Last summer, the Austin area's population quietly passed the 2 million mark — and it shows no signs of slowing down. In fact, some say we might hit our next major milestone much sooner than anticipated.

While the state demographer expects the population of the Austin metro area to surpass 3 million in 2045, LawnStarter reports that City of Austin demographer Ryan Robinson predicts it will happen 15 years sooner.

A recent post from the Austin lawn care startup explores the possibility of reaching 3 million residents by 2030, a feat that Robinson says is "in no way crazy ambitious, but it’s certainly not conservative."

To do so, the Austin metro area, which comprises Travis, Williamson, Hays, Bastrop, and Caldwell counties, would need a 15-year growth rate of nearly 50 percent. In other words, it would need to add the current population of the Honolulu metro area (about 1 million residents).

Robinson's aggressive model relies heavily on urban growth, which he says the state demographer overlooks in favor of suburban growth. "The amount of redevelopment within the urbanized [Austin] region over the next 15 years will be nothing less than stunning," asserts Robinson.

And where does Austin proper fit in? The city is poised for its own milestone — and soon. Robinson expects Austin to hit 1 million residents in January 2020, up from a little more than 900,000 in 2015.