Thanks for the above replies. Here is where things stand. Lots of hard work so far and about 80% of the leaves are removed using a leak rake (net). I used the shop vac to remove the sand and grit. Maybe about 40% of that is done. It is a 14 gallon vacuum so this piece takes a long, long time.

kelemvor: That sounds like a great suggestion. I will drain the water level down tonight. That makes a lot of sense. It will be much easier to clean the as the water recedes off the cover. From there I can more easily remove the leaves and pieces of concrete. Also I contacted the contractor earlier today and I asked for help from his crew with the cleanup effort. No reply yet. The good thing is I will withhold the final payment until this is done.

Hopefully this has a good ending...and soon.