Why aren’t these ANS regulations effective when you enter a water body versus when you leave?

Leaving any drained water, all vegetation, and potential ANS at the waterbody from which it originated reduces the risk of accidentally moving those plants or animals to a new waterbody. If weed and water removal didn’t occur until immediately before entering a new water body, then the potential ANS would be present at the ramp or along the shore and thus could easily find itself washed into a “clean” water body. Further, the transportation of weeds and water could infest other water bodies as the vehicle and boat/trailer travel across the state’s roads where ANS weeds, etc. could blow into uninfected water bodies. Likewise, ANS-infested water could be intentionally or unintentionally introduced into a new water body. Angler’s intentions and plans are always subject to change, thus addressing the problem at its source has the highest likelihood of success.