If by water in the oil you mean the yellowish paste that forms in the engine, then it is most likely due to condensation in the engine. You can get moisture from the cooling system, but you don't mention that you are losing coolant, so let's put that aside.

Every time you start up and later cool down the engine, you go through a heat cycle that results in condensation forming inside the engine. In the normal course of activities, you would drive long enough and hard enough so that the engine gets good and hot, and the moisture is boiled off out of the oil. If you don't get it hot enough, or drive it long enough (ie lots of short trips, never fully warming up) then it emulsifies with the oil at the highest point inside the engine (under the valve cover) and forms the condensate paste. This can happen at any temperature, it doesn't have to be freezing out. This is in no way caused by the CCV. The connection to the CCV is that if you do get this paste, and it collects over time, it can also collect in the CCV, which is the ventilation path from the valve cover. Not a big deal, except that the CCV is a distance from a heat source, and the paste contains moisture. So, if you now get a really cold spell, the paste can freeze. If the CCV freezes in the closed position, it can pressurize your crankcase and the oil will blow out the easiest path, usually a valve cover gasket. If it freezes in the open position, in conditions of high vacuum (overrun) then oil can be drawn from the dipstick tube up and into the intake manifold, and in extreme cases you can get a hydraulic lock in one or more cylinders. Bad news.

The CCV is not separating moisture from the oil, it is separating oil mist from the fumes inside the crankcase. It returns the separated oil to the sump.

It appears you do have the paste inside the CCV, since the CCV has a drain tube down to the dipstick, and so if you draw the dipstick and see it, that is the path.

First way to solve this is to get it good and hot, for 30 minutes or so, once per week. If that isn't possible, do more frequent (and hot) oil changes to clean out the engine. If you want to address the risk of freezing the CCV, take it off and service it, either cleaning it out or replacing it.

Lots of reading here on the site on this subject. There is also lots of confusion whereby the CCV is seen as a cause, rather than as a risk of freezing once the paste has formed and collected.

__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue