 This dumping of green waste can also lead to the blocking of drainage systems; directly through the build-up of plant debris, and indirectly through the spread of invasive plant species that colonise wet areas, reducing and or changing the flow of waterways.This change in flow, including path and velocity, can alter hydrological cycles, affecting frequency and intensity of floods.Green and garden waste has a direct impact to the visual aesthetics of land and can often attract further illegal dumping.