Creek repair - brush dams

Video of the water, downstream to upstream:

https://plus.google.com/photos/photo/101692247658816105998/6286568219087301474

How are the brush dams holding 8 months on, Ludi?

I've got a similar creek here in southern Australia, & am using various structures - rocks, wire, shadecloth - to make weirs to prevent the considerable gully erosion we have.

The comment above re such structures not lasting long enough - & the need for meandering - got me thinking.

They held up fantastically in the flood and I think helped save most of our driveway.  We'll be adding more to them in the coming cold season.  I think they, along with some strategic earthworks, will solve all our flood problems in the next few years - we have a 5 year goal of completing all this work, though it will probably be a good idea to continue to add more material as long as we've physically capable of doing so.

Tyler Ludens wrote:They held up fantastically in the flood and I think helped save most of our driveway.  We'll be adding more to them in the coming cold season.  I think they, along with some strategic earthworks, will solve all our flood problems in the next few years - we have a 5 year goal of completing all this work, though it will probably be a good idea to continue to add more material as long as we've physically capable of doing so.

Thanks for that.

What do you think of the idea (voiced up above) that weirs & barriers like this don't last long enough, & that changing the flow of the stream is more lasting?

(NB: I'm presently employing your method.)

I'm looking at the example of Peter Andrews, whose creek was filled with organic material which eventually grew trees, and seems stable.  I'm hoping to grow Switchgrass, which is supposed to be nearly as stable as rock constructions.  I can't know how this will behave over time, I can only guess it will eventually become stable and "permanent."

Working on this season's brush damming.  We're trying to induce a meander here and move the water away from the side of the hill:

It's looks so insignificant, but has so much impact. I amazed by how much you accomplish without heavy equipment. Reminds me that I need to get digging to spread out the runoff that goes across our front yard during heavy rain events.

I'm also building brush dams in the small gullies and washes/ravines on our 7 acres.  A few bags of leaves collected from neighbors will be dumped on the upstream side of the larger dams, and I intend to plant a seedlings like oaks, mountain laurel, and goldenball lead tree along the edges of the ravines.  The dams are, in my mind, a great way to keep organic material and some rainwater on our property,

Good deal!  They make a huge amount of difference in a short time.

A heavy downpour gave us the opportunity to see how the new brushdam is working, and it is working great, slowing the water and capturing a large amount of organic material.

Started another brush dam in a deeply eroded channel.

Here's some more of that brush dam we've been working on lately:

The original dam at the boundary got washed out a little on one side:

Is it taking a couple rains before the dams hold water? My first rain they didn't hold any, but I saw a lot of leaves etc that got deposited next to it. I assume they start clogging the branches.

They're really meant to slow the water rather than hold it, but eventually - after several years - they may trap enough sediment to actually hold water.  Initially they just filter larger debris such as leaves, and allow the water to pass through.

Okay, this might be the dumbest question ever... But what will happen once the dams actually become impermeable?  Is that your long term goal? Will there be a problem with where the water goes if it no longer can follow the creek bed?  I have said many times... I am pretty terrible at building things, so I think I am missing something here.

I am currently trying to come up with solutions for the flash flooding and erosion that happens here during our rainy season... Which will start in a few weeks.  I am a bit afraid of making everything worse. Thanks for any insight and experience you can share!

There will always be channels for the water to follow - it will simply move more slowly.  At least that's the goal!

This video explains the idea:

Tyler will probably jump in with more information but I can give you somewhere to begin. As the flash flood comes through it strips soil and organic matter down to the bed rock. There is nothing left to catch and hold rain water, think rain in a cement parking lot. The brush dams slow the water enough to make it drop some of those stolen materials. These build up into a healthy layer of soil and organic materials that can absorb a lot of water before it starts running off. Deep soil with high organic content absorbs water before the floods can form. Eventually plants can take root here and continue the process, both creating and capturing organic material. As an added bonus, such techniques also recharge ground water as the captured water seeps deeper. Sometimes it has an added bonus of reawakening dried up old springs.

That's pretty much the whole thing right there, Casie!

Thank you Casie and Tyler, that really explains a lot.

We're trying yet another strategy to slow down the water.  This morning it was too wet to work down in the lower creek channel, so we moved uphill to a place near the neighbors' fence where flood water enters our place as a sheet with force sufficient to flatten the fence.  Our strategy is to try building really big brush piles in the way of the water, to try to deflect it and de-energise it.  If our piles aren't big enough, they'll get pushed downhill by the water, but this shouldn't be bad as they will fetch up on a lower brush dam or form a new dam against trees.

Only another hour or two before we're finished with this 100 foot long brush dam filling the eroded channel:

Update on this dam with grass growing in upstream:

Tyler, I am really loving this thread.  It's awesome seeing how this is all coming together.  Thank you for posting it.

Unfortunately, that which we feared has come to pass - there is a new development upstream of us which is now dumping extra runoff into our already flood-prone creeks.  Some of the water enters our top basin and overflows into other basins, but much of it passes behind the upper basin and enters our land in a rock area where we can't dig a basin. We've talked to the neighbors about them digging a basin but so far no action on their part, so we'll probably have to fix the problem ourselves.  I think we could be able to slow and redirect the runoff by building a mighty brush dam about 150 feet long across the channel on our side of the fence.

Here's my design for three large brush dams to deflect the neighbors' runoff away from the creek channel and, eventually, I hope, direct it to a brush swale that will move it across the land to an infiltration basin.  This is a long term plan!

Started the first of these new brush dams this morning.  With the battery-powered chainsaw my husband gave me, I can do this work by myself, letting him work on his own projects.  I got about 2/3 of the length done, and half the height.  I might be able to finish the whole dam this week.  Pretty darn excited about this one.

A good cordless chainsaw is an amazing tool for our geography and tree types.

I added a cordless pole pruner. Its great for cedar type bushes. Keeps from having to go in the center.

Working on two more brush dams in the same area.  A short one almost finished and another very long one that needs a lot more work.

Finished the brush dams above and started another one in a new location.

Thanks for this post, and the pics help a lot also. My brother had a similar issue and his entire basement ended up getting flooded because he didn't take the precautions and didn't properly re-build/re-design the exterior paths of the water flow, etc. All it took was just a couple of days of hard rain and it cost him in repairs, new carpet, etc. Thanks for the post!

Made another brush dam a few yards upstream of the last one.  This one can probably use some more work, but it is a good start.  It goes clear across the lower creek channel, just upstream of where the two creeks join.

And another one!

Yesterday I completed another brush dam just downstream of the big dam we made 3 years ago.

Here's that original dam; it's been pushed downstream about 50 feet and crushed up against the side of the channel.  Today I started adding to it and reinforcing it.  Tomorrow I'll try to get better photos of the area.  Where we cleared trees, grass is growing in parts of the channel.

Are you not getting sediment buildup from the dams? It's not visible in the pics. Mine became this big spongy mass of brush, oak leaves, and cedar needles. It was pretty amazing,  where i could walk over it.

It might be because i did some clearing above it which added the debris.

It all came down with my  earthworks. It was added to a hugel. Cleared all the brush everywhere on the property. More always coming....

The lower old dams are building up sediment.  The original dam washed to the side, spilling most of the sediment downstream.  My hope is, with all these additional dams I've been building, we'll catch most of the sediment next time it floods.  These new dams haven't been in place for a rainstorm yet.

Makes sense.  I removed a big thicket in my ravine. I left a small part of the thicket where i put the brush dam. It did exceptionally well to hold it in place. The dam pushes against the thicket.

More material added to the original dam

I also made a couple of low dams across the wide part of the channel