Have agricultural management practices (AMPs) improved water quality?: A case study in Sugar Creek

Transcription

1 June 8, 212 Have agricultural management practices (AMPs) improved water quality?: A case study in Sugar Creek Jeff Frey U.S. Geological Survey U.S. Department of the Interior U.S. Geological Survey National Water-Quality Assessment Program (NAWQA)

2 Understanding trends Hydrology How does the water (and chemicals) move to streams and groundwater Chemical properties Does the chemical dissolve in water or attach to sediment Wet vs Dry years Do changes in water quality reflect changing streamflow instead of changing management practices?

3 Sugar Creek: Extensively Studied Since 1992 (17 years) Streamflow monitored since 1967 Nutrients ( ) 354 samples Sediment ( ) 325 samples Pesticides ( ) 325 samples Ecological community sampling 12 years Algae, fish, invertebrates Habitat

4 Sugar Creek is a Heavily Agricultural Basin 95 mi 2 basin Corn/ Soybeans Till plain Heavily tiled

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6 Ground Water and Precipitation

7 Overland Flow

8 Tile Drain

9 How Do Nutrients Get Into Streams?

10 Has Water Quality Improved with the Implementation of Agricultural Management Practices?

11 What are agricultural management practices? Conventional tillage Conservation tillage

12 No Till Conservation Tillage Increased Through the 199 s From Evans and others, 2 Soybeans 199 2% % 2 74% Corn 199 2% % 2 8% Hancock County

13 Sediment Concentrations over Time 3, 2,5 Discharge (ft3/sec) Suspended Sediment (mg/l) , ,5 25 1, May-92 May-93 May-94 May-95 May-96 May-97 May-98 May-99 May- May-1 May-2 May-3 May-4 May-5 May-6 Sugar Creek

14 Sediment Concentrations over Time 2. Log Median Suspended sediment concentrations Year Sugar Creek

15 Sediment Concentrations over Time 3, 2,5 2, 1,5 1, Discharge (ft3/sec) Suspended Sediment (mg/l) : No significant change : 3.6% decrease p-value = May-92 May-93 May-94 May-95 May-96 May-97 May-98 May-99 May- May-1 May-2 May-3 May-4 May-5 May-6 Sugar Creek

16 What are agricultural management practices? Riparian buffers Tile drains

17 Nitrate Concentrations over Time Discharge Nitrate 3, 14 2,5 12 2, 1 8 1,5 6 1, Sugar Creek

18 Tile Drain Variability The type of tile drain system within the watershed greatly affects the transport and type of nutrient and sediment in the stream, specifically: Surface connected Cloudy Contains sediment, total forms sub-surface inlets Usually clear Contains mostly dissolved forms Surface Subsurface

19 Nitrate Concentrations over Time Discharge Nitrate 3, 14 2, : No significant change 2, : 14.3% decrease 1,5 p-value =.363 1, Sugar Creek

20 Population in Hancock County Has Increased Hancock County, Indiana 4 Annual change in population (%) Year Sugar Creek

21 Sensitive fish species have increased in Sugar Creek Percent Relative Abundance of Bigeye chub and shiners Percent relative abundance of Bigeye Chub and Bigeye Shiner at Sugar Creek, Indiana, Relative abundance No-till Percent No-till Sugar Creek

22 Sensitive fish species have increased in Sugar Creek Percent Relative Abundance of Bigeye chub and shiners Percent relative abundance of Bigeye Chub and Bigeye Shiner at Sugar Creek, Indiana, Relative abundance No-till Percent No-till Sugar Creek

23 Sensitive fish species have increased in Sugar Creek 6 Abundance of the Northern Studfish at Sugar Creek, Indiana, Number of Northern Studfish Percent of No-till Sugar Creek

24 Sensitive fish species have increased in Sugar Creek 6 Abundance of the Northern Studfish at Sugar Creek, Indiana, Number of Northern Studfish Percent of No-till Sugar Creek

25 Summary Long term water quality and biological monitoring can help show improvements in water quality Implementation of Best Management Practices has improved water quality depending upon the BMP and the compound Multiple stressors (ag and urban) can influence trends Sugar Creek, Indiana

26 Indiana Water Science Center Web Page: Jeff Frey