Walker School expansion at Central Ave. continued after commission questions stormwater and riverfront work

Walker therapeutic and educational programs sought approval on July 9 from the Needham Conservation Commission for an expansion and site improvements at its 1968 Central Ave campus, but the commission continued the application to its July 23 meeting after detailed questions about stormwater, riverfront jurisdiction and construction controls.

Pat Tutwiler, chief executive officer of Walker, opened the presentation and said the nonprofit provides therapeutic special-education and residential programs and that the project would modernize aging facilities while protecting environmental resources. Brandon Lee of Kelly Engineering described the site as 12.4 acres adjacent to the Charles River, with bordering vegetated wetlands and a riverfront area. The proposal includes a 5,760-square-foot two-story addition to the school, a 5,520-square-foot expansion of an existing multipurpose building, demolition of a hexagonal building within the 200-foot riverfront area, and an outdoor amphitheater and seating in its place.

The applicants said the plan reduces overall impervious area on the riverfront from about 2,291 square feet to 506 square feet — a net reduction they calculated at 1,785 square feet — and that restoration planting and invasive-species removal would accompany construction. The engineering team said the stormwater design provides greater than the Needham bylaw’s 1.5-inch recharge requirement (the applicant estimated roughly four times that amount) through four recharge systems and an operation-and-maintenance plan.

Conservation staff and commissioners asked for additional documentation. The commission chair and staff said the new town Stormwater Management Bylaw includes elements of the Massachusetts stormwater standards that apply to some single-family and small-scale projects and that the commission expects the applicant to demonstrate compliance with the bylaw’s recharge and peak-rate requirements (standards 2 and 3) or to explain why compliance cannot be met. Commissioners flagged several technical items: clarity on how the applicant calculated pre- and post-construction runoff using comparable ‘‘design points,’’ apparent mismatches between system labels on the drawings and the report, and one infiltration system that may be undersized for the area tributary to it.

Staff also requested test-pit data and urged the applicant to provide a dewatering plan prior to any dewatering activity; at least one test pit reportedly reached standing water near 6–7 feet, which could require preapproved controls. Applicants agreed to provide test-pit results to the town DPW before construction and to show a dewatering area on the plan and an invasive-species removal protocol in accordance with the conservation staff’s suggestions.

During public comment, a nearby resident, Mark Schuman, said he has lived on Fisher Street for decades and raised complaints about traffic and neighborhood impacts from Walker operations; the commission limited comments to wetlands-related issues, and the applicant team said they would follow up on neighborhood concerns outside the commission’s jurisdiction. Another resident asked that the Fisher Street access not be used for construction and urged repair and reinstallation of a gate; the applicants said Fisher Street would not be used for construction and that the broken gate part is on order and will be locked.

Because several technical items remain — including documented compliance with the town stormwater bylaw’s applicable standards, a clarified set of stormwater calculations showing pre/post runoff at comparable design points, updated infiltration-system sizing documentation, test-pit reports and a planting/invasive-species plan — the commission voted to continue the hearing to July 23. No binding permit or order of conditions was issued at this meeting.