Induced Meandering

Paul and I got to talking about erosion and how we might want to cause erosion in an ordered way in the landscape sometimes. I came across this idea by reading Bill Zeedyk's work river restoration and the concept of induced meandering. Quivira Coalition publishes a great little free field guide.

Induced meandering field guide

They also sell Bill's book Let the Water do the Work which is a phenomenal book on stream processes, geomorphology, assessments, and applied ecology/restoration. Especially for dryland areas and large acreages. It's full of full color photos, detailed methods, assessment and design forms as well as good natural history stories.

Let the Water do the Work

Since rivers are sediment transport systems, erosion is part of their natural cycles of succession and disturbance. the induced meandering capitalizes on this process and guides it to repair incised channels, bring back vegetation, perennial flows and fish habitat. Quite phenomenal.

We built some ORDs (one rock dams) and wicker weirs at a restoration site last year. not doing much yet since we had so little precip last wet season. here's the quivira erosion control field guide as well.
erosion control field guide

Criag Sponholtz at Drylands Solutions is doing some beautiful work with these.http://www.drylandsolutions.com/
he's teaching a class at quail springs this Novemberhttp://www.quailsprings.org/event/applied-watershed-restoration/

is anyone on the forums using these techniques? I'd love to hear stories or see pictures.

Thank you for those helpful links!

my son is in the process of creating some pond on pond on pond areas along our overflow ditch from our main pond through our woods and open areas behind the house, thus allowing the water to instead of just flow away from the overflow ..flow into another pond and then another as many as we can dig on our property. It will take a while but we hope to start a second pond this summer.

was it a meander happens every 7 times the width of the stream ?

Morgan Morrigan wrote:was it a meander happens every 7 times the width of the stream ?

I'm not sure about this Morgan. I think the healthy ratio of meander length to stream width will vary with the channel type and valley setting. If possible, this is calibrated by finding a reference reach in the area, which is representative of a healthy channel in a similar soil, flow regime, gradient, and valley setting. if the channel is incised and returning to a meanderform, then this ratio will be changing. Another important ratio is the meander length relative to the valley length (see field guide for definitions).

This will also depend on how you define the width of the stream, bankfull width, floodplain width, etc. in a Rosgen E channel these can be very different, and the primary channel may meander within a meadowlike floodplain which also meanders within a valley setting.

According to Bill Zeedyk's induced meandering field guide, Induced meandering is only appropriate for incised channels (Rosgen F and G channels and sometimes B) to speed their succession back to C or E channels. the example in this guide has a bankfull width of 13', a meander length of 130', and a valley length of 100'. which puts the ratio at ~10:1.

some other techniques are great for arroyos or seasonal streams such as ORDs and Media Lunas.

I work is river restoration as well. In dryland incised streams in eastern WA and OR there is a lot of work with beaver, assisting beaver, planting food for beaver. In low gradient stream they can be ecosystem architects. Under that scenario, they drive a bunch of pilings to dramatically increase roughness and reduce velocity, giving beaver something to build off of and back watering the system, rebuilding the stream bed with deposition, and flattening out the hydrography downstream by storing floods and increasing base flow.

Check out some of the local work by Tim Beechie: http://scholar.google.com/scholar?q=beaver+restoration+channel+incision+beechie&btnG=&hl=en&as_sdt=0%2C48

With a severely incised stream, I am not sure that meander alone will get you back to historic conditions, but you might just end up building a small confined floodplain, while transporting a hell of a lot of sediment down stream. Not really my area of expertise.

Also... sediment budget, as well as longitudinal profile (what is the slope of upstream reaches compared to your work reach) also has a strong effect on stream planiform form.

Paul Cereghino wrote:

With a severely incised stream, I am not sure that meander alone will get you back to historic conditions, but you might just end up building a small confined floodplain, while transporting a hell of a lot of sediment down stream. Not really my area of expertise.

Great Info, thanks Paul. I agree, in severly incised streams, historic conditions will not be achieved. I struggle with the concept of restoration to 'historical' conditions in any case. My understanding of induced meandering is to 'accelerate' the natural floodplain regeneration that takes place in incised channels. structures are designed and installed both to erode and capture sediment.

The book has lots of detail on how this progresses in different valley and channel settings

I checked out the publication. It looks interesting. The theory looks consistent with what I've been taught. It makes me wonder, why does the stream lack planiform (plan view) complexity in the first place? The wicker/brush fence scheme and post fencing is very similar to what Beechie is doing, and the same technique is being used to 'train' BIG rivers, to reduce damage for farmland or where a transportation corridor crosses a floodplain. As the watershed hydrology changes with clearning and development and climate change, than rivers start adjusting to find a new equilibrium.

The most powerful concept I picked up in fluvial geomorphology is that streams are both flows of water and of sediment.

I think that the "process-based restoration" community that is developing at the interface of academics and restoration field practice has a lot in common with permaculture, although it is less adventurous. It is eroding the concept of historic condition as the only basis for design, rather we look for specific dynamics that we are trying to recover that change the trajectory of system evolution, so we are looking for core patterns of historic processes to mimic, rather than trying to rebuild the historic structure.

The IM field guide is a simple example of the overall concept. the details I was referring to are in the book 'Let the Water do the Work' where Bill and Van get more into both the theory and practice across a wider variety of scales. also the how-to's of taking a longitudinal profile, cross sectional profile, assessing valley setting and channel type, etc. What interests me the most about this work is the low-cost methodology and relatively minimal inputs when compared with many other riparian restoration approaches. I'm not promoting it as 'the best', just trying to provide more access to information and a variety of tools for our work. I'm guessing this will be most useful for ranchers and homesteaders who do not have tons of money or time to throw at a restoration project and just need to nudge some of their systems back into function while keeping the water on the land longer.

I agree the ? of how a channel got to be straight rather than meandering is an important one to ask since not all channels will meander like a classic C or E channel.

I'm very interested in the 'Process-based restoration' approach and the adaptive management layer, of which holistic management is an example. I also like the PFC assessment method for riparian areas because it looks for functional conditions rather than specific historic parameters.

Another great set of literature that has emerged from the field of systems ecology is the Resilience Science and the Resilience Alliance.

http://www.resalliance.org/

they host a scientific conference every year.

in particular, I like the concept of Panarchy and Cross-scale interactions that they have developed, and see it as a useful tool for designing and managing permaculture systems as well as regional socio-ecological systems.

since you mentioned fluvial geomorphology, I'll add a link to Rosgen's page as well, which has some great free and paid resources.

http://www.wildlandhydrology.com/index.htm

In my opinion, access to and understanding of info like this will allow permaculturists to speak the language of scientists and public land managers and both gain credibility as well as access to partnerships. I think it also provides us with a broader set of tools and a more complete perspective of the complexity of nature. not to say that we should let this replace observation as a critical tool.

We have a business that does stream, forest and severe disturbance restoration: www.watershedconsulting.com. We use many techniques similar to those used by Zeedyk & Clothier, here's a link to a reveg manual we built for stream restoration in Western Montana: http://www.watershedconsulting.com/UP0000000043.pdf

Nice piece of work... rarely do these kinds of manuals offer practical experience with variations on technique (squares of weed fabric vs. islands of weed fabric). Thanks for writing it down. It looks public domain, can I distribute it?

While we are wandering in socio-ecological systems cross polination... here is a set of links I gathered on the concept of 'Satoyama' - traditional Japanese landscape patterns.
http://stewardshipinstitute.info/wiki/index.php?title=Satoyama

And an interesting international policy group - http://www.ecoagriculture.org/publications.php - the primary value of which is learning how these kinds of high profile NGOs are talking about what they are doing (as compared to what they actually do?) Permaculture implementation (vs. just Pemaculture education) is the necessary backend that makes these kinds of ideas real, but might be less developed than the sales pitch...

Yes, distribution is ok. We have authored several of these for various ecotypes and situations. Here is a link to my first one, for Denali National Park, AK

http://alaska.usgs.gov/staff/biology/pdfs/DenaliBook.pdf

More river resources: A slide lecture on basic river dynamics with plain english explanations of terms, causes and consequences with examples of several western rivers shown from areal or satelite pics. At the end he recommends four publications on the subject.

http://www.youtube.com/watch?v=rFCKscF7ncw

http://wdfw.wa.gov/conservation/habitat/planning/ahg/

Here's a range of publications... also with a salmonid and Cascadian focus...

This page is deep in the Natural Resource Conservation Service site. They have many interesting and useful technical guides on all types of resources. Unfortunately some of the authors appear to have fallen into a sort of weird dialect, possible bureaucrat-lish, which is fairly hard to decipher even though it appears they do have good info and examples once you do the translation.

http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/national/water/quality/tr/?cid=stelprdb1044782

From the above page this protocol for a standard method of determining and recording stream status (health) seems helpful to those with surface water and is fairly readable.

http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044776.pdf

I've been looking at this, and I'd rather just build gabions to reconnect the stream to the original floodplain. On my land I have some incisions 2m deep, and numerous headcuts working their way upstream. The good news is that its not to wide yet, so it could be a lot worse.

The whole concept of creating a new floodplain at a lower elevation just seems so wrong to me. Especially for drylands. The whole water table drops when you lower the floodplain. IM only captures a tiny fraction of the soil that it erodes away, the rest is gone.

Ancient technologies have used check dams to prevent erosion, and address incision. I'd rather do that then create even more erosion, and dehydrating the land by dropping the water table.

Andy

Which sources proposed lowering the flood plain? I did a quick scan through a couple but didn't see anything that seemed what you were talking about; but maybe I'm not clear on what you mean. Be interested to see what they're saying and also the date because sometimes recommendations change over time.

Rufus

Rufus

My mistake, the correct word was bankfull, not floodplain.

I guess a good example would be fig4, 5, 6 in the Induced meandering field guide. How do you achieve the meandering without;
a) eroding a lot of perfectly good soil and
b) lowering the bankfull.
Keeping in mind that most straight streams have steep and deep banks.

One way is to divert the stream back onto the original floodplain if possible further upstream, then create a new meander for it. Another would be check dams or gabions to trap sediment and reconnect the stream to the floodplain during bankfull rainfall events.

I often look at modified streams and can see the original meander patterns still in the landscape, and the new stream is far lower. I'm not satisfied with that.

regards

Andy

I think I see what you mean, though I didn't find your reference. However, I've only read a couple texts from that site and skimmed half dozen others.

If I understand your point: that the undercut, slump, fill, spread, repeat chain of events carries away sediment while widening and changing the stream path in situ; if it raises the water table and stream bed it does so very slowly based on more sediment depositing from upstream. What you'd like to accomplish would be to speed the process by increasing sediment deposition dramatically while reducing erosion as much as possible. You're considering forming settling ponds in various ways to promote fast sedimentation. Also, given access to a stream bed of high enough elevation up stream of the problem area, possible try to use dams (quite small ones presumably) to block the incised channel and redirect flow onto the higher original flood plain, may even into part of an original channel.

Assuming you succeed in quickly redirecting the flow won't you still be left with a sizable gully where the problem channel will still exist? I would guess you could guide some flow to deposit sediment there but it sounds like it will need relatively intensive and continuous management. Also, flood events might be hard control to prevent wiping out your plans.

Rufus

Rufus

Basically thats what I mean. It's the loss of topsoil/organic matter that I'm not happy with, because it's gone for good. Also I don't believe it is possible to raise the stream bed with IM. The best you could hope for would be to not lower it further, though the diagrams suggest that you will lower it.

I won't be redirecting my stream onto the old meanders, but I have noticed that when it breaches its banks it will use the old meanders when it can. I mentioned it only as a possibility.

What I have noticed is that in places where the stream still has access to the original floodplain there is very little erosion from the recent 10 year flood we had. Though headcuts have rapidly advanced and deepened, as well as the bends getting deeper and scouring rapidly into the banks. The solution as I see it, is to dissipate the flow onto the original floodplain, using check dams/gabions. Over time the gabions will capture sediment, and the stream bed will be raised.

I don't intend to controll the flood events, what I'd like to do is give the water somewhere to go. Release it from the incised banks onto the wide original floodplain.

regards

> release it from the incised banks into... the original flood plain

I guess that means that your efforts will be concentrated upstream at a place where the channel hasn't fallen too far below the original flood plain.

> I don't intend to controll the flood events, what I'd like to do is give the water somewhere to go. Release it from the incised banks onto the wide original floodplain.

Hmm. That sounds like a bit of oxymoron because it is only during flood events that the "flood" plain is actually used. However, your general point is clear. Sounds like a good goal if you can juggle the elevations successfully. I guess if it works then theoretically you could fill the gully with sediment over the years, moving your gabions further downstream as each one collects sediment above it...

Thanks for raising the point. Not sure why it isn't mentioned anywhere but maybe it's because actual restoration work is constrained by project scope and property rights and it's difficult to access the needed elevations.

Rufus

Here is an example from http://floodwateragroecology.com/blog/uncategorized/10-guiding-principles-for-watershed-restoration-regenerative-water-harvesting/

The picture is from a stream not nearly as incised or as big, hence the use of one rock dam type structures instead of gabions, but the end result is what I aspire to. So as time and money allow I'll gradually add gabions. Thanks for discussing it, helps me clarify things for myself as well,

regards

I haven't checked the above resources, partly because my situation is not really the same as this. My creek is not a deep eroded gully. It is more like the last photo posted by Andy Reed, except that it's just inside the forest on the edge of my meadow, and my ground is steeper, I think.

Here's my problem... or more to the point, situation, not a problem yet, and I'd rather view it as a solution/opportunity:

When this south facing meadow was cleared, it appears the creek may have been pushed to it's present location by the bulldozer in the upper meadow. It is now in the forest partly against steeper ground as it rises to the east. I might be wrong, but there is a channel in the middle east of my meadow that looks like a good place for where a creek should be. But there is no mossy rocks or anything like that in the dry creek channel itself. The meadow has been used as a pasture for several decades, and the layers of grassy sod may have covered evidence of it being the true channel. (Right now the meadow dip is covered with a lot of snow and I will investigate this in the spring). It could be that the present creek is exactly where it is supposed to be and the small creek like dip in the meadow is simply the place it goes when it blows it's bank at high water on some years.

The meadow itself is clearly a fan of sediment, where the creek has meandered back and forth over many centuries (or... and this is a wee tad frightening... several large blowout events from landslides damming the creek above!), or a combination of different patterns. The mountain slope changes fairly dramatically just above this location from steep wild mountain to a broad cone of gravels, rocks, and silts with a skiff of soil. The creek enters my property basically right at the top of the meadow, and cuts a little east and stays just in the forest heading South.

My concern is that I would like to build my home on the meadow as the rest of my land across the creek is forested and I'd like to keep it that way. If I was to build in the forest I would have to clear a lot of trees for a passive solar house. The concern is house location and creek location.

My hope, beyond building my house on the meadow, is that I can utilize the flows of the creek to enable watering of my land system in the meadow.

I'm concerned that the creek, which isn't very high above the planer surface of the cone, and has jumped it's banks into the meadow gully in the recent past, will do so in a much bigger way, and possibly head toward my house site. My house site is on fairly high ground in relation to the creek on the same contour line. The house site is on the extreme west of my property. The house site is halfway down the meadow toward the road to the south. It is west of the creek (which is on the east side of the meadow). The dry steam channel is halfway-ish between the creek and the house, and is often lower than both the creek and the house site. But since the creek and forest/meadow area are on virtually the same plane right across the top of the property, if the creek blows out, and it doesn't go into the blowout overflow channel, then it could head Southwest-ish on the slight ridge of the alluvial fan ridge my house site.


I guess I'm looking for ideas on what I should do.

I'd like to keep most of the creek in it's bounds, since it seems to like where it is for the most part.

It's not really a steep deep gully situation, and I've thought about doing some work to induce meander, use it to collect sediment with willows and logs and rocks, and to bring a bit of water over towards the meadow so as to hydrate the soil on the creek edge a bit more.

I'm also considering bringing in a machine and making a large wall going east west basically at the top of the meadow, with a slight angle towards the South to keep the creek toward it's present course in high water/flooding events.

I was also hoping that if I built the wall, I could create a pond of sorts up there on the high side of the wall and from there feed water by pipe into the meadow gully at seasonal high water, creating a series of ponds in the dry creek form, and into a keyline system.

thoughts?

Well I recently had a major setback when we recently had a 100 year type flood event. Trees and everything wiped out, some areas of pasture now covered in rocks I can't even lift etc. I have dealt with floods in the past, but nothing as extreme as that, even the bridge for the main highway got taken out. I've decided to leave it for now, until I can work out a better idea.

In your situation, the easiest solution I have seen is to build an earthen mound around your house in a "U" shape protecting against the flow of the stream. Build it higher then you think is necessary, and build the long sides until they are well below the contour level of your house. My neighbours have this setup, unfortunately it wasn't quite high enough for the last flood, but it normally works well. Cover the mound in trees etc. and incorporate it into your plan. You could get the dirt from a construction company, or roading company. They are always looking for places to dump fill, though I suggest you view the site where they are removing it from, to make sure it's not toxic.
Hope that helps.

Roberto pokachinni wrote:
I guess I'm looking for ideas on what I should do.

I'd like to keep most of the creek in it's bounds, since it seems to like where it is for the most part.

It's not really a steep deep gully situation, and I've thought about doing some work to induce meander, use it to collect sediment with willows and logs and rocks, and to bring a bit of water over towards the meadow so as to hydrate the soil on the creek edge a bit more.

I'm also considering bringing in a machine and making a large wall going east west basically at the top of the meadow, with a slight angle towards the South to keep the creek toward it's present course in high water/flooding events.

I was also hoping that if I built the wall, I could create a pond of sorts up there on the high side of the wall and from there feed water by pipe into the meadow gully at seasonal high water, creating a series of ponds in the dry creek form, and into a keyline system.

thoughts?

I think without a site plan, including contours, and lots of pictures, we are going to struggle to give meaningful specific advice. As I understand it you are looking to to slow and spread the flow of water through the stream in your meadow. You probably want to look into gabions - these are basically leaky dams which hold back some water and collect sediment when you have storm events.

You don't really describe the land further up the water catchment from your property - is it owned/cared for? It may be that, with the owners cooperation, you could do some works on the stream even before it reaches your boundary to have a bigger impact on the overall water catchment, not just your little patch of it.

Also, depending on your slope and land you could even try building a small dam/fishpond at the high point of your land. This would provide a good head of pressure for irrigation where you need it. If you haven't seen it yet I suggest looking at this video. It is not specifically about streams, but the second half looks at keeping water high on your land to make use of it. I found it helpful for getting my head around these ideas.

Geoff Lawton

Andy Reed wrote:Well I recently had a major setback when we recently had a 100 year type flood event. Trees and everything wiped out, some areas of pasture now covered in rocks I can't even lift etc. I have dealt with floods in the past, but nothing as extreme as that, even the bridge for the main highway got taken out. I've decided to leave it for now, until I can work out a better idea.

Andy - sorry to hear that. Sounds like a major event! I have to ask - is there some aspect of the water catchment that has changed that might have led to a flash flood type scenario? Trees cleared up stream? areas tarmaced, a large property development in the catchment? I was having discussions with friends in Australia recently who were lamenting the increased frequency of flood events in their area and pinned it squarely on storm drainage from more and more urban development.

If there is something going on then it may be in the best interests of the community as a whole to take some steps to heal this water catchment - on contour swales to intercept surface flow, tree planting, diverting storm drains to infiltration basins rather directly to water courses.

@ Michael, there has been no change in the catchment for decades as far as I can tell. The stream does have a large catchment, which is mostly steep hills covered in pasture. We are semi arid, and even the pasture is pretty sparse on the sunny sides of the hill. We had about 120mm of rain within about 4 hours, and it all just ran off. During summer the stream only holds water in some of the pools.
I've planted thousands of seeds (wattle, locust, tagaste, almond) with very limited success to date, hopefully more will grow this year.

Hi Michael and Andy,

Thanks for your posts. Sounds like a hard time with that flood event, Andy. It might be a good idea to meditate upon the aftermath to figure out what to do next. I really appreciate Michael's comment's to you about it too.

Yes, Michael, I also need more information (such as contours), and was lucky to visit with the previous owner on my way up to the land, yesterday. He gave me some maps, though not contour maps, and some pertinent information for the land from his knowledge and archival stuff about the land's history.

I was correct in assuming that the dry streambed in the meadow was the original course. It was altered when the land was cleared in 1913, in several places including at the top of my 8 acre meadow (as I suspected). I asked him his opinion of moving it back to it's original course and he recommended not doing so. I was just throwing it out there, but in reality knew his answer and thought the same reasons as he for it. The present location is vegetated with trees and has built a creek form over 100 years. He said the government/public owns the creek itself, and a small area around it, so that is one of the reasons that the farmer pushed it as far towards the rise in the east as possible (more grazing land available without the animals having to cross, or further disrupt the creek). There was likely an agreement with the government agent to leave the creek area, and the rest of the parcel to the east vegetated/wild forest.

The previous owner was on a short lunch break, so I couldn't ask all the questions I wanted to, so I will be in email exchange with him for further information.

Michael, I am familiar with the permaculture concepts of storing water on the highest points in the land, and gambions. Both of these and swales, and possibly a keyline system I plan to incorporate in different ways.

Andy, Great idea about the "U" shaped protective berm around the house. I was already planning to put a berm behind the uphill/North side of the house, and was considering doing as you described further yet to the north. I have permission from the landowners above me to put in a long waterline above them (so long as I make a document that gives them primary water rights); I intend to put this in to have enough head on the line to do a micro-hydro project and get all my other irrigation/house needs taken care of. The pond system will be for back up of the water system, to charge the landscape with water, and to provide micro climate and habitat for plants and animals.

Michael, there is a landowner above me. My property is not square but a truncated square with one corner angled so that their water line is still on their land. There water line comes out of the creek not far above my property. Their property goes roughly in an L shape with mine nestled in the space of the L. The original property was 250 acres, and mine is 40 of that. The property above mine is forested, though some of it has had fire damage and has been logged, most of it has recovered with many decades of regeneration. Most recently the mountain pine beetle has killed off an area of Pinus Contorta on an upper ridge and sporadically on the two properties. This will probably result in some increased runoff, and erosion. I may go up and do some willow planting and minor swales on this area to help it recover a bit faster.

Supper time. Will write more later or tomorrow.

Well not everyone is in to dine yet so I pulled the salmon out of the oven and got back to this.

The creek comes off of a pretty steep mountain, which is the first in a series of ascending mountain peaks on Crown (government/public) Land. After that, not far to the North and North West is a wilder section of Jasper National Park, but that is way past effect of this minor drainage. I have not hiked up the full watershed. But I've been above it in the alpine. The creek watershed takes some turns and has some pretty steep sections but from what I can tell there is no major waterfalls, ravines, or gullies up there.

As I mentioned in the post a few minutes ago, there is land owned above me, and the creek is accessed for their water needs above me. There is also some interest from them on increasing the water in the creek. We discussed it briefly last year and I will likely meet with them in the next month to discuss some ideas. Including possibly, gambions, some swales and hugulkultur in the small meadow that comes near the creek above mine. At the top of that meadow, on the west side of their part of the land, the mountain begins to slope steeply, where as both of our properties slope steeply on the East side of the creek beginning well back on my land.

Alright it's supper time for real this time.

Here's a recording of a presentation by Bill Zeedyk that gives a great quick (and free) overview of many of his techniques, with before and after photos. About 1 hour.

http://www.conservationwebinars.net/webinars/wet-meadow-restoration-in-the-sagebrush-ecosystem

The Conservation Webinars page is a great resource. The main audience is NRCS employees, but almost all of it will be helpful for producers as well. Check out the list of On Demand Webinars.

I hope everyone has looked into the permit process before altering streams and rivers in any way.

Sadly I even have to have a permit to swale to anything more than 1ft deep. In fact she told me not to call what I'm doing "swales" but "planting trenches". Ah the law. More restrictive than good, imo.

I just hope you are all careful as the fines and potential for other charges would be great should you not get the permission required.

Several years on, has anyone got any results from applying the Induced Meandering techniques?

I've got a badly eroded creek 12' deep & 15 metres wide (from gold mining), & am thinking of applying some Zeedyk methods such as picket baffles & rock weirs, to make the creek bend.

I've gotten a good build up of soil and grass in an eroding channel.  I'll try to get some photos this morning.

Here's a photo of the meander away from the power pole, that seems to be working.  I made a rock pile to direct the stream away from the side of the channel and the pole.  You can slightly see the rock pile in this photo:

Tyler Ludens wrote:Here's a photo of the meander away from the power pole, that seems to be working.  I made a rock pile to direct the stream away from the side of the channel and the pole.  You can slightly see the rock pile in this photo:

Thanks Tyler, nice to see.

How much build-up of the stream bed has there been?

Will you extend the baffle so the meander keeps extending out beyond the pole?

So far there isn't much build up of soil except at this spot, and I haven't really measured it - the most obvious change is the thick growth of grass through here, so I think the soil has built up 2-4 inches since I built the first rock pile a few years ago.  I added to that and built a lot more rock dams across other parts of the creek a few months ago but those have only collected a small amount of silt.  I plan to keep adding rocks, especially near the power pole.