Riprap at pond edge

[kedpe]

Hey guys-my first post:
I've designed a fire supply and retention pond and called out 18" deep ODOT Type C (6"-18"; avg. 12") for the pond edges. The contractor wants to put #2 stone.
Any experience?
Thanks

 

[saruman26]

The reason for placing rip rap at the pond edge is to prevent wave action from eroding the embankment at the water line. No. 2 crushed gravel will simply wash away and provide no protection.

I suggest sticking to your guns and making the contractor place the specified material.

 

[DMcGrath]

Of course the answer is "it depends", this time on size of the pond, max wave height expected, etc. The VDOT drainage manual (Virginia) chapter 13 is all about riprap for shore protection. But if you have already figured out what you need and have the calculations to back it up, then for sure stick with the riprap. This contractor sounds like he is looking for cheaper and easier (for him).

 

[kedpe]

Thanks DMcGrath-I downloaded the info from VDOT and will look through it. My pond is 225'x375'x12'; I'm not sure how much 'wave action' will be generated after a cursory look at Chapter 13.

 

[blueoak]

kedpe,
You would be surprised. I like a rock on a road base or felt geotextile for wave action. It keeps the edges nicer. Of course in VT you probably get good wetland species that protect your edge.

 

[namdac]

kedpe,
I am currently working on a Bridge relocation project. The project required me to fill in part of a sand pit some thirty feet deep. I am filling in a very small percentage. For bank stabilization I am using filter fabric with Gabions.
Regards,
Namdac