The Brooklyn Navy Yard is being used as the testing ground for the waterfalls designed for the National September 11th Memorial and Museum.

Michael Arad's memorial design, "Reflecting Absence," features a 30-feet-tall waterfall that will spill down into the footprints of the World Trade Center and form reflecting pools surrounded by victims' names.

"One of the things I wanted the water in this design to do is to really mark this continuing sense of absence. This notion that time moves forward, but this absence in so many people's lives is persistent, it doesn't go away," said Arad.

Workers have been testing the waterfalls to figure out how to keep them running despite potential obstacles like below-freezing temperatures and mementos that could fall into the water.

The pools will be the centerpiece of the memorial plaza and will take up half of the 16-acre site.

The memorial is scheduled to open by the 10th anniversary of the terrorist attacks next year.