Removing Small Dams?

[flyfishnevada]

On a creek near my house, there are many man made rock and log dams. Most are near camping spots or in meadows. I can't imagine what the purpose is except maybe to make small shallow pools to swim in. This is not a blue ribbon trout stream, just you typical small trout creek that in many places you can jump across but it holds a good population of both wild and planted trout. You can see the damage those dams do to the stream. They broaden and make the water shallower behind them, they silt in behind the dam likely warming the water more than would normally happen, and in some cases probably prevent the movement of fish. On another much smaller creek, I removed a dam like that and while my son and I watched a 14 inch brookie swam up through the new opening I had created.

Anyway, I have some time on my hands and I would love to go remove some of these. Am I nuts? Are these really a big deal? Would removing them help the stream? Has anyone done this? Can I get in trouble from the Forest Service?

[Mrs.Finsallaround]

I believe you have to have a permit for that (believe it or not) from CA DFG.

They have a Lake & Streambed Alteration Program, which states "The Department of Fish and Game (DFG) is responsible for conserving, protecting, and managing California’s fish, wildlife, and native plant resources. To meet this responsibility, the Fish and Game Code (Section 1602) requires an entity to notify DFG of any proposed activity that may substantially modify a river, stream, or lake." (http://www.dfg.ca.gov/habcon/1600/). Not sure if it pertains to removing obstructions (although this would be modification), but it sure does pertain to creating them.

I would check with them just to be sure.

Your heart is definitely in the right place though!

[Ed Wahl]

FFNV, keep tearing them down. Fish do need to migrate up and down a stream system to find suitable food, cover, spawning locations, water temps, etc.

On one of my favorite creeks there's a small diversion dam with a minimum flow pipe the only outlet. People will put plywood over the outlet hole in the summertime to make a slightly deeper swimming hole. You can imagine how this goes over with the downstream trout population.

Robin, are you sure someone in Nevada needs a permit from the California DFG to remove swimming dams?

Ed

[Mrs.Finsallaround]

Robin, are you sure someone in Nevada needs a permit from the California DFG to remove swimming dams?

Ed

Didn't even notice he was in Nevada! DOH!

I'd still check with Nevada's equivalent.... but, that's just me

[flyfishnevada]

Thanks for the quick replies. I am sure there is some kind of regulation here in Nevada, but enforcement is another thing. I think I'm going to hit the Arny-Navy store and pick up a folding shovel. This particular stream is in Nevada and is moderately used, but not heavily patrolled.

Kind of makes me feel like I'm on a secret mission. Breaking the rules now and then feels pretty good.

[Darian]

Just a word of caution.... If you take it on yourself to remove something that has been placed deliberately, you may do more harm than good and you may be removing some agency's or club's conservation project.... From your description of the creek/stream it sounds like you might be creating a channel without any cover for fish....

I vote you try to find out more about this before jumping in to it....

[huntindog]

you do not need a permit in california to remove those small dams..unless you are doing it with a bulldozer. Yes keep removing them. They slow water down, and warm it up, they create impassable barriers and generally they are not good for the streams. We are constantly tearing down the rock makeshift dams on Chico Creek through Bidwell park.

[Scott V]

As Ronald Reagan once said to Gorbachev, "Tear down this wall".

[flyfishnevada]

Just a word of caution.... If you take it on yourself to remove something that has been placed deliberately, you may do more harm than good and you may be removing some agency's or club's conservation project.... From your description of the creek/stream it sounds like you might be creating a channel without any cover for fish....

I vote you try to find out more about this before jumping in to it....

Just to be clear, these are not engineered dams or structures. These have not been placed as part of a restoration plan or project. These are small, hand built dams made out of stones and debris taken from the adjacent river bed. They are maybe 6 to 12 inches high on average. They have, over the years, been widened as the stream seeks to bypass the unnatural barrier. Some have created pools that are 12 -15 feet in width on a stram that you can jump across in many places. There has been damage to the banks as the stream widens and the banks colapse. Same have been there so long they have silted in behind and become only a few inches deep. The area behind and in front of them is devoid of structure since all the stones and debri has been removed form the stream bed to build the thing.

I am an engineer and have toured several stream restoration projects. I know what that stuff looks like. I also have a fair knowledge of hydraulics(from being an engineer) and trout habitat (from being a fisherman) and these dams are not designed to produce quality trout habitat. In fact some fo the larger ones have no trout near them for a significant distance. No cover in stream or from overhanging brush, no depth, probably to warm and a lack of oxygen keep them away. They may hold trout when new due to the increased depth, but I am sure they silt in rather quickly.

Looks like I am not alone. Without some serious restoration, the stream may never be like it was, but I am always amazed at nature's ability to heal itself when left alone. Problem is these things will be rebuilt if they are blown out during the spring or dismantled. I know, I dismantled one a couple of years back on a lark and on a drive the other day it was back. I know I can't remove them all, but the ones further from the camp sites will likely not be rebuilt.