Say NO to Proposed Construction at the Grupes Reservoir

The New Canaan Land Trust and Norwalk River Watershed Association are challenging plans for significant construction at the Grupes Reservoir.


Norwalk’s First Taxing District Water Company is seeking a permit to do repairs on the Grupes Reservoir Dam, originally constructed in 1871. The dam is the fourth in a series of dams along the Silvermine River, and is located next to the Land Trust’s Browne Preserve on Valley Road.

The current plans call for the dam to be raised by four feet, to prevent water from spilling over the top of the dam in the event of a 500-year flood. The First Taxing District claims that this also necessitates the construction of nearly 1500 feet of berms and walls along the reservoir’s eastern bank.

Together, the New Canaan Land Trust (NCLT) and Norwalk River Watershed Association (NRWA) are challenging this proposal. After getting over 30 signatures from concerned citizens, the two organizations became interveners in the hearing process, overseen by the CT Department of Energy and Environmental Protection (DEEP).

Our Concerns

NCLT and NRWA believe that the current plan fails to identify, quantify, and minimize the impacts of constructing 1500 feet of berms and walls along the eastern bank of the Grupes Reservoir.

Some of the impacts of this project are very apparent, including the permanent removal of over 400 native trees and shrubs along the reservoir banks. Other impacts are less apparent, and could include diversion of natural water flows, impacts to wetlands, and changes to vegetation and habitat. The First Taxing District has not addressed any of these potential impacts, and has therefore disabled DEEP from evaluating the impacts of this project.

Additionally, the Norwalk First Taxing District has denied permission for NCLT and NRWA to access the proposed construction site, including requests for a soil scientist to identify wetlands and a consulting botanist to inventory vegetation and look for any rare/endangered plant species.

This project is of particular concern to the Land Trust because of its adjacency to the Land Trust’s Browne Preserve. This preserve is one of NCLT’s oldest and largest properties, and home to a walking trail that is enjoyed by many in the community. The First Taxing District has failed to identify the project’s impacts on the wetlands, watercourses, vegetation, and habitats at the Browne Preserve.


NCLT and NRWA are in full support of the First Taxing District’s plans to bring the dam up to current safety regulations, but are asking that the water company adopt alternative plans that minimize damage to the eastern bank of the reservoir.

In their proposal, the First Taxing District outlines possible alternatives to the proposed construction. Some of these alternatives, like lowering the existing spillway, would have far less of an impact on the surrounding area. Widening the existing spillway is another alternative identified by our consulting engineer. NCLT and NRWA support further exploration of these alternatives.

What You Can Do?

As part of the permitting process, DEEP hosted a virtual public hearing on September 29th. Over 70 people attended, and everyone who spoke asked DEEP to take a closer look at the environmental impacts of the project, or to consider alternatives to the planned construction. Thank you to those who attended and spoke up! DEEP also accepted written comments through October 6th.

Hearing Information

There are no additional hearings scheduled at this time. To view recordings of the public hearing, or any of the three days of evidentiary hearings, click HERE

Additional Information

One-pager about the proposed construction: HERE
CT DEEP’s Hearing Page: Click HERE
Coverage in the NewCanaanite: Click HERE
Coverage in the New Canaan Advertiser: Click HERE
Coverage in the CT Insider: Click HERE

Questions or Concerns?

Contact us at [email protected] or [email protected]

Click Images to Enlarge

Graphic showing approximate location of proposed berms and walls, in relation to adjoining Browne Preserve

Early detailed plans submitted by Norwalk First Taxing

Approximately 1.5 acres of pristine riparian buffer, home to over 400 native trees and shrubs, to be cleared during construction.