Quagga mussels are a problem at lakes across California, including Lake Piru Reservoir. The invasive species are extremely destructive, clogging pipes used for drinking water, irrigation and hydropower, and necessitating extensive containment efforts. They also block boat motors and harm native fish by altering the habitat and the food web. After quagga mussels were discovered in Lake Piru in 2013, United Water Conservation District (UWCD) developed a Monitoring and Control Plan to contain the infestation. As part of that plan, a strict inspection policy is in effect for all watercraft entering and leaving Lake Piru.

Personnel from United Water Conservation District, which owns the lake, inspect all boats entering and exiting Lake Piru to limit the spread of quagga mussels. Failure to undergo an inspection prior to launch may result in a citation. Boaters should download and print the Lake Piru Vessel Inspection Permit Application.

Until further notice, Lake Piru has suspended its joint Aquatic Invasive Species (AIS) tagging program with Castaic and Pyramid Lakes and will not be tagging any vessels leaving Lake Piru. We do not anticipate that it will impact our ability to provide recreation services to the visiting public. For more information, contact Lake Piru Rangers office at 805 521-1201 or United Water Conservation District at 805 525 4431.

Boats that spend just a few hours in the water are still at risk for picking up and transporting mussels that may be attached to aquatic weeds. Follow this Basic Inspection and Cleaning Check List for All Boats to minimize the spread.

Additional Quagga Mussel Resources:

• Quagga and Zebra Mussels Overview (California Department of Fish and Wildlife)
• Don’t Move a Mussel Video (Pacific States Marine Fisheries Commission)
• Molluscicide Treatment Pilot Study
• Investigation of Treatment Options on Quagga Mussels
• Lower River SystemQuagga Mussel Control Study Presentation
• Quagga Mussel Monitoring & Control Presentation