Does the Wicked Witch of the West know she can be killed by water?

Question

In The Wonderful Wizard of Oz, the Wicked Witch of the West lights the Scarecrow on fire. Dorothy picks up a bucket of water to douse him, but she splashes it on the Witch, who begins to melt.

It seems unusual to me that the Witch would allow a lethal substance anywhere near her castle, which makes me wonder: did she know that she could be killed by water?

I would like an answer from the original book series written by L. Frank Baum, not the movie adaptations or derivative works (e.g. Oz the Great and Powerful, Wicked).

Answer 1

So it would seem:

The Witch was too much afraid of the dark to dare go in Dorothy's room at night to take the shoes, and her dread of water was greater than her fear of the dark, so she never came near when Dorothy was bathing. Indeed, the old Witch never touched water, nor ever let water touch her in any way.

She also always carried an umbrella, presumably to avoid getting wet:

The girl had to work hard during the day, and often the Witch threatened to beat her with the same old umbrella she always carried in her hand.

As in Project Gutenberg's Wizard of Oz, in Chapter 12 - The Search for the Wicked Witch.

Answer 2

If you're asking about the book, the odds are decent that she does know that water is harmful to her as she "did not carry a broom in the novel, but rather an umbrella" according to the Oz wiki. Baum never elaborated on exactly why she was vulnerable, but Mombi is killed the same way in The Lost King of Oz and Singra was afraid enough of water to secure protection from it via a favor from a water nymph, so it seems to be a trait of wicked witches in the setting. There's some speculation on the wiki that their bodies were already used up and therefore were only barely held together by magic.

It is stated in Baum's book that the Wicked Witch of the West was so old and Wicked that all the blood in her body dried up long before The Wonderful Wizard of Oz takes place. And when she fnally comes into contact with water, it burns her skin like acid and she dissolves into a puddle on the floor. Baum described it as "melting away like brown sugar." In the beginning of the story when Dorothy's farmhouse fell on the Wicked Witch of the East, her body soon caved in and crumbled to dust under the fallen establishment. (The feet of the dead Wicked Witch had disappeared entirely and nothing was left but the Silver Shoes.) The Good Witch of the North explains that "She was so old that she dried up quickly in the sun." So whatever mysterious magic potion or spell that was holding the Wicked Witch of the East together was possibly something the Wicked Witch of the West used to keep herself alive as well, even though Baum never elaborated upon this aspect.

Answer 3

I'm not sure if this is explicit in the original Frank L Baum The Wonderful Wizard of Oz or the 1939 film The Wizard of Oz.

However in the book she does carry an umbrella, instead of a broom as in the film, a very convenient thing for someone allergic to water, and possibly more than a coincidence, almost as though she didn't want to get wet...

Once the Witch struck Toto a blow with her umbrella and the brave little dog flew at her and bit her leg in return.

_{- The Wonderful Wizard of Oz - Chapter 12 - The Search for the Wicked Witch}

The wicked witch of the south Singra in the book The Lost King of Oz is afraid of water killing her, though whether this is because she know it's bad for them or because of what happened to the wicked witch of the West and Mombi is open for speculation.

As the canonicity of Oz is pretty fluid due to so many people putting their spin on things I'm also going to mention the 2013 film Oz The Great and Powerful Theodora who becomes the wicked witch knows water is dangerous to her as she is burnt by her own tears, even before becoming wicked.

And a further twist from further along the canonicity scale, in the musical Wicked which I have recently seen for the first time:

The weakness to water is something that has been made up and Elphaba (the name of the Wicked Witch in this iteration) uses the belief everyone has in this to fake her own death to be with the man she loves.

Answer 4

Yes, just before Dorothy throws the water, you can hear the witch yell:

"Don't throw that water!"

Answer 5

She did. According to Baum's book The Wonderful Wizard of Oz:

The Witch was too much afraid of the dark to dare go in Dorothy's room at night to take the shoes, and her dread of water was greater than her fear of the dark, so she never came near when Dorothy was bathing. Indeed, the old Witch never touched water, nor ever let water touch her in any way.

So she never let water touch her in any way. We know that she knew that she melted to a puddle of scum once she touched water.