annual maintenance calendar. Keep consistent records of flow and water use across seasons to measure improvements and build a case for investments like pump upgrades or precision irrigation conversions. With a disciplined pre-season audit and prioritized repairs, Arkansas irrigators can protect yields, reduce costs, and conserve local water resources during the highest demand months.