The BayArc is an efficient, unobtrusive, and environmentally sensitive solution to the problem of sea level rise and resultant flooding in the San Francisco Bay Area. It consists of a flexible tensile net structure spanning the 1.5 miles of the Golden Gate. For most of the year it sits at the bay floor. When high tides or storm surges are predicted, the BayArc is temporarily deployed; the leading edge rises to the surface, creating a barrier that stretches from the bay floor to the surface of the water. Once deployed, it "shaves off" the peak high tide from outside of the bay, protecting more than 500 miles of vulnerable shoreline from flooding. The basic concept was informed by an analysis of tidal patterns in the bay, revealing the key fact that expected sea level rise would only cause major flooding in concert with high tides and storm surges.