February 8, 2016 Environmental Issues Written by Greentumble
How Can a Lake Simply Disappear Overnight
Imagine a pristine lake that you have been visiting,

swimming in, and fishing in for many years completely disappear within 24 hours. Is it a mystic mystery? Is it because of an alien abduction of water resources? While these explanations might be very interesting, there are actually a number of logical reasons why a particular lake might disappear overnight.

The following are a number of possible explanations as to why such a phenomenon might occur.

    • Dam Fails Due to Intense Rainfall

In some cases, a dam that was being used for containing a man-made lake can break as a result of very intense rainfall events. During such intense rainfall events, a lake can be quickly overfilled with rainwater, and the dam can become stressed, leading to a break in the dam structure. Given such circumstances, the entire lake could be drained within a few short hours.

This is precisely what recently happened to a 10-acre private lake in Newnan, Georgia in June 2015, leaving just a mud puddle where residents had previously enjoyed many recreational activities on the lake, such as fishing and swimming[sc:1].

With global climate change, there is predicted to be an increase in the number and intensity of rainfall and storm events throughout the world, potentially leading to an increased risk of damage to dams.


    • Karst Collapses

Karst topography is a type of landscape where the sedimentary rock is composed of soluble rocks, such as limestone, dolomite, or gypsum. Such a landscape typically leads to underground drainage systems over time.

If a lake happens to be located directly above underlying karst topography, it is possible that a hollow in the underlying substrate may be formed if enough of it has been dissolved by underground water sources, potentially leading to the draining of the entire lake within a short period of time, even overnight. This is the same process by which sinkholes can quickly develop, sometimes even swallowing entire buildings.

It is believed that such as scenario is what caused a lake to suddenly dry up overnight near a village in Central Russia in May of 2005[sc:2].


    • Melting of Glacial Lakes Due to Climate Change

In more polar-facing regions of the globe, there has been an increase in the melting of glaciers that is occurring more often and for longer periods of time due to an overall increase in global temperatures. This has been particularly the case for the glaciers of Patagonia that appear to be experiencing even greater melting than glaciers in other parts of the world.

During the cooler seasons of the year, these glaciers are frozen and act as dams, forming lakes where glacial water collects. However, when temperatures rise, the glaciers weaken and the water from the lakes can drain out through the ice wall, even occurring within a short period of time, such as within a single night.

With increased periods of warmer temperatures in places like Patagonia due to global climate change, such melting events are happening more often and are happening more intensely. Lake floods of this sort have even unleashed mud “tsunamis” in certain locations, burying entire local villages[sc:3].


    • Overdrawing of a Reservoir + A Faulty Dam = A Leaky Lake

In Westwood, California this past September, 2015, residents woke up to learn that their Mountain Meadows reservoir, Walter Lake, had dried up overnight. All that remained of the lake that following September morning was a muddy hole where thousands of fish lay dead.

The reservoir is used by the Pacific Gas and Electric Company to produce hydroelectric power for the local community. It is believed that such activities may have stressed the already low water level too much due to the existing four-year drought conditions there.

In addition, the dam kept getting clogged up with dead fish, leading to the eventual malfunction of the dam. That September night, the dam no longer had the capacity to hold back the remaining water, leading to drainage of the remaining water level of the lake overnight[sc:4].


    • Lakes in the Arctic Disappearing as Permafrost Melts

It has now been discovered that large lakes in the Arctic are disappearing as global temperatures have increased due to climate change, and many other Arctic lakes have been shrinking. Because the lakes are located directly above the permafrost, as the permafrost melts, the low-lying ground below the lakes slump, the lake water percolates through the soil, and then drains into below-ground aquifers. Given the right conditions, such lake draining can occur relatively quickly, even overnight.

Unfortunately, if most of the lakes in the Arctic disappear, many wildlife and bird species that depend on them as habitat and water resources will be negatively impacted[sc:5].



[sc:1] http://goo.gl/xh9FnB
[sc:2] http://news.bbc.co.uk/2/hi/europe/4566355.stm
[sc:3] http://goo.gl/4ztxzE
[sc:4] http://goo.gl/wcy14N
[sc:5] http://goo.gl/EU1oCS