Water Quality and Water Quantity: Two sides of the Same Coin Chris Jones
Unit of the College of Engineering Director: Larry Weber 90 Graduate Students from 16 countries 61 Research Engineers and Scientists Engineering Research Center since 1920
Municipal Water Supply Projects Boone Water Works Ottumwa Water Works Rural Water System #2 (Hospers, IA) City of Sioux Center Rock Valley Rural Water
http://ifis.iowafloodcenter.org/ifis/en/
2,500,000 300,000 30,000 to 10,500 130,000 500,000 years years Slide courtesy of K. Schilling, Iowa Geological Survey
Iowa Landforms
Climate Millett, B., Johnson, W.C. and Guntenspergen, G., 2009. Climate trends of the North American prairie pothole region 1906 2000. Climatic Change, 93(1-2), pp.243-267.
Iowa Land Cover
Pre-1850 Sandy or gravel bottom Gently-sloping banks with vegetation Perennial vegetation Wide, shallow streams Water table close to surface
Pre-1850 Surface runoff Seepage Groundwater exchange Infiltration
Now Tile drainage Annual vegetation Deep, narrow streams Steep, unvegetated banks Silt bottom Water table deeper
Now Surface runoff Tile drainage Seepage Infiltration Groundwater exchange
Incision
Where do streams begin? Tile outfalls! Slide courtesy of K. Schilling, Iowa Geological Survey
Downstrea m Walnut Creek Contribution of tiles to channel incision Channel depth at tile outlets = 1.4 m Channel depth at watershed outlet = 3.3 m 42% of channel incision may be sourced from tile drainage outfalls. Upstrea m Walnut Creek Slide courtesy of K. Schilling, Iowa Geological Survey
Drainage network developed on different age of glacial drift in Iowa Number of streams per unit area and drainage density increases with time Ruhe classic work (1952)
Extension of river drainage network from 1847 to 1972 Slide courtesy of K. Schilling, Iowa Geological Survey
Effects of tile drainage in Des Moines Lobe watershed Bear Creek Compared groundwater travel times various drained conditions: High Medium Low Perennial network Pre-settlement Slide courtesy of K. Schilling, Iowa Geological Survey Schilling et al., JEQ, 2015
Walnut Creek: Jasper County Slide courtesy of K. Schilling, Iowa Geological Survey
Extension of the drainage network Table 1. Comparison of morphological characteristics of Walnut Creek in 1847 and 1972 (after Anderson, 2000) Property GLO Survey (1847) 1972 USGS Streams Stream length (m) 37,185 60,286 Drainage density 1 0.9 1.52 Channel frequency 2 0.32 1.20 1 Total length of drainage system divided by watershed area 2 Total number of stream segments per unit area Slide courtesy of K. Schilling, Iowa Geological Survey Stream length nearly doubled Greater density and number of stream channels
It s Wetter: Increase over last century 16.2% 16.1% 8.1% 19.1% 8.4% 20.1% 7.1% 13.7% 5.8%
It s Wetter
Streams have more water Wapsipinicon Schilling, K. E. and Libra, R. D. (2003), INCREASED BASEFLOW IN IOWA OVER THE SECOND HALF OF THE 20TH CENTURY 1. JAWRA Journal of the American Water Resources Association, 39: 851 860. doi:10.1111/j.1752-1688.2003.tb04410.x
Streams have more water Wapsipinicon Schilling, K. E. and Libra, R. D. (2003), INCREASED BASEFLOW IN IOWA OVER THE SECOND HALF OF THE 20TH CENTURY 1. JAWRA Journal of the American Water Resources Association, 39: 851 860. doi:10.1111/j.1752-1688.2003.tb04410.x
Streams have more water Wapsipinicon Baseflow=is the portion of streamflow that comes from "the sum of deep subsurface flow and delayed shallow subsurface flow". Schilling, K. E. and Libra, R. D. (2003), INCREASED BASEFLOW IN IOWA OVER THE SECOND HALF OF THE 20TH CENTURY 1. JAWRA Journal of the American Water Resources Association, 39: 851 860. doi:10.1111/j.1752-1688.2003.tb04410.x
E. Nishnabotna Schilling, K. E. and Libra, R. D. (2003), INCREASED BASEFLOW IN IOWA OVER THE SECOND HALF OF THE 20TH CENTURY 1. JAWRA Journal of the American Water Resources Association, 39: 851 860. doi:10.1111/j.1752-1688.2003.tb04410.x
Des Moines R. at Stratford
Iowa R. at Marengo
Extreme Precipitation 2-day precipitation event that is exceeded on average only once in five years.
Perry, Iowa 24-32% increase in annual precipitation 2.3-2.7 o C increase in temperature Increase tile drainage flows Change distribution of flows within the calendar year
Hypoxia, Aquatic Life
Drinking Tole Water Toledo, OH Des Moines, IA
Predicted average riverine nitrate N yield, January to June, for all counties in the Mississippi River basin for the period 1997 to 2006. David, et al., 2010. JEQ 39:1657-67
Ways of looking at data Average Concentration: mg/l Important for drinking water uses and aquatic life standards Annual values biased low by low flow summer months with low nitrate Annual values biased high by low flow winter months with high nitrate
Ways of looking at data Loads in tonnes, tons, pounds, kg Total mass of pollutant carried by the river over a defined period of time. Important for Gulf of Mexico Hypoxia, TMDL standards and industry performance Loads follow discharge, hard to track progress in face of climate variations
Flow-Weighted Average Ways of looking at data Total load/total discharge for the period of interest Helps buffer the highly variable effects of weather and discharge Good for trending
Raccoon River Trends: Flow Weighted Average Flow weighted average = total load/total flow
Des Moines River Flow Weighted Average
1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Loads LOADS (tonnes) 80000 70000 60000 50000 40000 30000 20000 10000 0 Raccoon Des Moines N Yield (pounds per acre) >25% of inputs in 15 Raccoon Des Moines ave 17 16 max 45 38
Loads driven by discharge Long term: N loss is TRANSPORT LIMITED
Loads driven by discharge Long term: N loss is TRANSPORT LIMITED
Transport vs Supply Limitations Transport River nitrate controlled by how much nitrate could be flushed from soil stores by hydrological processes operating in the watershed. Supply Nitrate availability in soil stores limits nitrate transfer to the stream
Raccoon River Sediment
Sediment Load vs Discharge
Day of year matters
Supply Limitations vs Transport Limitations
In Iowa, we farm. 88,000 Farm Operations 30,500,000 Farmed Acres (12,700,000 Ha), 84% of the state s area. 13,050,000 acres of corn (2.5 billion bushels, value $8.8 billion) U.S. rank: 1 st 9,800,000 acres of soybean (554 million bushels, value $4.8 billion) U.S.A. ranking: 1 st 21 million hogs; U.S.A. ranking: 1 st 8.4 million turkeys; U.S.A. ranking: 9 th 52 million laying chickens; U.S.A. ranking: 1 st (15 billion eggs) 4 million cattle (including calves) U.S.A. ranking: 6 th 210,000 milk cows (4.8 billion pounds of milk) Sheep and Goat production: 6 th Oats: 7 th Hay: 11 th Corn for silage: 7 th
IIHR 2016 Real-Time Monitoring Network Iowa has 1/3 of all the continuous nitrate monitors in the U.S. About 80% of the water leaving the state will be monitored for nitrate in 2016.
Monitoring Network https://iwqis.iowawis.org/
Questions?