How does Pat Parelli approach desensitizing a horse to water crossings and water obstacles?

Water crossings are a practical necessity for trail horses and a scored obstacle in trail and working equitation competitions, and Pat Parelli's approach draws on the same Friendly Game principles he applies to all desensitization while adding specific considerations for the unique properties of water as a stimulus. Parelli identifies water crossings as a complex stimulus for horses because water combines multiple concerns simultaneously: the visual distortion the horse sees when looking into moving water, the unknown depth and footing, the sound of flowing water, the splash and pressure of water contact on the legs, and in some cases the smell. Each of these components can be a separate source of concern, which is why some horses that will wade into a stock tank will refuse a small stream — the stream has additional components the tank does not. His approach is to address the components progressively where possible. In a controlled setting, a shallow pan or puddle of water that the horse can investigate at liberty teaches it that water at ground level is safe and that there is solid footing under it. From there, progressively deeper and more active water exposures build the horse's confidence systematically. For horses that are resistant at the water's edge, Parelli uses approach and retreat exactly as he does for any other obstacle — bringing the horse to the point where it is concerned, allowing it to process, retreating before it decides to leave on its own, and approaching again. He is patient about the timeline, noting that a horse that is forced through a water crossing typically becomes more water-resistant rather than less, because the forced crossing adds negative emotional experience rather than positive discovery. Parelli also recommends allowing horses that are comfortable with water to demonstrate that comfort near water-resistant horses when possible, because horses learn from observing other horses navigating situations calmly — social facilitation that speeds desensitization significantly.