SAN ANTONIO (AP) -

San Antonio Water System crews using tractor-like robots equipped with cameras and water hoses to clear jammed sewer lines are finding a variety of man-made and natural causes for sewer clogs.

One image from a camera-equipped robot shows a Great Plains rat snake. Others have found turtles, rats, roaches, a basketball, toy car, car parts and baby wipes.

Agency spokeswoman Anne Hayden tells the San Antonio Express-News many items get flushed through a toilet or enter through valve openings around the city. She says the sewer lines can be as narrow as six inches.

The robot devices are part of the water system's $2.3 million settlement last year with the federal Environmental Protection Agency to reduce sewer system overflows.