What a catch-can irrigation check can tell you

Measure a single zone

Place matching collection containers across the area served by one zone and record the water collected during a measured run. Follow a published audit method for container placement and duration; a few containers beside one sprinkler do not represent an entire lawn.

Compare before calculating

A very low reading in one part of the zone can reveal an uneven pattern. Increasing runtime for that dry area also increases water everywhere else. University of Minnesota Extension separates a physical inspection, performance testing and controller programming for this reason.

Keep the evidence

Label the zone, date and container positions on a sketch. Photograph the coverage and share the readings with an irrigation professional if the pattern is inconsistent. Repeat after repairs under comparable conditions to see whether distribution improved.

Prepare a reliable observation

Choose a time when you can stay with the test and keep people, pets and mowing equipment away from the containers. Label each position on paper before the water starts. Use a consistent measuring method, note the start and stop times and record unusual wind or an interruption. Those details help explain why two tests may not be comparable.

For example, if containers along one boundary collect noticeably less than the middle, photograph that boundary while the zone operates. A head may be obstructed, misdirected or part of a wider design issue. The collection pattern identifies a question to investigate; it does not establish the repair by itself.

Understand what the check leaves open

A homeowner check is a useful record, while a professional audit can assess performance more formally and connect the findings to scheduling. Request help if readings vary widely, the test is difficult to perform safely or you cannot identify the zone components. Avoid presenting a rough check as a certified audit or a guaranteed water-saving calculation.