Thursday, October 10, 2013

USGS flow gauges in the Alley

CFS, Flow Gauges, Rain, No Rain, OH MY!!!

One of the most challenging things that I found for myself when learning how to steelhead fish was reading stream flow gauges provided online by the United States Geological Survey. When first looking at the charts, it is a bit intimidating. With a bit of practice, patience, and getting out on the water you can quickly learn how to use these tools to determine which river you can have the best chances at landing fish that day.

In the summer, the rivers are quite low. When the fall rains begin, the rivers will quickly rise, then quickly fall. As the ground begins to get more saturated in the fall and into the frozen winter, the rivers take more time to come down in flow. Some rivers are smaller and hence have less feeder creeks, which in turn allows these rivers to fish first. A river such as the Grand river is much larger and takes longer to come down due to its size, feeder creeks, and length of the river.

Each river has a prime fishable Cubic Foot Per Second of flow. Now known as “CFS”. Each angler has their own preference of what is fishable and what is not. A river such as the Grand River may fish at 400 CFS, while the Rocky River would be considered too high and fast at that rate. Learning what are the prime numbers for you on each river is critical, and highly recommended due to safety reasons.

Too low of numbers and you will have little to no flow. Crossing streams in low flows is little to no issue if you know the stream bed. Too High of numbers and crossing a stream can be deadly and has been in the past to anglers getting swept up in the current. Heed the warnings of other experienced anglers when it comes to flows. If they say it is too fast, listen to them.

Experienced anglers rarely stick to a particular river they will fish. They begin looking at the online CFS charts, and make a determination the night before, and even up to the hour they are leaving the house. While one river may be unfishable, heading east or west another river may be prime. Many anglers use the online resources on their phones as well.

For example, you are trying to sneak out in the morning before a storm hits. You head to your destination and begin fishing, all of a sudden right before your eyes, the flows pickup and the river gets dirty.

It is time to fire up the cell phone and find out that the rain has come, and the river will soon be blowing out. Rather than hanging up the rod for the day, anglers will look to find fishable water based upon experience by looking at the CFS gauges for other rivers.

This is when knowing fishable CFS readings becomes important.

Here are a few tips that I have learned.

1. Know the recommended prime numbers for a few rivers in the vicinity.

2. Is the river rising, falling, or steady?

a. If rising, is the CFS already out of prime range?
b. If Falling, will the CFS be in the prime range during your fishing?
c. Based upon past history during that month, how quickly is the river rising or falling?

3. If it is going to rain the day of fishing, a general guideline is to look back at the last time the river rose, and how long it took. If it took 6 hours to blow out, then you will have a good idea of how long you have to fish that river

4. Not all rivers rise and fall at the same rate. Some rivers may not get any rain at all that day even though a river east or west may be getting hammered with rainfall.

I have grabbed a screenshot of the latest CFS for a few rivers. I will use these as some examples.

Rocky River:
September 14th the river rose to about 400CFS, out of fishable range. September 15th, the river fell to within fishable range. September 19th, the river is low.

My thoughts on this river is that the flow cresting at 400 CFS has allowed fish to push up into the river. Quickly overnight the river fell to a fishable range. Within a few days the water has gotten low and clear. Fish are in the rivers, and holding in the deep pool or below damns.

Chagrin River:

Chagrin River crested around 950 CFS out of fishable range on September 15th, coming down to fishable ranges on September 17th. The next few days has been a steady runoff. The high flow earlier should have allowed fish to push up. Fish are most likely still pushing. At the moment it is raining, so I would expect the rivers to bounce up a bit.

Grand River:
September 12th the grand river was up over 1800 CFS. As you can see, the Grand River takes longer to come down to fishable levels. This is due to the larger watershed size and more feeder creeks dump into the main river channel. 

I have highlighted in red some general windows of prime opportunity when fishing these waters. Several other factors play into what water you decide to fish. Water clarity being a big part of that. You will learn that just because a flow looks good, it may not be the optimal clarity.

With experience you will learn that when flows go up, so does the suspended silt in the water. As the flows come down, so does the silt settle and you get into that Emerald Green water which all steelheaders love to fish in.
There is a lot of data on the USGS site.

By focusing on the CFS charts, you can begin to learn how to choose a river wisely. My recommended flows are by no means the end all be all. Many anglers enjoy fishing in higher or lower flows based upon their own experiences. While one section of a river may be bad fishing at 500 CFS, that same river may be great fishing in another area of the same stream due to the width of the river and depth of the streambed.

I hope this brief tutorial will assist new anglers in learning how to use what they research online, and translate that into more enjoyable fishing on the streams.

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