Dive Brief:
- The Copernicus project team at the European Space Agency team has used Sentinel 1 satellite imagery to scan the San Francisco city-scape, confirming the sink/tilt of the Millennium Tower and other buildings.
- Sentinel 1 employs multiple radar scans from twin satellites to map surface features down to millimeter scale fidelity.
- The Millennium tower has sunk 16 inches since completion in 2009, and it is experiencing a 2-inch lateral tilt at the base and a 6-inch tilt at the top of the tower.
Dive Insight:
So it takes a satellite to confirm what residents at the Millennium Tower in San Francisco have known for some time: their building, partially constructed on land reclaimed from the San Francisco Bay, is slowly sinking into the ground. In addition to the Millennium Tower, the ESA team found that buildings located on the seismically active Hayward fault and on reclaimed wetlands in San Rafael bay are also experiencing sinking and tilting issues.
Once touted as a marquee multifamily development and the tallest residential tower west of the Mississippi River (a title now held by the Austonian and soon to be surpassed by The Independent in Austin), the Millennium Tower faces an uncertain future as the building continues to lean and purchasers of units have seen their investments appraised for one dollar.
The City of San Francisco has filed suit against the Millennium Tower development team, alleging property managers failed to disclose known structural issues to buyers. The development team has countered that developers of the adjacent Transbay Terminal project have pumped millions of gallons of groundwater out of the substrate, weakening the soil and causing the building to sink.
As a result of the controversy, the Millennium Tower developers have redesigned the foundation of another of their San Francisco high-rises under construction. The situation has also led San Francisco Mayor Ed Lee to request more strict building regulations and a review of the city's 30-year earthquake plan to ensure the safety of its buildings.