swales in heavy clay soil

Hello
This is my first time on the forums (yes I'm a virgin!)
My surface well dried up this summer and I was wondering if building some swales and a pond higher up (very gentle slope) would help recharge the ground water?
I was think of adding some gypsum to the swales
I have about 2 inches of top soil and then it's heavy clay for 18 inches and then its clay and gravel for about 15 feet to the bed rock. When it rain he water stay on top

I live in the province quebec (about 200miles north of Montpelier VT)

Thank you very much

Jean-Sebastien Busque

Hi JSB.

Here in Nova Scotia, I have been experimenting building swales in heavy clay soil recently on a hillside that is 5 acres. I'm using a small Kubota B29 tractor to do all the digging. The ditch part is 5-6 ft across, 2 ft deep, with a 2ft berm behind so the ditch finshed is about 3.5 ft deep after settling out. It will run down the hillside at a 2 degree slope, with speed bumps along the way to help hold the water abit longer and loop back three times as it fills ponds which will be added at a later date, since winter is near. The hillside is not steep so I have been able to work facing down hill slicing into the soft soil with the blade. Flip the mowed sod down hill and then scoop dirt out of the middle of the ditch as far down a the blade will reach, equals a bueaty swale. This technique has allowed me to dig 150+ ft an hour.

I am unsure how the speed bumps will work. The plan is use hemlock and juniper slag boards like dam walls to be placed in the soil upright 6-12" backed with soil and the rocks to prevent wash out in big rains. The rocks will be pulled out of the berm wall by the frosts/freeze/thaw this winter. This worked amazing last year, providing most all gravel rocks for a large drain I built. Will be a large washboard in a sense. I can't wait for my first rain. whoo

I will let you know how things go.

On conture swales in series down the hillside sound like your answer, Geoff Lawton style. The water collected will seep in deeper than running on top. Tell us a bit more about your project. Why the gypsum use? ph? Thats new to me.

Amazingly we have had no rain yet the swale has exposed 3 small springs that are feeding the system already. The speed bumps will be put in next spring. I think the ground will freeze before I can finish the pond I have started to layout... going to make it shallow and level, to allow for a outdoor rink for the winter using the run off. I read up alittle on gypsum, any one have more info on the subject.

Just something to be aware of, gypsum will convert to sulfuric acid in water. I wouldn't add it into the swales themselves (although plants do need some), since it might end up in your well water.

Yes, swales and infiltration ponds will help recharge groundwater.

Thanks for the reply

The idea behind the gypsum was to help flocculate the clay soil ?! but I will put a hold on the gypsum.
I live in on a 15 acres in zone 3a. The ground needs a lot of love (low pH, low organic content, high water table when it's not a dry spell)
The slope is gentle I will do the work in spring so I can get a ground cover quickly and then add support plants, shrubs and trees on the swales

My challenge is to find (or make) clean organic mater to help the soil structure


all the best

That's a good idea. I think biochar might really help for that, and of course getting a lot of good deep rooted plants to provide organic matter, concentrate minerals etc.

Hi neighbor.

Yes, a pond high up should recharge the ground water as explained here:

Jean-Sebastien Busque wrote:

My surface well dried up this summer and I was wondering if building some swales and a pond higher up (very gentle slope) would help recharge the ground water?
Jean-Sebastien Busque