On Sunday April 12, 2020, a sinkhole was reported at Buena Sanitation District sewer manhole, which is located on District easements on a private property located at 6300 Yarrow Drive in Carlsbad. A van parked either on or near the manhole, fell into the sinkhole along with a palm tree.
Prior to this occurrence, the McClellan-Palomar Airport weather station reported approximately 6.2 inches of rain over a 6-day period, including 3.45 inches received within a 24-hour period on Friday, April 10, 2020. City/District Public Works and Engineering staff responded to the site at approximately 3 pm on April 12th. A sanitary sewer overflow was not observed by staff and sewage flow was continuing down the Buena Outfall. The pipeline conveys all of the District’s sewage flow to Encina Water Pollution Control Facility for treatment and disposal.
Previously to the San Diego County Public Health Order to shelter in place, the District was averaging 1.8 million gallons per day of sewage. Due to the rain events and the Shelter In Place order related to the COVID-19 public health emergency, the District is averaging approximately 3 million gallons per day of sewage. The pipeline is approximately 30 feet deep at this location and was beyond the capabilities of the District’s Public Works equipment. Outside services were immediately required to minimize the possibility of an SSO. An SSO would discharge untreated sewage into Encinas Creek which outlets to the Pacific Ocean.
