and indeed, water is an ever more desperate premium as the water levels in the colorado river reservoir at lake mead decrease at an alarming rate. but it ain't the casinos that are the culprits. in fact, vegas casinos are a model of water-efficiency and conservation. main culprit? the all-american lawn, a little square of green. robert kern is water police. he patrols the vegas streets, looking for evidence of water violations. >> robert: there's finally some water in the gutter, actually on both sides. this is not their day. we're in an area where there shouldn't be any watering. yet there's water here. so that's what we do, we drive around looking for something like that to give them a little educational visit. "hey, you're not supposed to water today." >> anthony: so you don't wrestle them to the ground, cuff them and drag them in. >> robert: no, no we do not. although we can go to a, a fee. >> anthony: around how much? >> robert: $80. >> anthony: $80. what about the -- >> robert: then it doubles.