Wastewater and Stormwater Management Guidance

In September 2026, the Cambridge Land Disturbance Regulations were revised to clarify project thresholds that determine stormwater requirements. A summary of public comment received and additional clarification in response to the comments is available here.

Under the revised Land Disturbance Regulations, projects in Cambridge fall into one of three categories for stormwater management based on project scope and size:

1. Stormwater Control Permits
2. DPW Stormwater Site Plan Review (under Building Permit)
3. Small Projects with No Cambridge Stormwater Management Requirements

Project applicants should review the September 2026 Supplemental Directive below to determine which category your project falls into and associated stormwater requirements.  The September 2026 Supplemental Directive provides guidance on Cambridge stormwater standards, including sample calculations.

September 2026 Supplemental Directive to Wastewater and Stormwater Management Guidance

All project applicants should also review the DPW Site Plan Review Requirements document for submission requirements and items that must be addressed in advance of DPW sign off on the pre-approval of the Building Permit Application.

Small projects with no Cambridge Stormwater Management requirements are encouraged to use construction and landscaping projects as an opportunity to evaluate on-site drainage and make improvements. For projects of this scale, the City recommends stormwater improvements such as pervious walkways and patios, reducing impervious surfaces, dry wells, rain gardens and rain barrels. Project applicants are encouraged to review the City's Stormwater Site Improvement Recommendations and resources for Projects of this Size.

Stormwater Control Permits