The investment will be spent on building a 65,000 sq ft temperature-controlled facility within the 625,000 sq ft distribution centre, so chilled and ambient lines can be handled together for the first time.
A new fleet of 220 vehicles and trailers is also planned, meaning stores can receive ambient and temperature-controlled goods in a single truck.
"This demonstrates our desire to increase efficiency and constantly improve benefits to members," said John Sharpe, MD of central distribution trading and logistics at Nisa-Today's. "From an environmental and cost point of view this is an excellent way forward. Once completed we hope to be able to offer even lower prices."
Bibby Line Group currently distributes Nisa's ambient products, while DHL distributes frozen and chilled goods. DHL will handle the entire supply chain from April 2011.
Meanwhile, Nisa-Today's has broken the 100 million case mark a month early. Nisa forecast that it would hit the total by the end of April but did so on 17 March. Strong sales of £1.4bn helped Nisa to the milestone, Sharpe said.
"To reach that level early is an example of the efficiency of our distribution model and the excellent contribution by our third party logistics suppliers," he added.