Old Saybrook officials, consultants present marsh study and flood models as residents report recurring street flooding

Consultants and town staff presented preliminary findings from a multi-year marsh restoration and flood-modeling study for Old Saybrook on the status of Cold Spring, Chalker Beach and Hagar Creek marshes and invited residents to ground-truth model outputs.

Town planner Chris Costa opened the meeting and described the project as grant-funded by a Long Island Sound program. Shauna Little, a senior environmental scientist with FAS O'Neal, laid out the project goals: collect updated field data, deploy tide and soundside sensors, build a flood model to identify pathways and test potential engineering and nature-based solutions, and engage residents to inform calibration and choice of options.

The consulting teams said they deployed water-level sensors across Hagar, Cold Spring and two locations in Chalker Beach (including a soundside gauge) over a full lunar cycle to capture tidal exchange, and performed remote-sensing plus boots-on-the-ground vegetation and elevation checks to refine land-cover inputs. The presenters said Chalker Beach is the most stressed system, Cold Spring is moderately degraded and Hagar Creek appears the healthiest of the three.

The study’s shoreline analysis compared imagery over decades and found notable changes tied to Superstorm Sandy: presenters said Cold Spring Marsh has lost roughly 3.3 acres of marsh and that an outlet channel migrated about 380 feet west since earlier imagery. Consultations of shoreline-change graphics and sediment-transport arrows showed areas of both erosion and accretion along Chalker Beach and Cold Spring.

Consultants ran animations of present-day and future water levels, showing that day-to-day tidal flooding is currently limited in some areas but that model runs for mid‑century (2050) and end‑of‑century (2100) water levels and 10‑, 50‑ and 100‑year storm scenarios produce larger, longer‑lasting inundation and slower marsh drainage. The team noted the flood model for this phase focuses on tidal and marsh exchange and is not modeling detailed storm‑drain or pipe networks; sediment transport for erosion and accretion is analyzed separately.

Residents reported that Chalker Beach streets and septic systems flood repeatedly and that floodwaters sometimes back up through catch basins into roadways. One resident who described post‑storm experience said, “The Chalker Beach Marsh took over two weeks” to drain after a recent major event, while another said Cold Spring drained in about two days. Residents argued that the tide gate and inland development/drainage changes amplify the problem at Chalker Beach.

Presenters confirmed the tide gate and sand blockage are factors in Chalker Beach’s drainage performance—the tide‑gate outlet there connects marsh water to the sound through a roughly 24‑inch pipe, officials said—and they encouraged residents to submit photographs and videos (ideally combined into a single file) to help ground‑truth model results. The team also cited a past state and Army Corps of Engineers involvement in tide‑gate and marsh maintenance at sites residents mentioned.

On modeling scope and limits, the consultants said this contract phase will simulate a marsh at capacity (from precipitation or inflow) and then add tidal forcing to evaluate how systems interact; it will not at this time produce permit‑ready engineering designs. The team expects to screen many candidate strategies, prepare multiple options, and return to the public with preferred options in a later meeting (the presenters said the contract deliverable would bring solutions to about a 30% design level; more survey and permitting work would be required to reach typical shovel‑ready levels).

Next steps the team listed include refining the model with resident‑provided photos and event dates, testing the modeled effects of options such as tide‑gate upgrades or localized beach nourishment, and preparing a fall public meeting to present screened design options for community feedback. The team set up stations after the presentation so residents could discuss shoreline‑erosion, marsh restoration and flood‑modeling details one‑on‑one with consultants.

No formal actions, votes or permits were taken at the meeting; presenters emphasized that no solutions have been chosen and that feasibility, permitting constraints and maintenance implications will guide what the town and consultants recommend going forward.