DESIGN TEAM:
Lisa North
Artistic Project Lead
Andre Del Re
Technical Project Lead
Da Vida Pools
Austin, Texas

James BufkinPrincipal
Bufkin Engineering
Austin, Texas

With no backyard space to accommodate a pool and spa, the team built inside the adjacent lake, which the client owned.

“It is a boat in the water, literally,” said Lisa North.

Fashioned to look like a black cube on the water, the pool/spa combination is surrounded by perimeter-overflow slots and a vanishing edge. Catch basins and gutters are topped with stone to conceal the overflow.

A spa is “hidden” underneath the pool water. The walls terminate just under the pool’s waterline, so it doesn’t interrupt the mirror effect of the pool surface. When the homeowner uses the spa, water drops through a slot running along the center line of its two dam walls, lowering the water level. The heated water then circulates and remains contained within the spa.

As stunning as the finished product are the extraordinary measures taken to literally build inside the lake. The team built a coffer dam — a container made of metal sides — to barricade the water from coming through the sides. Ground seepage would remain an issue, so crews continuously pumped away ground water while working.

In addition to the mere fact of having a pool inside a lake, designers and builders had to prepare it for an unusual reality: To combat an aggressive pest that takes over the lake, the city regularly drains and refills it, causing the water level to fluctuate wildly. Upon refilling, the lake generally will rise past the pool’s elevation and submerge it. So the vessel had to be built to withstand this. To support the poolscape, 19 pilings measuring 66 feet were driven into the lake floor to reach bedrock. The pile driver had to be brought in by barge. Between the horizontal beams, located directly under the pool and tying the pilings together, the team placed gravel so that the highly expansive clay soil could swell freely and without consequence.