In 2012, the New York shore was hit by Superstorm Sandy and it transformed the way we manage our coastlines. In the event of storms or high tides like Sandy, Canarsie’s Fresh Creek, an inlet of Jamaica Bay in Brooklyn, dumps water into the adjacent neighborhood’s storm sewer system— resulting in flooding in addition to the overflow from the creek itself.

To address the flooding into the shoreline sewer system, the Dormitory Authority of New York and the Governor’s Office of Storm Recovery hired the Urban Engineers and KS Engineers, P.C. Joint Venture consultant team to conduct restoration on the storm sewer system draining into Fresh Creek by constructing tide gates over five storm sewers along 108th Street and reconstructing the Avenue M outfall.

Innovative Application

Tide gates are not a typical solution for storm sewers but were chosen for Fresh Creek as an innovative design solution. The tide gates are essentially “flappers,” the exit point from the sewage pipelines into the creek. As water reaches high levels during storm surge and extreme high tides, these tide gate chambers will prevent creek water from back flowing through the storm water sewer system and flooding the neighborhood.

Coastal cities and communities near water will need to take proactive steps to protect themselves and local stakeholders from devastating floods. The benefits of projects like Fresh Creek include:

• Improved inland drainage and storm recovery
• Increased resiliency
• Private and public property damage minimization

Agencies responsible for communities that face flooding challenges across the country can benefit from the engineering design solutions utilized in this project.

Sustainable Development Considerations

Waterfront neighborhoods are uniquely vulnerable to the effects of climate change, which are rapidly accelerating. The goal of this project was to explore and implement strategic flood protection measures, to reduce both coastal and upland flood risks from sea level rise (SLR) and storm events, which are anticipated to increase in both intensity and frequency with climate change, while remaining compatible with on-going and long term ecosystem restoration and recreational plans.

Fresh Creek is a FEMA-designated Special Flood Hazard Area, and this project needed to employ strategic flood protection measures to combat high water levels during storm surges and high tide. The final set of design criteria used for the Fresh Creek drainage area analysis and development of mitigation measures is listed below:

• A five-year NOAA 2nd Quartile Storm Distribution over 24 hours
• 100-year Flood Surge Elevation in Jamaica Bay, per AdaptMap
• 50th Percentile SLR for 2050 (16 inches) [or Median value between 25th and 75th percentile]

The project’s deadline was met notwithstanding supply chain delays in securing stainless steel tide gates, manhole castings, and shoreline plantings.

At the completion of this project, the community came out to celebrate. “We're proud that this strategic investment will play an important role in protecting Canarsie and improving the quality-of-life for residents in these neighborhoods," said GOSR Deputy Director Eileen Méus.

The enthusiasm for this restoration was also felt by Urban Engineers and the rest of the consultant team, who are appreciative to have been a part of this project that was completed on time and on budget.