The water company responsible for Europe's biggest man-made lake has described a possible national water grid as "not a viable idea".
Kielder holds 44 billion gallons of water when full
The Environment Agency is studying the cost of a national water network, with the study set to conclude within weeks.
But Northumbrian Water - responsible for the 44 billion gallon capacity Kielder reservoir - said the plan was unworkable on cost and ecology grounds.
A national grid could pump water from wetter parts of Britain to drier areas.
The Institution of Civil Engineers says proposals for a national pipe network should be taken seriously, as it would offer one answer to summer shortages.
Professor Roger Falconer says a national water grid could be "one of the options to address the current and future problems we have with water supply for various parts of the UK."
An Environment Agency spokesman said: "In engineering terms, a national grid is feasible.
"But it needs to be looked at in terms of the pressures on water resources and what is the most sustainable solution".
But a spokeswoman for Northumbrian Water said: "A national water grid is not a viable option.
"Water is very heavy and very expensive to move around with pumps.
"Such a plan would also have cost implications in the construction process and also longer term for our own customers.
"There are also ecological concerns in that water from different parts of the country may not be suitable for the areas it is moved to. It could have an adverse effect on animal and plant life."
Kielder reservoir in Northumberland, one of 22 managed by Northumbrian Water, is currently 80% full.