What is the hole called in the middle of a reservoir?

Question

I want to know what the hole in the middle of a reservoir where the water goes into is called. It looks like a giant sink (sinkhole?). I have been facinated by these but cant get much info on them...please help!

Answer 1

Most dams have a section called a spillway or weir over which or through which it is intended that water will flow either intermittently or continuously.
A spillway is a structure used to provide for the controlled release of flood flows from a dam or levee into a downstream area, typically being the river that was dammed. Spillways release floods so that the water does not overtop and damage or even destroy the dam. Except during flood periods, water does not normally flow over a spillway. In contrast, an intake is a structure used to release water on a regular basis for water supply, hydroelectricity generation, etc. Floodgates may be designed into spillways to regulate water flow and dam height.

A spillway is located at the top of the reservoir pool. Dams may also have bottom outlets with valves or gates which may be operated to release flood flow, and a few dams lack overflow spillways and rely entirely on bottom outlets.

Answer 2

Welcome to the Intake Towers site
2003-04-04 12:05:27
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Intake Towers Project

At many dams, you can see towers partially submerged in the reservoir. These towers are called “intake” or “outlet” towers. They stand above the entrances to reservoir outlet pipes, and house controls that regulate the flow of water through the pipes. The pipes take thousands of tonnes of water away to water treatment works, for example, and hydroelectric power stations.

Earthquake damage to one of these towers could cause a catastrophe, as control over water releases from the reservoir could be lost. At worst, the dam could also be badly damaged. If the water held behind it could not be released from the reservoir, the dam could collapse causing flooding and loss of life and damage to property. Another problem could be fracturing of the outlet pipe downstream of the dam, with vast amounts of water gushing out of it. If this uncontrolled release of water could not be stemmed, again flooding and damage would ensue.


To avoid such problems, dam owners should ensure that these towers are safe. They can do this by checking that existing towers are strong enough to resist any significant earthquakes in the area, and by designing new towers adequately. The owners employ civil engineers to do these assessments. The engineers require an understanding of how the towers might behave during earthquakes, so that they can do appropriate calculations to assess their capacity.

The EPSRC have funded a research project, at the University of Bristol’s Civil Engineering Department, which will investigate how towers respond to earthquakes and ways of representing their behaviour with numerical models for hand calculations and computer analyses. The aim of the project is to develop techniques that engineers can use to prove the seismic safety of intake/outlet towers.

The seismic behaviour of an intake/outlet tower is very complex, as it depends on its dynamic interaction with the water surrounding it, the foundation it is built on and the dam to which it may be attached. Most towers are made from reinforced concrete, and can vary from a few metres to 100 metres in height. During an earthquake, taller towers will vibrate and sway from side to side. They may even adopt a snake-like motion. A sufficiently powerful earthquake will cause cracking of the concrete near the base, and permanent deformation (yielding) of the steel reinforcing bars. Further cracks may develop up the height of the tower, but their patterns will depend on how the tower is reinforced.

It is interesting that this sort damage is not always a bad thing, as long as the tower remains standing and the controls within are not damaged. When the concrete cracks and the steel yields, they absorb energy, reducing the vibration of the tower. At the same time, the relatively minor damage caused by the initial tremors of the earthquake can “de-tune” the tower from the bigger seismic waves that follow. This type of behaviour is called “non-linear” because the properties of the tower change during the earthquake.


The non-linear seismic behaviour of these towers can be analysed using complex computer models called “finite element models”, but these are expensive to develop and very time consuming to analyse. There is a need for a simpler, less costly analytical approach that captures the essential features of a tower’s response. The team at Bristol will be working on the development of such an approach, and aim to develop a computer program for engineers to use for the seismic assessment of intake/outlet towers. They will check their method by building scale-models of typical towers in their laboratory and testing them for earthquake type loads. The results of the tests will be compared with predictions from the new computer program.

Answer 3

Yep.

Plug-hole.

Answer 4

Is it the plug hole.

Answer 5

main stop plug valve or main **** valve.that is a true thing in plumbing

Answer 6

its the plug , surely. imagine the hairs u get in there ewww