In addition, as part of a $130 million and an estimated 18-month project, the MTA began installing new subway grates in September 2008 in an attempt to prevent rain from overflowing into the subway system. The metallic structures, designed with the help of architectural firms and meant as a piece of public art, are placed atop existing grates but with a sleeve to prevent debris and rain from flooding the subway. The racks will at first be installed in the three most flood-prone areas as determined by hydrologists: Jamaica, Tribeca, and the Upper West Side. Each neighborhood has its own distinct design, some featuring a wave-like deck which increases in height and features seating (as in Jamaica), others with a flatter deck that includes seating and a bike rack.