Civil engineer an RV park

I am looking for someone who can do the civil engineering for a sections of our 10 acres, to make the south end of the property (approx 3 acres) 40 RV campground spots. To start, I just need to design the site plan for the county to approve the rezone layout. Then we can have time to layout the septic/sewer, water, electrical hook-up plan in order to get building permit from our County. I have rough sketch of what I want it to look like but finished project must be able to pass engineering requirements for Navajo County - state of Arizona, USA. Septic already runs across the property on the north end. Power and well also available on site.
10 acre parcel is currently zones C-R (commercial residential)