May 25, 2022 James Leggate KEYWORDS flood protection / Maryland / stormwater management / WIFIA Order Reprints No Comments

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 Ellicott City Safe and Sound plan. County officials say they will upgrade local infrastructure after experiencing 1,000-year floods twice about two years apart. Multiple branches of the Patapsco River converge and join the river’s main channel near Ellicott City’s historic downtown, and the floods in 2016 and 2018 both caused serious damage there, as well as two deaths in the first flood and one in the second. 

The WIFIA money will go toward a project to build an 18-ft-diameter diversion tunnel that will carry high flows from Patapsco River 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 provide the most significant reduction to flood depths and velocities downtown. 

ENR previously reported on the Ellicott City’s difficulties with flooding and the 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 Corporation and SAK Construction LLC. 

Design of the tunnel is still underway. Construction is expected to start later this year and complete in 2026. 

The program’s plans also call for the 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 lead to water as deep as 4.5 ft on lower Main Street before the work would leave less than a foot of water there once the projects are complete.

Howard County Executive Calvin Ball said in a statement that $167 million has been dedicated to the plan from various funding sources, including this latest WIFIA loan. Some of the smaller projects are underway, and the county has also stepped up work like regularly clearing debris from the 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 storm water threatening homes and buildings,” Ball said.

Work on two of the 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. The long-term loans are given by EPA for significant water infrastructure projects. The agency says it has so far provided $15 billion via 85 WIFIA loans for various projects. Earlier this month, EPA announced a $441 million WIFIA loan to Los Angeles County, Calif., to help fund a wastewater tunnel project.