Every winter --- at some point during the winter --- Washington's Cascades get slammed by the Pineapple Express erasing weeks or months of accumulated snow and creating havoc in the lowlands. At present, we have floodwaters barricading I-5 south of Centralia, landslides blocking Blewett Pass and avalanches threatening every east-west route across the Cascades. Of course, all of the Cascade rivers are at flood stage though, by now, they have peaked and are receding.
These periodic winter floods sometimes wreak havoc with the rapids we guide commercially. I wrote earlier about the aftermath of the huge Sauk River blowout (~100,000cfs) which not only blew out the access bridge over the Whitechuck River which once led to the Sauk's put-in, it 'silted in' a every major rapid on the wild and scenic river.
Over the three decades I have been rafting Washington's whitewater, I have seen rapids get created by floodwaters, I have seen rapids get eliminated by high water and I have seen rapids reconfigured.
On the Wenatchee River near Leavenworth, a stand alone hydraulic known as Snapdragon was once a prime play spot for rafts and kayaks. It was at the head of an eddy an eighth of a mile downstream of Drunkard's Drop. It was an incredibly powerful souse hole located right beside this remarkably strong eddy fence. One summer it was there, the next summer it was gone and it has never returned. In fact, at this point it is hard to imagine there was ever a water feature there it is so damn tame and flat.
Granny's Rapids has migrated south over the years, but dramatically after a couple of 100 year floods. For one thing, the rapid used to be 'straighter'. Suffocator wasn't always a 'keeper' of unmanned boats (Maravias anyway. . . ). And the monstrous maw on river left in Granny's, which I think is referred to as the 'Granny's Wave', did not exist a decade ago. And, in my mind, the K2 and Annapurna waves were once bigger and more peaked.
On the Skykomish River, Boulder Drop, which consists of boulders of all sizes, but a few as big as barns, has not changed much over my whitewater lifespan, but one place in that run has been altered for sure --- The Ledge Wave. It seems to have become deeper and more fearsome and, at certain water levels, your odds of breaking through that trough of hard whitewater are slim to none. In the past, it was simpler to punch through it, and simpler to avoid it.
After the floods of the past few days, I suspect we are going to see some new features in some of our rivers. My hope is that the recent flush has scoured the Sauk of all that deposited silt. And perhaps, the rapid Popeye will have been returned to it glory days.