"Here is no water but only rock" is the first line of an extract from the last section of "The Wasteland". It relies on "What the Thunder said" about the desolation of the western culture. The thunder isn't able to provide the land with its need of water. Thus the reader can better understand why Eliot refers to a place where there is only rock. Life cannot grow from rock, as the culture cannot way out from the apathy in which had fallen.

Analyzing the layout the reader can single out two paragraphs: the first one has got the lines longer than the second one. , According to the layout, the last paragraph looks more poetic than the first one. The reader can draw the conclusion that Eliot has reached the objective of his search. But it isn't so.

The extract mainly works on the phonological level. The text doesn't follow a line pattern: there are a lot of enjambments and repetitions. There are also a lot of figures of speech in the text. In the first two lines the reader can find the opposition  between "water" and "rock". The repetition at the beginning of the line of the last word of the former line, goes on until line 4.

In the text the reader can notice that the word water is repeated eleven times and the world rock is repeated nine times. Therefore water almost always goes with its antonym rock: because of the impossibility to find a synthesis.

Another occurrence in the text is the world mountain: it conveys the desolation of a place where there is no life. It represents the symbol for all the "Wasteland". In lines five and six the reader can notice the rhyme between "drink" and "think" as if without water, therefore life, there wouldn't be a reason to stop and reflect about the problems of life and everything became meaningless (paralysis of modern society).

Late, at line nine, Eliot uses a metaphor: the mountains are ill as "carious" teeth. "Teeth" has an assonance with "spit" which is in rhyme with "sit". All these devices may communicate the difficult situation created ("spit", "nor sit").

Other elements sustaining such interpretation are the harsh sounds of "sneer and snarl" (in assonance) and "mudcracked". Those are not usually words for a poem.

Starting from line 16 the reader can notice the layout changes: it seems to follow the pattern of a waterfall.

The lines become shorter: "rock" and "water" are repeated twice. Such enumeration accelerates rhythm. The poem seems to recall a native Hindu rite of rain dance. As a matter of fact it ends with an onomatopoeic sound of rainfall "drip drop".

But the last line doesn't leave  place for hope: as a matter of fact says: "but there is no water".

 Eliot uses anthropological devices, but he isn't able to find a solution for the situation of the modern world. And the sad conclusion he draws is that the new awareness of the  condition of the world doesn't calm the search for "fertility", it rather stresses such search.

Therefore the "Wasteland" becomes more desolate than any described in the poem before.  

Excellent!