Here in Murrieta, the city's Public Works and Engineering Division issues permits for grading, storm drain work and the public right of way, and its list doesn't name parking lots. That leaves open whether your lot needs its own permit, so the city's Permit Center is the place to ask. When a job needs one, we handle the application and meet the inspector on site, and if we aren't sure, we check with the city first.
Bigger projects bring another check. The county's stormwater plan puts parking lots that create or replace 5,000 square feet or more of hard surface, counted across the whole site, in their own category, so it's worth raising your lot's size early. We do the same lot work in Temecula and Menifee, where many of our calls are for small parking areas behind shops, offices and rentals.