Creek laid silt; dammed colverts: Sustainabile backwoods culverts?

Hello,
I have been researching my topic here, but with some difficulty so I decided to make my own post for my unique situation.
My grandparents have a 25 acre six foot tall chain-length fence with hot wire ran at the top and bottom. The fenced area contains a one and a half to two acre pond, which is fed by a creek that has a large water-shed outside of the fenced lot, but the creek is not very wide or deep. The creek that feeds the pond runs into the fenced lot about 125 to 175 yards before it runs into the pond. Excess pond water feeds out into a creek which takes it out of the fenced lot. They have had this lot for eight or nine years now and until two years ago the fence went straight through the inlet and outlet of the creeks, using no culverts. Once every couple of years debris that built up on the fence where it crossed the creeks would take the fence out, but two years ago my grandfather decided to have culverts placed at the creek inlet and outlet to have the fence run across the top so that it would not build up debris and get knocked out. The idea of the culverts was to make the system more sustainable, but it has actually created more work than the old way. One of the factors continuing to cause trouble is that the pipes at the culverts have wood and wire box cages capping them to prevent dogs from getting out of the lot, and to keep pest animals out of the lot.
First I would like to address the issue of the creek feeding into the fenced lot. The following pictures are of the creek meeting the inlet to get into the fenced lot.
Attachment 2680
The culvert pipes are effectively dammed right now due to the cages placed on the pipes to keep pest out and dogs in. Due to this damming a lot of silt, leaf littler and debris have been laid down in front of the culvert pipes inlet.
Attachment 2681
The creek bed has been raised about 10 inches here. Last year I dug it out by hand because it is very difficult to get any heavy equipment to this location, and I left the cages off of the pipes for a long time, but the cages had to go back on.
Attachment 2682 Attachment 2683
The debris are laid so thick in the creek bed that I am afraid the pipes will get clogged if I take the cages off of the pipes. The pipes are pretty clear right now. Our goal is go get the system functional. Right now the fence is knocked out because water is diverted when a big rain comes and follows the path of least resistance, and this takes out the fence in another area on its new rout to reach the pond.
I am not sure where to start with this mess. I do not want to just dredge the ditch and be done with it because that will not be sustainable. I would like to know if there is a way to use water and water pressure to move the debris along, and if so how? The location is remote and very hard to get any big equipment into. It is even harder to get big equipment out. Any topics search terms or book references that would help my research would be greatly appreciated, but I could really use someone with experience that would enjoy passing on their knowledge in an ongoing friendly way.


I will revisit this post when I have more time and more pictures to help illustrate the situation.

From the looks of your pix, I'm not surprised you've got problems. You're creating it by giving debris a spot to catch on, i.e. the "cages". Get rid of them and put a couple of hot wires in the area of the culverts to keep your dogs away. If the debris and water can knock down that fence, you've got a large volume of flow and debris that will keep clogging those culverts.

Thanks for taking the time to reply jml755. I apologize if this comes across as rude and I do not mean to be rude, but your response seems as if all you did was look at the pictures of my post. I'm well aware of the source of the problem; I even clearly stated that in my previous post, and I'm looking for solutions to do the job properly. I'll explain a little further what my experience has been when the cages are just removed while the creek bed is loaded with silt and debris. Simply removing the cages allows all of the debris to flow freely into the pipes. The pictures may not show clearly the extent of debris that have gathered at the entrance of the pipes, but I will explain. Large limbs and sticks are among the debris and they get hung inside the pipes. After these debris get caught they add to the problem by catching leaf litter and more silt. I do not wish to go through this experience again using just my hands and hand tools.
I do not want to discourage anyone from posting helpful details, but I know from experience that simply taking the cages off will not solve the entire problem. That is likely the first step, but before I do so I will need a plan to work the debris through.