When mountain glaciers melt the run off water can flow into streams, lake, and oceans (And other bodies of water)
The water in a glacier is freshwater.
We would have to wait until the glaciers melt to collect the freshwater.
Polar Ice Caps
Ice caps are formed by glacial movements over many years.
The ice caps are also fresh water unless they melt into saltwater.
We could melt them before they go into the saltwater.
Floating Sea Ice
Floating sea ice is formed when the ocean water gets frozen. It does not come from icebergs or from land.
Sea ice is frozen seawater.
Sea ice is saltwater because it froze in the salt oceans.
Icebergs come from any glacier that reaches the sea. Then, the iceberg melts into the sea water.
Icebergs are fresh water, until they melt into the oceans and become part of the saltwater.
We couldn't use the water because it would already be salt water because it melts into the oceans.