Sherman Associates will soon break ground on two mixed-use riverfront apartments dubbed the West Side Flats Phase III in St. Paul, officials said Wednesday.

The $75.5 million project will be located by the southeast corner of the Wabasha Street bridge and should be completed by fall 2021.

The two apartment buildings will offer 253 units on 5 acres sandwiched between the West Side Flats I apartment building on Wabasha Street that Sherman completed six years ago and the U.S. Bank building that sits near the Mississippi River's edge and Robert Street.

Sherman's West Side Flats Phase III complex will be bordered by the river on one side and E. Fillmore Avenue.

Wednesday, Sherman officials announced they finalized the purchase of the land and a construction loan. A groundbreaking will take place "immediately," officials said.

Expectations are high for the two new buildings since the original West Side Flats Phase I project is now 98% occupied after its opening in 2014. Land for a planned Phase II property has been purchased but has yet to be developed, said Sherman spokeswoman Valerie Doleman. At this point Phase III will open first.

Once construction is completed, the first apartment, the Scenic, will include 171 market-rate luxury apartments at a cost of $46.9 million. The property will feature a pool, fitness studios, lounge rooms, dog run, a rooftop terrace and various "smart home" technologies for the tenants.

The second building, Verdant, will offer 82 affordable-housing units at a cost of $28.6 million. That building is designed for renters earning 50 to 60% of the area median household income.

Those affordability restrictions will be in place for 40 years.

"Were confident we're bringing the right product types and unit mixes to the market with these projects," said Sherman senior developer Will Anderson, noting that "demand for affordable housing is strong."

While rents for the luxury Scenic will run about $1,300 to $2,500 a month, rents will be more modest for Verdant — from $700 to $1,480 a month.

He noted that financing for the complex proved "complicated" and involved a host of players.

"There are many people committed to the success of building this community," Anderson said.

Getting the deal done involved an unknown portion of equity from Sherman, plus grants from the Metropolitan Council and the Minnesota Department of Employment and Economic Development, tax increment financing (TIF), a city of St. Paul HOME loan and loans from National Bank of Commerce, RBC Community Investments, MinnWest Bank, Whitestar Capital, and Cedar Rapids Bank and Trust.

"The project aligns the requirements of stakeholders and rental market/financing market conditions. It shows that long-term partnerships can yield really strong and impactful results," Anderson said.