The 143 million gallons of raw sewage have flowed from the Tijuana River Valley into San Diego’s shores, this according to California officials.

The large volume of sewage flowed into the coast over the span of two weeks during the winter storms that hit the region. While it is common for a few million gallons to flow into the region’s beaches, this huge spill is the largest in over 20 years.

“This was like a tsunami of sewage spills,” said Imperial Beach Mayor Serge Dedina, who has been working on obtaining answers from Tijuana authorities. “What’s worse is it looks to me like this was deliberate. It saves [Mexican agencies] a lot of money in pumping costs.”

The tide of sewage has been linked to the unpleasant odor along beach communities on both north and south of the border. Complaints about the odor have been emitted by residents from communities ranging from Playas de Tijuana through Coronado. The large amount of complaints in San Diego County has lead lawmakers in said entity to contact the corresponding authorities south of the border.

U.S. authorities have said that Mexican authorities have not given proper explanation for this case. However, it is believed that the overflow was caused by repairs being made to a major sewer line at the junction of the Tijuana and Alamar rivers.

“[Baja California’s State Public Service Commission] said it was a bypass of raw sewage into the Tijuana River during the rehabilitation of a large sewer pipeline in Tijuana,” said Lori Kuczmanski, spokeswoman for the U.S. side of the International Boundary and Water Commission.

The overflow was announced last friday by the International Boundary and Water Commission. On Tuesday, February 28, Mexican authorities finally offered details, although these were scarce.

“At least a notification [of ] would be a good neighborly thing to do, to let us know what was coming down the river before it got here so we could alert the public,” he added.