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River Characteristics Slide 2 What is a River? National Geographic: large stream of flowing fresh water EPA: natural and man-made bodies of moving water that empty into large waterbodies such as oceans and lakes. Consists of numerous tributaries joined together to form a main channel. Oxford Dictionary: a large natural stream of water flowing in a channel to the sea, a lake, or another river Slide 3 The Neponset River Location: headwaters at the Neponset Reservoir in Foxboro, near the Foxboro Stadium, and ends in Dorchester bay near the Boston Gas tank by I-93 Length: 28 miles northeast Tributaries: 31- brooks, rivers and tributaries 77.31 miles Range from 0.002- 13.7 miles Lakes: 65- lakes, ponds or impoundments 1,922 acres total Range from 397-3 acres Slide 4 Slide 5 Slide 6 Slide 7 The Neponset River: Unknowns Area Know length of river and all tributaries Do not know widths so do not know total surface area Depth This will be variable over time and space Need surveys of depth Needed to find total area Volume Without area volume is unknown Slide 8 Neponset River: Flow Speed Norwood Lat 42 1039", long 71 1205", Norfolk County, Hydrologic Unit 01090001, on left bank 200 ft upstream from Pleasant Street Bridge, 200 ft downstream from railroad bridge, 0.45 mi downstream from Hawes Brook, and 0.5 mi south of Norwood Drainage area 37.4mi 2 Slide 9 Slide 10 Slide 11 Neponset River: Flow Speed Milton Lat 42 o 1615", long 71 o 0408", Norfolk County, Hydrologic Unit 01090001, on right bank, 75 ft downstream from Baker Dam and 100 ft upstream from Adams Street at Milton Village. From March 14, 2007 to December 10, 2009, at site 20 ft upstream from Baker Dam Drainage area 101mi 2 Slide 12 Slide 13 Slide 14 What we do know about volume is total yearly flow Slide 15 Why is flow variable? See variability in year to year See variability is month to month Variability is driven by Inputs Rain May vary with future changes in climate Withdrawals Human consumption Leakage into pipes Slide 16 Multivariate Model Slide 17 Slide 18 Slide 19 Slide 20 Slide 21 Slide 22 Slide 23 Slide 24 Where is the water going? Over 160,000 people draw from this water table All towns in watershed expect Boston, Quincy and Milton 16 million gallons a day in permitted withdrawals This is 20% of rivers annual discharge This water is not returned to the watershed Lost by export or evaporation 18 million gallons a day lost in leakage Slide 25 Other Impediments to flow: Dams Number of dams? Variable answers NepRWA: over 100 Recent project Data and methods not yet publically available Ian Cookes Map: 71 My analysis: 35-49 Slide 26 Slide 27 MassGIS Data Many tributaries unnamed Many repeated names Many river systems blank Slide 28 Trends in Dams (my analysis) Only 10 of 34 on Neponset 3 in Foxboro 2 Milton 5 in Walpole The rest affect tributary flow 1 Boston 5 Canton 4 Dedham 2 Milton 4 Norwood 1 Quincy 4 Sharon 3 Walpole Often have several dams on one body of water Many water bodies have no dams Generally owned by the municipality 5 are privately owned 4 on the Neponset 1 on tributaries Slide 29 Other Issues: PCBs PCBs Polychlorinated biphenyls Toxic and highly stable Historically the Neponset has been highly industrialized Also drains large urban areas Dams block normal passage/ drainage of sediments Sediments potentially contaminated Slide 30 Slide 31 Slide 32 Other Issues: Water Quality Generally use Fecal Coliform Bacteria as indicator of water quality During dry weather 88% of samples support primary contact recreation- swimming During wet weather 46% of samples support primary contact recreation- swimming This data from 2000-2001 is an improvement over 1998 Problem areas: Meadow Brook Unquity Brook Hawes Brook lower Neponset Slide 33 Slide 34 Dominant Flora Affected Purple Loosestrife Reed Canary Grass Atlantic White Cedar White Ash Red Maple Leatherleaf Fetterbush Sweet Pepper Bush Common Winterberry Swamp Rose Slide 35 Dominant Fauna Affected Fish Present: Alewife Blueback American shad Smelt White perch Anadromous fish River herring Rainbow smelt American shad Live in saltwater- spawn in freshwater Dams obstruct this migration Slide 36 Sources Maps from Ian Cook Tributaries and Lakes Information: http://www.mass.gov/dep/water/resources/70wqar3b.pdf Rainfall data: http://www.nrcc.cornell.edu/ Flow Rate Data: http://waterdata.usgs.gov/usa/nwis/uv?01105000 http://waterdata.usgs.gov/usa/nwis/uv?011055566 Multivariate Model and Supporting Information: http://engineering.tufts.edu/cee/people/vogel/publications/multivariateNonStationary.pdf Dams Data: http://maps.massgis.state.ma.us/map_ol/dams.php http://www.mass.gov/dcr/pe/damSafety/downloads/List%20of%20Dams%20with%20ID%20Number.p df http://www.mass.gov/dcr/pe/damSafety/downloads/List%20of%20Dams%20with%20ID%20Number.p df PCB Info: http://pubs.usgs.gov/fs/2004/3083/ Bacterial Data: http://www.neponset.org/Reports/CWMN%20Final%20Report%20V%20test%203.pdf Plant Info: http://www.fws.gov/wetlands/Documents/Wetland-Status-and-Recent-Trends-for-the-Neponset- Watershed-Massachusetts-1977-1991.pdf http://www.fws.gov/wetlands/Documents/Wetland-Status-and-Recent-Trends-for-the-Neponset- Watershed-Massachusetts-1977-1991.pdf Animal Info: http://www.mass.gov/dfwele/dmf/publications/tr18_anad_p4_boston.pdf