The grass in a 100 acre lake here is pretty unfishable....It grows everywhere it seems, only time it doesnt get really thick is when the water is muddy which is rare...Several public and private pond have it too.

The stuff is real stringy,dark green, can grow from bottom to top in 30ft of water in some place. It also stinks like crazy and the only thing i have heard it called it stink grass. I think it is a product of runoff and sewage leaks. Ever seen this stuff and know exactly what it is?

It must be something else:

http://www.noble.org/webapps/plantimagegallery/Plant.aspx?PlantID=98&PlantTypeID=2