Pond Boss
Posted By: jeffreythree Leaving trees on a dam ? - 10/19/08 04:06 PM
I know you really are not supposed to leave trees on a dam, but this may be a different story. My pond uses an old 75' wide railroad berm along one side to hold water. Would it be okay to leave trees on it? No tree is over 4" yet. The fish sure love all of the critters that fall out of the brush there and it is very steep sided so tree debris would be less of a problem than dirt from erosion. Since I will be clearing the other part of the dam of trees next weekend, I figured I should find out if I need to do it all.
Posted By: GW Re: Leaving trees on a dam ? - 10/19/08 06:26 PM
From what I've read it's safest not to have any trees on a dam, but I do see a lot of dams in my area with large trees on them. I'm sure there's an element of risk, like with most things, but I still don't have a good idea of what degree of risk there is in this case. What's the worst case scenario? I would guess that it's having to drain your pond in the future for a repair, at least partially.

This topic always makes me curious about how often dams fail because of trees. Has anyone on this forum ever had it happen to them, or know of someone who had it happen?
Posted By: jsand13 Re: Leaving trees on a dam ? - 10/19/08 06:35 PM
I don't think the trees cause a problem when they are alive. But lets say you leave them on there for 15-20 years and now the roots go all the way through the dam then for some reason one of the trees die from lightening or insects. As the roots of the tree rot water begins to flow through the dam following corse of the decaying roots. This happend with my 1.5 acre pond when cotton wood trees were left on it to long. Now the pond goes from 10' deep in the spring to almost dry in the summer months. It looses almost a 1" of water per day.
Posted By: Ric Swaim Re: Leaving trees on a dam ? - 10/19/08 07:05 PM
Is the rr still in use?
I would remove any trees that have the potential to grow tall or have deep roots. If a large tree blows over it can lift a huge root ball from the berm.
If desired you could replace the trees removed with shallow root trees such as flowering dogwood or some other indigenous shallow root tree.
Posted By: jeffreythree Re: Leaving trees on a dam ? - 10/19/08 08:39 PM
The railroad was pulled up long ago. The majority of the trees there are ash and a couple of water oaks. The railroad bed has been there for over 100 years old with the top 75-100' across and the base is closer to 200' wide. If a tree was windthrown, I would have plenty of space to come in for a repair. I wonder how much these trees draw up in summer? I, luckily, have no cottonwoods and I am cutting most of the willow I find. The pond is not lined, the soil is pretty heavy clay, and was originally made in 1895 and repaired and refilled in the '90s after an unknown amount of time with a breeched dam.
Posted By: GW Re: Leaving trees on a dam ? - 10/19/08 09:24 PM
 Originally Posted By: jsand13
I don't think the trees cause a problem when they are alive. But lets say you leave them on there for 15-20 years and now the roots go all the way through the dam then for some reason one of the trees die from lightening or insects. As the roots of the tree rot water begins to flow through the dam following corse of the decaying roots. This happend with my 1.5 acre pond when cotton wood trees were left on it to long. Now the pond goes from 10' deep in the spring to almost dry in the summer months. It looses almost a 1" of water per day.


I agree with your description of how trees can cause damage. Just out of curiosity what makes you say the trees were the cause in your case?
Posted By: otto Re: Leaving trees on a dam ? - 10/19/08 10:24 PM
30 years looking at dams. One that had a problem with trees.

Otto
Posted By: jsand13 Re: Leaving trees on a dam ? - 10/20/08 01:15 AM
A few years after the die and were removed water started leaking through where the trees had been.
Posted By: Scott Trava Re: Leaving trees on a dam ? - 10/27/08 08:20 PM
In NY state from the down stream toe to the up stream toe there should not be any trees or shrubs with a canopy wider than 4 foot anything larger is trouble if the tree roots come near the freeboard level cut em down. Many problems arrise when winds uproot trees and cancel out the appurtenant workings If there are trees around the lake that are dead or leaning remove them. Dams ,service and auxiliary spillways and conduit should be serviced at least once a year. Number 1 mistake on service spillways flash boards to thick and do not fail during storm flow
Posted By: jeffhasapond Re: Leaving trees on a dam ? - 10/28/08 03:24 PM
 Originally Posted By: otto
30 years looking at dams. One that had a problem with trees.


Man am I glad to hear those words Otto. When I bought my place it had (and still has) some huge trees on the dam. But the dam is huge also. I had read a thread about trees on a dam and how bad they were and I was paranoid. I was trying to figure out how in the heck I was going to remove all of these large trees. So I have DIED out to my place and we walk the dam and I mention to him "so what am I going to do with all these damn dam trees, do you think they'll cause a leak?" He told me that based upon the size of the dam and the type of trees and the fact that the dam had been there for 60 years and there is no evidence that it has leaked so far he wouldn't worry about.

With that news and the application of two Capt'n and Cokes I slept much better that night.


Posted By: Midwest Dave Re: Leaving trees on a dam ? - 11/30/08 03:33 PM
JHAP, one thing you might want to consider before you put down that Capt'n and Coke, is the Emerald Ash Borer. There is a lot of buzz around here (pun intended) about that bug. They expect most of the ash trees in my area to be dead within 5 years because of this pest. I'm not sure about your neck of the woods, but its a problem in IL.
Posted By: Midwest Dave Re: Leaving trees on a dam ? - 11/30/08 03:38 PM
On a similar note, what do you guys think of this Hackberry at the base of my new dam? Do you think its going to be a problem, or ok since its on the edge?

[img]http://img224.imageshack.us/my.php?image=99backdam508dq9.jpg][/img]
Posted By: jeffreythree Re: Leaving trees on a dam ? - 11/30/08 05:56 PM
I would take it down. It appears that dirt from the dam has significantly changed the depth of its roots. It will probably die anyway from suffocation or lose a lot of its vigor on the dam side. Here are some pics of me enjoying some of my clearing work. Cleared about 150' of shoreline on the west side, got about 50' to go and got to cut out the mangled trees the old owner butchered with 5' tall resprouting stumps around the rest while leaving brush and healthy trees for the wildlife.

My wife fishing for the first time and mom watching 11/8/08:

Me fishing 11/8/08 while enjoying the fall colors and weather:

Posted By: Midwest Dave Re: Leaving trees on a dam ? - 11/30/08 08:02 PM
Looks great Jeff. I hope to have a picture of us fishing our pond for the first time next fall! So...what did you catch???
Posted By: jeffreythree Re: Leaving trees on a dam ? - 11/30/08 09:28 PM
Little bass, the bigger ones were not biting, and some mean old mongrel HBG. On 4 pound test, everything is exciting!

Mom with a LMB

Wife with her 1st fish ever

Posted By: Midwest Dave Re: Leaving trees on a dam ? - 12/01/08 02:09 AM
Very cool, thanks for the photos. Hopefully we'll have good luck with our stocking. Its going to be slow though, because I'm 2:20 from my lake and I doubt I'm going to have money to feed this coming year with the expense we just incurred on the dam.
Posted By: otto Re: Leaving trees on a dam ? - 12/01/08 11:24 AM
The book says that a tree that has to much dirt built up around the roots will die it looke like that tree might have to much dirt around it.. But I would leave it and see wnat it does over the next couple of years.
Posted By: Theo Gallus Re: Leaving trees on a dam ? - 12/01/08 11:50 AM
I left one tree, about 10" dbh, way down at the end of where we got rid of excess dirt below the dam at my new pond. It had fill over about 60% of the root area, with the rest of the root area left at the original elevation. There was a small ditch (maybe 2' wide, 4' deep) dug in the root area as well, to bury a water line to a freezeout hydrant just past the tree. That tree was fine for this last year, the first after the excavating.
Posted By: eddie_walker Re: Leaving trees on a dam ? - 12/01/08 09:24 PM
 Originally Posted By: Midwest Dave
On a similar note, what do you guys think of this Hackberry at the base of my new dam? Do you think its going to be a problem, or ok since its on the edge?


I don't know the species of the trees on the back of my dam, but there's probably half a dozen different types that are similar to yours in the picture. My thought was that I could leave it there and hope for the best, or take it out now and never know if it would have made it or not. I thought they had a chance because one side of the tree wasn't desturbed and they were all medium sized trees. The older trees die real easy, but the smaller the tree, the more you can do to it and it will live.

The ones that have died on my are on the other side of the pond and were I didn't dig or dam up anything. I think the ground is too wet for them now, and that's caused them to die. I don't know, but it's been disapointing to see them go.

You can always dig it out just as easy next year as you can this year. Let it live and see what happens.

Eddie
Posted By: jeffreythree Re: Leaving trees on a dam ? - 12/01/08 10:57 PM
And don't forget a healthy forest is supposed to have a few dead snags, if that hackberry does die. Hawks and owls use them for perches, and all sorts of other critters use them for food and home. I have a big dead bodark that almost always has a raptor of one kind or another watching for a tasty morsel to come have a drink at the pond.
Posted By: GW Re: Leaving trees on a dam ? - 12/02/08 02:36 AM
I agree with jeffreythree about the dead trees. I've left several around our ponds. We have lots of appreciative woodpeckers around here.
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