help: waterlogged anaerobic swale

Hi all-
I installed a two foot deep swale in my suburban back yard last summer and filled it with wood chips to make it more of a pathway. It has now become totally waterlogged following a week of heavy rain (I live in California). It was already fairly wet beforehand from previous rains. Our soils are high in clay so they don't infiltrate water very quickly. The problem is the runoff water where the swale is designed to gently overflow (it's working quite well I'm proud to say) smells of sulphur, probably from the anaerobic conditions in the wood chip path/swale. It's not awful but my neighbor has complained and I'd like to remedy it as quick as possible. I'd prefer not to dig all the wood chips out right now, because once things dry up a bit I think the problem will go away. I was thinking of purchasing some Effective Microorganisms (http://en.wikipedia.org/wiki/Effective_microorganism) which are used at some wastewater plants to prevent foul odors. I would then apply these as a spray to the swale. Any other suggestions? I'd appreciate both short term quick fixes to knock out the smell and longer term thoughts on wood chips in a swale.

Thanks!

(p.s. this is my first post here!)

I use EM in a very similar situation on purpose, no smell only heat. I have ditches at the base of my terraces 3-4th wide and 5 ft deep. About 400+ft of it. That wood filled swale is doing tremendous amounts of recharge for you. I'm in California too and it helps big time come July through september.

Hi Jordan-
Thanks for the reply. I think I'll order some EM. Glad to hear the encouraging words- I've been feeling like I'm a bit out in left field with all my neighbors wondering what the heck I'm doing. Once the various plants get going I'm hoping they'll come around a bit. How do you apply the EM? Do you activate it then spray it on? I've been thinking about getting a backpack sprayer for foliar sprays, compost tea applications, etc.

That sounds like an opportunity, not a problem. If you have adequate space, perhaps a small pond could occupy the most waterlogged area. I consider my waterlogged areas to be more valuable than some of the drier areas that are underlain with gravel.

Another option would be to keep going with the wood theme and pile it into a hugelkultur bed. Any smell would not escape the thick covering and your bed would be perfectly situated to absorb winter rains.

Both options assume adequate space for your pathway on higher ground to the side of the pond or hugelkultur bed . This may not work in your suburban setting.

I make activated em1, then dilute it 1/200. Pour it on with a watering can/bucket not a sprayer. For larger areas pour a cup or two every five foot or so.

As a cheaper alternative to EM you can culture your own native lactobacillus.

This is a concise description found in a quick search, I used basically the same method.

http://diy-bokashi.blogspot.com/2010/06/making-lactobacillus.html

depending on where it is in location to buildings, foundations, septics, etc.. If it is far enough away you could always plant a water loving tree in it..say a weeping willow or hybrid willow or some other water lover..they'll quickly suck up all that water and grow huge..

you could drain it..if there is a downhill area to drain it to..by installing some draintile materials..or just open up a channel

Even better plant willows that are good for basketry. Coppice them yearly. I have a few on the wetter spots of my terracing but plan to add more in a wider range of colors. Also good long straight firewood for rocket stoves. Can be done the same way with mulberry.

I been googling this, i am sure you did too. I get no real information on how to stop ditches from stinking under every subject i could find...but to no avail. I too wouldnt mind a solution to stinking ditches.

Of course, like you the information i get is that it is anaerobic decomposition. I imagine this means the water is not all moving out of the swale. In this case resloping it may help, sounds like a bunch of work. I liked your solution too, if it works please post that.

The suggestion of a tree is a good one, identify the dent holding the water and plant a water loving tree near by, that should keep it from puddling too long but how long would it take a trees roots to grow to that depression?

How about considering adding sand to the mix, right through the wood chips. Sand will sooner or later mix with the clay below allowing better drainage straight down and at first, it would displace some of the water in any depression allowing it to dry faster.

Put rocks in the bottom of the swale before adding wood chips to the top, the rocks will allow better water movement and they wont rot.

Just some thoughts, above all your solution if it works is a good one but short term. Maybe you can plant a tree for later.

Hi all,

Thanks for the helpful information. I thought I'd post a follow up, now that we're another year in. Last year I never really fully resolved the smelly ditch water runoff issue. Oftentimes it would be worst early in the morning. But before long the dry season hit and the problem went away on its own. After a particularly long dry spell we've finally started to get some decent rain here in California again and some runoff is taking place. This year I haven't detected any foul smells. Perhaps it is because we haven't been saturated for much more than a month, but I suspect the improved soil biology is responsible for the change. Two years ago the area in question was covered in asphalt, so the soil was almost completely devoid of life. I applied a lot of wood chips and sawdust/horse manure in the first year and I believe that it was the smell of this fresh material starting to anaerobically decompose that caused the smell. This year there is much less fresh organic material, and the previously applied material has started to break down and turn into humus which retains the water better and doesn't seem to smell bad even when it's saturated.

Also, another swale that I put in last year is draining much more swiftly this season. Last year it got waterlogged- this year my heavy clay soils seem to be handling the water better, and are allowing the water to seep in more quickly. And I've noticed bunches of worms on my patio seeking shelter from the water that I never experienced before. The other night I actually found 3 worms crawling up my porch sliding glass window. Needless to say, the chickens were very happy the following morning.

This seems to be a great example of do nothing and just let nature get on with it.

This also sounds to me like improving the soil ecology has had the effect of improving the soil's texture and water handling characteristics. This would be expected, but isn't it nice to see theory confirmed in application and practice?