Laguna Watershed Knowledgebase

Ludwigia is an aquatic weed, originally from South America that is now expanding throughout the wetlands of the Laguna watershed. The Ludwigia invasion has caused concern among land managers and public agencies because it is dramatically reducing biodiversity, altering wetland function and providing protective habitat for mosquitoes.

Sonoma County agencies and officials became aware of the Ludwigia crisis in 2002, after Mosquito and Vector Control officers found off-scale mosquito densities in the Laguna Wildlife Area owned by the California Department of Fish and Game (CDFG). They shortly identified a second Ludwigia/mosquito hot-spot in flood-control channels owned and managed by the Sonoma County Water Agency (SCWA).