Across the city, property managers are advising New Yorkers to seriously prep for the storm — beyond just stuffing their carts with water and D batteries. Paul Herman of Brown Harris Stevens Residential Management, which has over 150 buildings in its portfolio, says on-site managers are tying down scaffolding and any other construction-related materials and stocking up on water and candles in case their residents run out. BHS is also advising residents to stock up on essentials and, when the rains begin, fill up the bathtub with water for non-drinking purposes, like doing the dishes and flushing toilets (yes, those may not work if Irene sees fit to create tons of havoc). Dan Wollman of Gumley Haft, which manages 80 buildings in Manhattan and Brooklyn, says they’ve asked tenants who have terraces and outdoor spaces to empty them of furniture and the like. “Anchoring them isn’t enough,” he explains. “We had a situation where [someone] had a table anchored, but the tabletop popped and blew off and landed in the street. Fortunately no one was hurt.” (At last, a reason not to envy balcony owners!) But some buildings are taking the wait-and-see route. (Mayor Bloomberg is set to announce further recommendations tomorrow morning.) One Upper West Side board member says her co-op hasn’t sent out any warnings yet. “I don’t know,” she says. “I guess we just stay in and watch lots of movies.”