Swales & Water Management Question for Ben

Hey Ben,

Greetings from the far east! (Ben lives about 35 miles west of here)

I noticed that most swales and "hugel-swales" are built almost exactly on contour. Yet I recall that you were able to manage the flow of water on your land by using swales, berms, and ponds to force the water to take a long, twisting path to get down a slope, giving it many opportunities to soak in without ever allowing it to get moving too fast and cause erosion.

I want to know about building swales with a very slight angle to the contour lines to direct water across a gentle slope in a long zig-zag path with small catchment ponds on the "corners".

Q: Will this work, or just too risky? If so, how much angle is too much ? The soils here are fairly rich, but stony glacial till underneath, and drainage is very good -- very low clay content -- so maybe I can get away with this more than someone with more clay in the soil (?)

Congratulations on your book, and thanks for your thoughts.

OOPS! I probably should have posted this under Earthworks... Alison, please let me know if I should delete it here, and post it there... Thanks.

Brad Vietje wrote:Hey Ben,

Greetings from the far east! (Ben lives about 35 miles west of here)

I noticed that most swales and "hugel-swales" are built almost exactly on contour. Yet I recall that you were able to manage the flow of water on your land by using swales, berms, and ponds to force the water to take a long, twisting path to get down a slope, giving it many opportunities to soak in without ever allowing it to get moving too fast and cause erosion.

I want to know about building swales with a very slight angle to the contour lines to direct water across a gentle slope in a long zig-zag path with small catchment ponds on the "corners".

Q: Will this work, or just too risky? If so, how much angle is too much ? The soils here are fairly rich, but stony glacial till underneath, and drainage is very good -- very low clay content -- so maybe I can get away with this more than someone with more clay in the soil (?)

Congratulations on your book, and thanks for your thoughts.

Hey Brad!
Yes, swales puncuated by infiltration basins - GREAT approach. We do it with very small pools/ponds. It just is highly variable in this climate and more so in some others. They'll be full and overflowing in the early spring and sometimes at other points and then they'll be really dry at times. But they are AMAZING at catching pulses which is what we need to do. Your soil and slope have a lot to do with designing these. You'll not move much water most of the time when the ground is unfrozen with soils like that so you may need some decent pitch - 3% even, probably not too much more or you risk erosion too much.