ST. PETERSBURG — It’s official: Robots will soon be crawling under city streets.

The City Council unanimously green-lighted a $600,000 contract Thursday with RedZone Robotics to start inspecting pipes using the company’s “Solo” robots to help remedy its sewer issues.

The autonomous crawling machines will enable the city to detect leaks three to four times faster than current methods, senior water resources manager Lisa Rhea has told the Tampa Bay Times. That allows the city to make repairs faster and prioritize areas that need work, said RedZone Robotics sales operations manager John DePasquale.

The city’s aging system released up to one billion gallons during the 2015-2016 sewage discharges. Leaky pipes contributed to that. Even on dry days, as much as two-thirds of the sewage flow came from groundwater entering the pipes, a consultant said. When rain fell, the volume proved too much for the pipes and the overflow contributed significantly to sewage spills during storms.