A cause of improper sprinkler coverage is sunken sprinkler heads. Sprinkler heads settle after a few years and are too low to reach beyond a small area.
Common Reasons to Replace Your Sprinkler Heads - Smart Earth Sprinklers
Aquamist Plumbing & Lawn Sprinkling - This sunken rotor head is causing very poor area coverage. It is likely that heavy equipment has caused this problem over years of service. Poor coverage
Irrigation Issues: Sunken Sprinkler Heads
Do I Need A Sprinkler System Repair Or Replacement?
When Do You Need To Replace Your Sprinkler Heads?
Common Sprinkler Problems - Resource Central
Custom Design Products Sprinkler Protector Donut - 10 Pack - Prevent Grass from Blocking Sprinkler - Made in USA,Dark Green : Patio, Lawn & Garden
Why Your Sprinkler System Needs a Spring Inspection and Tune-Up - Smart Earth Sprinklers
Common Sprinkler Problems - Resource Central
Tips for Choosing the Correct Sprinkler Head : Drip Depot DIY Irrigation Support
Irrigation system upgrades … it doesn't have to be all or nothing - Golf Course Industry
Common Sprinkler Problems - Resource Central
Winter irrigation system projects