The Horn Pond Fish Passage project received final funding needed for construction with an anticipated construction start in Summer/Fall 2026, aiming to be complete before the river herring migration begins in spring 2027. Funding for this new fish passage is coming from settlement funds from the Industri-Plex Natural Resource Damages Trustee Council, a North American Wetlands Conservation Act (NAWCA) grant, and a generous $1M gift from an anonymous foundation to the Mystic River Watershed Association.
After completion, the new fish passage at Scalley Dam will give river herring access to 100+ acres of spawning habitat in Horn Pond. With this intervention at Horn Pond, it is estimated that the Mystic River herring run could reach over a million fish (Division of Marine Fisheries). Additionally, viewing areas at this new fish passage, including a state-of-the-art underwater window, will allow more people to witness this incredible migration than ever before.
The Horn Pond Fish Passage will consist of a pool and weir system, which allows herring to gradually make their way up from the bottom of Scalley Dam into Horn Pond. New educational signage and an ADA accessible pathway to an underwater viewing window will further improve the area for visitors.
In anticipation of increased public visitation to Horn Pond, designs and approvals are in progress to add approximately 30 more parking spaces, improved pedestrian safety and access, and a new rain garden to filter parking lot runoff before it enters the pond.
Beginning this spring the City will continue with the parking lot improvements we started last fall. We intend to expand the footprint of the parking lot and reconfigure the parking spaces to accommodate an additional 30 plus parking spots and additional handicap parking. The parking lot improvements also accommodate additional sidewalks and ADA accessible ramps to improve pedestrian safety.
In order to account for the additional 30 plus parking spaces, increased pedestrian safety measures and ADA compliance the City has undertaken a project to protect the water quality at Horn Pond and Horn Pond Brook. The proposed rain garden will reduce direct stormwater flows to the pond while removing sediments and phosphorous. The proposed rain garden involves a series of curb cuts with stone aprons along the edge of the parking lot to the north to route runoff into a proposed sediment forebay, providing pretreatment for total suspended solids (TSS). The stormwater runoff will overtop a granite curb check dam and flow from the forebay into a shallow rain garden basin. Stormwater in the rain garden will filter through a biofiltration media and infiltrate into the groundwater. A timber check dam will prevent extended ponding in the detention area and allow overflow into Horn Pond.
Rain Garden and Parking Lot Plans
Presentation to Conservation Commission-March 26, 2026
April-May 2026: Parking Lot Layout
Summer-Fall: Fish Ladder
Fall 2026: Parking Lot paving and Rain Garden