Google on Wednesday announced the most ambitious expansion of its Fiber Internet service to date.

The Web giant is bringing its super-fast gigabit Internet to San Antonio — the largest so-called "Fiber city" yet. But connecting one of the "biggest and fastest growing cities in the country" — which boasts 1.4 million residents — won't be an overnight job.

Google didn't reveal a specific launch date, but will "soon" kick off the design phase of the network build-out project. This will involve working with city leaders over the next several months to map out locations for the 4,000 miles of fiber-optic cables it plans to install across the metro area. That's enough fiber to stretch from San Antonio to Canada — and back.

"This is no small task, and it will take some time, but we can't wait to get started," Mark Strama, head of Google Fiber Texas, wrote in a blog post.

Google will use the data city leaders provide to create a map of where it can build, based on existing utility poles and water, gas, and electricity lines. Then comes the hard part of actually stringing and laying thousands of miles of fiber optic cable, followed by a sign-up phase to determine which communities are interested in the service. Finally, Google will complete the process by connecting the communities that show enough interest, and install the service in homes and businesses.

San Antonio has already been prepping for Google Fiber, even before the Web giant decided to provide service there. Last year, the San Antonio City Council approved a plan to let Google (and AT&T) deploy "network huts" on city property in order to facilitate the rollout of gigabit Internet down the line.

"From starting Bexar BiblioTech, the first all-digital public library in the U.S., to being named a leading city in cybersecurity, San Antonio has developed a thriving tech landscape," Strama wrote. "Hundreds of start-ups have found their home in the Alamo City through collaborative workspaces and accelerators like Geekdom and Cafe Commerce."

Google Fiber offers speeds up to 1,000Mbps — a huge upgrade from the U.S. average of just 12Mbps — promising to "further fuel the city's growth," Strama added.

At this point, Google Fiber is only available in a few select areas — Kansas City and some of its surrounding suburbs, as well as Provo, Utah and fellow Texas tech-hub Austin. Google has also promised to eventually launch the service in Atlanta; Charlotte and Raleigh-Durham, N.C.; Nashville, Tenn.; and Salt Lake City. The company is also exploring the idea of expanding it to Phoenix; Portland, Ore.; and San Jose, Calif.

For now, San Antonio residents can sign up online to receive information about the rollout as it becomes available.