“Steelhead Green” is a term used by NW anglers to describe a river that is dropping and clearing after a winter storm. When that happens, the river takes on a greenish look. It’s generally when fishing gets good for steelhead. The fish are on the move and in a mood to bite. Here in the Willamette Valley, we haven’t seen those conditions very often this year.
We finally have some rain in Oregon! After an extremely dry winter, we’re getting some good old liquid sunshine here in Pacific Northwest. The Little North Santiam, a river with a good run of Wild Winter Steelhead, has begun to rise.
For over a month, the Little North Santiam (aka North Fork) has been low and clear, running at under 200 cfs, reaching a low of 152 cfs earlier this week. Those are summer time levels. Normally we see flows between 800 – 2500 cfs this time of year with the 83 year average right at 1,200 cfs. When the flow is under 200 cfs, the gravel beds are dry and only the deep pools and troughs have water. The water temperature has also been impacted by the unusually dry weather. Temps spiked on the Little North Santiam to 53 degrees this week, where the norm this time of year is in the low 40’s. The same situation exists all over the Willamette Valley. As luck would have it, we’re having a pretty decent run of fish this year with nearly 2,800 winter steelhead over Willamette Falls so far.
This is the time of year when Wild Winter Steelhead are moving into the system and staging up to spawn. They use the entire length of the river. Just upstream of the rapids in the picture above, an average of 4 to 5 redds are visible each year. The gravel bar they use has been high and dry for the past 2 weeks. I’m sure that similar conditions exist all up and down the river. This rain will help. At the very least, the fish can get into the river and make some progress upstream. But will they have any gravel to use for spawning? They can’t use the solid rock shelves or boulder fields as redds. It doesn’t work that way.
Once the eggs are deposited and fertilized, they harden and seal over within 72 hours. Then, depending on water temperature, they hatch within 30 -50 days (lower temps = longer incubation time, higher temps = shorter incubation time). It’s a nice little system that Mother Nature has in place to deal with fluctuations in water temperature. But Mother Nature has no system to deal with lack of water. Eggs deposited in gravel beds that dry up don’t hatch at all. With little to no snow pack in the mountains that feed the valley rivers, this nice batch of rain we’ve had will work it’s way through the system and the rivers will drop again. Warm spring sunshine will have nothing to melt and the rivers will continue to drop further.
Assuming some fish will spawn, some eggs will hatch, progress to fry and fingerlings, they will need space to grow. Low water levels means a compressed ecosystem and warmer water temperatures. When rivers are full to the banks, the “edges” are where small fish hang out. They hide in log jams, side channels and other structure found along the side of a full river. They grow and mature there. When rivers are low, that structure is high and dry. They are forced to move into the mainstream along with the returning hatchery fish, native and non-native fish species. It’s survival of the fittest.
We’re going to need more storms, and preferably some that not only drop lots of rain in the valley, but also snow in the mountains. Detroit and Big Cliff dams don’t have much water behind them. The reservoirs are drained, ready for spring snow melt to fill them. It’s concerning for sure, but not critical just yet. We’ve had years in the past when we get snow in late March and even into April. Sure hope it turns out to be one of those years. If not, we’ll see the impacts 4-5 years down the road when the descendants of this years run return home.
Every wild fish matters, and that’s especially true for Winter Steelhead this year. The odds are stacked against this cycle of fish right from the start. Anglers can give them a hand by adopting the “Keep ’em Wet” idea. It’s pretty simple. Don’t take wild fish out of the water, or at the very least, limit the amount of time spent out of water. Not only does that apply to the returning adults coming home to spawn, but also to the smolts working their way back down the valley heading for the salt.
The official start of Spring is less than a week away. Here’s hoping it’s one of those long, wet ones. May flowers aren’t the only thing that need a good watering to grow and thrive.
Tight Lines and Keep Em Wet!