Sewage is flowing at a rate of 90 gallons per minute into Border Field State Park's Yogurt Canyon, the Department of Environmental Health said.
The ongoing sewage spill has not been capped. The Department has not released when the spill started.
Border Field State Park lies along the U.S-Mexico border in Imperial Beach, south of Downtown San Diego.
The access road to Friendship Park, within the park, may also be affected by sewage-filled runoff, the department said. Officials recommend avoiding the area.
Warning signs have been posted in the area, telling visitors and locals to avoid contact with contaminated water.
In February, more than an estimated 28 million gallons of sewage spilled into the Tijuana River and U.S. waters, near Border Field State Park, after a pipe collapsed in Tijuana.
For more information on the Tijuana River, please call the U.S. International Boundary & Water Commission at 619-662-7600.
For updates on beach closure information please visit their website or call the 24-hr. hotline at (619) 338-2073