TO: Andrew P. Powers, City Manager
FROM: Nader Heydari, Public Works Director
DATE: June 24, 2025
SUBJECT: Lynn Road Sinkhole and Storm Drain Repair
Public Emergency Declaration
Pursuant to Thousand Oaks Municipal Code (TOMC) Section 3 -10.308, please acknowledge below in order to declare a public emergency related to the necessary repairs in response to roadway settlement above the three existing 48-inch corrugated metal pipe (CMP) storm drain pipe culverts located underneath Lynn Road just west of Ventu Park Road. These CMP storm drain pipes and the associated roadway are both part of the City’s storm drain and roadway system. Confirmation of this Public Emergency Declaration will be requested at the July 8, 2025, City Council meeting.
Background
Earlier this year the Municipal Service Center (MSC) Streets Division received a call from a resident reporting a depression/sinkhole forming in the City’s right -of-way adjacent to the roadway on Lynn Road. In response, MSC staff conducted a visual inspection of the CMP pipes located beneath the affected area, which found that debris and sediment were obstructing the bottom of the pipe, requiring removal. Task Order #2 was issued to one of the City’s On -Call Contractors, J&H Engineering General Contractors, Inc. (J&H), to clean the pipelines and perform a video inspection. J&H completed the clean out work in late May 2025 and their subsequent video inspection revealed significant internal corrosion resulting in structural failure of the pipes. Due to the severity of the deterioration, MSC staff, in coordination with Public Works Engineering, determined in June 2025 that all three pipes have exceeded their service life and therefore need to be replaced.
On June 4, 2025, a new depression/sinkhole was discovered in the Lynn Road parkway, impacting the eastbound number one and two lanes. The CMP failure created a pathway for roadway bedding material to be displaced by water intrusion, compromising roadway stability. In response, the MSC Streets Division mobilized J&H with an amendment to the Task Order to implement a temporary solution by paving and covering the affected area with steel plates, while a permanent engineering repair plan can be developed. This settlement within the main portion of the roadway has escalated the situation as it now presents a significant public safety concern that requires emergency/immediate action, since there is a likelihood that there may be voids underneath the roadway in bedding and base material.
ATTACHMENT #2
DPW: 1030-20\ev\Council\2025\070825\Public Emergency Declaration Lynn Rd Sinkhole and Storm Drain Repair Att 2.pdf
Attachment #1
to June 24, 2025
Memorandum
LYNN ROAD SINKHOLE AND STORM DRAIN REPAIR
(CI 5670)
Attachment #1
to June 24, 2025
Memorandum
DETAILED SCHEMATIC SITE PLAN
Attachment #2
to June 24, 2025
Memorandum
ROAD DEPRESSION
SINK HOLE IN PARKWAY
WESTERLY DAMAGED 48-Inch CMP PIPELINE
CENTER DAMAGED 48-Inch CMP PIPELINE
EASTERLY DAMAGED 48-Inch CMP PIPELINE