Yorkshire developer Dransfield Properties plans to build the 50,000sq ft store at Low Stanners next to the River Wansbeck
Tolent is expected to start work on the store in the autumn, with the opening planned for 2013.
The superstore includes an underground car park which will act as a holding reservoir and help protect nearby homes in the event of flooding from the River Wansbeck.
Dransfield’s superstore plan was granted outline permission by the county council last June, beating off rival bids by retail giants Tesco and Sainsbury’s for new stores on the outskirts of Morpeth.