Although winter is practically over with, a March 2009 accident report from the USA’s National Transportation Safety Board that was recently mentioned in General Aviation News is still worth noting. The incident involved a Cessna 172 and occurred in Hazen, Idaho.
According to the accident report, the pilot took off from one airport where the taxiways had snow, water and slush; landed at another airport for fuel; and finally departed for his destination. The approach and touchdown at the the final destination was normal. However and when the pilot applied the brakes:
…the plane veered to the left and the left main wheel went off the runway. The pilot was unable to get the left wheel back on the runway and was unable to stop the 172. As the airplane slowed, the left wheel entered a snowbank, and the airplane nosed over. The pilot said that the plane acted like the right brake did not operate properly and suspected it may have frozen since his departure was from an airport with the snow, water, and slush.
Luckily there were no injuries but damage to the aircraft was substantial and a subsequent examination found no anomalies with the braking system. In other words, the water, slush and snow had cause the break to freeze.
Hence and if you are on a taxiway, do keep in mind that too much water, slush or snow might cause your breaking system to fail or freeze up.
(pssst: braking)