Floods, droughts and major storms that wash out highways, damage buildings and affect power grids could cost Canada's economy $139 billion over the next 30 years, a new climate-based analysis predicts. The report, titled Aquanomics, was published Monday by GHD, a global engineering and architecture services firm. In an interview with CBC News, the firm's Canadian water lead Don Holland said that the value of water and the costs associated with it are underacknowledged.