Ok, I'll try to do some math.
The bunkers at my course are similar to the first picture....manicured edges with "fingers" or "noses."
First, the cold, hard numbers: 39 total bunkers amounting to 93,454 sq. ft. and approx. 1226 tons of sand
Regular Maintenance:
Spot rake (drive around in a cart and manually rake any really bad areas):
3x week @ 3 man hours = 9 hrs/wk = 468 hrs/yr
Speed rake (Sand Pro 3-wheeler just rakes the bottom, as in the first picture above):
2x week @ 4 man hours = 8 hrs/wk = 416 hrs/yr
Full rake (Sand Pro + hand rake edges)
3x week @ 6 man hours = 18 hrs/wk = 936 hrs/yr
Mow Bunker Fingers (use manual push mower, because riding mowers can't access that skinny of a section)
Every other week @ 32 man hours = 16 hrs/wk = 832 hrs/yr
Full Bunker Trim (weedeat edges, push sand from bottom back up onto steep faces, pull weeds, mow fingers)
Every 6 weeks @ 72 man hours = 12 hrs/wk = 624 hrs/yr
Other Bunker Work (such as pumping water after storms, replacing small amount of sand lost by play, cleaning out wind debris)
Approx 300 hrs/ yr
Total Annual Maintenance = 3,576 hrs/yr @ avg wage of $10/hr = $35,760
Capitalized Costs = Bunker rebuilds after approx 8-10 years
(Involves removing all sand, reassessing/repairing drains, strip surrounding sod and regrade, install new sod and sand)
We just started doing this and the cost on our initial bunker recently completed are approx $2 per sq foot
Total Rennovation Cost every 8-10 years = Approx $200,000 = $20,000 per year
Never actually did that exercise before......good info for me to carry forward to my boss and golfers. I prefer to keep bunker maintenance as little as possible, but the design and aesthetic intentions of this course require the above as a minimum to keep the bunkers in sync with the rest of the course.
I've considered the options and they basically are to do minimal raking or rake less often (reduces quality of bunker surfaces and aesthetics and increases golfer complaints), rennovate less frequently (same issues as the last option) or try to redesign the original intention, create a different look for the course, possibly eliminate some bunkers.....but I have no idea what all that would cost. Significant money up front that may take many years to actually realize as savings.