A CoStar Group assessment of the impact of Hurricane Harvey and the subsequent flooding shows 175 million square feet of commercial space located within Metro Houston’s 100-year flood zone. This total includes 72,000 apartment units and 20 million square feet of office space that may have been affected by the storm. Another 225 million square feet is located within the 500-year floodplain. A total of 27 percent of that market’s gross leasable area (about 12,000 properties worth approximately $55 billion) is located within these two floodplains and is at risk. At 1.6 billion square feet, Greater Houston is sixth largest CRE market in the U.S., according to the report.