Contending with ever-changing residential market needs and a complex site alongside Tempe Town Lake, the team constructing three concrete multifamily towers at South Pier in Tempe, Ariz., is making rapid progress to take them vertical. Ranging from 21 to 23 stories tall, the high-rises known as Lot 6 make up the first phase of a $1.8-billion mixed-use development that will eventually include multiple apartment, condo, hotel and office towers along with an entertainment pier jutting out into the lake.

But that same body of water also added challenges to the foundation work, which penetrates three levels down into the Salt River’s alluvial soil and cobble. Some site preparation and geotechnical work had been completed In the early 2000s, but plans for the area at that time stalled due to the recession, and the site remained untouched, until now.

The current iteration of Lot 6, developed by Silverstein Properties, places it at a key spot on the south side of Tempe Town Lake, which will eventually be surrounded by the Novus Innovation Corridor, a 10-million-sq-ft mixed-use urban space where private businesses and Arizona State University will collaborate on various technologies.

Lot 6 architect Davis joined the project in 2021 and inherited some early programmatic design work from another firm that had been performed when the project was initiated by another developer team. “Our brief was really to come in at that point to reestablish the project direction in terms of its program and quality, do some value engineering and bring it to a good design development level,” says Richard Drinkwater, principal and director of design for Davis.

Construction began in August 2023 with contractor Clayco at the helm. The towers will include 724 multifamily units, amenity spaces and retail within 1.2 million sq ft.

Expansive amenity decks provide space for pools, fitness areas and clubhouses overlooking the lake.
Photo by Scott Blair/ENR

Water Management

The towers are supported by 9-ft-thick mat foundations that sit below the three levels of parking. “The water table level is right around 30 feet, which is about where our basement level three is,” says Scott Thomas, Clayco senior project manager. “So with the mat foundation set below that, we ran into quite a bit of dewatering, and it seemed to get worse as we pushed the water toward the east. We spent about 45 to 60 days just dewatering on the project, pumping anywhere from about 40,000 to 80,000 gallons of water per shift. It was quite the process that we worked through to get that water out, to be able to continue to push the mat foundations and all the rest of the footings.”

Davis had previously worked on another development to the west alongside a deeper part of the lake, where the water table required a more expensive bathtub-style foundation.

For South Pier, the firm “wanted to have a safeguard approach to the residences because there are three towers connected by a common parking garage below. So in the vertical culvert, there is an early warning water sensor,” says Buck Yee, firm principal and project architect.

In the system, which would likely only be needed for a 1-in-50-year flood, pressure release valves in the bottom level of the garage can open and deliberately flood the basement when too much hydrostatic pressure builds up. The system, which provides ample notice for residents to move their vehicles, eliminated the need for a much more expensive and complex bathtub-type design, Drinkwater says.

Concrete subcontractor Suntec places a new deck every six days and says work is running ahead of schedule.
Photo courtesy Clayco

Subcontractor Suntec Concrete says it has been delivering full 14,000-sq-ft floor decks for both Towers 1 and 2 every six days. The bottom of the floor decks will be exposed, requiring strict quality control.

The team aims to top off Tower 1 in August at 230 ft. Tower 2 will follow in September at 207 ft—with crews from the first tower then moving to the 226-ft-tall Tower 3 and set to finish concrete there by March. Placement typically occurs overnight to mitigate heat, boost safety and keep site logistics on track, Thomas says. PK Associates performed the structural engineering.

The project incorporates prefabricated panels on the building skin, manufactured in a 200,000-sq-ft shop in Gilbert, Ariz., by MKB using between 80 and 100 workers. 

“This allows us to work on our skin and incorporate all the elements of the building as we’re going vertical with our structure,” says Mike Broughton, Clayco senior project manager. Not only does the prefabrication boost sustainability by reducing construction waste, it also “allows us to maintain safety and overall quality, and make sure we have a good air/water barrier while doing that in the shop.” Windows are also being prefabricated in Mexico.

At peak, about 550 trade workers will be at the site. Thomas says Clayco has maintained a good safety record with no recordables or lost-time incidents.

Daily site manager meetings and a morning stretch-and-flex with all workers fills everyone in on “what is happening overall on the site to be safe and understand where they need to be and what could be happening around them, even with other trades,” Thomas says.

Clayco provides training space for safety and site orientation in both Spanish and English simultaneously.
Photo by Scott Blair/ENR

In addition to two full-time Clayco safety managers, the contractor also employs a full-time nurse to handle minor scrapes or splinters. The firm strategically places cool-zone tents in key spots around the site, including on the elevated decks, so workers can go into an air-conditioned space for a break from the Valley of the Sun’s intense heat.

At the jobsite trailer complex, where many of the project team members are colocated, Clayco provides a site-specific orientation classroom with two sides set up for training in Spanish and English.

“We can do around 40 individuals at a time. So far, we’ve oriented about 1,100 workers on site. As trades come in and out, we make sure that everyone is aware of everything that’s happening on site,” Thomas says.

Designers aim to maximize connection to the lake and views of nearby desert landscape with large windows and ample indoor-outdoor space.
Rendering courtesy Davis

Maximizing Views

Clayco expects to wrap up Tower 1 in early 2026, with the other two towers following in mid-2026.

The high density at the site provides design opportunities to maximize the unique environment of a “great urban enclave on the lake,” Drinkwater says. “We wanted to play on that with the design of the building to create some really wonderful residential units in terms of amazing views, amazing location, big balconies and outdoor space that is really a premium for residential units here in Arizona.” Having all parking below grade also helps create a pedestrian-centric landscape plan, designed by Dig Studio.

“One of the major differentiators for us here is the vast amenity space that we have among the three towers,” says Lindsay Bruckal, Clayco project executive. Tower 1 houses a pool deck, fitness area, clubhouse and workspaces that emphasize the indoor-outdoor connection. Towers 2 and 3 share an even larger amenity podium. Exterior spaces and parks emphasize the connection to the lakefront.

Project owners have been consistently focused on “making it a really unique and desirable place to live,” which has led to additional upgrades to the amenity spaces and interior design “to make them more marketable and more sought after for future tenants,” she says.

One such change recently relocated the fitness area from a double-height space next to the amenity deck in Tower 2 to the ground floor, so that a clubhouse could be added. Despite those floors already being poured, Davis quickly pivoted with new drawings and found ways to configure the space to provide power to workout machines, Yee says.

Lot 6 and its separately developed neighbor Lot 5 will be joined by numerous future mixed-use phases for the estimated $1.8-billion South Pier development.
Rendering courtesy Davis

Davis continues to work with the developers on other phases, including a conceptual design for an office building and another multifamily tower directly south of Pier 202 at Lot 1, which is a separate residential project under construction for several years by another developer/builder. Davis also provided a conceptual site plan for the South Pier’s future entertainment district, featuring a pier, pedestrian bridge and Ferris wheel.

Drinkwater hopes the design creates a “wonderful environment where people will say, ‘Oh, I want to live there!’”