HHR was the Drainage Task Leader for this interstate corridor improvement project. Design included storm sewer improvements, drainage and storm water management, drainage design coordination, floodplain impact studies, and third party review of drainage designs (PS&E) for 21 miles of freeway main lanes and frontage road reconstruction. Our role was also to coordinate drainage with external stakeholder agencies. The challenges of the project included hydraulics design of seven stream crossings and three stormwater pumping stations. Permitting issues required coordination of drainage design to minimize impact on jurisdictional waters. As part of project management, HHR provided PS&E review of drainage construction for ten construction contracts and preparation of corridor-wide drainage design criteria and special specifications.