> Specifically: A pipeline from the ocean.

The environmental cost of building a pipeline 750 miles across the country and then expending all of the energy needed to pump that water would completely outweigh any benefits.

You also don't need ocean water. Salt doesn't evaporate. It's still there. The water could be sourced from anywhere.

They could just buy up water rights from farmers and other heavy users and divert the water in the direction of the lake. A million times easier.