In urban areas where conventional stormwater BMPs are increasingly expensive, a very high efficiency stormwater method for the roof is needed. American Hydrotech, Inc. has developed its series of Blue Roof assemblies to handle very large quantities of water on the rooftop. Whether it’s within a typical stone ballasted PMR Assembly, a concrete paver surfaced roof or the Garden Roof® Assembly, very large quantities of stormwater can be temporarily stored on the roof.