December 17, 2017 Decker’s/Cheesman Canyon Fishing Report

Good Evening Folks!

Welcome back and let’s get right into it, shall we? With unseasonable flows almost reaching 200 (cfs) in the Canyon, Decker’s, and Trumbull areas of the South Platte, we’ve seen a drop this evening that has brought us back down to 139 in the canyon, with 135-130 through Decker’s and Trumbull.  Last year at this time, we were seeing flows range from the upper 70’s to the 115/120 range. What does all this flow change mean you ask? Well, a number of things. Let’s start with what this means as far as the tippet size you should be using. Typically this time of year, with the lower flows and gin clear water, it’s pretty important to stick with the 5x and 6x Tippet, along with keeping  your bugs in the #22-#24 range. With excellent clarity and lazy fish, due to the colder temperatures and shaded areas of the river that don’t see much sun this time of year, a good presentation and a meal that “belongs’ there, is going to be the key to your success, both in the Canyon and below the Wigwam Club. If it looks like a duck? Well, you get it! With the flows reaching the upper 130’s/14o’s ranges in the last few days, and more than likely we’ll continue to see some substantial fluctuation, you certainly have the chance to get out that 4x and take advantage of the higher flows. Thus, resulting in far more opportunities to net that 22” Rainbow that’s sure to push that 5x and 6x tippet to its’ limit.  With these increased flows, it’s also a wise decision to stick to the deeper runs and riffles that are providing increased oxygen and a greater supply of food. The amount of dissolved oxygen in the water is directly related to the water temperature. In case you don’t know, cold water holds oxygen much better than warm water. The effects of water temperature on the amount of dissolved oxygen doesn’t change at a constant rate. It changes at an accelerated rate.  In general, for most species of trout, the fish are most active when the water ranges from about 50 to 65 degrees. The cold-blooded trout feed at the maximum rates due to their metabolism level in this range. From 65 to 70, this accelerated rate I referred to begins to take place. In simple terms, at 65 there is no problem and the trout feed aggressively. At seventy degrees, there can be a problem depending on the type of water. The dissolved oxygen content can be low.  Still water is one thing and fast, turbulent water is another. The amount of dissolved oxygen will vary greatly. That is why you hear to “fish the oxygenated water” all the time. When the trout start hurting for oxygen, they will begin to cease their feeding activity. It is not a great deal different from the way they react in very cold water, just due to a different reason. When the water reaches about seventy-four degrees, the trout just about have to have highly oxygenated water to survive. Again, keep in mind that these temperatures are guide lines. Also, the particular species of trout and its location and more specifically the type of water it is in will vary this somewhat – not greatly, but a little. So, with all of this being said, let’s not forget about the food source of the trout, and how it is affected by higher flows. Higher flows generally result in a larger area of the stream bed that becomes wet, ultimately promoting the growth of vertebrates and invertebrates alike. When the river drops to levels that ultimately increase the water temperature, thus reducing the oxygen levels, we have the potential to see a decrease in the activity of the fish, along with a substantial chance for “fish kill.”  Alright folks, that’s enough Biology for one day! Stick to the midges and beatis patterns, but don’t pass up the chance to take advantage of the occasional BWO hatch, as we’ve regularly seen temps reach the upper 50’s and 60’s this time of year. Until next time, have a great time out there and I hope to see you on the river soon!