Westchester Flood Funds Target New Rochelle’s Stephenson Brook Watershed

NEW ROCHELLE, NY (October 21, 2025) — Westchester County has approved $1.925 million in flood mitigation projects to shield residents in New Rochelle, Croton-on-Hudson and Bronxville from recurring deluges that have flooded basements, closed roads and waterlogged school fields since 2009.

The Westchester County Board of Legislators this week greenlit the investments for modern stormwater drainage systems in three hard-hit areas, including the Stephenson Brook watershed in the City of New Rochelle. The upgrades will install new drainage pipes, catch basins and related infrastructure to reroute stormwater from flood-prone neighborhoods.

The county’s Stormwater Management Program will cover about half the cost of each project, with local municipalities footing the rest and handling maintenance after completion. All three initiatives are slated to wrap up within two years.

These enhancements aim to cut flood insurance premiums for residents and bolster emergency responses during heavy rains. The targeted fixes stem from scientific watershed studies that identify flooding hotspots and craft precise engineering remedies.

Overview of Stephenson Brook Flooding in New Rochelle, NY

Stephenson Brook is a key watershed in northern New Rochelle, originating in residential neighborhoods, flowing through areas like the Wykagyl Country Club golf course, and emptying into Long Island Sound. 5 It forms part of the city’s Stephenson Basin, one of six major drainage areas analyzed for chronic flooding issues: Burling Brook, Hutchinson, Pinebrook, Sheldrake River, Shoreline, and Stephenson Brook. 9 Flooding in this basin has long affected properties, roads, and public spaces, exacerbated by heavy rainfall, poor drainage infrastructure, and stormwater runoff.

Flooding Issues and Scale

The Stephenson Basin stands out as New Rochelle’s most flood-vulnerable area, with 93 documented problem locations identified through historic reports, topographic mapping, and infrastructure assessments. This accounts for about 30% of the city’s total 307 flood-prone sites across all basins. Common impacts include flooded basements, impassable roads, and waterlogged fields, particularly during storms, as noted in broader Westchester County flood studies dating back to at least 2009. While specific storm events aren’t detailed in available records, the basin’s high concentration of issues stems from its steep terrain, eroding banks, and concentrated urban runoff, including nutrient pollution from nearby lawns and fairways that worsens downstream water quality and flow.

In 2022, city lawmakers actively solicited photos and videos from affected residents to map these hotspots more precisely. 8 This input supported a comprehensive Watershed Drainage Analysis aimed at hydrologic modeling and recommending targeted fixes, with a final report expected to guide capital investments. Submissions were encouraged via the city’s flooding portal (newrochelleny.com/flooding) to highlight real-time damage in the Stephenson Basin and adjacent watersheds.

Mitigation Projects and Efforts

New Rochelle and Westchester County have pursued multiple initiatives to address Stephenson Brook’s vulnerabilities, focusing on bank stabilization, pollutant filtration, and drainage enhancements:

• New Rochelle High School Bank Stabilization (Completed): Located on North Avenue, this project regraded steep, eroding banks along the brook to prevent further degradation. 3 Temporary measures included coconut fiber mats and biologs for soil support, plus underwater logs to create natural riffles that boost dissolved oxygen in the water. Permanent vegetation—perennials, shrubs, trees, and native irises (yellow iris and blue flag iris) along nearby Huguenot Lake—was planted to filter pollutants like nitrogen and phosphorus while controlling erosion and improving wildlife habitat. 13 The effort enhances overall stream health but specific flood reduction metrics are not quantified.
• Stephenson Brook Pond at Wykagyl Country Club (Completed in 2000): On private property next to Trenor Road, this restoration targeted nutrient overload from fertilized fairway runoff entering the pond and brook. 5 Workers removed sediments and decaying leaves, then built submerged “shelves” around the pond using coconut fiber logs, planting them with aquatic species like yellow iris and buttonbush for natural filtration. 12 A vegetated buffer meadow of grasses, sedges, wildflowers, shrubs, and trees was added between the fairway and pond to trap stormwater pollutants. The area was designated an “environmentally sensitive zone,” treating errant golf balls as out-of-bounds to protect the habitat for birds and small mammals.
• Stephenson Brook Resiliency Planning Project (Ongoing, DPW #23-027): Launched in 2023, this city-led effort assesses drainage in the Stephenson Brook and Twin Lakes vicinity to develop conceptual improvements like new pipes and basins. Engineering bids were solicited in May 2025, focusing on flood-prone spots around Paine Lake and Valley Road. Completion timeline is TBD, but it aligns with Westchester County’s recent $1.925 million stormwater investment for the area, expected to finish within two years.
  

These projects reflect a collaborative push between the city, county, and partners like the Wykagyl Country Club to build resilience against intensifying storms. Neighborhood meetings in 2023 further engaged residents on the drainage study findings.

For the latest updates, check New Rochelle’s Department of Public Works or the Westchester County Planning Department.

The approvals build on more than $120 million the county has poured into flood defenses since 2009. Officials pledged to keep deploying tools, partnerships and investments to fortify Westchester against worsening storms.

This article was drafted with the aid of Grok, an AI tool by xAI, under the direction and editing of Robert Cox to ensure accuracy and adherence to journalistic standards.