Sunil, The cause of the flooding has been addressed so I think that I am ready for dock repair.
I thought of attaching a support for a 55 gallon drum (or two) on the piling then filling it with water but it's going to take a lot of weight for a long time to push those blunt 12" diameter telephone poles back down.
If you can rent or borrow a 2" (or you may need a 3" for a really big pole) gasoline powered water pump (note sometimes you local VFD will have one of these). You can get a suction or pickup hose (something that will not collapse to cut the water off) long enough to draw water and let the pump stay out of your way and a disharge hose long enough to reach the end of your pier. You can take a 3/4" metal water pipe long enough to reach the bottom of your post. Put a elbow and a connection on one end for the discharge hose to connect to. On the other end you can put a reducer or even hammer flatten the end to creat a pressure water jet. You can run this around the bottom of your post and blow away the dirt to allow the post to settle back down. You can steer the post buy using the water jet at different angles to blow the hole in a direction if the post is no longer a straight vertical. When you get the post back to where you want it you can use a 6" pvc pipe to pour sack create into it to direct it around the piling to help it set. Here is you a link on Wikihow that explains how to do something similar to what I am talking about. Hope this helps you some.
http://www.wikihow.com/Install-Posts-in-the-Water-for-a-Dock-or-Pier
