144 Addison Street ecological study
Goal: To evaluate the correlation between modern DEVELOPMENT and natural flood risk of the surrounding waterfront
The average vertical elevation within the site boundaries is 5-6ft
the highest elevation in the vicinity is a 52Ft Hill to the south west of the site
Most of the boundaries of the parking lot are at an elevation of approximately 12FT
Prior to urban development, the setting was composed of mainly salt marshes and tidal mudflats, both which function as important habitat for inter-tidal species.
Today, these low-lying areas are vulnerable as sea level rises, especially because much of East Boston is built on filled land. The historic channel that was previously located to the northeast of the site is of particular concern for modern-day flood risk, as it is predisposed to water intrusion.
The area is flanked on either side by water, increasing flood risk to this low-lying area. To the west is Chelsea Creek and to the east is Constitution Beach located near the Belle Isle Marsh inlet. The site did not flood during the Spring 2018 Nor’easters, though neighboring areas did.
Ecological Considerations
Coastal Squeeze
Coastal plants are specially adapted to tide zones and sensitive to changes in sea level. As the seas have risen and fallen over millennia, marshes have adapted accordingly by changing position on the shore.
As development continues along coastal areas, densifying populations and increasing flood risk generally mandate infrastructural protection measures such as seawalls and bulkhead. These hard structures represent a hard physical limit for marsh areas on the landward edge and prevent marsh migration. Coastal marshes are experiencing pressure from both the water and the land, and the integrity and longevity of marsh areas is threatened.
This parcel of land is located between Chelsea Creek and Constitution Beach, where there are existing marshes. Designs for this project might consider how environmental conditions will change over time, and specifically envision ways to allow landward migration of marsh areas as sea level rises.
Salt-Tolerant Species
The following species are native to New England salt marshes and could be considered in terms of marsh migration relative to current and future tide zones:
MTL = mean tide level MHW = mean high water ULW = upper limit of wetlands
RECOMMENDATIONS TO SUPPORT LOCAL ECOLOGY OVER TIME
Floodable Landscapes adapted for normal operation during flood conditions.
Ecological Corridors to accommodate marsh migration within landscape over time.
Additional Insights
Team: Ashley Cryan, Ph.D Candidate, Northeastern University Helmuth Lab for Marine Ecological Forecasting, Ecophysiology, and Physical Biology
Location: East Boston, MA
Definitions
Ecological Study: an analysis of risk-modifying factors on health or other outcomes based on populations defined either geographically or temporally
Ecological Corridor: a functional zone of passage between several natural zones for a group of species dependent on a single environment