The context

The Gowanus Canal is one of the most closely watched waterways in New York City and a federal Superfund site. When heavy rain overwhelms the area’s combined sewers, stormwater and wastewater can overflow into the canal. Improving how the neighborhood’s streets handle stormwater is part of the long-term effort to clean the canal and reduce flooding.

Phase 1 of the Gowanus Canal Storm Sewers program, a $52.9 million project delivered for NYC DDC and NYC DEP, attacked that problem street by street. The work installed high-level storm sewers, new catch basins, manholes and chambers, and replaced aging water mains, followed by full restoration of the roadway, sidewalks and curbs. The project was completed in 2025.

Project at a glance

Client: NYC DDC, with NYC DEP

Location: Gowanus, Brooklyn

Construction value: $52.9 million

Status: Completed 2025

SRE’s role: Construction management, construction inspection, community construction liaison

Scope: High-level storm sewers, catch basins, manholes and chambers, water main replacement, full street restoration

The challenge

Gowanus is not an empty site. It is a mix of homes, small businesses, industrial users and new development, on streets with decades of utilities beneath them. Every block of new sewer meant an open trench in front of someone’s door, traffic detours on a working street, and the near certainty of finding something underground that the old maps did not show.

How the work moved

Each block moved through the same four stages, and each stage asked something different of the construction management team.

Exhibit 1. Every block went through the same four stages

On a job like this, the storm sewer stage carries the most risk, because the deepest excavation is where crews meet the utilities the old maps do not show.

The results

The new storm sewers now carry street runoff that once fed the combined system, and the neighborhood has new water mains and fully rebuilt streets.

The program continues in Phase 2, a $67.1 million project that builds on the same approach.

The hardest problems on an underground job are rarely engineering problems. They are sequencing, utility conflicts and the patience of the block.

Four lessons for agencies and owners

1. Survey before you dig. Old utility records are a starting point, not an answer. Test pits and utility coordination before excavation turn surprises into planned work, and planned work is far cheaper than a stopped crew.

2. Sequence for the block, not just the schedule. The order that is fastest on paper is not always fastest in practice. Working with businesses and residents on delivery windows, access and parking keeps crews productive because the block is not fighting the work.

3. Put a person, not a flyer, between the project and the community. SRE’s community construction liaison coordinated with contractors, residents and businesses throughout the job. A reachable liaison resolves most concerns before they become complaints to elected officials or the agency.

4. Keep records that settle arguments. Daily reports, photos and measured quantities are the project’s memory. When questions arise about extra work or conditions found in the field, clear records resolve them quickly and fairly.

Sources

• SRE Engineering project records, Gowanus Canal Storm Sewers, Phase 1

• U.S. EPA: Gowanus Canal Superfund site