Manchester-by-the-Sea

Transcription

1 Manchester-by-the-Sea A Community Plans for Coastal Resilience Finding Solutions to our Coastal Challenges Salem Sound Coastwatch 25 th Anniversary Symposium March 18, 2016 Janet Moonan, P.E., Project Engineer

2 Sawmill Brook Watershed Concerns

3 Sawmill Brook Watershed Concerns Inland Flooding Poor Soils Impervious Surface Channelized Drainage Coastal Flooding High Tide Wave Action Storm Surge Water Quality Issues Bacteria Low ph Sedimentation

4 Sawmill Brook Watershed Concerns Inland Flooding Poor Soils Impervious Surface Channelized Drainage Coastal Flooding High Tide Wave Action Storm Surge Water Quality Issues Bacteria Low ph Sedimentation

5 Fire Station Town Hall & Police WWTP

6 Climate Change Adaptation- Town Hall & Police Fire Station Opportunities for Wastewater WWTP

7 Coordinated Grants Massachusetts Office of Coastal Zone Management Desktop Watershed Assessment Field Survey Identification of Locations for Flood Mitigation Conceptual Designs for Flood Mitigation Modeling with Climate Change Public involvement & participation Identification of Community Assets Enhance Hazard Mitigation Plan

8 Coordinated Grants Massachusetts Office of Coastal Zone Management Desktop Watershed Assessment Field Survey Identification of Locations for Flood Mitigation Conceptual Designs for Flood Mitigation Modeling with Climate Change Public involvement & participation Identification of Community Assets Enhance Hazard Mitigation Plan

9 Desktop Assessment Where does it flood? Where are critical community assets located? What opportunities exist to reduce flooding?

10 Field Survey Assessment of: 23 culverts 15 sites for Green Infrastructure/ Flood Mitigation Central Street Tide Gate / Culvert

11 Field Survey Assessment of: 23 culverts 15 sites for Green Infrastructure/ Flood Mitigation Central Street Tide Gate / Culvert

12 Existing and Future Conditions Model Model existing conditions Evaluate future potential flooding Impacts due to climate change Identify mitigation value of Green infrastructure and flood storage Assess adequacy of culvert sizes Identify impact on Community Assets

13 Existing Conditions Model Inputs Land Use Subwatersheds Waterbody Characteristics Soils Present Precipitation Topography Existing Conditions Model (2015) Tidal Influence

14 Future Conditions Model Inputs Future Precipitation Sea Level Rise Watershed Conditions Future Conditions Model Storm Surge

15 Future Conditions Model Sea Level Rise & Storm Surge Coastal influence from Inundation Risk Model (IRM) developed by Keil Schmidt of Geoscience Consultants Sea Level Rise Shallow Coastal Flooding Storm Surge Hurricane

16 Future Conditions Model Sea Level Rise & Storm Surge Coastal influence from Inundation Risk Model (IRM) developed by Keil Schmidt of Geoscience Consultants Sea Level Rise Shallow Coastal Flooding Storm Surge Hurricane

17 Future Conditions Model Outputs Future Conditions Model Sea Level Rise Storm Surge Sea Level Rise Storm Surge Sea Level Rise Storm Surge Balanced Energy Use Precipitation Balanced Energy Use Precipitation Balanced Energy Use Precipitation Balanced Energy Use Precipitation Balanced Energy Use Precipitation Balanced Energy Use Precipitation Fossil Intensive Energy Use Precipitation Fossil Intensive Energy Use Precipitation Fossil Intensive Energy Use Precipitation Fossil Intensive Energy Use Precipitation Fossil Intensive Energy Use Precipitation Fossil Intensive Energy Use Precipitation

18 Example Model Results 2025

19 Example Model Results 2100

20 Community Asset Locations

21 Sea level rise affects 23% of community assets in the near term (2025), Affects almost 37% of the community assets by 2100

22 Storm Surge affects 33% of community assets in the near term (2025), Affects over 50% of the community assets by 2100

23 Flood Storage Overview of Potential Flood Reduction Improvements Assessed Flood Storage Green Infrastructure Green Infrastructure Flood Storage in Flood Storage Golf Course Flood Storage Green Infrastructure Central Street Tide Gate/Culvert/Dam Green Infrastructure

24 Flood Storage upstream Old School Street (Culvert 2) Nine Planning Level Designs Green Infrastructure Coach Field Playground Parking Flood Storage in Golf Course Central Street Tide Gate/Culvert/Dam (2 options) Storm Surge Barrier in Harbor

25 Three Conceptual Designs Norwood Avenue Culvert School Street Culvert Central Street Tide Gate/Culvert/Dam Central Pond and Sawmill Brook Restoration

26 Tide Gate & Culvert Improvements

27 Central Street Tide Gate and Culvert Improvements Remove tide gate Replace culvert Restore seawall Restore Central Pond

28 Restore Sawmill Brook

29 Central Street Tide Gate and Culvert Improvements Option 2 Replace

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31 Culvert Improvements

32 Culvert Improvement at School Street

33 Porous Asphalt Parking Area at Coach Field Playground

34 Funding Permitting Discussions with regulators

35 Questions? Janet Moonan, P.E., Project Engineer Phone: Gabrielle Belfit, Senior Environmental Scientist, Project Manager Phone: Mary Reilly, Grants Administrator Phone: