Why does a reservoir supplying a town usually need to hold far more water than the town uses in a day?

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Question

Why does a reservoir supplying a town usually need to hold far more water than the town uses in a day?

Accepted Answer

To store water through dry periods, as rainfall is uneven through the year — Award 1 mark. Reservoirs collect water in wet seasons to supply the town in dry ones; water still needs treatment, and evaporation does happen from reservoirs.

Answer

Because water expands while it is being stored

Answer

To store water through dry periods, as rainfall is uneven through the year

Answer

Because water cannot evaporate from a large reservoir

Answer

To give the water time to become safe to drink

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