Flyfishing report: Yellowfish - East Free State

Date of Report: Monday, 23rd May 2022
Name: David Weaver
Phone: 083 303 4230

Sterkfontein saw the highest water levels in the history of the dam.  Some reports say that the dam got as high as 104% this last season.  It is currently at 102.5%.  One of the problems that they face at Sterkfontein is that there is no spillway to allow the flow of excess water, because it is not a dam but rather a reservoir.  It is a storage facility that has been over-filled by Rand Water.  There are two or three small streams that flow into Sterkfontein, but they are inconsequential in the grand scheme of things.  Water for Sterkies is pumped up from Kwazulu-Natal out the Tugela River. 

So why has the dam/reservoir got so full.  The first reason is that, with the high rainfall, the Vaal dam is full and doesn’t need any water, read, can’t handle any more water.  Secondly, they, the water affairs people, can’t pull the plug.  Yes, Sterkfontein has a plug, and it gets jammed and then they can’t open it, to let water out.  The last time this happened was about 10 years ago and it took three or four months for specialist divers to go down and get the thing open.  Remember that diving in 83m of water at altitude means you are spending a lot of time in a decompression chamber each day. 

These high levels changed the dynamics of the dam.  The water levels were reaching new banks/soil.  This resulted in the wave action eroding these new areas, which caused the water to get very dirty.  In some areas whole cliffs were collapsing into the dam.  As a result, the top area of the dam, South of Wildebeest Island, was murky for most of the season.  This hampered the sighting of fish and the fish’s ability to see flies at a distance.  Traditional spawning banks were flooded so the fish moved to new areas to find gravel beds.  All in all the dam was very unsettled this last season, making the fishing quite tough.  There were days when everyone was a professor but more days when very few fish were coming to the net.

The second reason that made the fishing tough this last season is the increase in weed in the dam.  The normal cats-tail weed has never posed a problem but there is a new weed that is spreading through the dam very quickly.  It is 2x tough, grows in deep water and is spreading fast.  It used to be only up near Driekloof dam wall (The Great Divide) as we call it, but now it is all the way down to Qwantani.  we lost a lot of fish to that weed.

I also believe that with the increase in aquatic vegetation you are going to get an increase in aquatic insect life.  Not a bad thing as there is more food available, but a cause for concern amongst the dedicated dry-fly fisherman.  In the early days the fish in Sterkfontein relied on terrestrials as their only source of food, because there was very little, if any aquatic vegetation and thus no aquatic insects.  This was the reason why it became a premier dry-fly fishing destination.  I believe this is changing and the fish are reverting to their aquatic invertebrate diets.  Looks like we’ll all be going to the “Dark Side” next season and fishing nymphs and sinking lines.

The fishing pressure this season was huge.  I have never seen so many Commercial operators and private boats on the water as I saw this last season.  Yellowfish spook easily and with so many boats on the water there were a lot of spooked fish, and spooked fish don’t come easily to the fly.  The Good Doctor’s Beetle is probably the most popular fly used on Sterkies and surely by now they are learning that this thing fights back.  I saw more fish refusing a beetle this season than ever before.  They would swim right up to the fly and then turn away.

And the last reflection as to why there were tough times this last season is that the weather has been completely wacked.  We have had more rain this season and certainly more rainy days than I have recorded in the last 22 years of guiding/record keeping on Sterkies.  Overcast days equate to inactive fish, they swim deep and are not easily caught.

So, if I had to sum up the 2021/2022 season on Sterkies in one word it would be “KAK” but because this is a family site and there might be sensitive viewers, I will just say that it was “TOUGH”, all capitals…