Sheri and encountered this while traveling with the Tiny Texas Tumbleweed recently.
We had to make a choice. Water & Electric *OR* holding tanks.
We chose water and electric since we were only camping for the weekend.
But if you are building a new park or remodeling an older park, you might consider NOT getting the sewer/septic connection too far from the rest of the connections.
I know some “well meaning” government code enforcement person has some ideas, but have a 12 foot stinky slinky and a water hose on hand – a reasonable length one – and show him that if they are too far apart you can't get an RV hooked up without long runs of one or the other.
It is also helpful to have an engineer ready for the meeting with the code people as I've found that the engineers can make a quantum difference.
As for Sheri and I, we'll get an emergency length stinky slinky just for parks which have made the runs way too long for smaller RVs.