Quincy-04
Quincy, Parkhurst Marsh
42.271089, -70.956484
Technical Specifications
Basic Properties
- Type
- Flap Gate
- Material
- Metal
- Control
- —
- Condition
- Unknown
- Geometry
- Circular
- Status
- Active
- Number of Gates
- 0
Operator & Management
- Operator Type
- PUBLIC
- Operator
- Town of Quincy
- Permits
- —
- Purpose
- Flood Protection
Dimensions & Elevations
- Dimensions
- 1ft diameter
- Invert Elevation
- —
- Installation Date
- —
- Tidal Influence
- —
Culvert Details
- Restriction Type
- Beach
- Geometry
- Circular
- Material
- Concrete
- Bottom Material
- —
- Number of Pipes
- 0
- Dimensions
- 1ft diameter
- Condition
- Poor
- Comments
- Reinforced concrete culvert was 36" at downstream end and 12" at upstream end. Outfall was located approximately 100' feet north of Bayswater Road on the beach and was partially exposed at low tide. Downstream end of culvert was severely deteriorated: most of the joints had separated and large 1'-2' gaps were observed in the pipe. Upstream end of culvert which entered the marsh off of Winthrop Street was in fair condition, but was partially buried and appeared to have the potential to get buried or silted in if not frequently maintained.
Salt Marsh Field Assessment Results
Comprehensive field assessment dataPhysical Conditions Assessment
Channel Conditions
- Channel Alteration and Ditching
- Limited (<133 ft/acre)
- Channel Constriction
- Equal to channel
- Channel Erosion
- Little (<10% of bank)
- Sediment Deposits
- Limited (<10% of channel width)
Blockages
- Debris Blockages
- None
- Evidence of Overtopping
- Yes
Ecological Assessment
Habitat Observations
- Ecological Impairment due to Tide Gate
- Limited
- Crab Burrow Intensity
- None
- Ponding and Die-off Depressions
- Severe (>60% of marsh platform
- Phragmites Present
- Limited (<10%)
Invasive Species
- Upstream Invasive Species
- Yes
- Downstream Invasive Species
- No
- Invasive Species Notes
- Phragmites limited to occasional 1 yard bands along upland fringe.
General Comments
Healthy and thriving low marsh community exists in marsh with very small bands of phragmites along perimeter. Some ponding is occurring but marsh appears healthy otherwise. Overtopping into adjacent yard is evident from wrack line and current flooding but house is raised and on stilts so appears to be a non issue. Overall marsh is in good condition.Habitat Transects
First Transect (50 yards upstream of tide gate)
No data
Second Transect (150 yards upstream of tide gate)
No data
Third Transect (300 yards upstream of tide gate)
No data
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
- Not Applicable
- Invasive Comments
- The upstream marsh had a mixture of Spartina Alterniflora and Patens and was bordered by Phragmites.
- Restoration Comments
- The marsh was previously studied for potential restoration by MADER; however, it was concluded that low lying infrastructure would be a challenge. Future restoration would likely need to consider sizing culvert to accommodate the balance between stormwater outflows and tidal flushing.
- Upstream Area
- —
Notes & Comments
- General Comments
- Tide gate was located in a manhole adjacent to Winthrop Street and was not accessible. Follow up with Franz Inglefinger of DER to obtain elevation data and with Town of Quincy to gain access to manhole to inspect tide gate.
- Operation Plan
- No
- Operation Comments
- Flap has been propped open to increase tidal exchange. Low-lying areas complicate additional restoration. DER has tide data for site.
- Gate Comments
- Flap gate is located within stormwater infrastructure pipe. At the time of the site visit, the manhole was not accessible. Assume that flap gate is circular and metal. Downstream end of culvert was 36" and transitioned to 12" at the upstream end. Assume tide gate has 12" diameter.
- Elevation Comments
- Staining could not be assessed at upstream or downstream end of culvert. In addition, no headwalls were present so invert elevation measurements were not obtained.
- Visit Comments
- —
- Other Comments
- A sewer manhole was located adjacent to the upstream end of the culvert in the marsh. Gravel had recently been placed around the manhole and evidence of previous scour was observed suggesting a history of overwash and stormwater inflows.
- External Data Comments
- Parkhurst Marsh Assessment 2010 (Other)
Part of the Massachusetts Bays Program© 2026 Massachusetts Bays Program. Monitoring tidegates across Massachusetts.