November 14, 2012 Presented By Jill Winton

BACKGROUND

JONES RIVER BASIN

PROJECT GOALS Document existing flow conditions and water supply management Conduct new analyses to forecast the feasibility of providing fish passage at Forge Pond Dam under different scenarios of flow management and structural modifications

FORGE POND

SILVER LAKE NATURAL OUTLET

FORGE POND DAM Spillway Walkway atop 3 stoplog bays Access road atop 3 culvert openings Forge Pond

FORGE POND DAM

LAKE STREET CULVERT & ACCESS ROAD

FISHERY RESOURCES

TARGET SPECIES – River Herring Blueback herring Alosa aestivalis Alewife Alosa pseudoharengus

OTHER SPECIES American eel Anguilla rostrata Under review as a threatened species under ESA Tidewater mucket Leptodea ochracea Eastern pondmussel Lagumia nasuta FRESHWATER MUSSELS Species of Special Concern in MA

HABITAT REQUIREMENTS Preliminary Summary of River Herring Habitat Assessment at Silver Lake ( )

PASSAGE REQUIREMENTS –Depth Targets for herring: ADULTS 8-12 inches MIN 6 inches JUVENILES 4-8 inches MIN 2 inches

PASSAGE REQUIREMENTS –Velocity Passage Success Rates for Alewife under Varying Velocities and Distances

PASSAGE REQUIREMENTS –Flow Timing Timing of Important Life Cycle Events for Target Species

WATER SUPPLY OPERATIONS

SILVER LAKE WATER SUPPLY SYSTEM Summary of Brockton Water Supply Sources *Increases annually up to 4.07 mgd. Not included in totals. **110 of systemwide safe yield via a 1995 DEP ACO.

SILVER LAKE LEVEL – Average Jan1-Feb1-Mar1-Apr1-May1-Jun1-Jul1-Aug1-Sep1-Oct1-Nov1-Dec Silver Lake Elev. (ft, NGVD 29) Forge Pond Dam Spillway Elev. (47.6 ft, NGVD 29) Silver Lake Berm Elev. (45.9 ft, NGVD 29) When SilverLake elevation drops below the natural outlet, it has been observed that water flows from Forge Pond into Silver Lake resulting from groundwater flow into Forge Pond. When theForge Pond water level exceeds the spillway crest, water is passed to Jones River. Spawning adults immigrating Juveniles rearing Juveniles emigrating Period of Record:

SILVER LAKE LEVEL – 2011 with Diversions

SILVER LAKE LEVEL – Duration Curves Spring Immigration Fall Emigration

AQUARIA PLANT – Cost Analysis Overall Cost of Aquaria Water per Amount Purchased by Brockton (2012 example) Fixed Rate = $167,480 per 0.1 mgd (total annual cost of $5,861,800 for 2012 for 3.5 MGD) Variable Rate = $1.23 per 1,000 gallons used Excess Rate = $0.60 per 1,000 gallons used

FISH PASSAGE ALATERNATIVES

FISH LADDER – Alaska Steeppass

FISH LADDER – Plan View

FISH LADDER – Detail View

NATURE-LIKE BYPASS CHANNEL

Elevation Profile of Potential Bypass Channel

DAM REMOVAL CONSIDERATIONS Water Supply Sediment Infrastructure Wetlands Historical Resources etc. Former Wapping Road Dam

DAM REMOVAL – Modeling Approach

NEXT STEPS Required flows for each alternative Feasibility of flow availability Budgetary cost estimates Selection of preferred alternative Conceptual designs LATER PHASES Detailed designs Permitting Implementation Monitoring

QUESTIONS?