Water filtration is important for all irrigation systems.
Now before someone argues with me, yes, some sprinkler systems are used to spread solids, such as treated sewage, for disposal. But even those in my experience have incorporated some form of filtration upstream of the system to prevent solids which are too large from entering the system. Filters can help extend the life of, and lower the maintenance on, your sprinkler system. For drip systems they are a necessity to prevent emitters from becoming plugged. Even if small sand particles can pass through your system without clogging it, they cause wear on the equipment.