TD&H Engineering was engaged to improve the drainage at the BNSF Billings Intermodal Hub. This 11-acre site is used to transfer cargo units from train transport to truck transport. Drainage was poor, resulting in ponding and treacherous working conditions, especially in the winter. TD&H Engineering designed a system that collects the water, stores it in a detention pond and slowly discharges it into the City of Billings storm water system. Not long after the system was completed it was tested during a large thunderstorm that produced 0.94 inches of rain in 15 minutes. The system safely and successfully accommodated the flood flow.