Creek repair - rock dams

More flooding rain. We were able to get out for photos while the water is still high.

Attempting to post a video:

https://plus.google.com/photos/photo/101692247658816105998/6286471146571543474

"I made some small rock dams in the lower part of the creek where brush dams are inappropriate".

One thing I have seen done that might be fast and simple is T posts to anchor brush.

I have seen X-mas trees and eastern cedar used to slow water and trap sediment in small creeks.
T posts were driven into the creek to provide a anchor for the base of the trees and shrubs. The trees are pointed down river from the T post.
Water can flow throw but sand and silt will tend to drop. Using X-mas trees you can put these in very fast.
The key is to get some type of tree (willows in my old area) to grow in the settled silt so it holds and is self repairing when trees and shrubs rot.
At which point you pull the T posts.

Thanks for that idea! In most parts of the creek it has eroded to rock, so there isn't anything to anchor t-posts into. I think the neighbor had their fence set into holes drilled into the rock.

We're going to try planting more Switchgrass, which is supposed to be nearly as stable as anchored rock.

OK something to note with your pictures showing how flooded the steam bed gets.

Do you have a place to move that kind of volume of water to? Is there an area you have a good sized depression that a good portion of the water could be diverted to where the water can be slowed let the silt drop and the water percolate into the ground?

Because with that sort of flooding, I would imagine if you were able to build the stream bed up, you would still be getting that kind of water trying to flow through form time to time. It seems to me, you need to figure out where that water can go, before you worry about repairing the creek bed too much. Most any work you do I am guessing will end up damaged during such flooding. If you do end up building up the stream bed, will that push water out into areas you don't want to flood? Could it cause the creek to widen or cut a new channel? It seems the water will flood that stream with some regular force. You might actually want to intentionally widen the creek while at the same time making the bed shallower. By increasing the spread of the stream, and decreasing the drop it takes over the area, you could slow it down quite a bit by separating the energy and force the water has built up in it.

The creek fills the entire lower portion of the land in extreme flood, so the channel is as wide as it can be already, I think. If we can raise the incised portion of the creekbed by building up sediment with the rock dams, in smaller events the water may spread out into more of the channel and perhaps dissipate enough energy to save our driveway. The ultimate goal is to be able to save the driveway even in large flood events, but we don't know if that's possible considering we only control a small portion of the drainage.

Here's a pic showing the bottom part of the land with the flood channel:

Here's the big picture of our land with drainage:

Yeah that looks like you got some struggles to tame that creek down. I can't think of ay other suggestions for the moment, but if I come up with something I will share with ya.

Thanks! It's a big challenge for sure.

I'm still fascinated by your situation and I still could not come up with a good answer. Now I've seen the pictures of a minor flooding I might have some ideas.

Blocking the channel/creek is clearly out of the question so saving the driveway is the main point. I see you have one culvert of I think about a foot wide, maybe a little more. In extreme floods that won't make any difference I'm sure it looks like that culvert is not even there. If debris come down as well it might even get blocked.

I think maybe the easiest solution is to lower part of the driveway, say about a 20 feet section, bring it 3 feet down so the water can overflow there. Compact both the slope up and the slope down on both sides and concrete that whole part of the driveway from below soil level on both sides. On the downstream side add an apron to avoid the water creating a hole when it comes down. Damage should then be pretty much avoided even in big floods.

Other than that I have no idea.

We have three culverts. We'd love a concrete crossing but can't see being able to afford it. Maybe we can get an estimate. It would beat having the driveway rebuilt every few years. The neighbors upstream and downstream have concrete crossings (one is a bridge which cost maybe $20,000?). Neighbors are far, far, above our income level, so we can't go by what they have. We will not be able to build it ourselves, we'd need to hire it done.

Tyler, did you ever check out the illustration called 'flood plain' on page 103 in Mollisons manual? Maybe you could plant these tree lines (or bushes) to spread the water flow?

Thanks for that reference. We have a lot of trees upstream which we hope to use to make brush dams to slow the water before it gets to the rock dams area. We can't plant any kind of tree or shrub because of the deer. Fencing to keep deer from eating stuff gets washed away in flood. We pretty much have to use what's already growing, although I might be able to plant some more large grasses to hold sediment and slow the water a little. I actually think there's a lot we can do, it's just a matter of getting up the energy, or money, to do it.

Seems to me, like the driveway could be saved with a gabion, and/or gabion-apron on the downstream side of the driveway. Takes some wire, and a lot of time/rock, but they are very doable.

That's an excellent suggestion, Joseph; I will definitely look into that. We have a lot of rocks to hand right in that area.

Tyler Ludens wrote:Thanks for that idea! In most parts of the creek it has eroded to rock, so there isn't anything to anchor t-posts into. I think the neighbor had their fence set into holes drilled into the rock.

We're going to try planting more Switchgrass, which is supposed to be nearly as stable as anchored rock.

If the rock is a softer rock like limestone or sandstone you could drill into the rock and use a concrete screw to anchor the trees. This way you would not have to remove the T posts. I have also seen old rock climbing pitons that were no longer usable for rock climbing driven into a cracks or seams in the rock with a hammer to anchor things in a rocky stream bed. Again, the tree or brush will rot away and hopefully you have some growing in the silt and sand that collected.

Another reason I only want to use rocks and grasses in this stretch of the creek is that when it flows it is a very cute little babbling brook that you can see from the road, if anyone bothers to look at the scenery...

The rock dams are working very well; we seem to be getting results fairly quickly.  Several parts of the creek are grassing in and soil is building up behind some of the dams.  I started adding more rocks to a few areas this morning.

One area in particular is becoming wonderfully covered with grass.  This is where the culvert from the other side of the road empties out, often with a forceful volume of water, so we definitely want this area reinforced with grass.

I love following this thread.  Sometimes I think there are great posts but I don't have anything to contribute to the discussion...just want you to know I hope you keep updating this over time.

Started a little more rock damming; reinforcing the gully wall and putting a little rock dam across a small bald patch.  In this area the channel is mostly grown in with grass, except for the little bald spot.  Upstream of the grown in area I plan to put one more rock dam.  Upstream of that will be mostly brush dams.  It's difficult to take photos that look like anything.

More about the inspiration for this work:  

I just watched it. Its funny how the solution for one guy is the problem for another guy(trees). Take the guy in Johnson city. The short take on his video is remove cedars and plant grass. In this video the answer is planting willows trees. I wonder what the difference/reasoning is for both.

I did like the rock dams. The little glimpse in the video showed what appeared to be an engineered marvel. The artistic side really comes out with some permies masters. I liked how they said in a couple of years it wont be visible anymore.

My little rock dam has collected sediment.  I need to add another layer. I may have a new personal record as far as my creek flowing. It originates on my property so its cool to see it springing out of the ground. 6 weeks is the record. Currently its been flowing since oct 5th. I cant take much credit, its the rainfall we have recieved. I have 3 swales up top and cedar brush dams along it. The cedar is catching twigs, leaves etc and is definately building a raised area.

Tyler, since we just went through a period of near record flooding, it seems like a good time to ask if your driveway and road survived this time.   As I remember it, less torrential periods of rain have taken both out in the past.

wayne fajkus wrote:I just watched it. Its funny how the solution for one guy is the problem for another guy(trees). Take the guy in Johnson city. The short take on his video is remove cedars and plant grass. In this video the answer is planting willows trees. I wonder what the difference/reasoning is for both.

The Willow trees are to slow the water and trap debris (I think).  In our region Switchgrass can be used for the same purpose.  Willows allow other things, including grass, to grow beneath and around them whereas Cedars usually prevent most other things from growing under them because of the dense shade.  Most of the areas where we have Cedar on our place are devoid of many other plants and especially free of grass.

Casie Becker wrote:Tyler, since we just went through a period of near record flooding, it seems like a good time to ask if your driveway and road survived this time.   As I remember it, less torrential periods of rain have taken both out in the past.

Thank you for asking, Casie!  We didn't get much local torrential rain, and it's the really local flooding that wipes out our road.  The creek never even got out of its channel this time.  We haven't had a test of our new structures yet with a really big local rain event.  I'm actually looking forward to the next one to see what happens!

As a Civil Engineer I have worked in this area, IE trying to tame water.
I can add, Willows were used extensively in Australia and 60 years later we have a willow problem Research it.
Taming water involves slowing it down and using walls, loose, to divert flow from poles etc that could be undermined.
By building your dams so the toe of the upstream on is level with the top of the lower one, helps reduce the speed of the water.
When meandering streams are straightened, the river gradient is increased, that water flows faster and erosion occurs.
Rocks need to be big enough not to get moved by the water.
Widening the culvert will also slow the water down.
If water is flowing over your drive because the pipe under is not big enough, its almost impossible to prevent the drive being washed away.
Again making the flood area bigger [ wider] over the driveway may help slow the flow and therefore slow the scouring. We would call it a floodway in Australia.
I am suggesting a foldaway say, 5 times wider than what you have now.
Natural sequence farming which you looked at relies on holding water back so it soaks in and does not runoff.
If your neighbours upstream worked with you, the problem may be solved for many of you.

Just finding this thread for the first time. It is great to see progress on a project like this over a period of a few years.

Tyler - have you found info on "one rock dams". The idea is that instead of building a high wall, which is likely be blown away in a flood event, you build a dam that is a single rock high. But you extend it upstream. As sediment builds up behind the wall you can keep building your dam back upstream, getting gradually higher. They act like a - very low profile - gabion, preventing erosion and slowing flow.

http://www.borderlandsrestoration.org/uploads/9/7/3/4/97346656/erosion_control_structures_by_bill_zeedyk.pdf

Thank you Micheal, that's the kind of rock dams I'm building.

Just finished this dam to augment the Switchgrass.

When it comes to your driveway:

The video will give you a good representation of a proper span across a stream vs tossing in an undersized culvert. I have both a culvert and a properly spanned crossing, you will see both in the video.  

You will probably never overcome that undersized culvert and will see your driveway washed out 2-3 times a year.   My gravel driveway into my place gets washed away at least twice a year, sometimes more.  The original owner/builder simply stuck in a culvert and tossed gravel over it all. All of that gets washed away at least twice a year. Luckily the gravel only ends up 10-20 yards away on the driveway and I can put it all back to where it belongs in about an hour or so with my tractor.

Once I purchased this place and watched my driveway get washed away the wife and I decided we had to come up with a better plan. Even though the wife and I both drive 4x4 Toyota SUVs we have to be able to get across that creek to get out of here. Our 4x4s can still manage to navigate the gravel drive when it washes out, but regular sedans and non 4x4 trucks could not so I had to come up with a solution.

After studying the stream for a year I chose a spot that had a solid rock shelf that ran perpendicular the steam. I then tore up the creek and dug down to that shelf using my tractor.  I then purchased a "lowboy" (flat metal semi-trailer used for transporting heavy equipment) at a junkyard.  I ordered several deliveries of concrete, had forms ready for the first pour to build my pillars to set the low boy on. I then placed the lowboy on the pillars to span the creek. The second concrete delivery was all used to backfill and bury both ends of the lowboy. When the third and last load of concrete was delivered I had forms made and in place that would permit a slab to be poured on top of the lowboy, the remaining concrete was used to backfill underneath the low boy/build back up stream banks under it with concrete. I later decided to have the new driveway paved (it turned into a muddy mess on both sides of the bridge and I was tired of gravel).  We rarely use this paved driveway, we have it gated off at the main road that is 1500 ft away through the woods. Kids love using it to ride bikes/skateboards and the wife and I take our evening walk after dinner each evening on it.

I have never seen the flow of water come over top of this span I put in over the creek. The water level in the vid is as high as I've ever seen it.

Here is a pic of the stream at "normal flow" roughly 60 yards above the paved over lowboy I cross in the video.



In the following video I start filming at my washed-out gravel drive that comes into our place, walk up stream to the "bridge" I put in with the low boy, then walk up to the highest part of the stream where the elevation change starts. The entire distance I film is about 130 yards. From where I start filming at my gravel drive to where I stop the video is approximately 8 ft  in elevation change.

Water in the creek.  

Planting willow creates the possibility for beavers to be introduced.  Yes, willows can be invasive, but beavers take care of them quickly.  In that sense, to quote Mr. Mollison, Australia doesn't have a willow problem, but rather, a beaver deficit.  

At one time, beavers were native to 49 of the 50 states (sorry Hawaii) and were found from Central America all the way up to the Yukon in Canada.  They would thrive in Texas if they were given a foothold with an ample supply of food and a starter pond to build off of.

An article about beavers in Texas:

https://tpwd.texas.gov/publications/nonpwdpubs/introducing_mammals/beavers/

Unfortunately this is a seasonal creek which does not have water in it often enough to support beavers.  There may be beavers in the area - a few years ago my sister found a dead one on the bridge over the river which is about half a mile from here.  I do hope to plant willows eventually in some moist spots.

Finished this rock dam this morning, upstream from a brush dam.

Lovely work Tyler!

I really like that the lower branches that I remove from trees as part of my wildfire mitigation strategy are perfect for making checkdams in the ravines.

how was the 2019 season?

We had one big flooding rain and not much significant otherwise.

Here's a rock dam just downstream of a big brush dam.

The lower creek where the original rock dams are is virtually healed with little erosion anymore.