Can anyone who knows about water management infrastructure help me understand whether there’s an explicit difference between a spillway tower and a water intake tower? (Note: for the latter, English Wikipedia says they can also be called “water outlet towers”, and German Wikipedia calls them a “Wasserentnahmeturm”.)
Do all of these correspond to the same concept, or are there subtle differences?
(Tagging @Duja and @Kovoschiz who participated in a closely related topic about a year ago.)
According to Spillway - Wikipedia, they should probably all be intake towers?
Water normally flows over a spillway only during flood periods, when the reservoir has reached its capacity and water continues entering faster than it can be released. In contrast, an intake tower is a structure used to control water release on a routine basis for purposes such as water supply and [hydroelectricity](Hydroelectricity - Wikipedia) generation.
As explained above, it’s functional. Physically, “Water intake tower” has another term, valve tower, having valves for you to control how much water to take. I don’t know what layout those “spillway tower” have. If they are self-regulating (as they should be), they would only have openings near the top for the excess water to automatically flow away uncontrolled.
I agree with Fizzie41 that those are all intake towers, and “spillway tower” seems to be an (apparently common) misnomer. There is no article or redirect about spillway tower on Wikipedia.
I found a very thorough and nicely illustrated article about spillways:
Appurtenant Structures for Dams Spillways and Outlet Works Design Standard. Chapter 3: General Spillway Design Considerations. Design Standards No. 14. U.S. Department of the Interior, Bureau of Reclamation. August 2014
See in particular sections 3.2.1 Spillways and 3.5.2 Spillway Type and Size; and illustrations therein. But basically, a spillway never takes the form of a tower, it’s an open or closed funnel.
Some of them are wrongly identified, eg Hoover Dam. But others are unclear
From my research (note: I’m far from an expert on dam engineering, just happened to research the subject out of curiosity), those two are intake towers combined with bell-mouth (morning glory) spillways; presumably, building them together reduces the overall cost. For our purposes, those are best mapped as two separate objects.
The difference is shown graphically here:
Left is the intake tower (Wasserentnahmeturm = Water Collection Tower = Water Intake Tower) for regular withdrawal of water, right is the spillway tower with the conical inlet for overflow control (Hochwasserentlastungsturm = Floodwater Release Tower = Spillway Tower).
In fact both are tower constructions but the term “spillway tower” is unusual to my knowledge, commonly these are know as “bellmouth spillway”.
As said above, intakes are to remove the debris. They are not designed to absorb the energy. Hydroelectric generators are converting this energy to electricity.
Aerial Images from Bell-Mouth Spillways: How Giant Holes in the Water are Possible illustrate the stairs in the bellmouth spillways to disperse the energy.
It shows that like any other spillway, they can absorb the energy from high volume of water + high elevations to prevent damages to structures and avoid catastrophic situations.
Usually intake towers are not constructed to remove debris nor to absorb energy. They are primarily designed to allow controlled withdrawal of water for drinking water production or irrigation and also to control the quality of the water at different depth levels. You have to be aware that most dams mainly constructed for hydroelectric power generation at the same time serve as storage basin for different purposes and that is what the intake towers are used for.
