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Reed canarygrass (RCG) is an aggressive, invasive species that crowds out native vegetation. RCG grows so thick that it restricts flow in a waterway and causes sediment and organic matter to fall out of the water column and accumulate on the bottom of the waterway. RCG can be removed by hand, by machinery, or by herbicide. Regardless of the method of removal, reed canarygrass (Acrobat pdf) will quickly reclaim the waterway unless the channel is shaded to prevent its regrowth. Shading of the waterway or repeated removal are the only long term solutions to RCG infestation. Over the long term, shading is a cheaper and/or an easier way to control RCG than repeated removal. Shading also provides other ecological and water quality benefits.

Reed canary grass along a stream
Waterway before RCG removal
Restored stream - reed canary grass
Channel that was previously choked with RCG after removal and about five years of shading.

For questions about the Agricultural Drainage Assistance Program or ADAP, please contact Brian Sleight, Supervising Engineer, King County Stormwater Services Section.