We had several greens that had drainage issues. A company called XGD installed drains deep below the surface of the green. It worked great during the golf season.
Unfortunately, when the ground froze the water would not drain. We had extended turf diie-out due to ice damage. XGD came back and put in tee junctions. Next winter we extended pipe form the tee junction deep below the green to a drain cap on the surface of the green. This allowed us to squeegee standing water down the drain cap into the drains.
This was the old drain after being capped.
This hex-plug was covering an old drain that did not have a drain cap. Bent grass grew on half the plug. The other half is Poa Annua. Most superintendents prefer bent over poa because the bent has a better root system. The better a root system, the better the plant’s resistance to disease and drought.
This is the other side of the plug shown above. You can see that the bent grass has a nice thick root mass. The Poa grass has hardly any roots showing.
When large amounts of turf on a green is damaged, hex-plugger can be used. I used a hex-plugger to remove remove turf that had grown around a drain