This morning and early afternoon I spent some time on the remains of the Black River, watching herons. The occasion was a gathering/open house hosted by the Herons Forever group, that is trying to raise community awareness over a new development going up nearby. But more on that later. Let me start off with talking about the land itself first.
A hundred years ago, the Black River was the outlet for Lake Washington, running through Renton itself. The Black flowed a few miles, then joined the White River to form the Duwamish (the White is now the Green River, but that's another story). In 1916, a new outflow for Lake Washington was created, at the Montlake Cut, at the north end of the lake. The lake level dropped nine feet when the cut was open, exposing a lot of new land and lowering the lake level to a point below that of the Black River. The Black River dried up quickly, such that fish were stranded in small pools in the former bed and people gathered them up by the armload. I have yet to find anything in my research that indicated people thought about the fate of the Black when they opened the Cut.
Removing the Black River did not end the river entirely, because there continued to be other streams and creeks leading into the former bed, and there were continued flooding problems along the former bed of the Black. To control these, they excavated a pond, fed by the Streambrook Creek (A name that could only be found on bad D&D Map), and allowed the remains of the Black River flowed out of that pond into the White (now Green) river to form the Duwamish.
The marshy land around the pond made this area a low priority in comparison to the wider, flatter lands to the south (where Longacres racetrack later gave way to Boeing offices), and it was pretty much ignored - its current neighbors are a quarry, an active rail line, a sewage treatment plant and a couple low warehouses (including one for Seattle's Best Coffee). The land was controlled by King County, who in turn spent money (about 8 mil) to turn it into the Black River Riparian Park. In the eighties the herons moved in, starting with about ten nests and now having over a hundred and thirty. They originally made their nests to the eastern part of the park, but moved west this year - part of this may be due to eagle predation (bald eagles, on the rebound in our area, are big heron-hunters), and part of it may be due to some commercial development along the eastern border (A lot of empty offices, when I checked, and a branch of local TV station Channel 11).
Now, across the railroad tracks and up the hill the City of Renton is planning to allow new residential construction. Originally it was going to be apartment buildings, but now has slimmed to single-family dwellings. I've looked at the land, and while large-scale construction looks "doable", it will have to involve retaining walls to keep the hill from coming down. The development has the optimistic name "Sunset Bluffs". Its going to have an impact on the Black River Park downhill. The vote is coming up next week in the Renton City Council, so Herons Forever is making people aware, and has had a few newspaper articles on the subject.
Herons congregate here at the rookery (more properly called a heronry) in the spring to mate and raise chicks - the rest of the year they have a more dispersed range. They are HUGE birds, with great, sawtoothed wingspans, and to see them in flight is to make you think of the age of the dinosaurs. Heavy beaks and slate-grey plummages, you can see them gliding in, carrying sticks for bundle-nests in the crooks of the cottonwoods. They're starting earlier than normal this year, which means a good year for fledglings.
The cottonwoods are still bare, so you can see the birds pairing up, displaying, nestbuilding, and mating. The people (about fifty when I was there) were gathered on the far side of the pond, with binoculars and scopes. Given the description above of the land previously, you realize that the heron are relatively tolerant of human presense, but do need some undisturbed turf to raise their chicks.
So its a short walk, and if you're in the area and HAVEN'T seen this, definitely go - The park is on Oakdale right before you hit Monster Road, and I've driven by it a bajillion times without realizing it. Its interesting that this abandoned and problematic chunk of land has been turned into a wetland greenspace, and the community has been rewarded by attracting a thriving population of these huge and attractive birds. It would be a pity to lose it just for one more development.