Incensed dog owners on the Upper East Side have hashed out a temporary compromise over the fate of their $1 million waterfront dog run, slated to open this summer at 63rd Street. Small dog owners have been lobbying for a roped off segment of the 5,000-square-foot run where their pets would be safe from the approaches of animals three times their size. Large dog owners say they are loathe to divide the open space, which they describe as a rare commodity in a dense neighborhood. “The decision was made at a committee meeting to install a temporary, experimental divider so that a small portion of the dog run would be set aside for small dogs,” the chairman of Community Board 8, David Liston, said. The board will take a “wait and see” approach and find out how the community responds to the divide, Mr. Liston said. “Small dog owners are happy,” Mr. Liston said, “and big dog owners took some comfort in the fact that it is temporary.”