Some 22 billion gallons of raw sewage have flowed from Mexico into San Diego County since the end of December, the International Boundary and Water Commission (IBWC) reported on Wednesday. … Acknowledging that sewage flows have dropped to 106 million gallons per day and continue to decrease, the agency noted that two wastewater collectors are out of service due to excessive sediment buildup. Last Thursday, flows reached 800 million gallons per day, according to the IBWC. The wastewater influx is the result of an extended bout of winter weather, which has made a chronic cross-border sewage situation worse over the past few months.