Grassing of bunkers at Pacific Dunes?

[Scott Weersing]

I am not sure what I am seeing in this video from Pacific Dunes.


https://www.youtube.com/watch?v=032ePISToJs



But it looks like at the 7:41 mark that they might have sodded a bunker on No. 14. And a fairway bunker on No. 15 at 8:15 mark.


What is actually taking place?

[David Wuthrich]

Yes, that would be a good question.

[Sven Nilsen]

The sod is used to build up the levels of the bunkers.  Add sand, a layer of sod that thatches together and more sand over that.  8 foot bunker becomes a 4 footer.

[Daryl David]

I can testify to that. My club had been reworking all the bunkers over the last three years. We have had 6 holes or so with sodded bunkers each summer for a few weeks. It always brings up questions from visitors up till the sod is killed with Roundup and sand is added. We even had a very prominent golf rater go nuts claiming the course was being butchered by making some of the sand bunkers into grass bunkers. 

[Alan FitzGerald CGCS MG]

I don’t know exactly but it looks like they’re using sod as a bunker liner, which is a cheap option to the porous liners or fabric.

As Daryl described, the sod is let knit so it creates a strong thatch, which bonds the soil. It’s then killed off and the sand added. The thatch keeps a separation between the soil and sand, which reduces contamination when the sand washes and also prevents stones from working up from the bunker floor. It works well provided there isn’t much water washing into the bunker as it erodes the organic layer at that point over time, but it works really well and holds up on flat areas.

[Tom_Doak]

I don’t know exactly but it looks like they’re using sod as a bunker liner, which is a cheap option to the porous liners or fabric.

As Daryl described, the sod is let knit so it creates a strong thatch, which bonds the soil. It’s then killed off and the sand added. The thatch keeps a separation between the soil and sand, which reduces contamination when the sand washes and also prevents stones from working up from the bunker floor. It works well provided there isn’t much water washing into the bunker as it erodes the organic layer at that point over time, but it works really well and holds up on flat areas.

Alan:


In this case, the sod liner is just there to stop the wind erosion from going beyond a certain depth.  Some of those bunkers had gotten six feet deeper than when they were built, despite regular replenishment!


I am not sure this will do much more than require them to refill the bunkers more often, though.

[Garland Bayley]

After they are done with this correction, will they be better able to keep sand in the bunkers? Currently the bunkers are woefully inadequately filled with sand. Some places you are hitting off of hard ground.

[Tom_Doak]

After they are done with this correction, will they be better able to keep sand in the bunkers? Currently the bunkers are woefully inadequately filled with sand. Some places you are hitting off of hard ground.

The sand there was all “native” to begin with - just whatever was there when we stopped digging.  Underneath, there are many layers of sand and hard pan and sandstone, and if you bust through that you’re often back to sand!  So what you were talking about is just a hard pan layer that’s been exposed, and that usually stops the erosion, so it just stayed like that until they replenished the bunker with sand.  By putting in the new sod layer, they shouldn’t ever get down to hard pan.


Actually though, I was amazed that the hard pan played okay and most golfers accepted it without complaint.  The wind erosion made the bunkers at Pacific Dunes the sort that C.B. Macdonald would have loved - the kind that should be respected and avoided.

[Alan FitzGerald CGCS MG]

Alan:

In this case, the sod liner is just there to stop the wind erosion from going beyond a certain depth.  Some of those bunkers had gotten six feet deeper than when they were built, despite regular replenishment!


I am not sure this will do much more than require them to refill the bunkers more often, though.

Thanks Tom, thats a use I never thought of, but it makes a lot of sense.