I would spend the $$ and use Rotenone to kill any fish that are in there. It is a LOT less expensive to do it now then later after it starts to fill. Dealing with rough fish and the issues that they will cause down the road is a huge headache that you can avoid.

15ac? You can definately put a ski boat in there and pull skiiers. An inboard ski boat can turn a lot faster than an outboard. There are water ski schools in Fl that use a long narrow man made BOW with an island on each end to absorb the boat wake when the boat Turns. They are narrow enough that you have to stay in the boat's wake when the go around the island or else you will run aground if you are outside the wake. They have different lakes for different uses. Slalom course, jump, trick skiing.


www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).