I'm going to skip the "should I or shouldn't I" but want to throw something out.
I know of someone that has what sounds like a similar creek although a little narrower. Although most of their creek bed is rock, it can get a bit hairy with a tractor. There's also the DEP issues. When they need silt removed, they let mother nature take care of it, but with a little help. Some strategically placed logs, rocks... obstructing the current flow (in your case, the outside around the island) will force any major flow back towards the silt. For day-to-day flow, it'll still go through their "naturally" placed logs/rocks but as flow increases, the water is forced through the silt. After a few good rains or a single snow melt, the island is gone. The log/rock "natural" obstructions get moved/adjusted between flows as needed.
I know of someone that has what sounds like a similar creek although a little narrower. Although most of their creek bed is rock, it can get a bit hairy with a tractor. There's also the DEP issues. When they need silt removed, they let mother nature take care of it, but with a little help. Some strategically placed logs, rocks... obstructing the current flow (in your case, the outside around the island) will force any major flow back towards the silt. For day-to-day flow, it'll still go through their "naturally" placed logs/rocks but as flow increases, the water is forced through the silt. After a few good rains or a single snow melt, the island is gone. The log/rock "natural" obstructions get moved/adjusted between flows as needed.
