Dam terminology-what do you call it?

[N80]

I have a ten acre pond on my property. Technically it is a 'watershed' built in the 1950s by the government to help control flooding. (We all call it 'the lake'.) It has a very large earthen dam at one end. There are two provisions for controlling water flow out of the lake.

1) On the north end of the dam is a low area that was dug so the water can go around the dam if it rises past a certain point, without overtopping the dam.

2) There is also a cement tower in the lake. There is a pipe at the bottom of it that passes through the dam and feeds the creek behind the dam. The water flows over a cement lip on each side of the tower.

I have a term for this tower and towers like it. I've used the term around all sorts of people and have never been corrected. But, my sister-in-law and her husband always correct me when I say it. Both of them have served on the local soil and water commission and they probably know what they are talking about. So I am probably using the wrong term.

I've done some research on the web that supports my use of the term, but not precisely.

Before I tell you what I call these towers...what do you call them. Other terms I've heard (which are probably more accurate) include 'riser' and 'intake'.

 

[MossRoad]

Overflow tube?
Water height regulator?
Water level regulator?
Tower O' Drainage?

 

[gotrocks]

Before I tell you what I call it;
You tell me what you call your SIL & Hubby.

 

[ToadHill]

Overflow tower.

 

[N80]

Before I tell you what I call it;
You tell me what you call your SIL & Hubby.

In-laws!

 

[Soundguy]

Here is florida we call them overflow weir's

The last big job we did last year had a large DRA with an overflow weir in it.. concrete tower and all.. went to a 12" drain pipe that exeted the berm at a spillway with energy disipators, and the water flowd down grade to a wetland.. etc.

This tower had weepholes machined into it.. etc..

soundguy

 

[orezok]

It could also be called a penstock.

 

[N80]

Well, I call it a spillway. When you look up the term 'spillway' in various sources it refers to any mechanism by which water can be released from dam but specifically to gated portions integral to the dam that can be opened or closed to release water.

I think for smaller dams the term 'spillway' is usually applied to the low part that the end of a dam that allows water to escape if it gets high enough.

I grew up near Lake Murray, SC which has one of the larger earthen dams in the world. I t has 5 250' towers near the dam that allow water to flow through the dam and/or into the hydro generators. Techically these are called intake towers. Many locals call them the spillway towers and I think that's how I got my improper terminology.

However, if you look up 'spillway tower' it is apparent that it is common to refer to such structures this way.

In any case, I'm sure 'riser' or 'intake' is the technically correct term. But I've been calling these things spillways all my life and probably won't be able to change.

Oh well.

 

[N80]

It could also be called a penstock.

From what I can determine, penstock refers to the pipe or conduit that runs into and through the dam. It is the intake tower that allows water into the penstock.

 

[Soundguy]

A spillway .. at least to FL DOT, is the exit flume.. with or without energy disipators ( rip-rap ) that the water actually flows down..

IE.. the spillway starts where that pipe comes out of the dam.

Look at a culvert exhaust pipe with a concrete mitered end section.. and then a concrete section in front of it.. that is the spillway. If there were blocks / bricks concreted into the spillway in a pattern as to slow exit water down.. it would be a spillway with energy disipators.. IE.. to controll water speed and thus erosion where the spillway goes from concrete to native ground.

The actual drainage structure ( tower ) in the middle of the tank is not really the spillway.. it's simply a drainage structure.. in this case.. an overflow style structure.

soundguy

Well, I call it a spillway. When you look up the term 'spillway' in various sources it refers to any mechanism by which water can be released from dam but specifically to gated portions integral to the dam that can be opened or closed to release water.

I think for smaller dams the term 'spillway' is usually applied to the low part that the end of a dam that allows water to escape if it gets high enough.

I grew up near Lake Murray, SC which has one of the larger earthen dams in the world. I t has 5 250' towers near the dam that allow water to flow through the dam and/or into the hydro generators. Techically these are called intake towers. Many locals call them the spillway towers and I think that's how I got my improper terminology.

However, if you look up 'spillway tower' it is apparent that it is common to refer to such structures this way.

In any case, I'm sure 'riser' or 'intake' is the technically correct term. But I've been calling these things spillways all my life and probably won't be able to change.

Oh well.