Wattles vs. drainage blanket

[swm25]

I have a site with a newly constructed 50 foot long 3:1 slope. Rills are forming from overland flows from a 5 acre mildly graded area above it that is overtopping the crest that is about 600 feet long. Wattles seem like they be an option, but I'm not sure if the application is appropriate to protect a slope that is getting flows from above I haven't found any information if there is a cfs/ft flow rate that would be a max or something like that. At what point are wattles inappropriate, and a drainage blanket would be needed, or is it just a cost analysis once you start needing so many wattles? Are there any references that can be recommended?

 

[cvg]

suggest neither option will be successful, you need to divert the water from above and either retain it or otherwise channelize it down to the bottom of the slope. the slope should be trackwalked, seeded and mulched asap

 

[darthsoilsguy2]

With the exception of the super-expensive options out there.... all the slope protection approaches out there are for stopping erosion from water that lands on the slope, not overland flow that traverses it. divert or channelize the flow

 

[swm25]

That was my concern. May have to look at some super-expensive options, as the site is up, running, and crowded with solar arrays so no space to create diversions, or retention.

 

[hokie66]

Just to satisfy my curiosity, what are "wattles"? To me, they are trees/shrubs. The Golden Wattle is the floral emblem of Australia.

 

[darthsoilsguy2]

hokie... 'Wattles' are what Elmer Fudd calls 'Waddles'

 

[fattdad]

the requirements for initial vegetation (i.e., typically in the U.S.) fall on the contractor. Denuded land is not a part of the completed works. The stability of denuded land, (typically in the U.S.) is often covered by an erosion and sedimentation bond, which is released after 75 percent vegetative cover.

A fetch of 200 ft will typically initiate channelized flow. If the land above the top of slope is 200 ft or greater such channelized flow will gully the slope face - especially if the slope is denuded. Slope drains can help with that. If the fetch is less than 200 ft, you may still need slope drains.

How to manage stormwater in the completed works assumes the ground has been stabilized. It seems you are dealing with ground that is not yet stabilized.

Then again, maybe I don't quite understand. . .

f-d

ípapß gordo ainÆt no madre flaca!

 

[swm25]

You are correct fattdad, the contractor didn't do a good job of protecting the site, and the nude slopes were ripe for eroding. It also highlighted that a mostly flat 1.5% slope area about 900 feet long exists above the slope produces sheet flows that crest over the slope in their journey.