drainage of the concrete floor in the forest beige color transverse cobblestone gutter drain the water into the ditch paved riverb

architecture beige block brick bumpy center central channel cobblestone color concrete constructing construction diagonal ditch drain drainage element elements eroded flood floor forest garden granite gravel gray green ground gutter gutters nature park path paved pavement paving perspective protection rain rainy riverb road rock rough shallow shape sidewalk slope square stone street surface transverse water way