Permeable Resin-Bound Surfacing in Hartford, CT

Section 6.14, the state manual and MDC sign-off

Under Section 6.14 of the zoning regulations, no zoning permit may allow untreated runoff to be channeled into ground or surface waters, or peak discharges from the 2, 10, 25 and 100-year storms to exceed pre-development rates. Stormwater systems must follow the latest Connecticut DOT Drainage Manual and Stormwater Quality Manual, and applicants must use low impact development wherever feasible; the listed options include permeable surfaces, bioretention, infiltration trenches and green roofs. The water quality volume has to be treated on site, and any system that outlets to an MDC-controlled drain must meet MDC standards and approvals.

Freestanding one-, two- and three-unit dwellings outside a larger plan, and disturbance under 2,500 square feet that is not part of a larger plan, are exempt from the stormwater plan requirement. The 2024 state manual raised the water quality storm from 1 inch to 1.3 inches and classes permeable pavement as an infiltration practice. Connecticut's MS4 general permit is administratively extended while DEEP reissues it.

River clays, a buried river and an overloaded combined system

Hartford sits on the Connecticut River floodplain behind flood-control dikes, with the Park River carried in conduits beneath the city. Much of the subsoil is fine-grained glacial lake sediment that drains slowly, so many permeable sections here will need an underdrain, and the engineer should present those as filtration and peak control rather than retention.

The combined sewer is the other driver. MDC's Clean Water Project includes separating Hartford's combined pipes, cutting inflow from downspouts and sump pumps, and the South Hartford Conveyance and Storage Tunnel, and North End neighborhoods have struggled with basement backups. A section that infiltrates keeps rain out of those pipes; one piped to the combined system needs MDC approval. For cold-weather performance, the state manual says not to sand permeable pavement, and for porous asphalt and pervious concrete it calls for pavement plus subbase thicker than 0.65 times the design frost depth.

Where it fits in Hartford

• Tree surrounds in new development: Section 6.2.3 calls for at least 70% of the canopy limits of preserved trees to have a permeable surface. A bound, permeable finish over structural soil is a candidate, subject to zoning staff acceptance.
• Office and insurance campuses: surface lots and plazas downtown and in Asylum Hill, where any redevelopment disturbing 2,500 square feet or more needs a stormwater plan.
• Multifamily courtyards: buildings of four or more units in Frog Hollow, Parkville and the South End rebuilding their outdoor space.
• School and park paths: walks where a firm permeable surface can replace worn asphalt.

Approvals in Hartford and what Resin Rock provides

Site plans and stormwater management plans go to the Planning and Zoning Commission or zoning staff in Development Services, with MDC review for any connection to its system. Expect reviewers to want infiltration testing, a long-term operation and maintenance plan under the state manual, and proof that the water quality volume is treated on site.

Resin Rock supplies UV-stable binder, stone blends, trims and the Rock Crete permeable sub-base, with technical data sheets for the design team. We do not install. Find an installer to be matched with an approved installer, usually within 24 hours, and contractors can apply for Connecticut installer training.