Cohasset-04
Cohasset, James Brook
42.237146, -70.801229
Technical Specifications
Basic Properties
- Type
- Stop Logs
- Material
- Wood
- Control
- —
- Condition
- Good
- Geometry
- Rectangular
- Status
- Active
- Number of Gates
- 2
Operator & Management
- Operator Type
- PUBLIC
- Operator
- Town of Cohasset
- Permits
- —
- Purpose
- Other
Dimensions & Elevations
- Dimensions
- 4ft diameter, 2.5ft height
- Invert Elevation
- —
- Installation Date
- —
- Tidal Influence
- —
Culvert Details
- Restriction Type
- Roadway
- Geometry
- Circular
- Material
- Corrugated Metal
- Bottom Material
- —
- Number of Pipes
- 2
- Dimensions
- 2.5ft diameter
- Condition
- Good
- Comments
- Culvert was CMP and appeared to be in good condition. Headwall was constructed of masonry block and also appeared to be in good condition. Downstream portion of culvert was overgrown and appeared to be a stormwater ditch rather than a permanent channel.
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
- No
- Restoration Status
- Not Applicable
- Invasive Comments
- Resident indicated that upstream impoundment used to be a pond; however, indicated that Town of Cohasset drains it for winter ice skating. Mowed cattails were observed throughout the upstream impoundment.
- Restoration Comments
- —
- Upstream Area
- Salt Marsh: 10-20 acres
Notes & Comments
- General Comments
- Site was located to the north of the intersection between Cushing Road and Oak Street directly to the south of a railroad berm and was easily accessible.
- Operation Plan
- No
- Operation Comments
- A resident indicated that the Town of Cohasett drains the impoundment and turns it into a skating rink in the winter. It did not appear that there was any tidal influence at the site and appeared that the impoundent receives stormwater runoff from the surrounding neighborhood and conveys it downstream over the stop logs.
- Gate Comments
- Control structure consisted of a concrete weir with wooden stop logs. The stop logs were set to a height of 2.5', but could be adjusted up to 3.8'. The weir and stop logs appeared to be in good condition.
- Elevation Comments
- Extent of tidal influence and invert elevation was not assessed. There did not appear to be any tidal influence at this site (i.e., it was too far upstream); however, the invert elevation was assessed. The below lists the measuredown taken with a surveyors rod and corresponding top of headwall LiDAR elevation (NAVD88 datum). 1) TG Inv (in this case measured to bottom of stop log): Top of HW El (D/S) = 8.12’; Inv Measuredown = 5.00’; TG Inv = 8.12’ – 5.00’ = 3.12’
- Visit Comments
- —
- Other Comments
- —
- External Data Comments
- —
Part of the Massachusetts Bays Program© 2026 Massachusetts Bays Program. Monitoring tidegates across Massachusetts.