The issue of having a 19th or alternate hole is only part of the story here; there are many of them elsewhere as several have already mentioned here.
The real story is that Don is one of the rare owners who is willing to lose yardage AND a par digit to make the course more fun to play. Currently, his first three holes are:
No. 1 - 142 yards - Par 3
No. 2 - 335 yards - Par 4
No. 3 - 516 yards - Par 5
Total 993 yards - 12
By making the existing first hole into a practice green the existing second hole becomes No. 10 after flipping the nines. Then, as he discussed above, the existing third hole is split into a real cool driveable (by some) par 4 along the crook of a large creek with the second part of the hole being occupied by a new par 3 to the existing par 5's greensite. Thus, the new yardages would be:
No. 10 - 345 yards - Par 4
No. 11 - 310 yards - Par 4
No. 12 - 160 yards - Par 3
Total 815 yards - 11
By constructing the new green for the future 11th hole 310 yards (265 straight carry over the creek), it will reside to the left side of the existing par 5, just beyond and 25 yards left of the existing fairway. After all other work is done on the course, some additional fairway work will be done to complete this new short par 4. But, in the meantime, it can act on its own to make up the difference while other holes are under the knife.
If all of this sounds confusing, I apologize but have asked Tommy to help me post a plan sketch that will suffice to explain.
And to answer JHancock's question, Don and I are working with the former superintendent from this very course who is now doing construction only. With our direction and his experience and ability to want to try new things, we are having a blast with this as the integrity of the greens is one of the only avenues we have to sex up the place. It is in a flood plain and as such is very flat with severe restrictions on filling.
I am sure that his patrons would probably be happier than most to see a near constant disruption of construction equipment, as it means SOMETHING is being done. Previously, the place was the equivalent of the formerly nice house down the street that has gone to hell for the past 30 years since the old crazy ladie's husband passed away. Just hacking down the weeds and fertilizing has made a big difference there. It is really unfortunate when golf courses are let go as badly as that one was. But, I should add, that Don has done an incredible job turning it around in short order.
So, while most public course owners, and certainly private club members cringe at ongoing construction, I think these people know that it means that, finally, some positive things are happening there.