Quagga mussels (Dreissena rostriformis bugensis) were discovered in Lake Piru, Ventura County, California on December 18, 2013.  United Water Conservation District (United) staff collected samples of the quagga mussels and contacted the California Department of Fish and Wildlife (CDFW). The collected samples were sent for analysis to the CDFW Shellfish Health Laboratory, Bodega Marine Lab. Testing confirmed that the samples were quagga mussels; and, subsequently, United notified CDFW, the California Department of Water Resources (DWR), and operators of nearby surface water reservoirs. This Quagga Mussel Monitoring and Control Plan (Plan) has been prepared by United to comply with State of California requirements under California Fish and Game Code (FGC) §2301.Since the discovery of quagga mussels in 2013, United has researched, developed, tested, and implemented various monitoring, containment, and control measures to delineate, characterize, and
address the infestation. The report also presents adaptive management process as a decision-making process to identify appropriate changes in control, containment, and monitoring actions.