Commission approves new elementary school at 280 Elizabeth St. Ext., with wetland mitigation

The Norwich Inland Wetlands and Watercourses Commission approved an upland and wetland application for a new three‑story elementary school at 280 Elizabeth Street Extension (IWWCC 25‑07), agreeing to required mitigation and standard staff conditions.

Designers described a project that will demolish the existing school only after the new building is constructed and will serve about 550 pre‑K–5 students. The project footprint includes stormwater basins, an underground retain‑and‑treat system, and sediment controls intended to meet Connecticut’s 2024 stormwater guidance. Engineers said they designed the basin and outlet structures to limit erosive velocities and to provide pretreatment using a hydrodynamic separator and isolator rows.

Megan Fogarty presented the wetlands delineation and mitigation approach. She said the site contains three primary wetland systems and two intermittent watercourses occupying about half an acre. The project includes two wetland impact areas — one lawn‑dominated wetland area of about 2,321 square feet and a filling of the northwestern portion of a second wetland — and proposes about 2,150 square feet of compensatory wetland mitigation focused on enhancing Wetland C, which Fogarty identified as the highest functioning system on the property. She said the mitigation would be implemented by regrading to intercept groundwater, placing screened topsoil and planting native wetland vegetation to increase ecological function and educational value.

City staff and the design team noted construction will be phased so the existing school remains operational during most of the build. The commission required that staff memos and E&S details be included in the permit file and that revised plans address city engineer comments. After discussion the commission voted unanimously to approve IWWCC 25‑07 with staff comments.

The approval includes monitoring and sequencing requirements and a condition that silt fence and sediment traps be installed along the limit of disturbance nearest the eastern wetland corridor. The design team said sediment and erosion controls will be adjusted through construction phases and that the sediment forebay and trap near the underground system will be used during installation and later removed or modified as the project moves to final stabilization.

Numbers on the record: the lawn/mowed wetland impact area described as an impacted wetland was 2,321 square feet; proposed wetland mitigation area was 2,150 square feet; the stormwater basin is approximately 5 feet deep and the underground retain system uses approximately 140–146 units (engineers provided a unit count during the presentation).