Infrastructure Finance
Maryland Stormwater Tunnel Project Gets $75M EPA Loan Boost
The Ellicott City Safe and Sound plan calls for several projects to protect it against severe flooding, including construction of a diversion tunnel to carry water past its historic downtown.
Rendering courtesy of Howard County, Md.
The U.S. Environmental Protection Agency will help fund a Maryland flood resilience project with a low-cost $75 million loan.
The Water Infrastructure Finance and Innovation Act (WIFIA) funds to Howard County, Md. will go toward the $167-million Ellicott City Safe and Sound plan, which county officials say will upgrade local infrastructure in a historic mill town south of Baltimore where multiple branches of the Patapsco River converge and join its main channel
The town has experienced 1,000-year floods twice in 2016 and 2018 that both caused serious damage there, as well as two deaths in the first flood and one in the second.
WIFIA money will support the project to build an 18-ft-dia diversion tunnel that will carry high flows from Patapsco tributaries directly to the river, allowing water to bypass Ellicott City’s lower Main Street area that experienced some of the worst damage in the previous floods. A U.S. Army Corps of Engineers report on the county’s flood risk management options noted the tunnel would be the most expensive option but also would most significantly reduce flood depths and velocities downtown.
ENR previously reported on Ellicott City’s difficulties with flooding and developing plans to address them. Since then, county officials have increased the length of the planned tunnel from about 1,600 ft to about 5,800 ft.
Howard County selected a Kiewit-Traylor Brothers joint venture as construction manager-at-risk for the tunnel project, records show. Other bidders included Clark Construction Group LLC, Lane Construction Corp. and SAK Construction LLC.
Design of the tunnel is still underway. Construction is expected to start later this year and complete in 2026.
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The program also calls for construction of several dry flood mitigation ponds, culverts and other improvements designed to protect a larger area. County officials say a 100-year storm that could cause water flow as deep as 4.5 ft on lower Main Street would measure less than 1 ft of once the projects are complete.
County Executive Calvin Ball said in a statement that funding dedicated to the plan comes from various sources, including the new WIFIA loan. Some smaller projects are underway, with the county also stepping up work such as regularly clearing debris from Patapsco River tributaries.
“We completed alert systems and are building water retention areas, and will now be able to move ahead on an innovative tunnel project that will help reduce the level of stormwater threatening homes and buildings,” Ball said.
Work on two 7.5-million-gallon mitigation ponds is expected to complete within the next year.
EPA says Howard County will save about $13 million by financing the work with WIFIA loans, long-term financing provided by the agency for significant water infrastructure projects. So far, EPA has provided $15 billion via 85 loans for various U.S. projects. Earlier this month, it announced a $441 million WIFIA loan to Los Angeles County, Calif., to help fund a wastewater tunnel project.
