Ключевые слова: background, blue, cascade, clean, clear, close, concept, conservation, construction, cool, current, curtain, dam, down, electric, electricity, energy, environment, fall, falling, flow, flowing, foam, green, hydroelectric, industry, lake, landscape, nature, outdoors, pattern, power, renewable, reservoir, riu, river, saving, segre, spain, speed, stream, streaming, summer, sunlight, sustainable, swirl, technology, water, waterfall, white,