Fresh water tank fill issue

We just purchased a new Vibe travel trailer and took it out Labor day weekend for the first time. One issue that I discovered is with the fresh water tank fill. Every other rv that I have had, you would just stick the water hose in the opening, and when water came spewing out, you knew the tank was full. This camper has a connection that you screw the hose into just like the city water connection has. But the problem is, there is a check valve. Most state parks that we stay in don't have water hook-up, so if we needed to add water to the tank, we just poured it in through a funnel. The check valve in this rig prevents that because there is not enough pressure through a funnel to push the check valve open. I am curious to know if anyone else has this set up, and how you get water into the tank without a water spigot near by.