What does the Ganges symbolize, according to Jawaharlal Nehru?

Concept: when a person's own writing states what a symbol or place represents to them, that stated meaning — not an inference from generic facts about the object — is what the symbol is said to represent to that person. Different writers can assign different symbolic meanings to the same object, so answering "what does X symbolize, according to person Y" requires locating Y's own explicit statement about X, not reasoning about X in the abstract.

Application: in his Last Will and Testament (21 June 1954), Nehru gives exactly such an explicit statement about the Ganges — he writes that the river “has been a symbol of India's age-long culture and civilization, ever-changing, ever-flowing, and yet ever the same Ganga.” This is his own stated meaning for the river, and it matches the description of India's age-long culture and civilization exactly.

Cross-check: contrasting each offered description against that same statement —

• India's prosperity: nowhere in this statement does Nehru tie the river's significance to economic wealth or material abundance.

• Changing seasons of India: Nehru's writing does touch on the river's changing moods and appearance through the year, but that is a description of how the river visibly changes, not a statement of what it stands for — the two are different claims, and only the latter is the symbolism the question asks about.

• India's struggle for freedom: the independence movement is a recurring theme in Nehru's broader writing and political life, but it is not the meaning he attaches to the Ganges in this statement.

Therefore, according to Nehru's own statement, the Ganges symbolizes India's age-long culture and civilization.