Pond Boss Forums POND CONSTRUCTION Soil questions Constructing a swale for surface water run-off?

I'm starting to stake the land for final grade and need to make a swale to carry any surface water that accumulates to the pond. I can get a maximum of 9" fall in 135 feet, but I don't want the water to run too fast and start to erode the sandy soil. Does anybody know the minimum fall that I could use and still have reliable water flow? Right now I have the swale staked out at 25' wide. The first part of the swale has to fall 15" in 140 feet to keep any water 2" below the level of the stable floor, then it can drop up to another 9" in 135 feet.

If I can get the final grading done in the next month I'll have a good shot at getting it planted before summer's heat.

Rule of thumb minimum for grass ditches on county roads here was 1%. I calculate .55% and .89% on the two grades you have proposed. I suspect that first one might be subject to ponding.

Thanks. If I increase the first grade, I'll have to reduce the 2nd one. Should I split the difference and make them both the same? (.72%)

I measured the drop from the road to the house crawlspace, and the road is actually 6" higher than the floor in the crawlspace. I guess that's due to them chip 'n sealing the road over the past 100+ years that the house has been there... But, that's another issue!

What ever you end up with make sure it has a good grass cover, that wat the dirt will not end up in the pond.

Thanks Otto. I've got 900# in the barn waiting for the dirtwork to end. I want to be walking on grass and not on the dirt! I'm tired of tracking sand into the house (I can take my shoes off, but the dog has a harder time of it. )