Are you worried about the sediments getting into the following city system?

I would bet that your "sewer system" is actually just rain water drainage that dumps out in a nearby ditch/creek.

If you think about it...your pond is actually a "sediment trap". When you slow the water down by making a wide deep hole in the path of the water flow, the heavier particles (sediments) have the opportunity to drop out. If you can't slow the flow down substantially with the sediment trap's design (read potentially as big as your pond) the water speed and turbulence will keep the sediments suspended and they will flow on downstream.

Without slowing the water's velocity way down to allow the dropout of debris, you would have to design a filter system which translates to a lot of money and maintenance.


Fish on!,
Noel