This image seems to imply a long term waterflow. The water was flowing along the channel up the image, then the meteor impacted. The water then flowed long enough to wear down the rim of the crater and probably flooded it.

This gives us two times. The water probably flowed long enough for the crater to cool which should be possible to work out. Then it also flowed long enough to breach the crater rim. The pattern inside the crater seems to be caused by flooding, and points to the breach in the rim.

Then it continued to flow long enough to carve a channel around the crater. Above the crater in the image there are the remains of two channels, one is the original and one the new channel with a ridge in between.

So it should be possible to estimate how long the second channel took to make and how similar it is to the first channel, which implies a steady flow rather than periodic flooding.

Also the age of the crater should be possible to estimate as to when all this happened. I doubt this would be a CO2 flow because of the apparent steady nature of the flow.