A number of years back the enviros at Reed College took it upon themselves to restore the Canyon. The good part of this was the elimination of exotic invasive species such as blackberry and English ivy. The bad part was the elimination of the swimming pool which was constructed in 1929. My kids learned to swim there. It was important to our summers. The reason for this heinous act was to replace it with a fish ladder from Crystal Creek providing access to the lake for trout and salmon. I was pissed! What trout and salmon? How could they survive in the lake which is shallow and heavily silted in if they could make it up the ladder? I bloviated about this for years.
Yesterday I visited the Canyon with Zac Perry. Zac is a graduate of OSU in Botany and Horticulture. He wrote the original plan for Canyon Restoration, which did not envision either the fish ladder or the restoration of steelhead and salmon runs in Crystal Creek. Zac set me straight on a couple of "issues"
1. The Reed blog describes the pond as the only naturally occuring lake in the Portland area. I pointed out that the pond is held in place by what is clearly a man made earth fill dam and has been since 1929. Zac responded that while this is true the original dairy farmers who cleared the site used the pond for irrigation. Apparently there was an impoundment held in place by a beaver dam. OK it is "more or less" a natural lake, albeit not a geologic formation. 
2. True, neither salmon or steelhead can spawn in the lake. They require clear, cool water and clean gravel beds for their redds. Why then was the fish ladder built? Zac advised that the lake is serving as a rearing pond for smolts hatched in the creek below. A camera is mounted at the base of the fish ladder and provides fish counts on a 24/7 basis. A number of adult steelies have visited the pond but subsequently retreated. The salmon of course spawn and die in the creek. Smolt do move up into the lake.3. The Canyon has become somewhat of a wildlife preserve and opportunity for study. The addition of the Environmental Studies Program at Reed has been greatly aided by this living classroom. When I suggested that the pond might be dredged and planted with black bass and crappies you can imagine the look that Zac gave me.
With the elimination of the blackberries and the release of native species in the canyon the site is more beautiful, accessible and interesting than before. Recently a pair of river otters have been spotted dining on freshwater muscles, beavers continue their campaign of destruction, turtles are making a comeback and the bird life is quite varied. Zac Perry has done a great job of managing the site and leveraging the enthusiasm of the students in the effort. Kudos to Zac.
