Pond Boss Forums INTRO Questions & Observations Sizing a Fish Passage in a Creek

Crazy FishinRod question of the week:

We have a half mile of a live creek across our property. It is clay-bottomed in many places, but is mostly actively migrating sand. Some years a spring flood may create some deep pools on my portion, and then when the water level goes down, my pools will aggregate an amazing number and variety of fish. During the summer, the creek may only be running a few inches deep through the riffles.

In the past, we have caught/observed LMB, GSF, BG, channel cats, common carp, yellow bullheads, black bullheads, white crappie, and spotted gar. My old neighbor even says he pulled a 40# flathead out of a pool when he was a kid.

We also have an abandoned oxbow "pond" on the property. When the creek rises enough, water will reach the oxbow and create a long, narrow pond that is about 0.4 acres.

My crazy plan is to build a small obstruction across the outlet of the oxbow pond, and create a pond that may last for a few weeks or even a few months. Further, I would like to trap creek fish into the oxbow to "stock" my ephemeral "pond". I am amazed how quickly the fish trapped in a pool grow over the course of a few months from spring to late summer. Of course, their pool is replenished after every small rain with a fresh supply of FHMs, gambusia, and a couple of shiner species.

The creek joins a significant river about nine miles downstream from our property. I believe the river is the source of the fish, because in many years the creek holds zero gamefish in the shallow riffles, and it may go completely dry every 10(?) years.

I want to create a "fish passage" through my obstruction/dam for the oxbow pond. That way, fish can migrate upstream into the pond. I will also install the means to put a stopboard across the fish passage when the floodwaters have receded to what I consider "normal pool level" for the pond.

I believe my trade-off is: the bigger the fish passage, then the quicker my oxbow will drain out.

My biggest problem is that I have zero expertise on the factors that control fish movement during flooding events.

Right now I am just contemplating using the corrugated plastic 6" flexible drain tile pipe. I can install some of my bits of larger diameter culvert if that is more recommended by the crowd.

If anyone has good knowledge of how/why fish move during flood events, then that would also be much appreciated in this thread.

[This is not a big deal, just trying to run an experiment and perhaps create some fun "kid fishing" opportunities. This creek has crested during floods at least 16' above normal elevation across my property, so anything I construct will get blasted to smithereens every 3-5 years.]

Thanks.

I'd use a bigger outlet, but move some dirt to make it higher to impound a wee bit more water. Maybe 12" dia? It all depends on the goals of how big of a fish you want to "stock" in there when the water rises. 6" is big for a BG, but small for a common carp.

Thanks esshup.

After I posted, I realized I could make the size of the passage somewhat "adjustable". I should put in a larger culvert and then use stop boards to alter the size and flow as needed. I have some pieces of 18" plastic double-wall culvert that should work just fine. I think blocking the top 50% would be a good size to start experimenting.


I still don't understand why fish swim upstream during floods or even moderately rising creek levels? Google returns me articles on why salmon swim upstream (which we all understand).

If I was a fish and the waters in my home started to diminish, I think I would swim downstream to find more water. But fish are certainly much smarter on fish behaviors than I am.

If anyone knows the reason, or wants to speculate, I would still like to read it.

Speculation is fish swim upstream to the source? The source should have water all the time and overflow when there is extra water? Purely speculation though.