Chesapeakes, IF I was going to fill the pond from the river, I'd use Pentair's mesh filter bags over the pump's discharge outlet. They're capable of filtering zooplankton, so I would think they'd filter fish eggs also. Having said that, I would still Rotenone the pond after filling. Starting out with a clean slate would sure make long term plans both cheaper and easier.

I might also put out construction silt fencing above the pond area that's getting the river water. That'll help keep silt down.

Is the river above or below the pond?

AL