I'm not sure if the creek actually runs underneath this specific site, but it might be the source of groundwater if groundwater is the problem. When I say excavation, I mean they literally just drilled the parking lot asphalt up and went down no more than five feet on one part of the site before it turned to mud as if they removed the skin off a bowl of pudding. They haven't really excavated anything. If the groundwater was that close to the surface, stiletto heels in the neighbourhood would sprout geysers like mini Jed Clampetts. Four condos and a hotel are on the way on the block immediately south of this seniors' home, though, so they might have problems with water, too. But I suspect it may not be a creek because the Duca office building, jsut feet to the east, didn't have this mud problem.
The necklace also runs NW.