Self Contained Fresh Water Tank Accident

I have built in pressure regulator on my motorhome (I'm sure most also have this) so regardless of the hose pressure, I don't get a lot of pressure into the motorhome. But the problem this causes is it takes about 20 minutes to fill my 100 gallon water tank. So I can't tell you how many times I've been distracted in that 20 minutes and walked away only to come back and find water streaming out of the overflow vent. I've flooded out a couple of campsites!