First a current report. The river was recently raised to 255cfs. Wadeable but much higher than normal this time of year, and the fish seem to have not adjusted quite yet. I like to fish dry flies, and on a trip up to the river yesterday I found very few fish up feeding on the surface despite a fairly heavy midge hatch happening on the river. Streamers and Nymphs will still work quite well though. Personally I turn to Streamers most often when the dry fly action is slow, and on the Owyhee any gray, brown, or tan baitfish streamer can work very well. Zebra midges are always a staple. Small pheasant tail nymphs, marabou nymphs, and San Juan worms will also work well.
Many have been asking so I will fill in some of my best guesses on the Owyhee River status this spring. We have had a lot of snowfall this winter, and while much of the snow at lower elevations is gone, there is still a lot of snow up in the mountains that drain into the Owyhee River. This is ultimately good news for all involved. There should be plenty of water this year for the farmers and ranchers of our area, good flows for the rafters, and kayakers that enjoy the remote upper stretches of the Owyhee drainage, and it's great news for the trout that live below the Owyhee Dam. But as this run off begins it's a good idea, if you plan to fish the river to keep a close eye on some of the readily available data, especially if you are coming from very far away. Current Flows from the dam are 255 cfs, which is fishable, but is about 10x what the river is normally at this time of year. Still wadeable, but it does change things a bit if you are used to fishing the river in March at 30 cfs.
As an amature mathmatitian, who likes to crunch data, and make wild assumptions, right now, my best guess is that the reservoir will be filled by March 25th this year. We will see how close that is, and obviously there are a whole lot of variables that could throw this guess off. Now what the flows below the river do is anyone's guess. Just because I feel the reservoir could be filled by the 25th doesn't mean that is when the flows will bump up to unwadeable levels below the dam. As they prepare for the run off they could deem it necessary to dump more water before that date. Or we could have a colder March than we did last year, and get even more snow in the mountains that could delay the runoff, but result in even more water when it finally does come off. But as of now my best guess is that by March 25th flows will make the river unwadeable. Take this guess for it's worth, but please be aware of the situation and keep a close eye on things if you are planning a March trip to the Owyhee River this year. I will tweak this guess a few times in the coming weeks and post if I hear of any flow increases coming in the meantime.
Below are a few links to the Snotel site, and Reservoir storage site that I used to make my wild projection. Feel free to make your own guess, and share them or your methods with me!