Upcoming projects

CALIFORNIA

Daly City
Vista Grande Drainage Improvements
The City of Daly City (California) began seeking prequalifications for its Vista Grande Drainage Improvements Project in February 2025. The City plans to issue an RFP in April 2025 with a target NTP of fall/winter 2025. The engineer’s estimated construction value is $135 million.

The project, located in Daly City and San Francisco, will upgrade the Vista Grande storm drain system, a regional stormwater system that drains northwest Daly City. The scope includes re-mining an existing 3,000-ft long tunnel to increase the size to 11.7 ft and installing a new lining. Upgrades also include replacing portions of an existing 3,600-ft long canal with associated civil works. Federal funding for the project has been secured.

Delve Underground is the designer for the owner. For information, contact Shawn Spreng at spreng@delveunderground.com.

Los Angeles
Eastside Transit Corridor Phase 2
Metro’s Eastside Transit Corridor Phase 2 project is an approximately 9-mile extension of the Metro E Line. Forecasted opening is 2035. The Metro Board of Directors approved the certification of the Final Environmental Impact Report (EIR) in May 2024. The Board’s approval finalizes the EIR for the two-phased project that will extend the Metro E Line further east from its current terminus at Atlantic/Pomona in East Los Angeles to Greenwood Station in Montebello via the Initial Operating Segment (IOS), with construction to start in 2029, as programmed under Measure M (2016). Alternative 3 (the locally preferred alternative) is approximately 4.6 miles in length – 3 miles underground, 0.5 aerial and 1.1 at grade. Metro completed community update meetings in January and February 2025 to engage the community in the project development process. Forecasted opening is 2035-37 (pending funding availability).

Web: metro.net/projects/eastside_phase2/

Los Angeles
Sepulveda Transit Corridor Project
Metro studying transit options between the San Fernando Valley and the Westside. The natural barrier created by the Santa Monica Mountains makes traveling between the Valley and the Westside challenging – and will require innovation and multiple solutions. Metro is working to evaluate alternatives for a high-quality, reliable transit service option connecting the San Fernando Valley and the Westside. The forecasted opening for service to connect the San Fernando Valley and the Westside is 2033-2035.

The Sepulveda Transit Corridor project is currently in the planning phase, and Metro is in the process of preparing a Draft Environmental Impact Report (DEIR). Alternatives range in length from 12.6 to 16.2 miles, with 7 to 9 stations, with underground alignments being considered for Alternatives 3, 4, 5 and 6. Alternative 6 is fully underground, while Alternative 5 is mostly underground. Alternatives 3 and 4 also have significant underground sections and include underground stations.

As of winter 2024, Metro planned to recommend a Locally Preferred Alternative in summer 2025.

Web: metro.net/projects/sepulvedacorridor/

Los Angeles
Southeast Gateway Line – Phase 2
The Project will feature 14.5 miles of new light rail connecting Slauson/A Line Station to Pioneer Station located in the City of Artesia, including 9 SGL stations. Plans include a jacked tunnel portion underway an interstate highway.In October 2024, the project was awarded $231 million by the California State Transportation Agency (CalSTA) from the Transit and Intercity Rail Capital Program (TIRCP). Forecast opening is 2035. In April 2024, the Project’s Final Environmental Impact Report (EIR) was certified in accordance with the California Environmental Quality Act (CEQA).

Web: metro.net/projects/southeastgateway/

Ontario
ONT Connector
The San Bernardino County Transportation Authority and the Ontario International Airport (ONT) have partnered to develop the ONT Connector, a project that will create a subsurface transit connection between the Rancho Cucamonga Metrolink Station and passenger terminals at ONT, one of the fastest growing commercial airports in the United States. The Rancho Cucamonga station is one of the busiest stations in the Metrolink system, which will also be the terminus of the Brightline West high-speed rail line connecting Las Vegas and Southern California. The project received SBCTA Board of Directors approval and certification on March 5, 2025.

The project is a 4.2 mile-long underground tunnel, approximately 70 ft underground, that starts at the Rancho Cucamonga Metrolink Station and travels south under Milliken Avenue, crossing beneath 6th Street in the city of Rancho Cucamonga and 4th Street, I-10, and the Union Pacific Railroad (UPRR) in the city of Ontario, before traveling west beneath East Airport Drive to Terminals 2 and 4 parking lots at ONT. The project would include three passenger stations. The current schedule has design and construction going through 2030, with service in 2031.

Web: gosbcta.com/ontconnector/

Sacramento
Delta Conveyance
The Delta Conveyance Project for the Department of Water Resources (DWR) includes a tunnel through the Sacramento-San Joaquin Delta that is designed to protect water supplies from sea-level rise and saltwater intrusion into the Delta. Additionally, the project will help to reduce the risk associated with earthquakes, improve water supply reliability, and reduce impacts on local Delta communities and fish. The project is being designed as a single tunnel, estimated to be 45 miles long and 36 ft in diameter.

DWR announced on Dec. 21, 2023, that it has approved the project. DWR has certified the Environmental Impact Report (EIR) and completed an extensive environmental review. DWR selected the “Bethany Reservoir Alignment” for further engineering, design and permitting.

According to the Delta Conveyance Design and Construction Authority, the estimated project cost is $20.1 billion in real 2023 dollars.

Web: water.ca.gov/deltaconveyance

San Diego
LOSSAN Rail Realignment
The LOSSAN Rail Realignment Project is being developed by the San Diego Association of Governments (SANDAG) to protect the Los Angeles—San Diego—San Luis Obispo Rail Corridor (LOSSAN) from impacts due to landslides erosion and seismic activity, which have led to temporary shutdowns. It is envisioned to relocate 1.7 miles of track. Tunneled alignments are among the options being considered.

SANDAG on Feb. 7 released the value analysis study report for the project. The value analysis study was conducted in response to public feedback received on the Notice of Preparation (NOP) for the project. The study’s goal was to examine alternatives proposed in the NOP and identify enhancements or new route alternatives for relocating the tracks.

An updated NOP will be posted in spring 2025 for a 45-day public comment period. Technical studies will also start in the spring to support the preparation of a Draft EIR that will be circulated for public review.

San Francisco
Alameda Street Wet Weather
Conveyance Tunnel
The Alameda Street Wet Weather Conveyance Tunnel (AWWCT), Phase II of the Folsom Area Stormwater Improvement Project for the San Francisco Public Utilities Commission, will accept and convey stormwater to existing downstream wet weather infrastructure. It is approximately 4,000 feet long with a 12-foot-wide inside diameter and three shafts. SFPUC issued a request for qualifications that were due in February 2025.

Web: sfpuc.org

San Francisco
Downtown Rail Extension
The Downtown Rail Extension (DTX), also known as The Portal, for the Transbay Joint Powers Authority is part of a plan to deliver transportation service to the hub at Salesforce Transit Center. DTX would extend Caltrain from 4th and King to the heart of downtown. The project includes a 2.2-mile rail alignment with 1.5 miles of tunnel. Design has reached 30 percent, according to TJPA.

The Portal is advancing in the Federal Transit Administration’s Capital Investment Grants Program, Project Development phase, which it entered in December 2021. TJPA has requested entry into the second phase of the FTA CIG process, Engineering, to continue to advance the project for a Full Funding Grant

Agreement execution in Spring 2025. Anticipated revenue service date is 2032, pending funding.

Web: tjpa.org/portaldtx

San Francisco
Folsom Area Stormwater Improvement Project – Phase 2
The Folsom Area Stormwater Improvement Project is a part of the San Francisco Public Utilities Commission’s (SFPUC) flood resilience efforts. Phase 2 includes constructing a new 4,000 linear foot stormwater tunnel from approximately the intersection of Alameda St. and Florida Street to the intersection of 7th Street and Berry Street. Crews will excavate an entrance shaft, two exit shafts, and a turning spot for a tunnel boring machine. Extensive analysis has been done to evaluate the location of the tunnel and portals, and monitoring equipment will be used during construction.

Web: sfpuc.org

San Francisco
Lower Alemany Tunnel
The project proposes to construct a 10-ft diameter pipe underground from Stoneybrook Ave to Industrial St via Alemany Blvd, Gaven St and Boutwell St to increase conveyance capacity. Construction would involve three tunnel portals or shafts to construct the tunnel and other sewer connections and related improvements in the area. The approximate length is 6,320 ft.

Web: sfpuc.org

Wilson Creek
Last Chance Grade Tunnel
“Last Chance Grade” (LCG) is a 3-mile segment of US 101 just north of Wilson Creek, between Klamath and Crescent City. Landslides and road failures have been an ongoing problem for decades and substantial funds have been invested in repairs. The road is currently safe to use, but a long-term solution is needed to ensure continued safe and reliable transportation on US 101.

Since 1997, Caltrans has invested more than $100 million to respond to a number of events that have occurred along the roadway. Geotechnical studies indicate continued movement of the roadway, signaling that regular investments will be required to keep the roadway safe and open.

The plan is for about a 6,000-ft, single bore tunnel that would accommodate two-lane, bi-directional traffic. The schedule has design and permitting from 2025-2030, with construction from 2030-37 (5-8 years).

Web: lastchancegrade.com

MASSACHUSETTS
Boston
Metropolitan Water Tunnel Program
The Metropolitan Water Tunnel Program for the Massachusetts Water Resources Authority (MWRA) will provide redundancy to a vital drinking water system that was impacted by a 2010 water main break and a 2024 tunnel incident (estimated impact = $360 million per day). The two main components are:

• -Northern Tunnel – ~5 miles long, 10-12 ft dia., 200 – 375 ft deep, 5 shafts
• -Southern Tunnel – ~10 miles long, 10-12 ft dia., 250 – 520 ft deep, 8 shafts

Web: mwra.com/mwtp/resources.html

MISSOURI
St. Louis
Project Clear Tunnels
Metropolitan St. Louis Sewer District (MSD) has begun an ambitious program called Project Clear, a multi-billion dollar investment addressing wastewater overflows. The system improvements include construction of multiple tunnels and underground infrastructure to control sewer overflows.

Upcoming tunneling components of Project Clear include (Project, Construction Begin, Construction Cost Estimate, Tunnel Length, Tunnel Inside Diameter):

• Lower & Middle Des Peres Storage Tunnel, 2027, $640,000,000, 8.6 miles, 30 ft dia
• River Des Peres Tributaries CSO Tunnel, 2028, $178,000,000, 3.1 miles, 17 ft dia
• Upper River Des Peres CSO Storage Tunnel, 2032, $188,000,000, 2.6 miles, 22 ft dia

Web: msdprojectclear.org/projects/tunnels/bid-schedule/

NEW HAMPSHIRE
Manchester
Cemetery Brook Drain Tunnel Project is designing the Cemetery Brook Drain Tunnel Project, an approximately 11,700-ft long, large diameter conveyance tunnel 30 to 80 ft beneath downtown that is the cornerstone of its Phase II Combined Sewer Overflow (CSO).

Parsons Corporation was selected by the City to help deliver the project. The City has engaged CDM Smith as its project engineer.

Although the majority of the alignment appears to be within good quality bedrock, the profile of the tunnel horizon along the alignment experiences several mixed face zones, as well as significant contiguous segments of soft ground below groundwater table. A pressurized face TBM is envisioned for tunneling through the soft ground and mixed face conditions. As of late 2024, bids were received and were being evaluated.

Web: manchesternh.gov/Departments/Environmental-Protection/CSO

New York
New York
Flushing Bay CSO Tunnel
New York DEP is planning the 25-mgd Flushing Bay CSO Tunnel as part of its long-term control plan. The scope pf work consists of a 2.5-mile tunnel with dewatering pump station to capture overflows from CSO. The tunnel is expected to be 18-20 ft in diameter. As of September 2024, DEP anticipated to complete design in 2025, with construction NTP beginning in 2026 and completed by 2035.

New York
Hudson Tunnel Project/Gateway
The Hudson Tunnel Project is a new two-track heavy rail tunnel along the Northeast Corridor from the Bergen Palisades in New Jersey to Manhattan that will directly serve Penn Station New York. It consists of three major elements: the Hudson Yards right-of-way preservation project, the Hudson Tunnel, and the rehabilitation and modernization of the existing North River tunnel.

Several components of the project have been awarded, including the 10,200-ft long Palisades Tunnel, the approach the Hudson River Tunnel in New Jersey, and the 600-ft long Manhattan Tunnel, the connection between the Hudson River Tunnel and Penn Station.

The Hudson River Tunnel will span 26,400 ft under the Hudson River. In October 2024, GDC issued an RFP for the Hudson River Tunnel. At this time, GDC is conducting a two-step, Best Value procurement process (RFQ followed by a Request for Proposal of the qualified firms) with the goal of selecting a Contractor to perform the work in 2026. This solicitation is part one of the two-step procurement process.

The new tunnel will be in service by 2035 and the full rehabilitation of the existing tunnel will be complete by 2038.

Web: gatewayprogram.org

New York
Kensico-Eastview Connection (KEC)
This 2 mile tunnel is part of a $1.9 billion drinking water upgrade program for New York DEP. The project includes a 27 ft diameter tunnel and two large shafts, 400-500 ft deep. The new tunnel will connect the Kensico Reservoir to the Catskill-Delaware Ultraviolet Light Disinfection Facility in Eastview. It will allow DEP to conduct maintenance and inspections on other facilities without disrupting water service.

DEP held a ceremonial ground-breaking with project officials on July 23 in Mt. Pleasant, New York. All phases of the project are expected to span a 10-year period and be fully online by 2035. A JV led by AECOM has been selected to provide inspection services for the project.

Tutor Perini Corp. announced Oct. 23 that its subsidiary, Frontier-Kemper Constructors, has been awarded a contract valued at approximately $1.1 billion by DEP for the Kensico-Eastview Connection Tunnel Project. NTP was expected in early 2025.

Web: nyc.gov/site/dep/about/kensico-eastview-connection.page

New York
Second Avenue Subway – Phase 2
Design is underway for Phase 2 of the Second Avenue Subway. A joint venture of WSP and STV is working on the design for the project that extends the line northward from 96th Street to 125th Street – a total of 1.5 miles with three new stations. The alignment will use some existing tunnels originally built in the 1970s, in addition to new soft-ground TBM tunnels. The cost estimate for this phase of the project is $7-8 billion.

The scope of work for the first contract for Phase 2 of the Second Avenue Subway incorporates the lessons learned from Phase 1 and will involve the relocation of critical public services, laying the foundation to advance construction of three future stations and necessary infrastructure. of the system. The contract will be solicited as an A+B Design-Bid-Build contract.

On March 26, 2025, MTA voted to approve a $186.6 million contract with AECOM-HNTB JV for project management consultant services. The JV will oversee work on three of the four construction contracts, ENR reported. C.A.C. Industries was awarded a utility relocation project in January 2024 in advance of the major underground work. However, work was delayed as officials sort out funding issues related to congestion pricing intended to help pay for MTA projects.

Web: web.mta.info/capital/phase2_sas.html

OHIO
Cleveland
NEORSD Project Clean Lake
Project Clean Lake for the Northeast Ohio Regional Sewer District (NEORSD) includes several major tunnel components to store and convey combined sewer overflows. The major upcoming tunnel projects include:

• Kingsbury Run Consolidation Sewer – ~6,400 ft of 90- and 120-in. tunnel along with several large concrete structures. This contract has an estimated value of $105 million. Bidding was scheduled to close Jan. 22, 2025.
• Big Creek Storage Tunnel – ~22,500 lf of 20-ft diameter CSO tunnel in Chagrin shale. Under design. Project expected to bid in 2026. This will be the final large-diameter tunnel of Project Clean Lake.

Web: neorsd.org

PENNSYLVANIA
Pittsburgh
ALCOSAN CSO Tunnels
The Allegheny County Sanitary Authority (ALCOSAN) is implementing a multi-billion improvement program to control combined sewer overflows (CSOs) as part of a consent decree with EPA. The program is expected to include tunnel segments to convey and store overflows for treatment. The improvements are slated to be complete by the end of 2036. The system comprises three large tunnels, to be delivered by design-bid-build: the Ohio River Tunnel (~4.9 miles), the Allegheny River Tunnel (~6.2 miles) and the Monongahela River Tunnel (~5.4 miles). Additionally, the program will include consolidation sewers, a dewatering pump station and treatment plant improvements. NTP for the Ohio River Tunnel is expected in 2025. Program completion is set for Dec. 31, 2036.

CDM Smith is the Clean Water Program Director, Jacobs is the Tunnel Program Manager Consultant, Mott MacDonald is the Ohio River Tunnel Final Design Consultant, and Hatch is the Ohio River Tunnel Construction Manager.

Web: alcosan.org

TEXAS
Austin
CapEx Drainage Tunnel
The I-35 Capital Express (CapEx) Central project under development by the Texas Department of Transportation involves improvements to 8 miles of corridor through the capital. Part of the $4.5 billion program includes the construction of drainage tunnels under the highway to allow for the redevelopment.

The drainage tunnels are designed to be 22-ft internal diameter and stretch approximately 6.5 miles, one leg of 3 miles and one leg of 3.5 miles. It is anticipated that the tunnels will be driven through Austin chalk. TxDOT is planning to start construction in 2025 with completion by 2028, weather permitting.
The project was awarded on Dec. 18, 2024, to SAK Construction/J.F. Shea for $698 million. NTP was issued Feb. 13. The contractor has 45 months to deliver the work.

Houston
Flood Control Tunnels
The Harris County Flood Control District is exploring the feasibility of building deep tunnels to divert storm water to prevent flooding. Following the devastating impacts of Hurricane Harbey in 2017, voters in 2018 approved a Bond Program that includes Bond ID Z-08, with $20 million for Feasibility Study of Stormwater Conveyance Tunnels. According to the 2022 presentation by the district, the proposed tunnel system comprises eight segments, each ranging from ~8-25 miles in length, 30 to 40 ft in diameter, and 40 to 140 ft deep, with a preliminary cost estimate of $30 billion.

Web: hcfcd.org

WASHINGTON
Seattle
West Seattle Link Extension and Ballard Link Extension
The West Seattle and Ballard Link Extension projects will provide fast, reliable light rail connections to dense residential and job centers throughout the region. In addition, a new downtown Seattle light rail tunnel will provide capacity for the entire regional system to operate efficiently. These two separate Link extensions are part of the regional transit system expansion approved by voters in November 2016 and as of May 2023 are on two separate environmental review processes and timelines.

Web: soundtransit.org