The answer to 'why is my sprinkler system brown patches' is that brown patches in your lawn are often a sign of an issue with your sprinkler system. This could be caused by several factors, including improper coverage, broken or clogged sprinkler heads, or a problem with the water pressure or timing of the system.
Some common symptoms of sprinkler system issues include dry, brown patches in the lawn, uneven watering, and water pooling in certain areas. To troubleshoot the problem, you'll want to inspect your sprinkler heads, check the water pressure, and ensure the system is running on the correct schedule. In some cases, you may need to adjust or repair the sprinkler heads or make adjustments to the system's programming.