Answer: When water pressure shuts down and the sprinklers stop running, the water remaining in the line tends to leak out of the sprinkler heads. Usually this water is absorbed into the soil. In your case, it sounds as though the water is puddling around the sprinker and draining so slowing that it is suffocating the roots and killing the grass. You may need to lift the sod that runs along the concrete path and raise the soil level just a little bit, then re-lay the sod. This should keep water from puddling around the sprinkler heads.
Q&A Library Searching Tips