"Is the secret to weight loss really this simple?"
No. Stop lying to people, clickbait scum.

Source Article:
http://www.news.com.au/lifestyle/health/diet/is-the-secret-to-weight-loss-really-this-simple/news-story/dc1786abcca9cf978c33449cdbd9d2d6

Authors website:
http://www.susieburrell.com.au/about/

It's interesting to find an article where you're not sure if the writer is grossly incompetent, or an amazing liar. In the new article on news.com.au, written by Susie Burrell, amazing "scientific" claims are made about the association between water intake and weight loss. When we break into the science of these claims later, the reader should be able to make up their own mind.
Susie, according to her website is a Dietician. Dieticians are obligated in the same way that doctors are to never disparage the profession by lying or by publishing false or misleading information.
However, the major source of Susies money, seems to be this modern sort of "wellness blogging". You know, the kind of thing that people pretend to have cancer for, so they can sell you juice diets. It's an industry full of bad science and shoddy practices. If you publish an article entitled "please eat fewer calories and more vegetables, the end!", you tend to not get hired, so the people in this industry are under massive pressure to produce AMAZING new "secrets" and uncover new "science" in the field. Otherwise, you cant publish books.
However, I think we have a right to expect more from Dieticians, who are almost the doctors of the nutrition world.

One of the biggest claims in the article, is a supposed study from 2003, in which Susie claims the human "metabolism" increases by 30% in response to simply 500ml of water. With apparently 2 degrees in Nutrition and Dietetics, Susie should apparently know the first rule of science club - if someone only did it once and it wasn't replicated, treat the results with caution. The experiment she is talking about was repeated in 2006, as someone with even a casual interest in research should have been able to see literally right next to the 2003 effort in a search.
http://www.ncbi.nlm.nih.gov/pubmed/16822824

This repeated experiment demonstrated that this "30% increase" is not true. we got a 4.5% increase over the course of 1 hour, before returning to homeostasis. over the course of a day, this would amount to less than 1%, assuming you drank chilled water on several occasions. The actual details of the experiment leads to another question. Susie's article literally states: "drinking 500ml of water was associated with a metabolic boost of 30 per cent" given that she didn't clarify this was over a short period of time, and was actually confirmed to not be true, one has to wonder what the intent of this statement was.

The article goes on to tell us, that apparently between 70-75% of us are dehydrated. The dictionary defines dehydration as "a dangerous lack of water in the body resulting from inadequate intake of fluids or excessive loss through sweating, vomiting, or diarrhea". Scary, right?
Well, searching for the source of this claim leads to a lot of wellness blogs, the main marketplace in which Susie competes. Following them to their source, leads us to a report by the US food and Nutrition Board (an irrelevant authority where Australians are concerned). The report ACTUALLY states that 75% of americans don't drink up to their arbitrary water intake recommendation of 2.7L/day for women, and 3.7L/day. It does not mention dehydration, and in fact goes on to state: "The vast majority of healthy people adequately meet their daily hydration needs by letting thirst be their guide. - See more at: http://iom.nationalacademies.org/Reports/2004/Dietary-Reference-Intakes-Water-Potassium-Sodium-Chloride-and-Sulfate.aspx#sthash.Og7YixvD.dpuf"
This does not translate to "70-75% of us are dehydrated at any point in time"

The article goes on to state some less controversial things, like water intake increases satiety, and is useful psychologically to prevent binge eating or drinking sugary drinks containing high calories. There was at least a small amount of logic and reason put into this article after all.

One of the big boo-boos is in Item 4:
"It is proven that drinking cold water, especially icy cold water will help you to burn up to 400 extra kilojoules per day for every 2L of water you drink, which the equivalent of an extra snack every single day."
This is advice that could get someone killed.
Given that we proved her projected 100kj/500ml wrong, where does this number come from? I think it rhymes with "brass". 2L per day for an energy consumption boost sounds pretty good, right? Until you ask, 2L on top of your regular consumption? or does she mean 2L on top of 0 water,and 2L being about recommended anyway, which brings us up to the usual amount of calorie expenditure anyway?
What happens if in response to this article, an overweight person decides to take in 4L or 6L of additional water a day? I'm sure a qualified dietitian knows that dilutional hyponatremia is fatal, right? Well, for those who don't know, you can literally kill yourself by drinking too much. It's most common in marathon runners, but could happen to someone trying to act on this advice.

I will be forwarding this article to the Dieticians Association of Australia, and hopefully the author gets reprimanded for the errors, either intentional or mistaken.