The Second World War saw extensive river operations, including effectivemining of the German canal system as well as the Yangtze andRangoon rivers. The British successfully mined inland waterways, in particular the Kiel andKoenigsberg Canals, and the Danube River.
Later, the United States conducted large-scale aerial-mining effortsin Vietnam, with mining of the Song Ca,Giang Song Ma, Kien, and Cua Sot Rivers in 1967
http://www.dtic.mil/dtic/tr/fulltext/u2/a425762.pdf
1) The German Fluss Minen (FM) mine seriesconsisted of three types, FMA, FMB, and FMC.The FMB and FMC were completed and usedoperationally; the FMA was abandoned shortlyafter production was started.The FM mines were small moored contactmines intended primarily for use in shallowwaters of the Baltic and Black Seas and
inrivers and estuaries. The FF11 was designedand developed In 1920, but was abandoned infavor of FMB. The FMB was completed in 1926;however, none were produced during World WarII, and only supplies on hand were laid. The FMC was developed and produced between 2;e76and 192E and only the supplies on hand atthe beginning of the war were laid operationally.The FY series was consider.d Ineffective,primarily because of the small explosivecharge and the ease with which :tcould oe swept. It was abandoned In favor oflater improved models...
see OP 1673A German Underwater Ordnance mines for further details
2) the British very successfully used in ww2 a 30lb floating river mine. I have details somewhere - I'll try to look and upload them.

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3) the US Tenth Air Force closed the RangoonRiver for the duration of the war by using British mines from early 1943. FourteenthAir Force laid airlifted mines in China’s rivers, including theYangtze.