How to Read and Understand River Levels on the Columbia – Part II

We laid out some of the basics for reading water levels on the Columbia in Part 1.  Part II gets into some more advanced concepts.  It would be over-simplistic to just point you to the raw numbers and leave it at that.  Other things matter as well.  Things like:

  • Where the influence of one dam ends and the other begins.  Of course this isn’t a distinct line or location.  It is a gradual effect.  But where is that effect most prominent and where do you need to take it into consideration.
  • What numbers from which dam do I need to pay attention to for the section of the pool that I want to fish

The Upriver Outflow Effect

For this first scenario, we’ll use Priest Rapids Dam as our example.  The effect of what is coming out of Priest Rapids Dam (outflow) is felt all the way through the Hanford Reach down to the North Richland area.  By the time you get to Columbia Point, the transition is well under way for McNary Dam having the most impact.  This is why it is common for anglers to leave Columbia Point Marina to one water level only to run upstream (up the “Reach”) and find the opposite water levels.

Priest Rapid’s outflow numbers fluctuate wildly on most days. The effects of those numbers are not noticed for many hours the further downstream from Priest Rapids Dam you go.

If I plan on fishing closer to the Richland area, say from Columbia Point downstream, then I will want to mostly pay attention to the Reservoir Elevation at McNary.

If I plan on fishing below McNary, then I will want to focus in on the outflow numbers coming out of McNary.  If I’m going to be fishing in the Boardman or Crow Butte areas, I will want to focus in on the elevation numbers at John Day Dam.

Going up the Reach

If I intend to fish up the Reach, I will want to take note of outflow at Priest Rapids in the early morning hours of that day.

On an hourly basis, the numbers will be even more varied. It can take many hours (6-10) for those flows to get down to the Richland area. In general, if I want a sense of what water levels will be like in the morning, I will pay attention to the numbers from midnight on.

I can then use another site to see how those outflow numbers translate into “feet”, something that will make a lot more sense to most anglers.

The NOAA website is another tool to help me understand water levels. I can easily see how flow corresponds to height.

Historical Averages

The NOAA website will also show me what “normal” is.  It would be easy to say this year that the Reach has been really high, but that is just not the case.  It’s just that compared to last year, it is more normal.  Last year (2016) was the aberration.

I can see that June levels coming out of Priest Rapids are pretty average, despite the constant rumor of flows being high. Now, compared to last year in June (6th column over), you can see how abnormal last year was.

I can also look for what is “normal” instead on relying totally on my memory.  No more B.S. dock talk about the river is up or down.  Find out for yourself for certain.

 

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