MUDDY RIVER FLOOD RISK MANAGEMENT PHASE II Jennifer Flanagan - - PowerPoint PPT Presentation

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MUDDY RIVER FLOOD RISK MANAGEMENT PHASE II Jennifer Flanagan - - PowerPoint PPT Presentation

Dec 27, 2023 109 likes •317 views

MUDDY RIVER FLOOD RISK MANAGEMENT PHASE II Jennifer Flanagan Project Manager New England District/PPMD Date: 30 June 2020 2 MUDDY RIVER THE HEART OF OLMSTED PARK 1894 The park was designed by Fredrick Law Olmsted & completed

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MUDDY RIVER FLOOD RISK MANAGEMENT – PHASE II

Jennifer Flanagan Project Manager New England District/PPMD Date: 30 June 2020

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MUDDY RIVER THE HEART OF OLMSTED PARK

  • The park was designed by Fredrick Law Olmsted &

completed in the 1890’s

  • Olmsted designed some of America’s greatest city parks
  • “The Necklace” is the oldest remaining linear park in the

United States

1894

Images from http://www.muddyrivermmoc.org/restoring-olmsteds-vision/

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MUDDY RIVER – 1996 FLOODING

Boston received 10.8 inches of rain A month’s worth in one day

  • Extensive damage to MBTA in

Kenmore Square

  • Over $60M in damages to MBTA
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MUDDY RIVER – ADDITIONAL FLOODING EVENTS

  • June 1998, March 2001, March 2010 (6” over 2 days with water levels 2.5 feet

higher than normal)

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MUDDY RIVER – COMPREHENSIVE PLAN

  • A comprehensive plan was developed to

address

  • Flooding
  • Accumulated sediment
  • Reduced aquatic habitat quality (high

SOD, low DO)

  • Contaminated sediments (metals,

PCBs, PAHs)

  • Invasive species (Phragmites)

impacting biodiversity & reduction of

  • pen water
  • Corps completed Decision Document

and Environmental Assessment

  • Muddy River Flood Control and

Ecosystem Restoration, September 2003

Sedimentation Flooding

  • Undersized culverts
  • Restrictions
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MUDDY RIVER – COMPREHENSIVE PLAN

  • Decision Document approved

– Director’s Report December 2003

  • Review by ASA office – costs
  • f ecosystem restoration

features are prohibitive on a per acre basis.

  • OMB concurs with ASA

recommendation NOT to fund ecosystem restoration components.

Recommended Plan

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MUDDY RIVER – FLOOD RISK MANAGEMENT PLAN

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2001 2019

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  • Looking upstream from new UFP culvert
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MUDDY RIVER – PHASE 2

Work Areas 1 – 12

EXCAVATION

  • Excavate the sandbar and island at

Leverett Pond

  • Excavate five stretches of areas of

constriction in the Riverway section of the river

  • Excavate the river in the Back Bay

Fens area to create a continuous channel

  • Excavate deepened channel sections

to delay need for maintenance dredging

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MUDDY RIVER – PHASE 2

Work Areas 13

  • Provide additional flood proofing at the Boston Fire Department

Building in the Back Bay Fens.

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PHASE 2 WHAT TO EXPECT – DURING CONSTUCTION

In the Wet Construction

https://www.youtube.com/watch?v=nXN__c_dwVI

Barge Mounted Excavator Long Reach Excavator

In the Dry Construction

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PHASE 2 WHAT TO EXPECT – DURING CONSTUCTION

Stockpile, Direct Loading & Transport

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PHASE 2 WHAT TO EXPECT – DURING CONSTUCTION

Tree Protection – Critical Element of Work

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PHASE 2 WHAT TO EXPECT – DURING CONSTUCTION

Some Tree Removal

Work Area 2 – the river on both banks have lots of vegetation and trees. These various trees need to be removed for access as well as the new channel slope will cut into the existing tree root system. Work Area 7 – both trees are within area of phragmites to be excavated 18” deep. Concern for the tree root system and trees are not healthy.

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MUDDY RIVER – PHASE 2 – RESTORATION EFFORTS

  • Remove Phragmites in the Back Bay Fens and Riverway areas where necessary to create flood risk management channel

and provide ancillary benefits of ecological habitat improvements.

  • Restore wetland vegetation in dredged areas by seeding or planting appropriate wet meadow and emergent wetland plants.
  • Restore riparian vegetation in upland areas where Phragmites or oriental knotweed are removed by planting grass, trees,

and shrubs.

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MUDDY RIVER – PHASE 2 – RESTORATION EFFORTS

  • Work Area #6:
  • Wetland shelves
  • Wet meadow
  • Trees
  • Shrubs
  • Restored lawn
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PHASE 2 WHAT TO EXPECT – AFTER COMPLETION

Primary Project Goal

  • Improved water

conveyance

  • Charles River will still strongly

influence the Muddy River water level

  • Water will move through the

system faster

  • Designed for 20-year’ storm
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PHASE 2 WHAT TO EXPECT – AFTER COMPLETION

Ancillary Project Benefit - Restored River Bank

  • Stabilized river bank

reducing erosion and improving water clarity

  • Removal of poor quality

sediment

  • Increased aquatic habitat

quantity and quality

  • Increased plant diversity
  • Partial restoration of

Olmsted’s vision

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Contact

Wendy Gendron, Civil Works Program Manager wendy.c.gendron@usace.army.mil Jennifer Flanagan, Project Manager jennifer.w.flanagan@usace.army.mil