This article has been updated to include comments from Richard Suttle Jr., the Austin lawyer who handled the zoning case for the developer of the project.

A developer has released new details and images of an office tower it plans to build just south of downtown Austin, on a high-profile tract once owned by the family trust of the late Charles Schulz, creator of the "Peanuts" comic strip.

Dallas-based Stream Realty Partners intends to break ground early next year on the 15-story tower, which has been named RiverSouth, said David Blackbird, regional managing partner in Austin with Stream. The site, at 401 S. First St., currently is home to a Hooters restaurant and a parking lot.

The building will have about 330,000 square feet of office space and about 18,000 square feet of ground-floor retail space and 843 parking spaces in five levels of underground parking. The building is expected to open in the second quarter of 2021.

Stream and city planners say the project is expected to serve as a model as land along the south shore of Lady Bird Lake gets redeveloped in coming years under the city’s South Central Waterfront Initiative.

"It’s a pretty iconic site," Blackbird said. "We want to do something unique there, a signature building that reflects the importance of that site. We’re real excited about it."

Slated for land bounded by South First Street, West Riverside Drive and Barton Springs Road, the project received zoning approval from the Austin City Council in May for a planned unit development, which became known during the process as the "Snoopy PUD," a nod to Schulz.

The purchase was among a series of restaurant and land acquisitions Schulz made as he bought real estate around the country to diversify his investments. Schulz died in 2000. Blackbird said Stream closed on the purchase of the triangular, 1.4-acre site in April.

Blackbird said the Hooters restaurant will close prior to Stream starting construction on the tower.

Stream anticipates receiving final site development permits from the city late this year and starting construction on the project in the first quarter of 2019.

Stream is not releasing a figure for the project’s estimated cost. Blackbird said there are no signed office leases to date but said Stream is talking to prospects.

On the retail side, Blackbird said Stream anticipates a lively tenant mix that complements the character of the popular shopping, dining and other offerings along nearby South Congress Avenue, South First Street and South Lamar Boulevard. He said there will be an opportunity for "a cool restaurant" overlooking Auditorium Shores, on the northwest side of the building.

Blackbird said RiverSouth’s amenities will include a rooftop bar and lounge, a fitness studio, locker rooms and a bicycle valet and storage, among others.

He said the parking will be made available for a fee for public use on nights and weekends.

With construction imminent, Stream’s site is poised to become the first property, among 33 individually owned tracts on Lady Bird Lake’s south shoreline, to be redeveloped under the city’s South Central Waterfront Initiative.

The initiative’s intent is to transform a patchwork of properties — 118 acres in all — into a pedestrian-friendly district with public benefits such as more green space, trails and public areas, improved public access to the waterfront, new street connections and affordable housing. The goal is to have a unified road map in place, to help guide the anticipated surge of development destined for the area in coming years, city planners say.

Richard Suttle Jr. with the Austin law firm Armbrust & Brown handled the zoning case for the RiverSouth project.

"The owner of this project worked closely with the city to lay the groundwork for the implementation of the South Central plan," Suttle said. "It’s one of the early steps in encouraging other landowners to opt into the plan to create a special place on the south waterfront."

As part of its agreement with the city under the waterfront plan, Stream will provide more $3.1 million in infrastructure improvements and community benefits, Stream and city planners said.

"RiverSouth will create a network of corporate and recreational spaces, streets, lakeside parks and trails," said Daniel Woodroffe, president and founder of dwg., the project’s Austin-based urban landscape architecture firm. "It’s the perfect project to kick-start the South Central Waterfront plan and to improve the pedestrian experience, making the area a major destination."

Alan Holt is a principal planner with the city spearheading the waterfront initiative.

"Working together, the developer and the city shaped the project and the community benefits contributions" outlined in the plan’s framework, Holt said. "As a result, the developer will provide in-kind and cash contributions, worth over $3 million, for off-site transportation improvements, protected bike lanes, district piping for recycled water, rain gardens, and affordable housing. On site, the project will set a new high bar for streetscapes, street trees and landscaping, water quality treatment, and green building technologies."

Holt said the regulations and financing tools that the city is currently is developing for the waterfront plan incorporate "many lessons learned" from the zoning process for Stream’s site.

Jesse Moore, president of the Bouldin Creek Neighborhood Association, said the group had decided not to oppose the PUD zoning for the project, "based on the understanding there would be some money devoted toward the waterfront area in general and affordable housing in particular."

Blackbird said RiverSouth will be an "extremely sustainable" building. Along with other green features, it will have a landscaped roof atop the parking deck and will be harvesting condensate.

In addition to Stream, Suttle and dwg., the team involved in RiverSouth includes the Beck Group, Big Red Dog, Cardno and MEJ & Associates.