Ключевые слова: architecture, background, blue, canal, cement, channel, concrete, construction, culvert, danger, dirty, ditch, drain, drainage, dump, ecology, environment, environmental, flow, flowing, fluid, garbage, green, industrial, industry, irrigation, liquid, nature, old, pipe, pipeline, pollution, river, road, round, sewage, sewer, sewerage, stream, system, toxic, treatment, tube, tunnel, underground, urban, waste, wastewater, water,