Iowa DNR
AQuIA

Water Quality Monitoring

Surface Waters - Groundwater
Physical - Chemical

Ambient Stream Monitoring

Since October 1999, the Iowa Department of Natural Resources has maintained a network of stations to monitor ambient water quality in the state. Currently, a total of stream sites are sampled. However, the total number of stations monitored each year has varied. The most stations sampled were a total of 84 stream sites and 1 spring from 2003 to 2006.

Sites in this statewide ambient stream network have been sampled on a monthly basis since October 1999 for a variety of parameters. These data are used for a number of purposes, such as determining status and trends, to determine if Iowa’s rivers support beneficial uses for which they are designated, to calculate nutrient loads, and to support development of new or revised water quality standards.

Current Ambient Stream Sites

SiteID Site County

Stream Water Quality Summary 2008 to 2018

Summary statistics last calculated 12/10/2018 9:25:02 AM
Analyte Units # Results Min 10th Percentile 25th Percentile Median 75th Percentile 90th Percentile Max Max Sample Date % Non-detection
Alkalinity, total mg/l 1,718 55 150 190 230 280 300 460 12/2/2014 0.00
Ammonia-nitrogen mg/l 6,867 Not calculated when non-detections exceed 50% 79.25
Calcium mg/l 1,718 15 55.7 67 80 95 110 150 12/2/2014 0.00
Carbonaceous biochemical oxygen demand, standard conditions mg/l 6,690 Not calculated when non-detections exceed 50% 84.08
Chloride mg/l 6,984 <1 10 14 19 24 34 180 9/4/2013 0.03
Chlorophyll a, free of pheophytin ug/l 6,843 <1 2 3 8 20 56 580 10/1/2012 4.14
Dissolved oxygen (DO) mg/l 6,976 <2.2 7.7 8.6 10.3 12.4 13.7 20.3 1/10/2012 0.01
Escherichia coli #/100ml 6,856 <10 10 52 160 580 2300 820000 10/1/2014 5.50
Flow cfs 4,764 <0 0.1 63 290 880 2500 50000 5/1/2008 4.14
Hardness, carbonate mg/l 6,714 3 200 240 290 350 410 790 3/2/2015 0.00
Inorganic nitrogen (nitrate and nitrite) mg/l 6,867 <0.05 0.7 3 5.8 8.1 11 30 5/8/2013 4.69
Kjeldahl nitrogen mg/l 6,867 <0.1 0.2 0.4 0.6 1 1.6 19 6/4/2008 7.15
Magnesium mg/l 1,718 2.9 15 21 26 32 37 68 12/2/2014 0.00
Organic Carbon mg/l 1,718 <0.5 1.6 2 2.7 3.675 4.9 25 3/6/2018 0.23
Orthophosphate mg/l 6,830 <0.02 <0.02 0.04 0.08 0.14 0.23 5.9 1/14/2013 11.61
pH None 6,916 5.8 7.7 7.9 8.2 8.3 8.5 10.9 1/6/2009 0.00
Phosphate-phosphorus mg/l 6,867 <0.02 0.07 0.12 0.2 0.33 0.56 9.2 10/6/2015 0.17
Potassium mg/l 1,718 <0.88 1.6 2.1 2.8 4 6.2 23 3/6/2018 0.47
Sodium mg/l 1,718 1.8 5.9 7.5 9.6 12 17 110 9/6/2017 0.00
Sulfate mg/l 6,831 <2.3 17 21 29 48 87 350 2/3/2014 0.13
Temperature, water deg C 6,984 -1.9 0.2 2.3 12.4 20.3 24.1 33.2 8/1/2012 0.00
Total dissolved solids mg/l 6,865 4 260 300 350 430 500 960 12/9/2013 0.00
Total suspended solids mg/l 6,867 <1 4 11 40 110 290 16000 6/3/2008 0.57
Turbidity NTU 6,823 <1 2.6 6.2 18 47 120 5100 4/6/2010 1.47
Volatile Suspended Solids mg/l 6,713 <1 1 3 8 18 36 2100 4/1/2008 2.38
Project Codes in this Program

Project Type Description

Program Details

Results (2008 to 2018) 138,432
# of Sites