1. 2011 Storm impacts on nutrients and sediment in the Susquehanna River Basin Presentation for the Impacts of Tropical Storms Irene and Lee on the Hudson River Hudson River Environmental Society Cary Institute of Ecosystems Studies Wednesday September 19, 2012 Kevin McGonigal Environmental Scientist Susquehanna River Basin Commission

2. Site Location Drainage Area (Sq. Mi.) Water/ Wetland UrbanAgForest Towanda7,797252271 Marietta25,990271972 Where Towanda – Mostly NY Marietta – Above Dams What Precipitation Flows Loads Average Concentrations When September 6-day peak flow period How Estimator

4. Precip Inches September 2004September 2011 PrecipDeparturePrecipDeparture NY4.151.2810.557.13 PA5.852.5212.609.07 Source data at: http://www.erh.noaa.gov/marfc/Precipitation/Departures/ September Flow Daily High 2011 Monthly Average Monthly % of LTM Towanda 2004 154,00027,943491% 2011 250,00036,785647% LTM 5,687 March 2011124,00047,732202% Marietta 2004 390,000*110,893465% 2011 664,000137,867578% LTM 23,610 March 2011434,000162,713217%

5. September Loads in Tons TowandaDaily HighAve Mon QTNTPSS 2004154,00027,9431,9754891,588,205 2011250,00036,7852,3618165,020,671 LTM5,68740777295,844 March 2011124,00047,7324,033367578,135 MariettaAve Mon QTNTPSS 2004390,000*110,89314,2033,4597,333,922 2011664,000137,86715,2424,71212,014,186 LTM23,6102,878431830,628 March 2011434,000162,71318,8541,6502,342,749

6. September Average Concentrations mg/L TowandaAve Mon QTNTPSS 200427,9430.870.216703 201136,7850.790.2741,688 LTM5,6870.890.168643 MariettaAve Mon QTNTPSS 2004110,8931.580.386818 2011137,8671.370.4231,078 LTM23,6101.510.226435

7. Focus on Suspended Sediment SS Tons 2011 TowandaMarietta 2011LTM2011LTM March578,135214,9442,342,739517,595 April818,977348,3032,363,189586,536 September5,020,67181,07912,014,186364,647 3 Mo Total6,417,783644,32616,720,1141,468,777 Annual6,848,6591,660,53219,071,8383,888,205

8. 2011 6-day totals Towanda Ave FlowDaily HighSS Tons March 10-1577,850124,000182,501 April 25-3081,033128,000294,713 Sept 7-12115,717250,0003,158,767 2011 6-day totals Marietta Ave FlowHigh Daily AveSS Tons March 10-15292,833434,000816,043 April 25-30225,667370,000720,619 Sept 7-12390,167664,0006,800,111 6-Day loads over peak of storm events

9. September Towanda YearDaysAve FlowHigh daily Ave.SS TonsAc-ft 2004 - Ivan18-2371,216127,000809,553627 2011- Lee7-12115,717220,0003,158,7672,447

10. Time Periods (Months)% FlowTNTP% SS Top 10% flow10.09%10.06%18.17%28.73% 1993+2004+2011 (top 3 SS)3.95%4.03%11.83%23.75% 2004+2011 (September)2.03%1.81%8.17%19.90% 2011 (March, April, September)3.70%3.03%7.92%17.20% 2011 (September)1.12%0.94%4.71%12.36% Historical High SS Comparison At Marietta 25 years

11. Take home The “bad” Individual high flow events versus sustained high flows Increases in sediment due to scour of reservoirs The “good” Timing of storms At end of summer

12. ??Questions/Comments?? Image taken August 30 8/30/11 max 83,500 cfs Image taken September 13 9/9/11 max 778,000 cfs (>390,000 cfs = scour - USGS) Satellite Image Source http://earthobservatory.nasa.gov Columbia, PA South of Route 462 aka Marietta Site 9/10/11