Hull-04
Hull, Hull Bay
42.303229, -70.915078
Technical Specifications
Basic Properties
- Type
- Flap Gate
- Material
- Metal
- Control
- —
- Condition
- Unknown
- Geometry
- Circular
- Status
- Active
- Number of Gates
- 1
Operator & Management
- Operator Type
- PUBLIC
- Operator
- Town of Hull
- Permits
- OOC, ACOE
- Purpose
- Flood Protection
Dimensions & Elevations
- Dimensions
- 2.25ft diameter
- Invert Elevation
- —
- Installation Date
- —
- Tidal Influence
- —
Culvert Details
- Restriction Type
- Beach
- Geometry
- Circular
- Material
- Concrete
- Bottom Material
- —
- Number of Pipes
- 1
- Dimensions
- 2.25ft diameter
- Condition
- Fair
- Comments
- Outfall to culvert was located below high water mark approximately 150' downstream of the tide gate. A metal (rebar) trash grate was installed at the outlet. The culvert was in fair condition - the culvert bell/segments were beginning to decouple and gaps were observed in the joints. It appeared that the cause of the decoupling was lowering of the beach profile (i.e. longshore sediment transport).
Salt Marsh Field Assessment Results
Comprehensive field assessment dataPhysical Conditions Assessment
Channel Conditions
- Channel Alteration and Ditching
- Severe (>398 ft/acre)
- Channel Constriction
- Narrower than channel
- Channel Erosion
- Severe (>60% of bank)
- Sediment Deposits
- Moderate (10-60% of channel wid
Blockages
- Debris Blockages
- Limited (<10% of opening)
- Evidence of Overtopping
- No
Ecological Assessment
Habitat Observations
- Ecological Impairment due to Tide Gate
- Moderate
- Crab Burrow Intensity
- None
- Ponding and Die-off Depressions
- Limited(<10% of marsh platform
- Phragmites Present
- Moderate (10-60%)
Invasive Species
- Upstream Invasive Species
- Yes
- Downstream Invasive Species
- No
- Invasive Species Notes
- Phragmites most prevalent along front but encroaching downstream into marsh.
General Comments
Lack of low marsh community and spread of phragmites indicates moderate tidal restriction. Tide gate inaccessible inside concrete manhole overflow structure but supposed to be left partially open per the OOC. Increasing tidal exchange may be difficult due to proximity of houses at similar elevation to marsh.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)
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
- Unknown
- Invasive Comments
- The upstream impoundment conisted of a core of high marsh (e.g., s. patens) surrounded by extensive phragmites.
- Restoration Comments
- Small low lying area, lots of Phragmites, potential self-regulating tidegate site, need to be careful of adjacent housing.
- Upstream Area
- Salt Marsh: 3-5 acres
Notes & Comments
- General Comments
- Tide gate is located in a locked subsurface vault adjacent to the intersection between Ocean Avenue and Main Street. At the time of the site visit, the tide gate could not be accessed. Additionally, upstream culvert was not located due to a dense phragmites stand. Next steps: Contact Hull DPW to obtain access to tide gate for further investigation and locate upstream culvert during vegetation die off.
- Operation Plan
- No
- Operation Comments
- Gate is maintained in a partially open position as required by OOC.
- Gate Comments
- Wedged flapper in manhole. Installed as part of MassDOT roadway project. Tide gate was inaccessible, diameter and shape assumed based on observed downstream culvert outfall.
- Elevation Comments
- Staining could not be assessed at upstream or downstream end. In addition, no headwalls were present so invert elevation measurements were not obtained.
- Visit Comments
- —
- Other Comments
- —
- External Data Comments
- —
Part of the Massachusetts Bays Program© 2026 Massachusetts Bays Program. Monitoring tidegates across Massachusetts.