Creating dam overflow for pond

We have a permanent cold water (50degrees) spring flowing down 1/4 mi. to area in which I want to create a pond of about an acre.  Pond base is pretty solid rock, so I won't go deeper.  On the dam side is the crossover to the west half of land.  That has a 36" x 60+ Foot PVC culvert-- which has never over filled in the 11 years since installed.  Pond depth can easily be 8 feet at that point.  Don't want to disturb the well packed clay in the dam, thus wondering if anyone has experience with placing a 'standpipe' to est. depth down to an 'elbow into a culvert.

Would prefer to have means of setting overflow level, & ultimately drain pond if needed.  

And I just turned 80, so who how long I have to get this project finished.

Thanks for help

The term you want to search is a monk pipe. It is something Zach Weiss and Sepp Holzer incorporate into their ponds. It is a pvc elbow. They do not glue it. This allows them to tilt it to drain the pond. I see no reason why it would need to be able to tilt if draining was of no concern.

There are benefits to this vertical pipe to keep a pond at a constant level. The main one is the pipe should never clog if the top of the pipe is cut level.

Any  chance of pictures? Word talk is pretty good sometimes, but it's just plain easy to misunderstand the situation trying to figure out physical layout, lay of the land, that stuff. Sounds doable, sounds like it's half done already. But everything depends... On the details...

Regards,
Rufus

I found this video. Its 6 minutes long. The monk pipe shows up about 4 minutes in.


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Timber Guy wrote:We have a permanent cold water (50degrees) spring flowing down 1/4 mi. to area in which I want to create a pond of about an acre.  Pond base is pretty solid rock, so I won't go deeper.  On the dam side is the crossover to the west half of land.  That has a 36" x 60+ Foot PVC culvert-- which has never over filled in the 11 years since installed.  Pond depth can easily be 8 feet at that point.  Don't want to disturb the well packed clay in the dam, thus wondering if anyone has experience with placing a 'standpipe' to est. depth down to an 'elbow into a culvert.

Would prefer to have means of setting overflow level, & ultimately drain pond if needed.  

And I just turned 80, so who how long I have to get this project finished.

Thanks for help

PERMIES DAM THREAD


The idea is borrowed from normal large dam spillway design e.g. a Bell-Mouth spillway, also called: ‘Morning Glory’, ‘Glory Hole’ spillways.