Quincy-07C
Quincy
42.263640, -70.974002
Technical Specifications
Basic Properties
- Type
- Flap Gate
- Material
- Metal
- Control
- —
- Condition
- Fair
- Geometry
- Circular
- Status
- Active
- Number of Gates
- 0
Operator & Management
- Operator Type
- PUBLIC
- Operator
- Town of Quincy
- Permits
- —
- Purpose
- —
Dimensions & Elevations
- Dimensions
- 3ft diameter
- Invert Elevation
- —
- Installation Date
- —
- Tidal Influence
- —
Culvert Details
- Restriction Type
- Roadway
- Geometry
- Circular
- Material
- Concrete
- Bottom Material
- —
- Number of Pipes
- 0
- Dimensions
- —
- Condition
- Good
- Comments
- There are two, 30 inch diameter culverts at the site.
Salt Marsh Field Assessment Results
Comprehensive field assessment dataPhysical Conditions Assessment
Channel Conditions
- Channel Alteration and Ditching
- Limited (<133 ft/acre)
- Channel Constriction
- Narrower than channel
- Channel Erosion
- Severe (>60% of bank)
- Sediment Deposits
- Moderate (10-60% of channel wid
Blockages
- Debris Blockages
- Moderate (10-60% of opening)
- Evidence of Overtopping
- No
Ecological Assessment
Habitat Observations
- Ecological Impairment due to Tide Gate
- Limited
- Crab Burrow Intensity
- Moderate (10-60% banks are dens
- Ponding and Die-off Depressions
- None
- Phragmites Present
- Limited (<10%)
Invasive Species
- Upstream Invasive Species
- Yes
- Downstream Invasive Species
- No
- Invasive Species Notes
- Phragmites limited to upland fringe with some mixing in high tide bush.
General Comments
Efforts have been previously made to restore marsh. Talking with homeowners, the marsh has come a long way from mowed upland grasses to a healthier marsh. Low marsh only exists along channel but high marsh is abundant. Due to proximity of houses this may be as open as tide gate can be. Grate is partially covered in debris and may need regular maintenance.Habitat Transects
First Transect (50 yards upstream of tide gate)
Second Transect (150 yards upstream of tide gate)
Third Transect (300 yards upstream of tide gate)
Restoration Potential
Assessment
- Salt Marsh Impairment due to Tidal Restriction
- Moderate
- Potential Extent of Marsh Restoration
- Moderate
- Implementation Feasibility
- High
- Restoration Priority
- High
- Recommended Improvement Type
- O&M and Infrastructure
Notes
Site shows moderate salt marsh impairment due to restricted tidal flow. Replacement with self-regulating tide gate could restore approximately 5-8 acres of degraded marsh habitat. Good access for construction equipment. Regional coordination completed with town DPW and conservation commission.Historical Records
Environmental Data
- Invasive Species
- Yes
- Restoration Status
- —
- Invasive Comments
- Phragmities was observed upstream
- Restoration Comments
- —
- Upstream Area
- —
Notes & Comments
- General Comments
- Tide gate is located directly off of Post Island Road to the southwest. Outfall is located on the beach to the northeast of Post Island Road and is submerged at high tide.
- Operation Plan
- —
- Operation Comments
- The flap gate is completely closed and mostly submerged during the site visit.
- Gate Comments
- Rock crabs were seen covering the closed flap gate and some barnacles.
- Elevation Comments
- —
- Visit Comments
- —
- Other Comments
- —
- External Data Comments
- —
Part of the Massachusetts Bays Program© 2026 Massachusetts Bays Program. Monitoring tidegates across Massachusetts.