17" is a good sized fish for the cattle ponds that pass for lakes around Omaha. If you want 'big' fish you pretty much have to have a largish body of water that can feed that beast.
Around Omaha, Zorinsky (being killed right now), Chalco, Cunningham, the Platte river, the Elkhorn river and the Missouri river are the largest bodies of water. If you're strictly catch & release the Missouri is fine, but I wouldn't eat anything out of it.
Someplace that has had me curious - Lonergan Reservoir. North of Omaha, NE of Cunningham. Doesn't seem to be State land - no idea who's it is.?.?