A detention pond meant to control stormwater runoff at the new North Lake Square shopping center on Dawsonville Highway may be leaking sediment into Lake Lanier. Recent rains have spotlighted the potential problem that the Lakeshore Heights Neighborhood Association and nearby residents of Ahaluna Drive warned about when the development, which includes a Hobby Lobby and Academy Sports + Outdoors, was first proposed in 2012. “Our initial concerns about a polluting pond next to the lake are real and everlasting,” Michael Proulx said.