I need some good advice on a drain valve. I plan to renovate my overflow pipe this summer, and I would like suggestions and input on what type of valve is most trouble free/dependable. I plan to use welded steel pipe and will need about a 6" valve. All input is appreciated.

Personally I wouldn't even consider a pipe underground. My over flow consists of a v trench lined with stone theat feeds into an 8 inch pipe, and then the water tumbles out of the pipe into a ditch. No erosion and no water working around the pipe as all is above ground. The pipe slants down and is weighed down with stone. Foolproof!

Mr. Baird, thanks for your input. I have a great deal of water flow when it rains, I can gain 2 to 3 feet of water on 5 surface acres in no time, so I will have to be prepared for that. I could use a pipe straight through the dam, but as I understand it would be difficult to maintain any type of fertilization program with the water drawing straight off the top. I currently have an 18" riser pipe and a 12" through the dam, and I plan to go with even larger pipe due to the state diverting more water my way.
Please reply with more thoughts!!!!!!!!!

I have to agree with Cecil, especially if you are in an area that gets a freeze over. Ice can do wonderful things to anything that sticks out into a pond. I know from experience that even if you have anti-seep collars on a pipe running through a bank all it takes is a little heave of thick ice and there goes your overflow pipe. If you are lucky all you will get is a little leak along the bottom of the pipe, if you are as unlucky as I tend to be it can be much worse. In my opinion a safe minimum in 'colder' areas is to make the inlet flush with the pond banks. (Of course if you never see ice this tidbit of info is of little interest)

Waymon,

Sounds like your pond is really undersized for your watershead. Maybe more than one overflow above ground as I suggested? Like Pottsy I do not trust pipes even with antiseep collars. Maybe I'm paranoid.

I have seen this problem in a few ponds that I ended up getting the job of rebuilding.The way that it was thought 30to40 years ago that sending the overflow pipe straight down the dam at such an angle that it was running with enough pressure to move a house right off the foundation.Now with the new style pipes it makes the job of installing a good solid overflow system much easier.The problem with the steel pipes was the corrugation the vibration of the water from start to finish would not only cut the flow rate in half but in most cases if there was a coupling joining the pipes together it would shake them apart.Lets not forget that copper sulfate has been around since the beginning of time and the damage that it can do to steel goes without saying.The cheapest way that I can think of with no risk of problems down the road 5to10 years is take some firehose cap one end fill it with water throw it in the pond uncap the end behind the dam below the water level or the desired level that you want and watch the level go down.If you have alot of flow add another hose when your done hang the hose in the shed. It won't end up costing you a dime in the future. Anyway, there are alot of options out there to get the draw down that you need without putting a large amount of dollars out of your pocket that you could use on beer.DOC

The way that I like to establish the nomal overflow and it works in most cases is to cut a swell at one corner or the nearest location that is possible to where the flow needs to go.I like to put down a small liner at the mouth of the swell then line it with rip rap.You will need to calulate you flow to see how big you need to make you flow but you won' have that ugly pipe sticking out of your dam.DOC

The way that I like to establish the nomal overflow and it works in most cases is to cut a swell at one corner or the nearest location that is possible to where the flow needs to go.I like to put down a small liner at the mouth of the swell then line it with rip rap.You will need to calulate you flow to see how big you need to make your swell but you won' have that ugly pipe sticking out of your dam.DOC

Just wanted to give you folks an update! Thanks for your replies. I finally got my pond drained and the valve that was in place was an armco 12" slide gate valve, it was perfectly preserved with no rust or deterioation at all, it had been coated with tar so I plan to use the same valve.
As for as cutting a swell at one end of the dam, it would present a whole new set of problems ( check out tropical storm BILL he plans to be around for a few days dropping tons of RAIN) I currently have a 40' long cement wall at one corner of the dam for an emergency overflow and enough freeboard space on the dam to allow the wall to work perfectly when needed. I know in Indiana you folks don't have to prepare for tropical storms or hurricanes but on the Gulf coast it pays to be prepared, and sometimes maybe over prepared!!!!!!
Thanks again for your advice!!!