Flowery Branch, which has set aside money over the next few years for stormwater management, plans to study four culverts along Flowery Branch Creek. City Council voted Thursday night to pay Norcross engineering firm Pond & Co. $21,000 for the analysis. Stormwater problems have plagued the city for years, highlighted by the December 2009 collapse of the Spring Street culvert, stranding residents in a 50-unit apartment complex.