I recall Combs saying that on the West Coast, they figure an average of 10% strays in any system, sort of a natural fail safe system.  If all the fish returned to their natal streams and you get a Mt St Helen's event like on the Cowlitz, you would never get another run without the dribs and drabs from other systems, also maintains  genetic diversity.
 
I got called for spot burning a couple of years ago and last fall  as well, so I'm not using "real" stream names anymore except for big rivers.  Suffice it to say that everything from step a crossers like Mustela creek to the Genny, Black and Niagara, gets a fish now and then.  And some have natural reproduction documented back to mid 20th century rainbow plantings way before the current program.  Certainly water temperature is a huge limiting factor for recruitment (fish attaining a size that allows them to be a part of the fishery), but the eggs have to hatch out to fry, and what Mike C was saying is that a lot of the streams have limited substrate of the right size for the number of fish that come into spawn.  If Pair B spawns where Pair A spawned last week, a lot of Pair A's eggs are wiped out by Pair B.  And Kings need the bigger, rounder stones, areas of which are limited in these shale bottomed streams that were stripped of a lot of cobble over the last 200 years for building all those beautiful cobblestone houses we see in WNY (and yes a lot of those were also picked up from fields after frost heaving from the winter, but the ease of gravel harvesting from streams is well known, part of the reason for Article 15 of ECL).  Low flow is also a function of shade removal, but it is related to conversion of the whole watershed to greater amounts of impervious cover, rooftops, parking lots, roadways, etc, that cut off percolation to groundwater and route runoff directly to streams in rainstorms, causing higher highs, lower lows and shorter duration to the " events", what is called greater flashiness in the stream, instead of the aboriginal forested condition where a lot of water gets held in the leaf canopy and slowly reaches the ground and mainly infiltrates to groundwater, keeping flows between storms higher and cooler. definitely what has  happened in IC over the last 30 years.  Also, the silt at Russo may come from development upstream and settle at Russo due to lower gradient.  Eliminate the source of sediment upstream in the PM area (and at places like the old Sheafer Landfill in Ontario County), and the stream will gradually clean itself in the depositional places downstream.  This is also evident in the areas below Philbrick since the wall got built.
 
I think I am in the run-on sentence competition!
 
L13
 

L13,thank you for the informative post.All that sounds very familiar as to what occurs here in the Lehigh Valley to the limestone streams that were at one time premier trout streams.Details are different but it's all the same when you boil it down to basics.

O K while I don't know anyone who enjoys fishing for rustbelt chrome more than I do, although you Lucky have been doing it as long as anyone and go back to your early childhood on the Finger Lakes tribs as I do and  big Bill was pretty excitable the day this year when we were hooking sparkly bright steel every 3 or 4 minutes between us for several hours straight ,would have been less often had we been more intent on landing them instead of concentrating on getting walloped repeatedly, I wasn't trying to imply that our GL tribs would be self sustaining of chinooks no matter what we do and I don't think I would even want that since they are non natives and I would rather see coaster brookies or landlocks  if we could take our tribs back to a pristine condition again but only that we could have perhaps some eggs in each streams basket in case there was trouble at the hatchery.
 
 
Another pretender to my thrown.
In your face.
 

Yep, more houses, less fish.  All those Webster tribs get runs, but have very limited access, really the only "real" public access in Webster is in the County Park.
 
There is a proposal floating around to remove the dam on Silver hammer, but I think that should be rejected unless the state can get access above the dam.  Why would you spread out a license buying public's fish, all of which are accessible now because they are all on public access land up to the dam, and make them inaccessible, unless maybe you knew you would get natural reproduction and recruitment, or you had a senator living upstream!
 
L13

Access should be secured first.
Fish do get beyond the falls at times.
I thought you were with me when I went up and found redds aplenty.
It was pretty silted above the dam so unless it flushed out I'm doubtful much success would come of the spawning up there
Seen them swim up the tube on the east side channel.
They should have spent some money on access a decade+ ago.