Permits for slabs, barn aprons and retaining walls go through the City of Norco Building Division. The strip between the pavement and your front property line is a separate question, it is right-of-way, and Norco bars impervious paving across the pedestrian-equestrian zone on a residential lot unless Public Works issues an encroachment permit to the City Engineer's standards. We file both and meet the inspector at norco.ca.us, so you never queue at City Hall.
The ground is not one thing across town. The flats along the Santa Ana River and River Road are alluvial sand and gravel that compacts well and drains fast; the rising ground in Norco Hills and above the bluffs is heavier, with decomposed granite and enough slope that a pad needs cut and fill and often a wall to hold it level. You can check a parcel on the USDA Web Soil Survey, and we take our own readings at the estimate.
We are 8.9 miles from Norco at our Riverside yard, which puts a crew on Sixth Street or Hamner Avenue inside twenty minutes and lets us start a pour early enough to finish before the afternoon heat. Homes here run from the 1960s and 1970s ranches that went up after Norco incorporated in 1964 to the 1990s hillside tracts, so we are as often replacing sixty-year-old unreinforced flatwork as pouring a new arena apron.