The Taunton River's Last Major Tributary: Chemical Analysis of a Freshwater Dam System in the Upper Assonet River

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2005 The aT unton River's Last Major Tributary: Chemical Analysis of a Freshwater Dam System in the Upper Assonet River

Recommended Citation Bridgewater-Raynham Regional High School, Bridgewater, Massachusetts (2005). The Taunton River's Last Major Tributary: Chemical Analysis of a Freshwater Dam System in the Upper Assonet River. In Watershed Access Lab Projects. Project 38. Available at: http://vc.bridgew.edu/wal_projects/38

This item is available as part of Virtual Commons, the open-access institutional repository of Bridgewater State University, Bridgewater, Massachusetts.

The Bridgewater-Raynham Watershed Team (BRWT) Presents:

The Taunton River's Last Major Tributary

Chemical Analysis of Water in a Freshwater Dam System in the Upper Assonet River

Fall 2005 Purpose of the Study

• To study how a dam system in the upper Assonet River effects the chemical and nutrient levels downstream. • To prepare the Science Olympiad Team for the Freshwater Ecology section of their December 22nd meet at Bridgewater Raynham regional High School. • Figures will help students complete the eagle scout communication merit badge. • To increase stewardship and knowledge of the Taunton River Watershed (TRW) across Southeastern Massachusetts. The Taunton Watershed Basin (southern portion pictured) • Basin for 38 towns. • 221 lakes and ponds • 173 canoeable river miles • Home to the 16,800 acre Hocomock Swamp • 29 species of fish (brook trout included) • 114 species of birds • Source: http://www.trwaonline.org/ Location of Study

Weather and Site Conditions

• Cloudy with some precipitation. • Cool Air Temperature (45oF) • Deciduous Trees dominate the landscape • Dark Water (leaves release dark acids) • Relatively Shallow Pond

Sample Locations

* * Pond and Dam System Spillway Hydrolab Data

• Probes for hourly readings. • Graphical Analysis of Temperature,pH, Dissolved Oxygen (DO), and Specific Conductivity. Temperature vs. Time

10.6

10.4

10.2

Temperature(oC) 9.8 Forge Pond (Upstream) Mill Pond 9.6 (Downstream)

9.4

0:00:00 1:00:00 2:00:00 3:00:00 4:00:00 5:00:00 6:00:00 7:00:00 8:00:00 9:00:00

17:00:00 18:00:00 19:00:00 20:00:00 21:00:00 22:00:00 23:00:00 10:00:00 11:00:00 12:00:00 13:00:00 14:00:00 15:00:00 16:00:00 Time (HHMMSS) DO vs. Time 10

7 DO (mg/L)DO 6 Forge Pond (Upstream)

5 Mill Pond (Downstream)

1:00:00 3:00:00 5:00:00 7:00:00 9:00:00 17:00:00 19:00:00 21:00:00 23:00:00 11:00:00 13:00:00 15:00:00 Time (HHMMSS) DO Saturation (%)

100

60 DO SaturationDO (%)

50 Forge Pond (Upstream) Mill Pond (Downstream) 40

1:00:00 3:00:00 5:00:00 7:00:00 9:00:00 17:00:00 19:00:00 21:00:00 23:00:00 11:00:00 13:00:00 15:00:00 Time (HHMMSS) pH vs. Time 7

6.5

5.5

5 pH Units pH 4.5 Forge Pond (Upstream) 4 Mill Pond (Downstream) 3.5

1:00:00 3:00:00 5:00:00 7:00:00 9:00:00 17:00:00 19:00:00 21:00:00 23:00:00 11:00:00 13:00:00 15:00:00 Time (HHMMSS) Specific Conductivity (mS/cm) 0.105

0.1

0.095

0.09

0.085

0.08

SpecificConducivity (mS/cm) Forge Pond (Upstream) 0.075 Mill Pond (Downstream)

0.07

1:00:00 3:00:00 5:00:00 7:00:00 9:00:00 17:00:00 19:00:00 21:00:00 23:00:00 11:00:00 13:00:00 15:00:00 Time (HHMMSS) More Dissolved Substances in Mill Pond??? Sigma Data

• Hourly water samples collected in bottles. • Analyzed at the Bridgewater State College Watershed Access Lab by Kim McCoy. • Larger amounts of phosphate and nitrate downstream. • Rainfall and storm events effect nutrient availability. Discussion and Conclusions

• Dam systems can effect water temperature. • The dams changed the habitat by created pools and larger pond surface area. • DO levels were higher after the dam. • DO levels were higher in slightly warmer water. • DO effects the water pH by pushing other dissolved gasses out. • Specific conductivity is effect by narrow stream beds.

Future Studies

• Include data from the third dam. • Historically, the Assonet River was known for its trout. Then the dams were built. • Check seasonal variation (vegetation & evaporation) • Measure flow, discharge, and nutrient loading from the spillway. • Measure DO in the turbulent spillway. Thank you to…

• Dr. Curry for his insight during the site visit. • Kim McCoy for her help with the equipment and data.

Bridgewater-Raynham Watershed Team • Mark Madonna • Ray Seekell • Ann-Marie Illsey • Sehrish Abid • Laurie Soderbom • Kara Son • Mr. Levesque