Creating a Dry Creek Bed - with Tips for a Natural Look

Current State of the Creek. Two stone bridges, rough mounds, boulders not yet in place.
It took me three six-hour days to get this far, roughly.

I'm quite liking the look of the stones so far. As a rule of thumb, the middle sized stones go in the middle, smaller ones towards the banks. I don't have middle sized ones though. Large and small only. And it's a small creek, width wise.

I posted about how I backed into this hugely fun project here. In this post, I'll provide what advice I gleaned from the web, and show how I extended the dry creek across our south garden, to drain down into the chaparral slope.

I'm not done yet, but it's amazing how much you can do in a short time.  Friends gave me all the river rocks - Yesterday, local friends offered me 4 bags of small pebbles which really helps vary the look - a mixture of small and medium river rocks are really required.

So, to get back to the beginning of this project. After I put a short creek for drainage in the succulent bed that is next to the house, I decided to continue it, and break up the south garden layout a new way --  nibbling into Experimental Bed #1 on the left, and rerouting the cross-wise path towards the right.

First I did a rough layout with a hose, creek with three meanders. Meanders make for a natural look. 

I played around with the hose quite a bit - and when I was digging out I made more adjustments. I made the river widen on the outer curves of a meander.

Then I started digging out the channel. I recommend a wider channel than I used. It's easier to arrange the river rocks naturalistically in a wider channel. But - it also uses more rocks.

When I was putting the stones in, I made the outer curves even wider - mimicking erosion. I think I should have made them even wider perhaps. I like the changes in width - maybe it exaggerates reality a little.

I tried to create a little beach on the promontory of an inner curve (it's a small grey blob in the photo below, near the bird bath end) that is, on the "deposition" side of one meander - as shown in this fishing blog picture:

I'm going to work on that a bit more - I found some road gravel and used it, but I don't like the color or texture.

Here's how it looked yesterday. Today I started mucking about more with the mounds and moved one large rock roughly into place. I might put small pebbles into the succulent bed creek too. Not sure.

At the end - the swale end (I'm standing on the chaparral slope across from the house).
Not done here yet -- I'll probably extend it to distribute water more evenly down the slope and add small pebbles.

The rest of the post has some pointers I picked up from sites about dry creek beds, and some ideas based on how rivers flow, and deposit sediment, and erode banks.

Basic Advice

The best instructions I found for building a dry creek bed were on this Washington State University site. Here are the main points I used from their site (there is more info on their page):

• A width to depth ratio of 2:1 should look about right. For example, if you want your dry stream bed to be about 4 feet wide, make it about 2 feet deep. 
• Your dry stream bed should follow a meandering or curving path rather than a straight line. You may want to include a promontory or small beach to add further interest.
• Line the channel with landscape fabric, to suppress weeds. (Note: I did not do this - I'll just weed.)
• Choose rocks, stones, and gravel in a variety of shapes and sizes, combining smooth river rocks with sharper-edged rocks to make it look natural. 
• Use rocks that are in scale with your setting and with each other-don't overwhelm a small stream bed with huge boulders.
• Boulders that are too large for the current to move remain in the middle of the stream, while smaller ones are washed to the sides. 
• Put large boulders at the bends in the stream and to disguise the headwaters. 
• For a more natural appearance, put some rocks on top of each other or partially bury them. 
• Avoid organizing the rocks in any pattern. 
• Move the stones around to get the look you want, filling the spaces with more river rocks. 
• Spread fine gravel at the lower end of the dry stream bed to create the appearance of naturally deposited sediment.

Advice About How Rivers Flow Round Meanders

I was particularly interested in how natural rivers meander and how it might affect rock placement. Here's basically how it works:

• Deposition occurs along the inside bend where the water flows slower
• Erosion occurs along the outer bend where the water flows faster

You can see it clearly in this small image I found on this watershed hydrology page:

And on this similar graphic from an The Encyclopedia of Earth page:

So I tried to follow that idea when I dug out the meanders of my dry creek bed. Not terribly successfully but I am still tweaking.

I'm not exactly sure how the rock sizes are distributed on the meanders. These graphics from a page about rivers on The Encyclopedia of Earth are helpful because they show where water runs fast and slow:

I'm figuring that the slower water areas have the larger rocks and, and the faster ones will have smaller rocks -- because the faster (stronger) flow can move the bigger rocks along and they'll get stuck in the slower areas. But I'm not sure. I'll have to go look at a real creek sometime soon!

I tried to put small rocks to indicate the areas of faster flow. A wider channel would make that more clear. My little creek is probably too small for these finer points to make much difference.

I don't think I'll get into riffles, but thought this was interesting. In a larger project you could add texture this way.

I hope all this inspires you to have a go yourself. Of course this is a real honeymoon period - before weeds grow!

I'll post again when I've tweaked and twiddled and put a couple groups of rocks in (reused from another part of the garden). Maybe I'll have a plan for plants, too.

For sure I'll want a couple mini gnomes - so my granddaughter and I can take them for little hikes along the creek, and go camping in the "mountains."

I'm just having too much fun with this project!