A little-known local developer has submitted big plans for the site of the Mahi Shrine building on the Miami River that call for replacing the bunker-like auditorium and its parking lot with a stacked big-box retail building, about 440 residential units in two towers and a lushly planted public river walk with waterfront restaurants.

The nearly nine-acre, $150 million River Landing project would be the third mega-development in central Miami after Brickell CityCenter and the Miami Design District redevelopment, both multi-block projects now under construction. These mega-projects are known as Special Area Plans under the city’s Miami 21 zoning code, which is designed to foster mixed-use, pedestrian-friendly urban development.

River Landing, in a still-gritty location next to Miami-Dade County’s criminal justice center and the Jackson Memorial Hospital health district, does not aim to compete with the high-end retail and chic environs of the Design District and CityCentre projects.

Attorney-turned-developer Andrew Hellinger says River Landing would fill an underserved market niche by providing housing, a supermarket and affordable chain retail to the tens of thousands of workers in the justice complex and the health district, while also drawing residents from surrounding working-class and gentrifying neighborhoods who now have few places to shop.

The Jackson complex alone sees 55,000 daily workers and visitors, but retail and restaurant offerings are largely limited to a busy nearby Winn-Dixie and some new restaurants on the ground floor of the University of Miami’s Life Science & Technology Park.

“There’s just nothing there right now,” said Hellinger, chief executive of Hellinger-Penabad Companies. “What makes our site the most viable for retail is its proximity to the I-95 and 836 corridor and the visibility from the expressway.’’

Because of its size and location, the Mahi Shrine site has long been seen as a key piece in the redevelopment of the portion of the Miami River running through downtown Miami and the Brickell and health districts. The city has sought to transform the waterway, once largely industrial and commercial, into a mixed-use corridor of residential, office and retail development linked by a continuous river walk or greenway.

River Landing would be the largest project to date for developer Hellinger-Penabad. As the former head of Leviev Boymelgreen’s Florida operations, Hellinger developed the Marquis Miami luxury condo on Biscyane Boulevard. River Landing, which is under review by city planners, is not the first massive project to be proposed for the underused site, which is wedged between the soaring State Road 836 river overpass and the approach to the 17th Avenue bridge. It’s owned by the Mahi Shriners fraternal organization, an affiliate of Shriners International, whose fez-wearing members are well known for their support of a network of childrens’ hospitals.

A Mahi Shrine representative said he could not comment under the terms of the agreement with Hellinger.

Seven years ago, the city approved a major condo project on the site, but it fell victim to economic recession and a ruling from the Federal Aviation Administration that its three towers intruded into protected air lanes for nearby Miami International Airport.

Hellinger said his project’s towers — 12 stories atop a 12-story parking and retail deck — would be well below the 310-foot maximum height for the site set by the FAA. The project consists of two separate structures, one a retail and parking-garage block that would rise on the east end of the site, roughly bounded by the 836 overpass. The retail portion would include a multi-level design similar to the one used at Dadeland Station or Fifth & Alton in Miami Beach. But this one would be even taller with six floors of retail.