Monday, November 26, 2012

Needwood bunker rebuilds

About 3 weeks ago now, Needwood broke ground on some important bunker renovations.  This work will continue as weather allows into late fall and early winter, with the goal of finishing rebuilds of the remaining bunkers on the front 9.  There are 12 bunkers left to rebuild on the main course; others have been completed (or eliminated) over the last couple of winters.

It's ironic how bunkers are a hazard, but there is an expectation for them to be well groomed, well drained, trimmed and proper.  Don't worry, if you fall into this category, you're not alone; this is something that permeates the golf industry, and probably is mostly due to conditioning of golf courses shown on TV for tournaments, where they have many dozens or sometimes hundreds of volunteers to help make things, like the hazards, perfect! 

Much data has been comprised regarding bunker maintenance, and believe it or not, there are courses out there where bunkers require as much as 50% of the entire golf course labor budget!! 

About 4 man-hours of work will get just this one small bunker playable again after being washed out by a storm. Silt has to be manually removed by shovel, new sand added, and all the sand has to be redistributed by machine and finished by hand.  This example is from Falls Road, where there are 59 bunkers.  Repeat the process every time there is a major rain event!!  And yes, this is a HAZARD.  :-)

A large portion of maintenance labor is expended while trying to put bunkers back together after a major storm.  For us, while precipitation amount trends are only very modestly increasing on an annual basis, the frequency of rain days seems to be changing, especially in the summer, where we get most of our monthly rainfall amount from 1 or 2 storms.  What does this mean for bunkers?  More washouts and vastly more intensive work to make them clean and playable again! 

While not all bunkers a ruined to the same degree as in the above picture, there is plenty of work to be done.  The above bunker was not originally constructed with a liner, which would help the water flow underneath the sand to the drain and reduce washouts.   Installing proper drainage lines and installing a roughly 1/2" thick synthetic fabric liner especially on sloped areas, is what we are undertaking at Needwood, along with adding new sand.

Similar projects are occuring at every course in our system over time, and most every off-season as necessary.  This periodic maintenance allows us to be more efficient with our resources and focus on turf-related playing conditions!

Below are some pictures of the process going on at Needwood!
Old bunker sand is pushed into a pile and then buried into a hole inside the bunker.  The excavated soil is essentially "swapped" to the surface and used for creating the new floor of the bunkers.  This eliminates having to haul as much as 20 - 30 tons of sand out of the bunker across the course, and speeds the process.
After the new bottom of the bunker is installed, drain lines are trenched.  One of the big issues with these bunkers at Needwood is that they either completely lacked drainage, or the drainage had failed over time.
With drain lines complete, this bunker is ready for pipe, gravel and liner installation.
Outlet drains are also trenched.

Pipe is installed and trenches are backfilled with pea gravel.
Ready for liner!
Liner is carefully installed in the bunker, using a LOT of sod staples (about one per foot).

Once sod staples are in place, each one gets some Liquid Nails to help hold them in place.  Without this, freeze/thaw and natural minor heaving can allow the staples to work themselves loose.
As liner is installed, thin pieces of plywood also help maintain a proper edge when adding sand later.
Final touches need to be made outside the bunker where some bunker edges are modified.  These spots will be sodded and re-established quickly.

Once the liner is trimmed up, sand is added and distributed throughout the bunker, generally to a 6" depth on bottom and a 4" depth on the sloped areas (less sand makes bunker faces a little firmer to prevent fried-egg lies)

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