Pond "outlet"

[Ouch]

I'm having a pond built behind my house (~1.5 acre). The guy doing the work suggested putting in a horizontal culvert in a dam corner for the main outlet, with an emergency spillway in the opposite "downstream" corner. I'm not sure how I feel about it, though he showed a couple dozen photos of some he's set previously that are holding up.

I have always thought I'd put in a vertical pipe on the backside of the **** dam for overflow, 90 connected to a horizontal pipe laid through the dam.

Thoughts?

[AntlerCollector]

I’d trust his experience

[dclifton]

There is pros and cons to both. Pipe on the top laying horizontal is the most easily repairable if it needs repair or leaks.

The pipes put in the bottomn of the **** and then stubbed up with a 90 for depth control have their pros and cons.

IMO spend the money on some crushed concrete and rock to armour where it comes out the discharge side of the culverts then seed grass on emergency overflow asap and you will be fine. OR even liner it then put dirt and seed on top. Cost a little extra money up front but you will be glad you did it.

Problem with the 90 up depth control pipes is either something stops them up on the pond side or they rust out on the discharge side and leak to much. Ive seen both happen.

Sounds to me like he will take care of you. Just make sure he spends the time to walk the dirt in good around the culverts and seal them up best way you guys can.

[Dale Moser]

If that culvert rusts out or clogs up, it's a much simpler problem, and much higher on the dam, to fix, if done his way. And it doesn't mean you have to drain your pond to replace.

[retrieverman]

I’d trust his experience

My experience is that very few pond builders know a dang thing about calculating watershed and thus have no idea how big to build a spillway.

[Ouch]

There is pros and cons to both. Pipe on the top laying horizontal is the most easily repairable if it needs repair or leaks.

IMO spend the money on some crushed concrete and rock to armour where it comes out the discharge side of the culverts then seed grass on emergency overflow asap and you will be fine. OR even liner it then put dirt and seed on top. Cost a little extra money up front but you will be glad you did it.

Problem with the 90 up depth control pipes is either something stops them up on the pond side or they rust out on the discharge side and leak to much. Ive seen both happen.

Sounds to me like he will take care of you. Just make sure he spends the time to walk the dirt in good around the culverts and seal them up best way you guys can.

This will be done either way. Good input.

If that culvert rusts out or clogs up, it's a much simpler problem, and much higher on the dam, to fix, if done his way. And it doesn't mean you have to drain your pond to replace.

True dat.

[BrianL]

I would look at bottom syphon if I were building again.