Erosion and sedimentation control Wildlife impacts Wildlife - PowerPoint PPT Presentation

 Erosion and sedimentation control  Wildlife impacts  Wildlife impacts  Multi ‐ Use Path detour and signage g g

MWRA’s LTCP for CSO Control  Sewer separation of CAM004 To be completed by December 2015. b l d b b 20  Closure of the CAM004 regulator  Reduces volume and frequency of CSOs to the Alewife Brook ▪ 50mg annually  7 3mg ▪ 50mg annually  7.3mg ▪ 63 activations per year  7

BMP Devices (temporary) BMP Devices (temporary) Sediment control basins Flood protection berm Cover crop seed mix and/or matting Compost filter socks/silt fences Turbidity curtain Alewife Reservation

Stormwater Stormwater wetlands provide water quality t treatment through t t th h the interaction of the water, soil and , plants.

 Sedimentation  Adsorption to Sediments  Physical filtration Volatilization NH 3 N 2 CO 2 , CH 4 Volatile organics Plant storage  Microbial breakdown  Plant Uptake  Plant Uptake Decomposition Denitrification Organic C NO 3 ‐ Inflow Sedimentation  Extra Detention and/or xtra etention and/or Plant uptake Burial Retention Adsorption ‐ NH 4 + , metals, P, organics (to clays, Fe / Al hydroxides, Soil storage organic matter) Precipitation (peat) ‐ P (with Fe, Al, Ca) ‐ Metals (with sulfides) Metals (with sulfides) Source: K.R. Reddy

Habitat Creation Deep, emergent and high marsh  Wet meadow, broadleaf floodplain and open water   Scrub/shrub and riparian woodland O Over 115,000 new wetland plants 115 000 tl d l t  Over 3,800 new upland plants 

DCR Reservation Features  Multi ‐ use connector path (Mass DOT)  Trails and boardwalks (1,600 linear feet)  Overlooks (3)  Amphitheatre p  Benches and bike racks  DCR Kiosk and interpretive signage

Forebay = 0.27 acres b (50ft x 170ft)

Stormwater Wetland Stormwater Wetland Footprint = 3.4 acres Primary Wetland = 2.8 ac. y Peninsula = 0.2 acres Habitat Diversity Habitat Diversity High Marsh Low Marsh Low Marsh Open Water Upland Island p

 Erosion and sedimentation control  Wildlife impacts  Wildlife impacts  Multi ‐ Use Path detour and signage g g

Wildlife Impact/Risk Assessment Conclusions: Wildlife Impact/Risk Assessment Conclusions: October start maximizes use of food resource  Minimal breeding season/migratory bird risks  Avoid Little River disturbance during Alewife run A id Littl Ri di t b d i Al if  Licensed Wildlife Trappers were consulted: pp American Woodcock  Predicted resident wildlife will leave work area when clearing and grubbing commence   Relocate wildlife outside of Relocate wildlife outside of the work area

Preconstruction Wildlife Reconnaissance Preconstruction Wildlife Reconnaissance  Search work area for burrows, dens, nest sites  Provide “gaps” in construction fencing  Site monitoring to detect any fauna at risk Preconstruction Rare Plant Reconnaissance  Botanist searched entire impact area

 Wetland Construction W tl d C t ti  Pre Wetland Activities P W l d A i i i  Utilities relocation  Grubbing  Species identification  Species identification  Earthwork: soil excavation E h k il i and berms  Erosion control and impact mitigation  Cover crop planting Cover crop planting  Clearing – began October 1  Boardwalk and amphitheater construction  Wetland soils, plantings and seeding  Final path paving Fi l th i

 Fall/Winter 2011 ‐ 2012 Spring 2012 Fall 2012/Spring 2013

Alewife Reservation

 Observe plant growth  Observe plant growth  Replace vegetation as needed  Identify invasive species for removal d if i i i f l E Exclusion Fencing l i F i

Alewife Reservation Project Benefits j Fully integrated with DCR Alewife Reservation and Greenway Master Plan:  Water Quality Improvements: 3.4 acre treatment wetland, and future closure of the CAM004 regulator future closure of the CAM004 regulator  Ecological enhancements of fish and wildlife habitat quality  Mitigation of invasive plant species g p p  Improved site amenities  Educational and recreational opportunities

Cambridge in 1777