Plan to Minimize Flooding Using Ivy, Grass and Drainage Pools on Rooftops-

Under a plan announced by Mayor Michael Bloomberg, New York City plans to catch and store rainwater in new roof systems to prevent sewage from overflowing into city waterways during heavy storms. The mayor’s strategy is to use “blue” roofs that contain a row of drainage pools and “green” or grass/ivy covered rooftops to catch and hold the water. If the state allows the plan to take effect, NYC could save $2.4 billion over the course of 20 years, according to estimates. As of now, the city employs storage tanks and tunnels to manage torrential rainfall which have proven to be ineffective. The 14 wastewater treatment facilities currently in operation throughout the city are a major source of pollution, given that they were built roughly 150 years ago. In order to prevent treatment plant flooding during heavy rainstorms, bypasses are activated which divert sewage into harbors, canals and rivers. “Our PlaNYC goal of making 90 percent of City waterways suitable for recreations requires us to do more, and that means reducing the combined sewer overflows that have plagued the City for decades,” Bloomberg said in a statement. By the year 2030, the mayor says that his initiative could lower instances of sewage runoff into waterways by 40 percent. He also warns that, if the state denies the proposal, NYC will spend roughly $6.8 billion to fix the ongoing problem of flooded treatment plants.