DC Water McMillan Reservoir Stormwater Storage Facility

McKissack’s design services mitigated consistent flooding and sewage backups in the historic district of Washington, D.C. The Bloomingdale and LeDroit Park neighborhoods were developed in the early 1900s and their outdated sewer systems no longer accommodated demand from the growing population, causing flooding and basement backups during rainstorms. The stormwater management project involved using two existing abandoned underground filtration tanks at the McMillan Reservoir site to store stormwater during intense rainfall events, which would mitigate flooding in the downstream Bloomingdale neighborhood. Structures with sluice gates and diversion sewers were designed to divert water flow from the First and North Capitol Streets trunk sewers to these tanks. The flooding controls employed numerous green infrastructure strategies, including bioswales, infiltration trenches, rain gardens and interconnected planting beds. McKissack served as the engineer of record and provided design and construction management services for this design-build project.