Latest Update as of May 14, 2026: Los Angeles County is committed to reopening the underpass as soon as conditions safely allow while protecting sensitive ecological habitat.

County crews removed the majority of accumulated sediment and debris from the underpass during the weeks of April 13 and April 20, 2026. After the debris was cleared, the underpass quickly filled with approximately 10 inches of persistent standing water caused by seasonal site conditions, including elevated groundwater and surface water flowing from Zuma Creek.

The County then shifted efforts toward evaluating dewatering options and coordinating with regulatory agencies regarding potential permitting pathways.

On May 7, 2026, the Los Angeles Regional Water Quality Control Board (Regional Board) notified the County of its determination that all existing site conditions are to be left in-place until groundwater levels naturally lower to avoid significant adverse effects on Zuma Creek.

The County will continue monitoring the area regularly. Once groundwater and creek flow through the underpass roadway have ceased, the County will notify the Regional Board for further review and confirmation on whether remaining sediment and pooled water may be removed to allow the roadway to reopen.

Background

Seasonal flooding, accumulated sediment, and standing water near Zuma Creek can affect safe access through the underpass. This can result in temporary closures throughout the year.  

Because the underpass is located immediately adjacent to Zuma Creek, work in the area must comply with state and federal regulations designed to safeguard protected jurisdictional waters, sensitive habitat, and wildlife. This requires coordination with agencies including the California Department of Fish and Wildlife, Los Angeles Regional Water Quality Control Board, and the U.S. Army Corps of Engineers.

Once the appropriate clearances are obtained from these agencies, debris-clearance work is supervised by a qualified biologist. All work must follow applicable permit requirements, including strict limitations on conducting work when Zuma Creek water is flowing through the underpass roadway.