Alewife Reservation Stormwater Wetland

Sustainable water infrastructure planning in Cambridge, Massachusetts

MCWRS Symposium May 17, 2017 Overview

1. City of Cambridge role in Boston Harbor Clean Up Program 2. Planning Goals 3. Small Scale Facilities to Large Scale System 4. Alewife Wetland Cambridge Role in Boston Harbor Clean Up

CAM004 Area

1980s Federal mandate to clean up Boston Harbor + Court order to clean up Alewife Brook by 2015 = 25 years of adaptive planning, engineering & implementation Planning Goals EPA:

Reduce CSOs by 85% (43.6 Alewife Reservation million gallons) annually to Stormwater Alewife Brook Wetland City: • Flood relief • Reduce sewer backups • Protect primary drinking water supply reservoir (Fresh Pond) • Low maintenance • Community friendly Stakeholder Interests: ✓ Improve Stormwater Quality ✓ Hydrologic Restoration ✓ Habitat Enhancement ✓ Recreation & Transportation ✓ Education & Culture ✓ Public Engagement Small Scale Facilities to Large Scale System

Integrated city planning with DCR in order to:

• Provide location for stormwater storage and treatment • Habitat restoration • Park recreation • Pedestrian/bike path to connect Alewife T station to community • Ampitheater for public education and engagement

Sewer Separation & Private Inflow Removal Private Inflow Removal Flush Vaults 72-in drain with sediment

• Active mechanical controls • “Self cleaning” sewers and storm drains • Preserves system capacity Upstream Green Infrastructure Bending Weir Structure

Alewife wetland • WQ benefit of first flush • Passive control Legacy outfall to • O&M friendly Alewife Brook

New Bending Flow to Weir Wetland Junction Structure Hydraulic Devices at Wetland

• Passive controls • O&M friendly Water Quality Swale Forebay: Sediment Capture Main Basin: Natural Treatment Pathway Transportation and Information System Synergies Landscape and Energy System Synergies December 21, 2015

On December 21st the Mayor of Cambridge, David P. Maher, and the City Manager, Richard C. Rossi, joined city staff, MWRA staff, contractors (Barletta, Inc. and P. Gioioso & Sons, Inc.), and the design and construction management consultants (MWH, Kleinfelder, and Chester Engineers), as the final piece of the weir wall was removed in the underground structure in the Fresh Pond Rotary; allowing stormwater to flow to the Alewife Wetland.