Some time ago I heard a comment on some National Geographic or Discovery Channel program that the earth rotation is slowed down due to water trapped in dams I did not pay attention to this at the time as it was said to be a fraction of a second.

Planning my next vacation I came across this [article][1] and this made me wonder about the effects of a major dam failing at full capacity this dam has [$180\,\mathrm{km}^3$][2] of water and will spill over and also take out this dam having another [$55\,\mathrm{km}^3$][3] combined this is a substantial mass of water that will run into the ocean. 

Will the release of these amounts of water affect the rotation of the earth?


  [1]: https://www.dailymaverick.co.za/article/2016-11-30-op-ed-a-clear-and-present-danger-of-kariba-dam-collapse/#.WHprEfl97IU
  [2]: https://en.wikipedia.org/wiki/Kariba_Dam
  [3]: https://en.wikipedia.org/wiki/Cahora_Bassa_Dam