Granite JV Wins $325M Big Creek Tunnel Contract in Cleveland

Granite Construction has won a $325 million joint venture contract to build the Big Creek Tunnel in Cleveland, Ohio — a 20-foot-diameter tunnel designed to divert 550 million gallons of combined sewer releases annually from Lake Erie.

The project addresses one of the Great Lakes region's most persistent water quality problems: combined sewer overflows. During heavy rainfall, Cleveland's aging sewer system carries stormwater and sewage in the same pipes, and excess volumes discharge directly into waterways, including Lake Erie.

The tunnel forms part of the broader infrastructure effort to contain those overflows. At 20 feet in diameter, the bored tunnel will capture combined sewer flows and convey them for treatment rather than allowing them to reach the lake.

The contract, valued at $325 million, adds a major water infrastructure project to Granite's joint venture portfolio. Granite, headquartered in Watsonville, California, is one of the largest heavy civil contractors in the United States, with operations spanning transportation, water and other critical infrastructure sectors.

The award signals continued momentum in large-diameter tunneling work across the U.S. water sector. Cities including Cleveland have committed to multibillion-dollar consent decree programs to cut combined sewer overflows, driving demand for deep tunnel storage and conveyance systems.

For Lake Erie, the stakes are concrete. The tunnel's projected 550 million gallons of annual diverted overflow represents a measurable reduction in pollutants entering a lake that supplies drinking water to millions of residents across the region.

Work on the Big Creek Tunnel will proceed under the joint venture structure, with Granite sharing execution and financial responsibility with its partner.