The industrialization of the Soviet period polluted the Yauza drainage basin to a point where "an oil-soaked tributary of Yauza burst into flame in 1971"; the Yauza itself "was called a river only by force of habit... the biggest gutter for waste in Moscow" and caused a prominent surge in Moskva River pollution below the Yauza inlet. By 2005 this surge disappeared, although pollution levels in the lower Yauza remained 2–3 times higher than in the Moskva just below the Yauza inlet.