Invisible Structures, Inc., has been in the stormwater management business since 1982 with our porous paving systems Grasspave2 and Gravelpave2, ring and grid structures for grass and gravel drivable surfaces. Large rolls sizes cover areas quickly while either protecting grass roots from compaction or containing small gravel to eliminate gravel migration. Invisible Structures now has a complete line of Stormwater Management Products to choose from. Our products were developed to help manage stormwater and protect and enhance the environment.