Behind flooded intersections lies a quieter culprit: plastic bags of dog waste and fist-sized tangles of pet hair, turning storms into neighborhood disasters. In Héroes de Churubusco, residents patrol storm grates at night, catching dog walkers tossing bags into inlets. The Surprising Science of Poop, Plastic, and Pet HairTwo decades ago, public campaigns made picking up after pets a civic duty. Córdova Valdez says his crews spend six or seven hours at some sites, hauling out not just pet waste but bottles, cooking oil, and wipes. That leaves the basics: bag hair and pet waste, then put it in trash containers—not grates, sinks, or toilets.