Cohasset-02
Cohasset, Richardson Brook
42.257400, -70.812782
Technical Specifications
Basic Properties
- Type
- Flap Gate
- Material
- Metal
- Control
- —
- Condition
- Unknown
- Geometry
- Circular
- Status
- Removed
- Number of Gates
- 1
Operator & Management
- Operator Type
- UNKNOWN
- Operator
- —
- Permits
- —
- Purpose
- Flood Protection
Dimensions & Elevations
- Dimensions
- 2ft diameter
- Invert Elevation
- —
- Installation Date
- —
- Tidal Influence
- —
Culvert Details
- Restriction Type
- Roadway
- Geometry
- Circular
- Material
- Corrugated Metal
- Bottom Material
- —
- Number of Pipes
- 1
- Dimensions
- 2ft diameter
- Condition
- Fair
- Comments
- Deformation of the corrugated metal culvert was observed on its downstream end indicating that it was potentially beginning to collapse. Significant spalling and cracking was also observed on the downstream concrete headwall.
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 was dominated by high marsh and was fringed with Phragmites.
- Restoration Comments
- Unknown if any restoration efforts had been performed at the site. Future restoration considering upsizing the culvert would need to investigate low lying areas including adjacent farm land directly to the south of the impoundment.
- Upstream Area
- Salt Marsh: < 5 acres
Notes & Comments
- General Comments
- Site was located directly off of the east side of Jerusalem Road and easily accessible.
- Operation Plan
- No
- Operation Comments
- —
- Gate Comments
- It appears that the previous tide gate fell off or was removed from the hinge located on the stone headwall. The metal hinge was corroding and did not appear to be robust.
- Elevation Comments
- Extent of tidal influence and invert elevations were not evaluated as there was no tide gate at this site.
- Visit Comments
- —
- Other Comments
- Area on the upstream side of the flapper was used for grazing years ago. The upstream channel was full of killifish
- External Data Comments
- —
Part of the Massachusetts Bays Program© 2026 Massachusetts Bays Program. Monitoring tidegates across Massachusetts.