Agency staff reported that a two-phase cleanup of Arroyo Conejo is complete and removed a total of about 33.5 tons (approximately 67,000 pounds) of debris from agency-managed riparian areas.

Brian Stark, agency staff, said Phase 1 removal (completed in 2024) yielded 13.4 tons and a volunteer cleanup removed an additional 3.5 tons; Phase 2 removed 16.6 tons. Phase 2 covered a section measured at 4,300 linear feet with cleanup extending roughly 75 feet from each stream bank; together the related floodplain cleanup covered about 6,400 linear feet.

Stark described the sources of debris as primarily urban storm-drain discharges, blown litter from urban areas, and material associated with upstream encampments. He said removing the accumulated trash reduces pollutants to local waterways, improves wildlife safety and habitat quality, and reduces downstream microplastic loads.

Cost and funding: Phase 1 cost $87,400 (the agency paid $62,400; the city public-works department paid $25,000). Phase 2 cost approximately $268,000 (the agency paid $33,600; the city's Department of Public Works paid about $235,000). Stark said the city's contribution came from its solid-waste funds and the agency publicly thanked the city for the partnership.

Board members asked about related matters: the county watershed protection district has installed a trash rack in an upstream drain that captures some debris but has suffered damage in large flow events; the city is pursuing separate palm-removal work to address invasive species; and the agency is seeking grant funds to support invasive-species removal on agency property. Stark said the removal work consisted mainly of mechanical access and, in some areas, required contractor access where vehicle access is limited.

Stark emphasized that most of the trash represented a decade's worth of accumulation and that keeping the channel maintained will require a program of volunteer events and periodic contractor cleanups. He said encampments in the arroyo have decreased relative to previous years, and agency rangers and the Thousand Oaks Police Department have been active in management and response.

Action: This was an informational item; no board action was required. Staff said they will present an invasive-species management plan at a future board meeting that will include priorities for palm removal and other treatments.

Why this matters: The cleanup reduces immediate wildlife hazards and pollutant loads, establishes a baseline for routine maintenance, and suggests recurring maintenance costs will be lower now that accumulated debris has been removed.