Basically, for the money spent, trout and catfish purchased from large producers East of here are among the cheapest and best deals TPDW can get for fish to put in its urban fisheries program, unlike a lot of their programs, one which I believe is more of a genuine success than a public relations one.
Bass are expensive to produce, difficult to grow and manage in city ponds, and are quickly and easily removed from the fishery anyway. Not the best choice for urban fisheries. Catfish and trout can be purchased "ready to catch" for cheap from large farms and provide for a good alternative to be used in a "put and take" type fishery.
Or put like this, even a fairly well stocked and managed bass pond will be quickly "fished out" if more than about ten or twenty pounds of bass per acre are removed annually. In most cases the bass can be caught and removed about as fast as they get big enough to bite a hook, yielding the 10 pounds of catch or so per acre per year. Say twenty or so half pounders.
In one day for not much money, an urban pond can be stocked with a few thousand pounds of trout and provide a lot of fishing activity for a good period of time before they are all caught out. Generally the state stocks 1/3 pound (three count) trout most of the time. In some ponds these may grow to several pounds before being caught.
Basically the same deal for catfish.
And price structure.....maybe they get trout for around $2.75 or $3/lb. catfish for around $1.50 or so. I got no idea on their fingerling production cost, but know by the pound, even 1/3 or half pound bass are costly. More like $20 to $50 a pound.
For the money, trout and catfish are darn good deals for urban ponds.