Nicknamed ‘Cannonball Run’ –– after the recommended method of entering the water –– this sleek Massaranduba deck is perched just above the clear, green ripples of the San Marcos River. Although wooden decks are a common sight dotting the banks of the spring-fed river, this one, designed and built by A. GRUPPO Architects, allows its users to engage with the water in a unique way, explains principal partner Andrew Nance. He says Cannonball Run is a simple composition of two forms: a rectangle, representing space, and a line, representing movement. 

“I love the simplicity of the forms and their relationship to each other with the pecan tree pinning it to the ground,” says Nance of the deck completed in 2013. “I think this visual and physical anchor is really important to the composition.” 

The deck, constructed out of the durable Brazilian hardwood Massaranduba, facilitates water access to San Marcos resident Brett Baer’s riverfront property –– one of less than a dozen existing in the city’s limits. Baer, who runs a staging company in Los Angeles during the week, spends his weekends at home with his wife and daughter in San Marcos. With his time in LA being all about ‘work,’ his weekends spent with his family on their picturesque waterfront property are all about ‘play.’ The only thing missing from the Baer’s riverfront property was a way to access the river, located three and a half feet below the level of the bank, so they hired Nance for the job. 

“Brett’s vision of having a place to gather at the water’s edge was spot on,” says Nance who met Baer when their wives were in graduate school studying dance in Boulder, Colorado, and reconnected when both of their wives began teaching in the dance program at Texas State University. “The deck is the center of activity on the weekends, and it is so enjoyable to have gatherings. It’s an absolute treat to see the Cannonball Run operate as intended –– with adults gathered around sipping their drinks while the kids run and jump into the river.” 

Nance’s personal experience floating the river and watching his own two young children enjoy the water inspired the design’s two central features: a conversation area where adults can stay dry, relax and watch over their children swimming below, and the cannonball run which encourages children to run, jump and splash into the river before climbing back out to do it all over again.

Positioned near a natural drainage feature and wrapped around a mature pecan tree, the deck offers both visual and literal anchoring to the site. The ‘run’ resembles a fishing dock and cantilevers out over the shoreline from the bank without impeding the flow of water, explains Nance. Canoes and kayaks are easily launched from the natural drainage feature and an integrated storage bin hides the clutter of life jackets, paddles and snorkel gear with a ‘lid’ that is part of the deck’s surface. 

But ensuring the deck’s longevity in an ‘active flood plain’ posed some technical challenges, says Nance. The site, located in a 100 year flood plain, is characterized by expansive soils and flooding so a mat-foundation system allows the deck to ‘float’ in the soil while the natural buoyancy of the structure is counteracted with earth anchors enabling it to stay submerged to protect it from floating debris during a flood. 

Both strategies were put to the test in October 2013 just three months after construction, again in May 2015, and later in October 2015 where the deck was submerged in up to 15 feet of water for a 36-hour period.

The A. GRUPPO-designed and -built structure was the only deck on the block to have survived the most recent flood. In fact, beyond losing the loungers and looking like it had been pressure washed, Nance says the deck survived with no adverse effects. 

“Each time it floods, all who have spent time around it call, text or ask ‘how’d the deck do?’” says Nance. “So far, so good.”


A. Gruppo Architects

512.557.2140 |