Under the color and pattern, stamped concrete is still flatwork, the ground-level slabs like walks, patios and driveways. It needs a packed subgrade, which is the soil it sits on, plus the right thickness for its use and steel reinforcement sized to the job. That matters here because many Murrieta neighborhoods sit on moderately to highly expansive clay, which swells when it's wet and shrinks as it dries.
We see the effects on jobs here and in Temecula and Menifee. The old slab that cracked and dropped usually sat on dirt that was raked level, so we dig out the soft material and pack the base before any forms go in, and the new slab has something solid under it when the clay moves.
The City of Murrieta's Public Works and Engineering Division issues permits for grading, streets, storm drains and work in the public right-of-way, and stamped concrete isn't named on that list. The city's Building and Safety Division enforces the codes. That doesn't settle your job, so if we aren't sure, we check with the city before we start, and when a permit is needed we handle the application and meet the inspector on site.