Pond Boss Forums INTRO Questions & Observations New member, new pond, physics major needed

Hello all. First off, this is an awesome site! You guys are amazing and selflessly giving of your vast and hard earned knowledge. My hats off to you and thanks for all the tips and tricks I have learned through my readings already. I look forward to being a bigger part of the forums and hopefully adding things that I learn along the way.

I have the same old problems as most all new pond owners...35 year old pond, huge bluegill (like a dozen or so), and millions of 10-15 inch bass. It is a clear water 3.8 acre pond about 20' deep in the middle and fed by a couple of springs. I just purchased the property about six months ago and will be doing some major renovations and will keep "The Boss" apprised of my happenings and learnings as I go.

But first a couple of questions to you pros out there.....I have an amazing rock-bottom spillway at the end of the dam and a drain pipe through the center of the dam. Not sure what this type of pipe is called...sure there is a technical description but it drains the pond to the same elevation as the pipe extends in the air on the opposite side of the dam (see pic). Also, it has a valve that allows me to drain the pond to the elevation of the end of the pipe on the pond side of the dam (makes the pond about 1.5 acres in size, wont allow me to drain it completely).

I had a wonderful gentleman from the local NRCS office out to take a look and he agreed the pipe could be plugged or extended to an elevation higher than the spillway to allow the pond to stay at "flood stage" without a problem. The spillway has an amazing waterfall on the backside of the dam and is awesome. There is no concern for erosion and it makes the pond much bigger and look like the pond of my dreams.

And finally the question: A friend of mine and I have a bet on wether or not this pipe can be plugged easily and if there is additional pressure on it as the pond fills and eventually reaches flood stage. I feel the pressure will be somewhat constant and will not exceed light pressure at best. A "cap" of sorts could be placed on the pipe (welded or otherwise) and not be blown off by pressure caused by the growing body of water on the pond side. So.....what do the pros out there think? Easy capping or creating a British Petroleum type situation that will eventually have the Feds moving in and confiscating my man-made Old Faithful? Also, any unforeseen problems/consequences I may be overlooking by doing this?

Question #2: I have taken 200 bass out of the pond but still catch around 30 bass per hour. I plan on taking at least a couple hundred more. When I stock my CNB/BG (thanks for all the previous post about this), how large do they need to be to avoid being bait? I have read adds for 4-5 inchers from local hatcheries but nothing bigger.

Thanks in advance for the advice and hopefully the pics I have will actually make this post.

http://i866.photobucket.com/albums/ab229/larryboy918/pond/E87V2810.jpg?t=1277249363

http://i866.photobucket.com/albums/ab229/larryboy918/pond/E87V2818.jpg?t=1277249363

http://i866.photobucket.com/albums/ab229/larryboy918/pond/E87V2819.jpg?t=1277249363

Welcome to Pond Boss!

I tried to get your pics to post, but didn't have any luck on the initial try.

I think this will work to show the photos:







Well, I was a Physics Major. I just don't have a good answer.

First, I have a few questions. Would you be plugging the pipe at the intake or at the exit? How big is the pipe? If you put the cap on the intake, it should stay on without any issues. If you can plug the intake, then you probably should put some kind of screen on the exit to keep critters from crawling into the pipe. Putting it on the exit could probably be done, but I can see a number of issues that would make it far more difficult.

Nice looking pond.

Ken

Welcome, Larry. Great looking pond. Hold on good advise is on the way (not from me, but from one or three of our "experts").

Thanks Ken for posting those pics. I guess I'll work on that skill next.

The pipe is around 12" in diameter, need to measure to be exact. Plugging the intake is a good thought but here are my issues with this....first, it is approx 13 feet under the water and I have never even seen it. Secondly, if I plugged the intake then I would not be able to use the valve allowing me to drain the pond to a lower level when desired, ie. during winter to kill moss around banks, working on any issues with dam, future dock building projects, etc. And lastly and most importantly, I saw a snake in the water last week and I don't go anywhere snakes might go. But I agree, plugging the intake would probably be easier.

Larryboy, you and I are going to get along just marvelously!

Its easy to calculate the pressure at the outlet...
Just multiply the depth of the intake (in feet) by 62.4 pounds per cubic feet. There will be some minimal headloss (pressure loss) through that short section of pipe and the couple of angles that the water must traverse, but those are negligible and should just be disregarded for the purposes you are concerned with.

If the "flood stage" is 5 feet above the normal water level, your pressure at the outlet would be (13'+5')x62.4 pcf = 1123 pounds per square foot (divide by 144 to get about 8 pounds per square inch). So, a cap on a 12 inch pipe would have to resist 1123 psf X 3.14159 X 0.5 X 0.5 = about 882 pounds of pressure.


In my opinion, it would be much easier to just extend that pipe 5 feet vertically, or however much higher you want to maintain the pond level, than it would be to try to cap the pipe and have to worry about it springing a leak under the pressure of 13 feet + flood stage water elevation of water. The extension would just have to be able to handle the thrust resulting from the water rushing through. A good weld and maybe a small supporting framework for the additional pipe length should easily handle this.

could you dig a few feet into the backtoe to where the pipe is about 2.5 to 3 ft deep and install a valve.then place a valve box and cover over your pipe so it wont freeze and backfill what u dug up. then use the extra pipe you cut off to extend back to the drainage ditch. you could also drain the whole pond if you wanted after cutting that riser off. the reason for that pipe being the way it is is probably because they laid it in there as a drain pipe for the spring water to run through as they built the pond. then they decided to put that riser on back to control the water level. did freddie trujilo from the nrcs look at your pond?

hawgtusk has a good idea too as long as it still moves some water.it looks to me like it could freeze and bust

That's what I thought even before I read that far down!

Riddle me this:

You won't go anywhere snakes might go. The snakes in your area live on land. The snake was swimming in your pond. So, the snake had to enter the pond from some point on the land, and had to exit on land as well.

How far do you walk around the pond??

Welcome to PB!!!!

thats why asked which nrcs guy looked at his pond there is a couple of them i have to walk in front of or they wont stake the pond. one of them wont get out of the truck unless i strip the grass off to where he can see. think i'm gonna get him some snakeproof boots one of these days

My questions that immediately come to mind are:
#1)What brand of beer do you normally drink in that part heaven?
#2)How much should i bring?
#3)And do i need to bribe the guard at the pearly gates?

Welcome to PB, Larry.

You are a sick, sick man, Scott!!!

Nah, just curious.

Thanks Hawgtusks, that's just the equation I was using to do the math, hahahaha! I guess I was wrong. I thought the pressure would be much less. Thanks for making quick work of this and giving me the info I need to make the decision....to simply extend the pipe instead of capping it.

NRCS gentleman was named Paul. He was fantastic. He is located in the Tahlequah office (Cherokee county). Made tons of great recommendations and was very helpful....said the pond was built by them originally and was still in marvelous condition.

The pipe extension would be open on the end. This would allow the water to freeze and expand out of the end and should keep it from expanding and causing damage to the pipe....I would think.? It would simply be a taller version of what is already there and it doesn't appear to have ever suffered damage from expanding ice. But good thought...

#1) Cold
#2) A lot
#3) More of #1

Thanks Skinnybass!

That's funny! Well, at this point I haven't seen any snakes on land so I'm assuming mine all nest on the bottom of the pond, heehee. Besides that, I'm fairly certain I can outrun one on dirt but I swim about like a rock!

Thanks Todd! We may have to start some kind of support group if I see another!

Ewww!

Maybe we'll call it something like the "Snake Sissy 12 Gauge Toters of America Club" or something!

Awe heck....must have had a couple too many brews last night....just realized that what I previously posted is not accurate.....the pressure on a cap placed on the outlet would only be the difference between the elevation of the water surface level in the pond and the elevation of the cap on the outlet X the density of water. So, if you are wanting to raise the level in the pond by say, 5 ft, then the pressure on the cap would only be 5 ft X 62.4 pcf = 312 pounds per square foot (2 psi or a total of about 250 pounds of force). The pressure at the bottom of the pipe structure, however, would still be the full difference between the elevation of the water level in the pond and the elevation of the bottom of outlet structure (horizontal portion going through the dam) as I posted yesterday, so leaks developing at any of the joints could still possibly be an issue.

Sorry for any confusion I may have caused...

Still think that, barring the freezing issue that Tim mentioned, a simple extension is your best bet. I would be concerned about a hard freeze busting that pipe, but if it has lasted this long, maybe the steel in the existing pipe is thick enough to resist the expansion pressure from freezing water. You'd definitely want to make sure the extension is equally as strong at the existing pipe...

YES HAWGTUSK I AGREE I WAS JUST WORRIED THAT IT NEVER HAD A CHANCE TO FREEZE. BEING SPRING FED AND PULLING WARMER WATER OFF THE BOTTOM OF THE POND THAT MIGHT NOT HAVE EVER CEASED RUNNING OUT THE PIPE DUE TO THE SPRING. IF HE RAISES IT ABOVE THE SPILLWAY IT WILL STOP RUNNING ALLOWING IT TO MAYBE FREEZE. BUT I'M JUST GUESSING CAUSE LIKE I SAY I'M A WORRY WART AND IF IT BUSTED AT THE BOTTOM IT COULD DRAIN MOST THE WATER OUT OF THE POND. IF IT CAN HAPPEN IT WILL HAPPEN TO ME SO THIS IS INFO FROM THE DARKER SIDE OR WORSE CASE SCENERIO.

Too many brews or not enough brews? Its just how you want to look at it I guess. Thanks for the new info. The way you describe this makes good sense. The pipe appears to be in perfect condition so hopefully wont have to worry about joints.