Pond Boss Forums POND CONSTRUCTION Building a dam Convert an Overflow?

I am relatively new to the pond management scene, and a few days ago knew absolutely nothing about pond and dam construction. I was reviewing the different overflow systems and thought of a way to convert a convetional / top fed system. I figured that if it has been done before (almost certainly has) this would indeed be the place to find out. I was looking at a siphon / bottom fed overflow system versus a conventional / top fed overflow system (not sure about the terms there) and from what I understand a bottom fed system is better (for most situations) because it can potentially get rid of the water with low DO levels rather than more productive surface water, but slightly more difficult or expensive to construct. However, for people that already have a conventional system in place, couldn�t you convert it into a bottom fed system (without the siphoning ability) simply by slipping a larger pipe over the vertical drain pipe with the above open end a few inches above the water level? Then you would have the ability to remove the pipe and return to a conventional system if needed (winter). I am going to try to attatch a quick diagram i made. My engineering might be completely off here, or I could be overestimating the benefits so any input would be great.

Using the suspended large pipe to bring up (less desirable) bottom water into the top of a drain pipe is a recognized method. I personally had not thought about making one seasonally convertible, but it sure would work and I can see where it might be an advantage (preventing ice damage, for instance)

GREAT diagram, btw.

Looks pretty good.
How would you center or suspend the larger pipe?

What type of valve is that at the bottom?

Sorry for the novice questions.

Wivell,

Here is a link to the Canal Gate Valve:
http://www.amvalve.com/catalog.htm