water in gas tank

You probably did not pick up too much rain. What water you did get will settle to the bottom of the tank where the fuel pump will pick it up and send it up the line to the fuel filter element which can hold a certain amount of water. That is part of its job. I would have the filter changed. You could add a bottle of "gas dryer" to the fuel tank before that. It is an alcohol which will mix with the water droplets and help transport them out. When I change out fuel filters on cars I always dump the contents out and frequently see rust, dirt, and water.

Do not worry, this is not dangerous, unless water will freeze in the pipes from the tank to the engine. Then you will have to be tow to the warme area.
At the end of 60-ties we performed experiments with injecting watter into the carburators in order to decrease combution temperature and increase efficiency. Experiments indicates also that NOx emission was lowered. Those experiments leaded to invention of EGR.
Few engine design centers around the world had prototypes with additional water injection, but it was not convenient for every day car user. It has to be distilated water in order to avoid stone building. This would be a problems in the area where tempretaure goes below freezing point.
In order to lean up your tank, you can poor about 1 liter of denaturated alcohol per 20 liters gas (5% max) into the tank aybe twice and then replace fuel filter.