US: Disruptions due to flooding ongoing across San Diego County as of late Jan. 23 /update 1

Disruptions due to flooding are ongoing across many parts of San Diego County as of late Jan. 23. Heavy downpours Jan. 22 caused the San Diego and Tijuana rivers to overflow, leading to widespread flooding, road closures, and power outages in the city. The worst affected were areas along the San Diego River, central parts of San Diego City, low-lying areas near the coast, and the Tijuana River Valley. Rainfall totals of 5-7.5 cm (2-3 inches) fell within three hours during San Diego's wettest January day on record. Hundreds of people had to be rescued from their homes due to the flooding. Around 14,500 customers lost power during the severe weather; as of late Jan. 23, most power has since been restored. Several roads remain closed. Some MTS bus routes have been detoured; more information can be found here.

San Diego and Coronado cities and San Diego County declared states of emergency the evening of Jan. 22 due to the extreme rainfall and flash flooding and advised residents to avoid unnecessary travel and not to attempt to drive on flooded roads. The California Governor declared a state of emergency for San Diego and Ventura counties Jan. 23 to aid in recovery. Emergency shelters are located at Lincoln High School in San Diego and Bostonia Recreation Center in El Cajon.

River levels are starting to recede in the San Diego River as of Jan. 23. Further light showers are expected over the region through Jan. 25, before drier conditions prevail Jan. 26-29.

Further sustained heavy rainfall could trigger additional flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil. Disruptions to electricity and telecommunications services are likely where significant flooding, landslides, or strong winds impact utility networks.

Floodwaters and debris flows could render some bridges, rail networks, or roadways impassable, impacting overland travel around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track inundation. Localized business disruptions may occur in low-lying and riverine areas.

Disruptions triggered by inclement weather and resultant hazards, such as flooding or landslides, could persist well after conditions have improved - it could take days before any floodwaters recede and/or officials clear debris. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.