TAMPA — After 80 years near downtown Tampa, the ConAgra flour mill could be headed to a new home with a Port Tampa Bay berth north of Apollo Beach.Ardent Mills, which owns the plant, would lease about 10 acres at Port Redwing under proposed lease terms expected to go to the board of Port Tampa Bay on Dec. 18. During negotiations, the possible move has been known as “Project Hawk,” according to port records.Ardent Mills agreed to move the plant after selling its downtown property to the developers of the $3 billion Water Street Tampa project last month. It says it wants to have a new mill in operation sometime in 2021.A TRANSFORMATIONAL DEAL: Water Street Tampa developers buy ConAgra flour mill for future expansion of their $3 billion projectAt this point, the terms headed to the port board are basic and non-binding on both the port and Ardent Mills, a joint venture between ConAgra and two other agri-business companies. If both sides proceed, they would be written into a more formal and detailed agreement that would require another round of approval.The port said it identified 10 acres zoned heavy industrial at Port Redwing in response to Ardent Mills’ site requirements. Depending on what the mill needs, the port has said additional acreage might be available.The lease would run for 40 years, and Ardent Mills would have 12 months to perform its due diligence, get permits and design its facility. During construction, rent would be $12,500 per acre per year or $125,000 a year.Starting after Ardent Mills builds its mill, or in the fourth year of the lease, the company would pay the port rent starting a $24,000 per acre per year, or $240,000 a year, indexed to the consumer price index. After 20 years, the rent would be adjusted to reflect market conditions.The mill would be expected to handle at least 450,000 tons of material a year, with at least 100,000 tons of it being moved by ship. The port’s railroad can currently handle trains of 100 cars, but the two sides are talking about expanding that, at the mill’s expense, to accommodate 110-car trains.Ardent Mills said Thursday it "has explored several sites, including sites not owned by the Port of Tampa Bay. Most of the sites explored, including Port Redwing, are located within the Tampa region.""The schedule for construction of our new mill is dependent on the successful negotiation of final agreements mutually beneficial to both Ardent Mills and the owner of the selected site," company spokeswoman Mary Ann Strombitski said in a statement. The port property, as well as the others the company looked at, allow "Ardent Mills to flexibly serve the current and future growth needs of our customers in the great region of Tampa and throughout the state of Florida."Meanwhile, Strategic Property Partners, the development company formed by Tampa Bay Lightning owner Jeff Vinik and Cascade Investment, a capital fund launched by Microsoft founder Bill Gates, plans to expand Water Street Tampa onto the former ConAgra property once the flour mill moves out.“We’ve expanded the footprint of the project all the way up to Whiting Street,” Strategic Property Partners CEO James Nozar said this week.Built in 1938, the 80,000-square-foot flour mill grinds wheat around the clock and ships 1.5 million pounds of flour a day to bakeries across Florida, the Southeastern United States and the Caribbean.But the mill was built when the southern part of downtown was a working waterfront dominated by heavy industry, shipping, warehouses, and rail yards. Since the 1990s, a slow evolution has been underway, with the port attracting more cruise ships, apartments and condominiums going up in the nearby Channel District, Amalie Arena drawing crowds for hockey games and concerts, and the Riverwalk opening the waterfront itself to recreation.Now Vinik and Cascade are poised to turbocharge that transformation. With 9 million square feet of planned development spread across about 50 acres, Water Street Tampa is expected to include three hotels, downtown’s first new trophy office tower in 25 years, a new home of the University of South Florida’s Morsani College of Medicine, three apartment complexes, a grocery store, new park space and dozens of restaurants and shops. Strategic Property Partners also plans to re-invent Channelside Bay Plaza as Sparkman Wharf, with its first 10 restaurants opening on Nov. 30.Had it stayed in place, ConAgra would have remained a jarring counter-note to Water Street Tampa’s plans to create a live-work-play neighborhood next door.“This will complement Water Street,” Tampa Mayor Bob Buckhorn said of the move, while allowing “Ardent Mills to build a modern, far more efficient facility in a location that’s more conducive to the work that they do.”MORE: Go here for more Business NewsContact Richard Danielson at [email protected] or (813) 226-3403. Follow @Danielson_Times.