Diamond Creek
Catchment Improvements Investigation and Assessment Project
Project Overview
In 2022, Revere received funding through the Massachusetts Vulnerability Preparedness program to address climate vulnerabilities in the City.
According to the 2019 City of Revere MVP Summary of Findings Report, coastal flooding, inland flooding, and high temperatures have been identified as three of the top four overall priority hazards for the City.
Project Goals
The goal of the Diamond Creek Catchment Improvements Investigation and Assessment Project is to reduce inland and coastal flooding and urban heat island effects in the Diamond Creek catchment area.
The project includes strategies to reduce stormwater discharge from the catchment area into important natural resources – the Rumney Marsh and Oak Island Salt Marsh.
Field Investigations
Wet weather field investigations were conducted at areas reported to experience localized flooding.
Potential locations to intercept and infiltrate stormwater through nature-based solutions were identified.
Nature-Based Solutions
Nature-based solutions such as tree plantings and green infrastructure were explored to mitigate flooding in the Diamond Creek catchment area.
Green Infrastructure
Opportunities to install the following types of green infrastructure were identified:
- Bioretention basins
- Sub-surface infiltration chambers
- Porous pavement
- Stormwater planter
- Tree box filter
Proposed Solutions
Through this project, over 30 locations for potential tree plantings and 28 opportunities to install green infrastructure (GI) were identified in the Diamond Creek Catchment Area. Zoom into the map to look at locations more closely.
Tide Gate
The project also included an assessment of the existing Martin Street Outfall Tide Gate which is currently broken. The assessment included hydraulic analysis of the implications of the broken tide gate, as well as the benefits of repairing or replacing it.
Flood Model
Flooding was quantified using a hydrologic and hydraulic model under present (baseline) and future climate scenarios. The flood reduction benefits resulting from the installation of the proposed green infrastructure and tide gate repairs were estimated using this model.
Impact of Tide Gate Repairs
Present Day 24-hour 10-year storm
The map on the left shows the current extents of flooding with the broken tide gate within the Diamond Creek catchment area for the present day (baseline) 24-hour 10-year rainfall event. The map on the right, shows the flood reductions expected from the repaired tide gate, during the same rainfall scenario. Use the slider to view the difference between the two maps.
Present Day 24-hour 100-year storm
The map on the left shows the current extents of flooding with the broken tide gate within the Diamond Creek catchment area for the present day (baseline) 24-hour 100-year rainfall event. The map on the right, shows the flood reductions expected from the repaired tide gate, during the same rainfall scenario. Use the slider to view the difference between the two maps.
Future (2070) 24-hour 10-year storm
The map on the left shows the extents of flooding with the broken tide gate within the Diamond Creek catchment area for the future (2070) 24-hour 10-year rainfall event. The map on the right, shows the flood reductions expected from the repaired tide gate, during the same rainfall scenario. Use the slider to view the difference between the two maps.
Summary of Findings
The flood model results demonstrate that the Diamond Creek catchment area is vulnerable to climate change in the following ways:
- Sea level rise under future climate conditions will exacerbate overland flooding in the catchment area if the tide gate remains broken.
- Extreme precipitation is already a source of inland flooding, and flooding impacts will continue to worsen under future climate scenarios.
- Increases in future flooding are caused primarily by increased rainfall rather than sea level rise.
The flood model results also indicate the following flood reduction benefits are possible if mitigation solutions are implemented across the catchment area:
- If tide gate is repaired, the catchment area is projected to see a reduction in flooding by up to 19% in the near future and up to 11% by 2070 under various design storm events.
- If green infrastructure is installed in areas with flooding, significant localized benefits are projected under present and future climate scenarios.
