Other Control Methods

Mechanical / Physical

Cutting of aquatic plants, by any method, increases the risk of spreading invasive species through fragmentation; the reproductive growth through a small fragment of plant tissue. This is particularly troublesome for Clear Lake, which has a historical presence of Hydrilla, a very noxious, invasive aquatic plant that if left untreated would devastate the ecology of the lake and negatively impact the economy of the County. For this reason mechanical harvesting is prohibited within ¼ mile of sites where Hydrilla is being actively managed. Mechanical control and retrieval of cut vegetation may be allowed in areas more than ¼ mile away from active Hydrilla management areas. Coordination with the California Department of Food and Agriculture (CDFA) Hydrilla Eradication Program will be ongoing to assure compliance with program concerns.

Any control program that results in fragmentation must include a method for the collection of plant fragments and disposal of fragments landward of the high water mark. Fragments must be prevented from reentry into any waterbody until fragments are dead.

The recent changes to the legal status of Clear Lake Hitch (Clear Lake's endemic minnow) as a candidate endangered species now affords the hitch, Endangered Species Act, protections. Any mechanical harvesting of aquatic weeds must make every attempt to scare fish from the treatment area so that there is no likelihood of hitch being removed from the lake with the harvested vegetation. Every mechanical permit application includes a list of these stipulations that might be acknowledged and signed by the permit holder.

A fee of $48 per permit will be required for mechanical/physical cutting and/or pulling projects. For any questions regarding mechanical permits please contact the Invasive Species Coordinator Angela De Palma-Dow by email or by calling 707-263-2344.


Applications for the use of Bottom Barriers, Spot-Dredging, Weed Rolling, UV treatments, etc. will not be accepted at this time.