Underground Storm Drain
District Programs & Departments

GLACVCD field technicians used to spend countless nights flushing out storm drains below downtown Los Angeles in response to service requests about mosquito problems. District Vector Ecologists initiated surveillance measures and subsequently trapped thousands of mosquitoes in Los Angeles County’s underground storm drain system in 2001. In response to the findings, the District placed four full-time staff members in charge of controlling the mosquitoes in the 9,000 miles of urban, underground tubes and conduits that transport urban run-off to the ocean.
Today, the program is a permanent sub-section of the Operations Department with 15 crew members. Vector Control Specialists work out of both the Sylmar and Santa Fe Springs offices. The team has created 58 work zones and color-coded the systems for necessary treatment. To date, the team has mapped a total of 20,000 manhole covers.