Pemberwick Park Drainage Area Improvements

Pemberwick Park W


Project Update

Phase 1 (installation of drainage pipes through Pemberwick Park) and Phase 2 (installation of drainage pipes from the bottom of Rex Street to Pemberwick Road, along Rex Street. Phase 3 began on December 22, 2023 and is anticipated to be completed in spring 2024. 

Project Description

This project aims to improve drainage in the Pemberwick Park area, which includes modifications to an existing headwall, replacement of a trash rack, and installation of a new drainage pipe to increase the drainage capacity. The new catch basins include two-foot sumps to trap sediment. To prevent erosion during large storm events riprap will be placed along the south corner of the trash rack headwall. Restoration of the ball field, park turf, sidewalk, curbing, and pavement will take place upon completion of the installation of the new drainage pipe.

Project History

Following the impacts of Tropical Storm Ida, the Town of Greenwich Department of Public Works (DPW) began to review several areas in the Town for alternatives to reduce the impacts of future storms. It was determined one area of the Town that required further study is the Pemberwick Park drainage area. 

Project Improvements 

  • Raise the existing trash rack headwall.
  • Replace and install a sloped trash rack grate.
  • Install new catch basins including two-foot sumps to trap sediment.
  • Chip the existing boulder at the north corner of the headwall to widen the channel.
  • Install an additional drainage pipe parallel to the existing pipe to increase the capacity.
  • Install a new 24-inch pipe (in the park area) that will run from the headwall to Pemberwick Road and a new 36-inch pipe that will run from Pemberwick Road to the outfall at the Byram River via Rex Street. 
  • Install modified riprap at the south corner of the wing wall to stabilize the slope, with appropriate grading.

Hydraulics and Drainage

A detailed Storm Water Management Model (SWMM) watershed and hydraulic conveyance model analysis was performed to evaluate existing and proposed conditions. Appropriate hydrologic methods were used to estimate the flows through the watercourse. The hydraulic model was run for both the existing and proposed conditions for the various scenarios. The proposed improvements will result in conveying more flow than existing. The proposed changes do not have any adverse impacts on residential properties or Federal Emergency Management Agency (FEMA) elevations. 

Timeline

  • 2022 -- Detailed Storm Water Management Model (SWMM) watershed and hydraulic conveyance model analysis was performed to evaluate existing and proposed conditions.
  • 2022 -- Developed plans for the project.
  • November 9, 2022 -- Hosted public meeting.
  • August 2023 -- Filed project application with the Inlands Wetlands and Watercourse Agency (IWWA) for the proposed work.
  • October 9, 2023 -- Construction began.
  • October 27, 2023 -- Phase 1 completed (installation of drainage pipes through Pemberwick Park).
  • October 30, 2023 -- Phase 2 to begin (pipe installation from the river to Pemberwick Road along Rex Street).
  • December 22, 2023 -- Phase 2 completed.  
  • Spring 2024 -- Construction anticipated to be completed. 

Project Funding

This is a Town of Greenwich Department of Public Works project with design completed by the Town and construction funded through the American Rescue Plan Act of 2021 (ARPA). 

Public Involvement

DPW hosted a public meeting on November 9, 2022, to provide the status of the project. 

CLICK HERE to view the presentation. 

Contact

Project Manager: Civil Engineer and Project Manager Town of Greenwich Department of Public Works

Pemberwick Park Drainage Area Improvements Project Info Sheet