[Paul]

We where given the go ahead on a project that most here would have turned to a retaining wall. The problem; a culvert that runs into a large river here receives large amounts of run off and velocities reach 450 cu ft a minute. They wanted the bottom to support wildlife (larva and crayfish ect... ) the side slopes are less than 1 to 1. The original engineer on the job wanted to use Geo-Web slope protection, After receiving the specs and plans I consulted with the manufacture of the product. Typically there is no problem but I wondered if they had given the manufacture the right info. The original documents called for a 2 to 1 slope! We had a 1 to 1 slope if that! After a bit of though we switched material and had the engineer review our plan.

What the site looked like before we started...........

[AZTLANLC]

Where the after picture?
I'm ansious to see it

[Paul]

Next in the series cleaning out the bottom and installing a TRM to support small plants among the rocks that slow the water down.

[Paul]

Installing the Pyramat, here is where we ran into some problems...... The soil conditions here are all rock and gravel we had originally wanted to use duck bill anchors to hold the HPTRM to the bank but they wouldn't hold well or kept hitting all the rock under the topsoil.

[Stonehenge]

You guys must have de-watered beforehand. Looks like a dry creekbed once the work began.

[Paul]

We opened up the channel that brought the water level down a bit and we ran pumps there. Final pictures will be posted tomorrow it was too dark to get them today.

[Paul]

Here's what it looks like ready for winter............

[Paul]

Here's it with water filled back in........

[Nebraska]

When you say 'they' was this for a private owner, municipality, or "natural resource district"?

Why did they want larva and crawfish?

Do you do a lot of this type of "habitat" improvement?

I ask because I have a close friend who own's a company that specializes in habitat improvement on public and private lands. Fisheries, waterfowl, upland game, big game etc.

[PSUscaper]

If some pesky neighborhood kids playing army one day decide to to play the battle of 'porkchop' hill and slide up and down that, could they potentially pull the whole thing down in one shot? Or, when the vegetation grows in, will that thing be anchored in like a rock.

For some reason, it looks like the people who originally put that culvert in didn't think about the way this thing was going to turn out. Did you play a part in the culvert's design also? Or, did they come to you with the culvert already installed and ask for answeres.

Those concrete walls just look wrong. I'm sure there's formula's for the width of the outlet and what not, but it seems to open up and have such a steep grade. Is this area kind of a retention basin also?

Looks like a cool project though.........I would of hated to have been the guy to had to put those supports in the matting! (by the way, is that what all those white dots are?)

steve

[Stonehenge]

The project is misleading in it's size. The first pics make it look rather big, the last one makes it look smallish. Though I do agree, that thing is a behemoth, and I would be none too thrilled about having to have that adjacent to my land.

[PSUscaper]

I'm with you on that one stone. I would put a fence up quick if I live next to that.

By the way, surprised there's no guardrail above that thing. Looks like its only a few feet from the road. Hate to slide of the road into that thing one snowy jan morning.

steve

[Paul]

Nebraska; We were asked to do this by the company installing the head wall, the project was a repair for the last one that blew out from last years rain storm. 450 cubic feet of water per minute thru a 42" culvert causes lots of erosion. My projections tell me that water will shoot out of that pipe about 12' during a heavy rain storm. The Army Corp is the one that drew up the original specs for the water quality that they wanted. Since it's mostly storm water run off we needed to introduce elements that would support wild life. This get more into micro habitats,not so much as larger projects look for larger habitat for ducks, ect...... This is more of a test site to see if the rest of the channel can be done. The next project will be about one mile of stabilization.

Pennscapes; I don't worry about the kids playing army on it, you really can't walk down it, >1 to 1 slopes means there are no foot holds No really the blanket is installed with a S fold at the top and pinned with 20" cable anchors, thru the loops in the cable anchors are 6" long epoxy coated rebar. The sides of each blanket are trenched in and buried with a C fold and pinned the same way. The design is for the fabric to stabilize the soil until roots of the seed take hold growing thru the Pyramat. The Pyramat supports the roots from tear out. Pyramat is a 3 dimensional fabric that has very little stretch (less than 10%) it is dirt filled (1/4" to 1/2") then seeded and covered. The white dots you see are steel pins 18" long that hold the Pyramat tight to the "topsoil". I use the word topsoil loosely here, it's mostly sand and rock.

The outfall is to protect the road way above it remember the Army Corp doesn't do small things No we had no input on the culvert design, we where called in to correct the problem of erosion along the banks and make it wildlife friendly.

Stonehenge; project size was just over 165 sq yds of Pyramat, 35 sy yds of 450 TRM under layment, and 400 sq yds of S2 double net straw blanket. All the stones that were used on the job came from on site. With out the protection we installed the home owner that is located on the side of the project would lose his home in 5 years.

Oh and just for your information this job ran just over 15K........

[Nebraska]

Why the concern for "wildlife" on a micro level? One would think that with one storm and that amount of water they would literally be washed away???

[Tim]

We did some similar head wall work for a Super Walmart's parking lot's storm drain piping. They spilled into an adjacent stream. Had a terrible time doing the walls environmentally. Had to protect the Iowa State's Bird - the Mosquito! EPA etc. How many G- boxes did you end up covering? We had to use coarse rip rap for our apps out side of the boxes. Was the use of existing smooth stone an environmental concern, or was it a economical choice? Tim