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 60 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.
Program Details
| Sampling Results (2015 to 2024) | 155,361 |
| # of Sites | 60 |
Current Ambient Stream Sites
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SiteID | Site | County |
|---|---|---|
| 10030001 | Upper Iowa River near Dorchester | ALLAMAKEE |
| 10030002 | Yellow River at Ion | ALLAMAKEE |
| 10040002 | Chariton River near Rathbun | APPANOOSE |
| 10070001 | Beaver Creek near Cedar Falls | BLACK HAWK |
| 10070002 | Wolf Creek at La Porte City | BLACK HAWK |
| 10070003 | West Fork Cedar River at Finchford | BLACK HAWK |
| 10070004 | Black Hawk Creek at Waterloo | BLACK HAWK |
| 10090001 | Cedar River at Janesville | BREMER |
| 10100001 | Wapsipinicon River near Otterville | BUCHANAN |
| 10120001 | Shell Rock River at Shell Rock | BUTLER |
| 10180001 | Little Sioux River near Larrabee | CHEROKEE |
| 10220001 | Turkey River near Garber | CLAYTON |
| 10220002 | Volga River near Elkport | CLAYTON |
| 10220003 | Bloody Run Creek near Marquette | CLAYTON |
| 10250001 | South Raccoon River near Redfield | DALLAS |
| 10270001 | Thompson Fork - Grand River at Davis City | DECATUR |
| 10300001 | Little Sioux River near Milford | DICKINSON |
| 10340001 | Cedar River at Midway | FLOYD |
| 10360001 | East Nishnabotna River near Shenandoah | PAGE |
| 10360003 | Nishnabotna River at Hamburg | FREMONT |
| 10400001 | Boone River near Stratford | HAMILTON |
| 10420001 | Iowa River near Gifford | HARDIN |
| 10430001 | Boyer River near Missouri Valley | HARRISON |
| 10430002 | Soldier River at Pisgah | HARRISON |
| 10440001 | Cedar Creek near Oakland Mills | HENRY |
| 10460001 | West Fork Des Moines River near Humboldt | HUMBOLDT |
| 10490001 | North Fork Maquoketa River near Hurstville | JACKSON |
| 10490004 | Maquoketa River near Maquoketa | JACKSON |
| 10490005 | Maquoketa River near Spragueville | JACKSON |
| 10500001 | Indian Creek near Mingo | JASPER |
| 10520001 | Old Mans Creek near Iowa City | JOHNSON |
| 10540001 | North Skunk River near Hayesville | KEOKUK |
| 10550001 | East Fork Des Moines River near St. Joseph | KOSSUTH |
| 10560002 | Skunk River at Augusta | LEE |
| 10570001 | Cedar River near Cedar Rapids | LINN |
| 10580002 | Iowa River near Lone Tree | LOUISA |
| 10580003 | Iowa River at Wapello | LOUISA |
| 10620001 | South Skunk River near Oskaloosa | MAHASKA |
| 10630002 | Cedar Creek near Bussey | MARION |
| 10630003 | Whitebreast Creek near Melcher-Dallas | MARION |
| 10640002 | Iowa River near Marshalltown | MARSHALL |
| 10650001 | West Nishnabotna River near Malvern | MILLS |
| 10670001 | Monona-Harrison Ditch near Turin | MONONA |
| 10670002 | Maple River at Mapleton | MONONA |
| 10670003 | Little Sioux River near Turin | MONONA |
| 10700001 | Cedar River near Conesville | MUSCATINE |
| 10730001 | West Nodaway River at Shambaugh | PAGE |
| 10730002 | East Nodaway River near Clarinda | PAGE |
| 10750001 | Floyd River near James | PLYMOUTH |
| 10770001 | Beaver Creek at Johnston | POLK |
| 10810001 | North Raccoon River near Lake View | SAC |
| 10820001 | Wapsipinicon River near De Witt | SCOTT |
| 10840001 | Rock River near Hawarden | SIOUX |
| 10850002 | South Skunk River near Cambridge | STORY |
| 10890001 | Des Moines River at Keosauqua | VAN BUREN |
| 10910001 | Middle River near Indianola | WARREN |
| 10910003 | South River near Ackworth | WARREN |
| 10920001 | English River at Riverside | WASHINGTON |
| 10970001 | Little Sioux River near Smithland | WOODBURY |
| 14000359 | North River near Norwalk (Hwy 28) | WARREN |
Stream Water Quality Summary 2015 to 2024
Summary statistics last calculated 2/19/2025 2:38:45 PM
| Analyte | Units | # Results | Min | 10th Percentile | 25th Percentile | Median | 75th Percentile | 90th Percentile | Max | Max Sample Date | % Non-detection |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Alkalinity, total | mg/l CaCO3 | 4,269 | 62 | 150 | 180 | 220 | 260 | 300 | 420 | 3/2/2020 | 0.00 |
| Ammonia-nitrogen | mg/l | 7,200 | Not calculated when non-detections exceed 50% | 6.6 | 12/11/2023 | 80.61 | |||||
| Calcium | mg/l | 4,154 | 15 | 53 | 63 | 75 | 88 | 100 | 150 | 1/14/2015 | 0.00 |
| Carbonaceous biochemical oxygen demand, standard conditions | mg/l | 7,180 | Not calculated when non-detections exceed 50% | 37 | 3/7/2016 | 81.52 | |||||
| Chloride | mg/l | 7,200 | <0.1 | 12 | 16 | 20 | 26 | 36 | 200 | 1/8/2024 | 0.01 |
| Chlorophyll a, free of pheophytin | ug/l | 7,198 | <1 | 2 | 4 | 9 | 22 | 62 | 570 | 11/8/2023 | 2.83 |
| Dissolved oxygen (DO) | mg/l | 7,189 | 3 | 7.8 | 8.7 | 10.5 | 12.3 | 13.5 | 20.1 | 8/11/2021 | 0.00 |
| Escherichia coli | MPN/100ml | 6,875 | <10 | 20 | 52 | 160 | 500 | 1900 | 610000 | 9/5/2018 | 4.31 |
| Hardness, carbonate | mg/l | 7,200 | <1 | 200 | 240 | 290 | 340 | 400 | 790 | 3/2/2015 | 0.01 |
| Kjeldahl nitrogen | mg/l | 7,200 | <0.1 | 0.3 | 0.44 | 0.66 | 1 | 1.6 | 11 | 6/6/2019 | 5.38 |
| Magnesium | mg/l | 4,154 | 2.9 | 15.3 | 20 | 25 | 32 | 36 | 60 | 1/14/2015 | 0.00 |
| Nitrate + Nitrite | mg/l | 7,200 | <0.1 | 0.45 | 2.3 | 5.1 | 7.5 | 10 | 23 | 5/8/2024 | 6.14 |
| Organic Carbon | mg/l | 5,326 | <0.5 | 1.6 | 2.1 | 2.8 | 3.9 | 5.2 | 25 | 3/6/2018 | 0.24 |
| Orthophosphate | mg/l | 7,192 | <0.02 | <0.02 | 0.04 | 0.0795 | 0.13 | 0.23 | 4.5 | 1/11/2023 | 11.97 |
| pH | None | 7,129 | 5.8 | 7.7 | 8 | 8.2 | 8.3 | 8.5 | 9.7 | 8/11/2021 | 0.00 |
| Potassium | mg/l | 4,154 | <0.88 | 1.7 | 2.1 | 3 | 4.3 | 6.1 | 23 | 3/6/2018 | 0.60 |
| Sodium | mg/l | 4,154 | 1.8 | 6.4 | 8.2 | 11 | 15 | 23 | 240 | 10/6/2021 | 0.00 |
| Sulfate | mg/l | 7,200 | <0.2 | 16 | 20 | 28 | 46 | 81 | 550 | 10/5/2023 | 0.15 |
| Temperature, water | deg C | 7,198 | 0 | 0.4 | 2.9 | 12.4 | 20.7 | 24.3 | 32.3 | 7/5/2022 | 0.00 |
| Total dissolved solids | mg/l | 7,200 | 70 | 270 | 310 | 360 | 430 | 500 | 2580 | 5/3/2021 | 0.00 |
| Total Phosphorus, mixed forms | mg/l | 7,200 | <0.02 | 0.06 | 0.12 | 0.19 | 0.32 | 0.54 | 9.2 | 10/6/2015 | 0.50 |
| Total suspended solids | mg/l | 7,200 | <1 | 4 | 11 | 35 | 90 | 230 | 6020 | 7/7/2015 | 0.42 |
| Turbidity | NTU | 7,190 | <0 | 2.8 | 6.2 | 17 | 41.75 | 100 | 2600 | 7/7/2015 | 0.81 |
| Volatile Suspended Solids | mg/l | 7,199 | <1 | 2 | 3 | 7 | 16 | 34 | 420 | 7/2/2019 | 0.74 |
Project Codes in this Program
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Code | Description |
|---|---|
| AMBIENT | Ambient stream water quality monitoring |
Inactive Ambient Monitoring Sites
Sites may no longer be monitored due to a variety of reasons. They may be temporarily or permanently moved to a new site, or abandoned completely. Reasons for inactivity include construction on nearby roads/bridges, traffic safety concerns, or changes to stream morphology and/or accessibility.
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SiteID | Site | County |
|---|---|---|
| 10040001 | Chariton River near Centerville | APPANOOSE |
| 10070005 | Cedar River Upstream of Waterloo/Cedar Falls (US1) | BLACK HAWK |
| 10070006 | Cedar River Downstream of Waterloo (DS1) | BLACK HAWK |
| 10160001 | Cedar River at Cedar Bluff | CEDAR |
| 10170001 | Winnebago River at Mason City | CERRO GORDO |
| 10170002 | Winnebago River Upstream of Mason City (US1) | CERRO GORDO |
| 10170003 | Winnebago River Downstream of Mason City (DS1) | CERRO GORDO |
| 10210001 | Ocheyedan River near Spencer (US2) | CLAY |
| 10210002 | Little Sioux Upstream of Spencer (US1) | CLAY |
| 10210003 | Little Sioux River Downstream of Spencer (DS1) | CLAY |
| 10250002 | Raccoon River Upstream of Des Moines (US2) | DALLAS |
| 10340002 | Flood Creek at Greene | FLOYD |
| 10370001 | North Raccoon River near Jefferson | GREENE |
| 10490002 | Maquoketa River at Maquoketa | JACKSON |
| 10490003 | Maquoketa River near Bridgeport | JACKSON |
| 10520002 | Iowa River Upstream of Iowa City (US1) | JOHNSON |
| 10520003 | Iowa River Downstream of Iowa City (DS1) | JOHNSON |
| 10530001 | Wapsipinicon River near Olin | JONES |
| 10560001 | Des Moines River near Keokuk | LEE |
| 10570002 | Cedar River Upstream of Cedar Rapids (US1) | LINN |
| 10580001 | Iowa River at Columbus Junction | LOUISA |
| 10630001 | Whitebreast Creek near Knoxville | MARION |
| 10640001 | Iowa River near Marshalltown (Hwy 14) | MARSHALL |
| 10640003 | Iowa River Upstream of Marshalltown (US1) | MARSHALL |
| 10750002 | Big Sioux River near Akron | PLYMOUTH |
| 10770002 | Des Moines River Upstream of Des Moines (US1) | POLK |
| 10770003 | Des Moines River Downstream of Des Moines (DS1) | POLK |
| 10810002 | North Raccoon River Upstream of Sac City (US1) | SAC |
| 10850001 | South Skunk River near Ames | STORY |
| 10850003 | South Skunk River Upstream of Ames (US1) | STORY |
| 10900002 | Des Moines River Downstream of Ottumwa (DS1) | WAPELLO |
| 10900003 | Des Moines River Upstream of Ottumwa (US1) | WAPELLO |
| 10910002 | North River near Norwalk (R57) | WARREN |
| 10940001 | Lizard Creek near Fort Dodge (US2) | WEBSTER |
| 10940002 | Des Moines River Upstream of Fort Dodge (US1) | WEBSTER |
| 10940003 | Des Moines River Downstream of Fort Dodge (DS1) | WEBSTER |
| 10970002 | West Fork Ditch near Hornick | WOODBURY |
| 10990001 | Iowa River near Rowan | WRIGHT |
| 14000135 | Maquoketa River near Spragueville | JACKSON |
| 10570003 | Cedar River at Palisades-Kepler State Park | LINN |