Pond Boss Forums INTRO Questions & Observations Public ponds and adding structure

I live very close to a river fed pond/small lake that is about 10 acres in size. My city's parks department controls it.
It has a maximum depth of 22 feet and an average depth of 10 feet. The small lake is basically devoid of structure.
Now for the not-so-legal thing I did about 5 years ago. The city's water department has a road that goes around this small lake and they routinely cut down small trees and pile them near the bank. One winter I decided to jump on this opportunity to place some structure. So I loaded up some cinderblocks in my ice sled and some nylon rope, and dragged a few of these trees onto the ice and attached the blocks to them.
Now these trees sat on the ice for about three weeks before they went through, so everyone that visited the park knew they were there. Next ice season the fish were loaded on the sunken trees. I had fellow anglers coming up to me saying that the city did a great thing by sinking those trees (all the while keeping my mouth shut about me doing it).
So I just recently contacted the parks dept about sinking structure in the lake with thier permission and at my own cost. There is no swimming allowed at this body of water, and it gets limited use in the summer by very few pleasure boaters.
My question is, if the city agrees to let me sink structure in the water, what type should it be? Also, what can I do to help the city to see my point of view?
It's a quality fishery with bass, bluegill, crappie, pike, and some walleye (shad seem to be the main forage fish)...but the fish have very little structure to relate to.

See this thread from the archives for ideas.

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=92463#Post92463