There is a lot of work going on to the front left of #15 green including the face of the front left bunker. Hopefully this picture can help explain.
Inside the red box is an area that is very wet. Therefore, Assistant Superintendent Carey Bailey (in green shirt) is leading a team to dig up and expose the greens irrigation loop, noted with blue arrow, to determine the source of the leak.
As of now the source has not been found, hopefully it will be discovered soon!