What do these markers indicate along shoreline at Maui Lu?

7/24/18 #kihei 

The mystery of the future of the Maui Lu, a former resort property in north Kihei near Kalepolepo park, continues. Comments of start days have gone on for years, but no action takes place. In the last week, we noticed these ground markers are appearing along the shoreline, but we are not sure what they mean. One says ” ¾” pipe”. Is this for a water line? Do you know?  For a prior post on the Maui Lu see https://gokihei.org/?s=Maui+Lu.