Just a thought, but an electric water pump would move the water much faster. I've seen installations that are semi-permanent, wired to the battery (either permanently or with detachable leads) and capable of being deployed very quickly. And, if you buy an identical model to that in your trailer, you've got that spare when the pump goes out in the middle of nowhere.
2009 Tacoma Crew Cab, TRD 4WD
2007 Tundra Double Cab TRD 4WD
2014 Escape 19
2007 Norwegian Elkhound "Baxter"