Legal Question in Personal Injury in California

California is a one suit state; you must sue for all of your damages in a single lawsuit. There are exceptions. If it is a continuing tort [directing water from your property onto his] you can sue for the damages up to the date of filing the lawsuit and then file another suit later for that earlier date to the filing date of the second suit.

Mr. Shers is right. The plaintiff can, however, also cross-appeal for a bigger judgment if the judgment was too little as a matter of law, or if there was an error in the trial that resulted in too low of a judgment.