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Accessibility Version: Tracking the Iowa Nutrient Reduction Strategy v2

Version 2.0 | May 2023

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The Iowa Nutrient Reduction Strategy is a science- and technology-based approach to assess and reduce nutrients delivered to Iowa waterways and the Gulf of Mexico. The strategy outlines opportunities for reducing nutrients in surface water from both point sources, such as municipal wastewater treatment plants and industrial facilities, and nonpoint sources, including agricultural operations and urban areas, in a scientific, reasonable, and cost-effective manner. The Iowa Nutrient Reduction Strategy was developed in response to recommendations provided by the United States Environmental Protection Agency (EPA) in its March 16, 2011, memo, “Working in Partnership with States to Address Phosphorus and Nitrogen Pollution through Use of a Framework for State Nutrient Reduction.” Ongoing action for nutrient load reductions is further supported by the recent EPA recommendations, “Renewed Call to Action to Reduce Nutrient Pollution and Support for Incremental Actions to Protect Water Quality and Public Health,” released September 22, 2016, and “Accelerating Nutrient Pollution Reductions in the Nation’s Waters,” released April 5, 2022.

This page presents an analysis of changes for each indicator of the Iowa Nutrient Reduction Strategy Logic Model to facilitate reporting.

From 2014 to 2020, a comprehensive progress report was released annually by the Iowa Department of Agriculture and Land Stewardship, the Iowa Department of Natural Resources, and Iowa State University. The process of reporting nutrient reduction efforts transitioned in 2021 to a revised approach by publishing data and findings in a set of web-based dashboards

This page presents screen reader-friendly versions of the text and tables in the web-based dashboards. Updates for the 2021 reporting period will be made in May and June 2023.


Tracking Inputs for the Iowa Nutrient Reduction Strategy

Introduction to INRS Inputs

Tracking efforts of the INRS – the amount of funding, outreach, practice implementation, and changes in water quality – are completed to summarize changes made to advance the INRS goal of reducing nitrogen and phosphorus loading by 45%. The dashboards serve as a comprehensive reporting tool to report ongoing efforts from multiple entities collectively working to advance the adoption of conservation practices to improve water quality. The INRS Logic Model provides a structure to evaluate the progression of changes in resources, practice adoption, and impacts of practice adoption over time. Materials for reporting on INRS efforts – funding, outreach, practice implementation, and changes in water quality – are collected annually, and dashboards are updated after data is collected, aggregated, and processed.

Each of the four indicators of the INRS logic model is described below:

  • Inputs indicator summarizes staff, funding, agency resources, and NGO sector resources;
  • Human indicator summarizes partner organizations, farmer knowledge and attitude, point source communities, and management knowledge and attitude;
  • Land indicator summarizes land use changes, practice adoption, and point source implementation; and
  • Water indicator summarizes annual statewide nutrient loads by year and modeled load reduction

Inputs are necessary to expand Iowa's capacity for encouraging and realizing changes in human behavior and for promoting and incentivizing conservation practice implementation to improve water quality. Targeting inputs toward specific NRS facets may be required to support the goals set forth by the NRS. Due to data availability, this report aims to provide an overview of reported statewide funding and staff resources supporting or complementary to the NRS.

Estimates of investment encompass public and non-governmental organizations' (NGO) funding summarized through voluntarily submitted reports of WRCC and WPAC member organizations and by other partner organizations. Most public programs described in this report are considered base programs (described briefly below) and have generally existed for decades. In addition, these estimates include the farmer and landowner contribution to the implementation of cover crops, terraces, water and sediment control basins (WASCOBs), and grade stabilization structures based on landowner costs to install the practice(s). These estimates do not account for the investments made by private entities, farmers, or landowners for practices financed independently of public sector programs.

A growing number of private sector funds are available to facilitate conservation and best management practice adoption on private lands. Many of these efforts operate independently of the NRS and cannot be reliably quantified through existing reporting mechanisms. The importance of these opportunities is acknowledged, but the lack of trackability does not diminish their importance.

Continued Research on Nutrient Reduction

Continuation of research in the physical and social sciences is necessary to better understand the processes driving nutrient losses in Iowa and how conservation measures can alleviate nutrient losses. The Iowa Nutrient Research Center (INRC) has continued to be a dedicated source of research funding for nutrients since its’ founding in 2013. The INRC fosters innovative research led by Iowa researchers at a Regents institution on land management, edge-of-field practices, nutrient management research, or multi-objective research.

More information regarding projects funded at Regents Institutions through the INRC may be found at

INRC Projects relate to Nutrient Management, Land Use, Edge-of-Field Practices, and Multi-Objective. These project themes include:

  • Nutrient Management: Agronomic activities related to the timing, source, rate, and placement of fertilizers based on crop and replacement needs depending on the cropping rotation.
  • Land Use: How cropping, livestock management, and wildlife habitat intersect for a farm operation and environmental benefits.
  • Edge-of-Field Practices: Best Management Practices designed with water quality benefits as a primary benefit.
  • Multi-Objective: Research into Iowa's agroeconomic system and components that influence water quality.

INRS Priority Watersheds

Priority watersheds across Iowa were identified by the Water Resources Coordinating Council in 2013 to conduct outreach and focus targeted conservation and water quality efforts. Nine priority watersheds (hydrologic unit code 8 basins) were identified to focus implementation activities as demonstration projects. Current project information for nonpoint efforts is available at Clean Water Iowa

Iowa Nutrient Reduction Strategy Priority Watersheds and Location within Iowa.
Priority Watershed NameWatershed ID (as HUC-8 Watershed)Watershed Location within Iowa
North Raccoon River07100006Located in west-central Iowa the river originates near Marathon Iowa before flowing into the Des Moines River in Des Moines.
Boone River07100005Located in north-central Iowa the river originates near Hutchins and flows into the Des Moines River south of Webster City.
Middle Cedar River07080205Located in east-central Iowa the watershed originates at the confluence of three rivers (the Cedar River, Shell Rock River, and the West Fork Cedar River) and is designated another watershed immediately south of Cedar Rapids.
Turkey River07060004Located in northeast Iowa the river originates near Saratoga and flows into the Mississippi River east of Millville.
South Skunk River07080105Located in central Iowa the river originates near Hamilton and flows into the Lower Skunk River Watershed north of Richland.
Lower Skunk River07080107Located in southeast Iowa the Lower Skunk River watershed receives flow from the South Skunk River and North Skunk Rivers north of Richland and flows into the Mississippi River south of Burlington.
Floyd River10230002Located in northwest Iowa the river originates near Sanborn and flows into the Missouri River in Sioux City.
West Nishnabotna River10240002Located in southeast Iowa the river originates north of Manning before becoming a larger watershed north of Hamburg.
East Nishnabotna River10240003Located in southeast Iowa the river originates east of Manning before becoming a larger watershed north of Hamburg.

Data Sources for INRS Inputs

Funding and staffing levels have been voluntarily reported since 2015 by members of the Water Resources Coordinating Council (WRCC) and the Watershed Planning Advisory Council (WPAC). Organizations report via a common template to standardize responses to the number of full-time employees (or equivalent) by employee function. In addition, funding by program category and shared funding source are submitted. Where data was unavailable, public records were utilized for public investments for appropriations and expenditures.

Information is collated for all partners to summarize funding, staff, outreach efforts, practice implementation, and monitoring efforts, then reported efforts are distilled to minimize duplication. For example, a grant disbursed by one organization and awarded to another may be reported by both organizations, but double-reporting was minimized by obtaining specific information about different funding sources.

Reports submitted by partners may be downloaded as supplemental materials of the INRS web page, 2021 report available here (available as an xlsx file).

INRS Funding by Partner Organizations from 2012 to 2021

A summary of investment by the four primary investment categories - public sector programs, farmer and landowner investment, non-governmental organizations (NGOs), and land rental as Conservation Reserve Program (CRP) payments - are summarized in the table below. Note that partner funds became available for reporting in the current INRS methodology in 2016 for reporting purposes. NGO investments occurred prior to this time but are not available.

Investment in INRS Practices through public financial assistance programs (public and NGOs), private investment from farmers and landowners, and Conservation Reserve Program payments for land retirement.
YearPublic Sector ProgramsPrivate Investment: Farmer and Landowner InvestmentNon-Governmental OrganizationsCRP - Rental PaymentsTotal
201291,233,89515,302,863 212,942,766319,479,524
2013107,516,59510,708,875 216,365,107334,590,577
201498,161,48516,211,646 214,402,613328,775,744
2015121,613,27915,452,535 221,360,787358,426,601
Total Investment 2012-20211,344,025,001220,042,58819,420,7952,945,237,0214,528,725,405

Farmer and landowner investment in the table above includes cover crops, terraces, water and sediment control basins, ponds, grade stabilization structures, and sediment basins that utilized a public sector program.

State and Federal Funding in Support of INRS by Program

Programs funding is reported as state appropriations by fiscal year or federal year obligation for programs pertaining to the INRS in Appendix A (available at the end of this document) or the tracking period data summary available here (csv on an external site). FSA expenditures are reported from the CRP Enrollment and Rental Payments by State, 1986-2022, and NRCS from annual At-A-Glance reports by federal fiscal year. 

Full-Time Employees (FTEs) Reported for the INRS

A summary of FTEs by category as reported by partners can be found in the table below. Changes in tracking staff were reported by several organizations since 2019 and are known to impact FTEs reported, both as the total and within reporting categories "on-the-ground implementation staff" and "infrastructure staff."

Full-Time Employee Equivalents from 2016 to 2021 Reported to INRS by Lead Organizations and Supporting Organizations.
YearInfrastructure StaffOn-the-ground implementation StaffOther StaffResearch StaffTotal FTE

Changes in Funding

State conservation programs have evolved from 2012 to 2021, with funding for longstanding conservation programs independent of the INRS continuing to receive increased funding. To directly support the INRS, the Water Quality Initiative was first established in 2014. Additional funding became available in 2018 with the establishment of the Water Quality Infrastructure Fund funded by Senate File 512.

Changes in federal conservation program expenditures have largely increased from the beginning of the INRS. Programs offered for nonpoint sources facilitate the implementation of conservation practices through financial assistance programs or for land set aside through the Conservation Reserve Program (CRP). Expenditures through CRP in Iowa have increased, driven by an average rental rate per acre increase from $132 to $230 from 2012 to 2021. Programs to implement conservation programs administered by the NRCS are funded through the Farm Bill, for which programs have evolved over the past decade, both in programs and funding for each program. Funds obligated to projects in Iowa through conventional programs have been strong. In addition, Iowa entities have been competitive and demonstrated innovative conservation delivery concepts to receive grant funding through the Regional Conservation Partnership Program (RCPP).


Tracking the Human Dimension

Overview of the Human Indicator

The Human indicator summarizes knowledge, attitudes, and behavior related to water quality and nutrient reduction. Changes in management and conservation practices reflect the outreach, training, and educational events aimed at increasing knowledge among communities, farmers, landowners, the public, and conservation professionals. The outreach impacts have been assessed using farmer surveys to gauge farmers’ knowledge, attitudes, and awareness related to water quality and nutrient reduction.

Outreach activities regarding water quality and management practices are summarized in the following panels of this dashboard. These efforts primarily capture outreach regarding nonpoint sources and the extensive network that supports educational opportunities across the state.

While point source activities directly engage fewer people, outreach amongst POTWs continues through education for plant operators by organizations such as the Iowa Water Environment Association and direct contact with permitting agencies. Individual contacts amongst DNR, municipalities, and consultants who assist with plant operations and ensure regulatory compliance standards are not tracked; however, the development of phase one and phase two assessments for major POTWs as required by the INRS requires significant time and dedicated funding to ensure community and commercial needs are economically met. More importantly, urban and rural partnerships continue to be explored across the state through the creation of Nutrient Reduction Exchanges (NREs) by pilot cities in consultation with the DNR. Nonpoint conservation practice benefits are assessed by the Nutrient Tracking Tool, validated, and then registered via the Regulatory In-Lieu Fee and Bank Information Tracking System (RIBITS) database to foster nutrient trading within a watershed.

Changes in Public Education and Outreach

INRS partners remain engaged in outreach, with 678 events reported for the 2021 reporting period that reached an estimated 38,746 attendees*.  These events ranged from general public programs such as fairs and educational program visits to schools to educational opportunities for professionals such as workshops and conferences. Information on attendance by year, as the number of events and attendance, are summarized in the table following this section. Program delivery modes have evolved over the past two years with the widespread adoption of virtual programming. The extent of virtual program development by INRS partners varies and includes webinars for general audiences to virtual field days that facilitate virtual attendance of programming conducted in the field.

The geographic distribution of events continues to be evaluated with county-level data summarized for the number of events and attendance. For example, counties with an event center will likely host larger programs that draw attendees from multiple counties or statewide. In contrast, rural counties may host more programs focused on local issues for farmers and landowner audiences. The total number and attendance of partner-reported events are summarized by county and event type in the top-right panel.

Changes in event mode and travel restrictions led to smaller group programs that fostered greater engagement, primarily as youth education events coordinated by the Water Rocks! program in 2021. Similarly, many conferences transitioned to virtual or hybrid formats making participation possible for a wider audience.

These events, which provide information to make informed decisions about conservation practices and educate attendees about water quality issues, were self-reported by WRCC and WPAC member organizations, and include five general categories:

  • Conferences – multi-session events to facilitate knowledge-sharing, networking, and partnering.
  • Community Outreach - includes fairs, tours, and other community events.
  • Field days - Often serve to educate farmers, landowners, and agribusiness representatives through direct demonstration.
  • Workshops - Entail training in a particular skill or topic area related to nutrients and water quality.
  • Youth – focuses on spreading understanding about natural resources and watershed issues through K-12 educational programming.
  • Supplemental – A training that included a discussion on water quality but was not the primary reason for the contact. 

*Supplemental contacts are not included in the statewide total because water quality was not the primary reason for the contact. In addition, attendance at these programs is reported as a statewide total as the mode by which attendees engaged in a training does not facilitate county-level reporting.

Summary of Outreach Program by the six categories specified above from 2016 to 2021.
YearCommunity OutreachConferenceField DaySupplementalWorkshopYouthTotal
AttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. Events
20169,724631,757109,523114  7,4732726,1526834,629527
201721,3311604,763189,849145  7,62525918,55112562,119707
20189,3231583,507184,861138  6,74821628,71019553,149725

A summary of programs by county can be in Appendix B (available at the end of this document) or the tracking period data summary available here (csv on an external site).

The Nutrient Reduction Strategy Farmer Survey

Completed over five years, the NRS Farmer Survey was designed to assess farmer knowledge, attitude, and behavior related to water quality and to gain insight into practices that are favorably received or barriers to BMP adoption. With surveys completed by respondents over multiple years, results from five of the six HUC6 watersheds in Iowa have been published and are summarized in this report.
Surveys were completed within the larger HUC6 watersheds and priority HUC8 watersheds across the state. Watersheds for each survey appear in the panel to the right.

Reports may be found in the INRS webpage supplemental documents ( or through the Iowa State University Extension Outreach Store (search for Iowa Farmers and the Iowa Nutrient Reduction Strategy).

Each watershed was surveyed in the years summarized in the table below. Data summarized in the tables below reflect the respondents' answers in the first year in the first year of the survey.

Summary of the large basins (hydrologic unit code (HUC) 6) by which the Iowa Nutrient Reduction Strategy Farmer Survey was completed.
INRS Farmer Survey Basin (by HUC-6 Watershed)HUC6 IDYears SurveyedINRS Priority Watershed (HUC-8) within the BasinHUC8 ID
Des Moines0710002017 and 2018North Raccoon7100006
Iowa0708022015 and 2019Middle Cedar7080205
Upper Mississippi-Maquoketa-Plum0704002016 and 2017Turkey7060004
Upper Mississippi-Skunk-Wapsipinicon0708012019South Skunk7080105
Lower Skunk7080107
Missouri-Little Sioux1023002015 and 2016Floyd10230002
Missouri-Nishnabotna1024002018 and 2019West Nishnabotna10240002
East Nishnabotna10240003

Selected results from the Iowa Nutrient Reduction Strategy Farmer Survey are summarized below. The INRS Farmer Survey tracked farmers’ knowledge, attitudes, and behavior related to nutrient reduction beginning in 2015 with the final survey completed in 2019. Responses are aggregated in the table below by topic area from the survey and by the basin in which the farmer operates.

Summary of Farmer Responses to Questions Relating to Nutrient Management, Awareness and Support for the INRS, Knowledge Barriers Related to the IRNS, and Economic Barriers Potentially Impacting Practice Adoption by the HUC-6 Basin Scale by which Respondents were Surveyed for which Responses were 'Strongly Agree' or 'Agree' (out of five responses from 'strongly agree' to 'strongly disagree').
Watershed by which Farmers were SurveyedDes MoinesMissouri-Little SiouxMissouri-NishnabotnaUpper Mississippi-Maquoketa-PlumUpper Mississippi-Skunk-Wapsipinicon
Self-assessment of nutrient management
I am already doing all that I can to reduce nutrient loss from my farm into waterways40.649.645.448.743.6
I don’t know how well my farm operation is doing in terms of keeping nutrients out of waterways21.320.121.618.120.1
The nutrient management practices I use are sufficient to prevent loss of nutrients into waterways58.961.457.165.758.9
Awareness, concern, and support for action
Helping to meet the Nutrient Reduction Strategy’s goals is a high priority for me49.153.552.854.350.9
I am concerned about agriculture’s impacts on Iowa’s water quality81.88482.980.781.8
I am concerned about Iowa’s contribution to water quality problems (e.g., hypoxia) in the Gulf of Mexico57.259.958.762.261.1
I would be willing to have someone help me evaluate how my farm operation is doing in terms of keeping nutrients out of waterways47.744.848.354.144.5
I would like to improve conservation practices on the land I farm to help meet the Nutrient Reduction Strategy’s goals74.376.678.276.777.2
Iowa farmers should do more to reduce nutrient and sediment run-off into waterways70.974.674.875.475.4
Nutrients from Iowa farms contribute to water quality problems (e.g., hypoxia) in the Gulf of Mexico43.944.144.847.453.5
Knowledge-related barriers
Farmers need help learning how to reduce nutrient loss more effectively65.364.464.964.664.2
I don’t know how to further reduce nutrient losses from my farm13.619.118.218.916.9
Many farmers are not aware that nutrients from agriculture can impact water quality22.121.219.822.217.6
Many farmers don’t know how to further reduce nutrient losses from their farms33.736.138.23734
Economic barriers
I can’t afford to implement more conservation practices39.430.741.734.439.3
Many conservation practices have negative impacts on yields29.319.918.121.322.8
Many farmers don’t have the economic resources to adopt sufficient conservation practices4836.147.94152.6
Pressure to make profit margins makes it difficult to afford conservation practices69.365.
There is not enough cost-share and other support available from government agencies51.952.25847.652.6

The source from which farmers who completed the Iowa Nutrient Reduction Strategy Farmer Survey learned about the strategy is summarized in the table below by the basin in which the farmer operates.

The Percentage of Respondents, by the Number of Respondents by Survey Area, who Learned About the INRS by Source.
Knowledge SourceDes MoinesMissouri-Little SiouxMissouri-NishnabotnaUpper Mississippi-Maquoketa-PlumUpper Mississippi-Skunk-Wapsipinicon
The farm press85.879.777.181.980.7
NRCS or SWCD64.463.563.867.865.3
Iowa State University Extension and Outreach59.363.153.952.561.6
Commodity or farm organization59.550.446.35355.2
The popular press55.849.146.752.650.1
Government agency52.548.444.84547
Other farmers45.342.341.144.242.4
Agricultural retailer31.531.426.826.427.6
Crop advisor or agronomist21.821.814.617.217
Seed company rep.

The source(s) from which farmers who completed the Iowa Nutrient Reduction Strategy Farmer Survey learned about nutrient management is summarized in the table below by the basin in which the farmer operates.

Summary of Farmer Responses to Questions Relating to Where They Learned about Nutrient Management by the HUC-6 Basin Scale by which Respondents were Surveyed for which Responses were ‘Very Strong Influence or ' Strong Influence' (out of five responses from 'very strong influence' to 'no influence’).
Knowledge SourceDes MoinesMissouri-Little SiouxMissouri-NishnabotnaUpper Mississippi-Maquoketa-PlumUpper Mississippi-Skunk-Wapsipinicon
NRCS or County Soil and Water Conservation District23.732.927.432.325.8
Iowa State University Extension (e.g., field days, workshops, pInfluenceublications, videos)19.825.81918.118.5
Landlord/farm management firm17.718.116.214.315.7
Independent/private crop adviser/agronomist14.715.413.911.211.4
Iowa Water Quality Initiative (WQI)9.812.611.713.410.9
Custom operator/applicator8.
Iowa Soybean Association9.98.387.87.7
Practical Farmers of Iowa4.83.16.557.1
Iowa Learning Farms4.


Tracking Nonpoint Source Nutrient Reduction Practices - Agricultural Conservation Practices

Agricultural Land Use in Iowa Over Time

Iowa’s total land area is 35.7 million acres. Based on data from the USDA Census of Agriculture, nearly 90% of Iowa’s total area is dedicated for agricultural purposes, with total agricultural land averaging 31.4 million acres since 1982. Land area dedicated to field crops — corn, soybeans, and other annual and perennial crops — has remained relatively steady since the 1980s, averaging 27 million acres. Acres enrolled in the United States Department of Agriculture Conservation Reserve Program, which aims primarily to convert environmentally sensitive land from crops to perennial cover, has fluctuated between approximately 1.5 and two million acres in Iowa since the start of the program in 1986.

Iowa Agricultural Land Use Since 1980.
Corn13,376,06613,416,695 10,352,369 12,773,58511,000,00012,600,00011,600,00012,400,00011,930,54212,200,00011,800,00012,000,00011,400,00011,761,39211,900,00012,400,00012,500,00012,350,00013,842,28212,800,00013,300,00013,050,00013,733,50413,949,34013,301,68413,395,65413,218,93913,585,13813,024,47412,891,94413,230,24913,437,74512,714,499
Hay2,317,391 2,035,0331,968,2071,762,425    1,575,777    1,533,027    1,125,565    996,3161,220,0001,220,0001,240,0001,010,0001,069,770995,0001,115,0001,225,0001,350,000
Oats871,460811,716544,907367,517225,000430,000225,000 190,000214,485185,000175,000180,000130,000143,513130,000140,000125,000110,00066,65175,00095,00075,000113,308125,084142,288134,567121,230111,05197,071124,584150,014145,488108,301
Pasture5,764,822       4,256,172    3,639,397    3,144,321    2,478,116    2,360,349    
Wheat31,86398,68831,047 25,00045,000  35,00040,00022,75832,00031,00018,00018,00018,31721,00024,00015,00018,00029,51230,00022,00010,00018,87014,23226,20217,21317,37921,16014,35614,09912,22211,58617,255

Records from the United States Department of Agriculture (USDA) Census of Agriculture, the USDA National Agriculture Statistics Service (NASS), and the USDA Farm Service Agency (FSA) were compiled to estimate historical and recent crop acreages from 1992 to the current reporting period. Acreages prior to 1992 were tabulated from digitized documents in the USDA Census of Agriculture Historical Archive. Crop acres from the Census of Agriculture and National Agriculture Statistics Service (NASS) were used for annual values from 1993 to 2010. For both periods, harvested acres were used when available; planted acres were used as an alternative value when harvested acres were not available. NASS survey values were used for years when the Census did not occur. For annual crop acres since 2011, planted crop acres were aggregated from Farm Service Agency (FSA) crop acreage reports and reflect the annual crop acreage values provided in NASS (in lieu of combined records from archival, NASS, and FSA databases).

Iowa Acres in the Conservation Reserve Program (CRP) Since 1986.


Acres enrolled in the Conservation Reserve Program in Iowa were obtained from the FSA crop acreage reports and aggregated by year.

Iowa Cover Crops

During the baseline and benchmark time periods —1980-96 and 2006-10 — there were no or very few acres of cover crops in Iowa. The USDA Census of Agriculture reported that 970,000 acres of cover crops were planted in Iowa in fall the fall of 2017, and the Survey of Agricultural Retailers estimated 1.6 million acres. That survey estimated that 2.8 million acres were planted in the fall of 2021. Based on county-level data from the 2017 USDA Census of Agriculture, the eastern and southern regions of Iowa show the highest rates of cover crop use.

Of these statewide estimates, public conservation programs accounted for more than 1,000,000 acres in 2021. It should be noted that these publicly funded cover crop acres – including state and federal cost share programs as well as the crop insurance discount program - represent a portion of Iowa’s total cover crop acres; annual publicly funded acres do not represent a total statewide estimate of Iowa cover crops.

Iowa Cover Crop Acres, by Data Source
Data Source201020112012201320142015201620172018201920202021
United States Department of Agriculture - Census of Agriculture  379,614    973,112    
Survey of Agricultural Retailers       1,597,6142,015,6882,179,3043,107,0632,768,754
Portion Funded by Public Conservation Programs18,70230,98769,955211,235161,000275,854324,097549,638600,972558,278818,6061,010,822

A summary of cover crop distribution in Iowa, summarized in Appendix C, was created using the USDA Census of Agriculture county-level acres planted in the fall of 2017. County values were assigned proportionally to Iowa HUC8 watersheds based on the percentage of county land area that intersects each watershed.

The type of cover crop species planted, as reported by the INREC Ag Retailer Survey, from 2017-2021 are summarized below. The benefits of cover crop species N and P benefits vary slightly by species that reflect the benefits from winter-hardy and winter-kill cover crop species.

Cover Crop Species or Types, as a Percentage of Total Cover Crop Acres, from 2017 to 2021
YearRye Cover CropOat Cover CropMix of Cover Crop SpeciesOther Cover Crop
201769.4%9.1% 21.5%
201882.8%9.8% 7.4%

The use of cover crop mixes were not included in the INREC Ag Retailer Survey in 2017 and 2018.

Data Sources - Iowa Cover Crops

There are currently three data sources utilized for tracking the rate of cover crop adoption in Iowa. First, the Survey of Agricultural Retailers, conducted by the Iowa Nutrient Research and Education Council, has estimated annual statewide cover crop acres since 2017 (capturing the cover crops planted in the fall of the prior year). Second, the United States Department of Agriculture (USDA) Census of Agriculture provides county-level cover crop acres for fall 2012 and fall 2017, allowing for aggregated statewide totals for those years. Third, state and federal conservation programs (whereby government cost-share is given to farmers and landowners) provide spatially explicit records of publicly funded cover crop acres. All state programs recorded by the Iowa Department of Agriculture and Land Stewardship were included in this analysis of cost-share acres, as well as acres under the federal Environmental Quality Incentive Program and Conservation Stewardship Program, and are summarized in the table below.

Iowa Tillage Practices

In the last few decades, the use of no-till and conservation tillage in Iowa has increased dramatically. Conservation tillage represents a range of reduced tillage practices that leave at least 30% of crop residue on the soil surface following harvest and planting. No-till further minimizes soil disturbance by leaving most of the crop residue on the surface.

During the INRS baseline period from 1980-1996, no-till was used on an average of two million acres. In 2012, the USDA Census of Agriculture estimated 6.9 million acres of no-till. Since 2012, no-till acres have increased to approximately 9.5 million acres, according to both the Census and the Survey of Agricultural Retailers. No-till practices account for a higher portion of row crop acres in the rolling landscapes of western Iowa, for example, the Loess Hills region and some southern and northeastern watersheds.

Conservation tillage was practiced on 5.2 million acres during the baseline period, on average, and on an estimated 8.8 million acres in 2012. Since then, conservation tillage has increased to approximately 5.3 million acres annually, according to both the Census of Agriculture and the Survey of Agricultural Retailers. The use of conservation tillage is distributed across the state, with higher rates of use in the western, north-central, and northeastern regions of Iowa.

The increased use of no-till and conservation tillage in row crop operations since the 1980s is paired with a marked decrease in the use of conventional tillage. Conventional tillage was used on an estimated 12 million acres during the baseline period and has decreased to approximately 8.3 million acres in 2021.

Iowa Tillage Practices, by Data Source
Data Source and Practice Name1980-1996 Average Annual2006-2010 Average Annual201220172018201920202021
Iowa Nutrient Reduction Strategy - Derived from data from the Conservation Technology Information Center        
Conservation Tillage5,190,1706,064,720      
Conventional Tillage12,042,5858,288,043      
Census of Agriculture        
No-Till  6,950,8368,196,199    
Conservation Tillage  8,760,34810,132,599    
Conventional Tillage  7,882,5565,018,129    
Survey of Agricultural Retailers        
No-Till   7,707,6956,972,4348,153,5028,589,2429,461,121
Conservation Tillage   11,611,28810,247,2299,475,3814,935,4935,253,814
Conventional Tillage   3,676,1465,733,4075,294,8069,822,9988,259,545

A summary of tillage practice distribution in Iowa, summarized in Appendix C, was created using the USDA Census of Agriculture county-level acres planted in the fall of 2017. County values were assigned proportionally to Iowa HUC8 watersheds based on the percentage of county land area that intersects each watershed.

Data Sources - Iowa Tillage Practices

Tillage acres were estimated using three data sources. First, the 1980-96 baseline period (displayed here as 1996) and the 2006-10 benchmark period (displayed here as 2010) are derived from the Crop Management Residue Survey, conducted by the Conservation Technology Information Center for Iowa from 1982 to 2011. Methods for using these findings to determine average annual acreages are described in the Iowa Nutrient Reduction Strategy Nonpoint Source Science Assessment and the corresponding Iowa Nutrient Reduction Strategy baseline study, both of which can be found at the Iowa Nutrient Reduction Strategy website.

Statewide acreages for the 2012 and 2017 crop years were estimated using the United States Department of Agriculture Census of Agriculture, which provides county-level data for no-till, conservation tillage, and conventional tillage.

Annual statewide acreages of tillage practices in corn and soybean fields are estimated by the Survey of Agricultural Retailers, conducted by the Iowa Nutrient Research and Education Council, for the 2017 to 2021 crop years.

Nutrient Management in Iowa - Nitrogen Rates and Phosphorus Application

During the 1980-96 baseline period, corn-soybean rotations received an estimated average of 149 pounds of commercial and manure nitrogen; continuous corn rotations received 199 pounds per acre. This figure was estimated using a similar methodology for the 2006-10 benchmark period at 151 pounds per acre for corn-soybean rotations and 201 pounds for continuous corn. These estimates were derived from the state fertilizer sales data, which is publicly available from the Iowa Department of Agriculture and Land Stewardship (IDALS), and the USDA Census of Agriculture’s reported animal units in Iowa.

The Iowa Nutrient Research and Education Council designed a Survey of Agricultural Retailer Survey to estimate the extent of in-field practice use, including commercial fertilizer application practices, and has been completing the survey since 2017. The annual survey has found that in corn-soybean rotations, corn acres received, on average, between 170 and 183 pounds per acre during the 2017-21 period. On average, continuous corn rotations received between 200 and 202 pounds per acre during that time.

Percent Distribution of Commercial Nitrogen Rates from 2017-2021 by Crop Year and Rotation.
Category (Pounds Nitrogen Per Acre)20172018201920202021
Continuous Corn     

These annual nitrogen fertilizer rates represent statewide averages; however, nitrogen application rates to corn vary across agricultural fields and, in some cases, vary by acre within a field. The percent of total acres that received various levels of commercial nitrogen rates varies by crop rotation. In 2021, for example, 33 percent of corn-soybean acres received 176-200 pounds of commercial nitrogen on their most recent corn year, and 32 percent received 151-175 pounds. Some fields lay at the ends of this distribution, with 21 percent of acres receiving 150 pounds of nitrogen per acre or less and 11 percent receiving 201 pounds per acre or more. There was a similar distribution for continuous corn rotations, with 47 percent of acres receiving 176-200 pounds of commercial nitrogen fertilizer.

These estimates of annual nitrogen applications from 2017-21 represent an increase in fertilizer use since the 1980-96 baseline period. While the 2017-21 estimates of commercial fertilizer rates were obtained via a different data collection process than for the baseline and benchmark time periods, there is complementary evidence from recent fertilizer sales data that commercial fertilizer application rates for corn-soybean operations have increased gradually since before 1990. Increases in Iowa’s corn acres since that time have not increased at the same rate as the increase in commercial nitrogen fertilizer sales, that is the ratio of fertilizer sales to corn acres in the state, supporting the finding that average commercial nitrogen application rates (in pounds per acre) have increased over time.

Research into nitrogen application rates lies at the forefront of the Iowa Nitrogen Initiative, a research program piloted in 2021 that utilizes soil, weather, and management systems. With the goal of developing a probability-based decision system that incorporates regional weather parameters, expanding from the crop rotation to the individual region will help address productivity, profitability, and environmental performance, the initiative will encourage fertilizer application decisions to be made based on financial and local environmental conditions. The initiative will offer a decision-making tool based on local conditions and facilitate the evaluation of needs relative to the Maximum Return to Nitrogen (MRTN).

Phosphorus fertilizer application methods that inject or incorporate it into the soil, compared with broadcasting across the soil surface, reduce potential nutrient losses from the field. The Survey of Agricultural Retailers estimated 14.4 million acres received phosphorus fertilizer was incorporated, injected, or knifed into the soil within 24 hours of application for the 2017 crop year and decreased to 11.8 million acres for the 2021 crop year. These estimates account mostly for commercial fertilizer. Only 16% of surveyed fields received manure, with a small portion of these acres receiving manure and commercial P each year. In addition, approximately 80% of fields receive soil test phosphorus, more than 18,000,000 acres, that guide phosphorus application.

Phosphorus Fertilizer Application Methods, as Annual Row Crop Acres.
Phosphorus Management Type20172018201920202021
Commercial P Incorporated with Planter2,523,799862,841270,492639,271144,756
Commercial P Incorporated in Knifed Bands656,919627,900619,632692,078625,440
Commercial P Broadcast & Incorporated within 1 week10,807,03016,143,90515,847,4469,440,9349,916,964
Liquid P (commercial/manure) Injected416,049865,3642,048,8501,825,2321,155,754
Other P Application Type8,591,3314,468,9314,137,26910,750,21811,130,161

Data Sources - Nitrogen Rates and Phosphorus Application

Commercial nitrogen application rates were obtained from the Iowa Nutrient Research and Education Council's Survey of Agricultural Retailers, which has been conducted annually since 2017. The statewide average annual rates of commercial nitrogen fertilizer application were calculated using a stratified, weighted average approach, based on each field's size and the number of observations within each major land resource area in Iowa.

The distributions of varying application rates for continuous corn and corn-soybean rotations were determined using the survey's records for agricultural fields that received only commercial nitrogen fertilizer in 2021.

The total application of commercial nitrogen fertilizer, in tons per year, was estimated from Iowa’s fertilizer sales data and the USDA Census of Agriculture, using the methods described in the NRS Nonpoint Source Science Assessment, which can be accessed at

To estimate the total plant-available nitrogen from manure applied to crops since the 1980-96 baseline period, researchers evaluated livestock animal unit data, USDA Census of Agriculture data, and published studies on manure nutrient availability. The methodology is described in the NRS Nonpoint Source Science Assessment, which can be accessed at

Acres of various timing methods for commercial phosphorus application were obtained from the Iowa Nutrient Research and Education Council's Survey of Agricultural Retailers, which has been conducted annually since 2017. The statewide acreages of each phosphorus application method were calculated using a stratified, weighted approach, based on each field's size and the number of observations within each major land resource area in Iowa.

Nutrient Management in Iowa - Nitrogen Application Timing

Nitrogen application timing also affects nitrogen loss. Shifting nitrogen application from fall to spring reduces nitrogen loads by 6% and shifting from spring pre-plant to in-season application (i.e. side-dress) reduces nitrogen loads by 4-7%. The Survey of Agricultural Retailers provides recent estimates of when nitrogen is most commonly applied. In 2021, a split application of spring and side-dress was used on 6.9 million corn acres. That year, 1.7 million corn acres received only side-dress application and 5.2 million acres received only spring pre-plant.

Fall-applied anhydrous with nitrapyrin has been shown to reduce nitrogen loads by approximately 9% when compared with applications without an inhibitor. Based on the NRS Nonpoint Source Science Assessment, researchers estimated that during the 2006-10 benchmark period, fall anhydrous was applied annually to 5.7 million acres of corn-soybean and continuous corn acres. Of these acres, nitrification inhibitor was applied to 3.5 million acres. According to the Survey of Agricultural Retailers, farmers’ nitrification inhibitor use has increased since the benchmark period. As a comparison to the 1980-96 baseline period, researchers associated with the NRS Nonpoint Source Science Assessment suggest, based on professional knowledge, that nitrification inhibitor was used on a negligible number of acres due to the recent development of the technology.

Commercial Nitrogen Fertilizer Timing for Corn Acres.
Timing Category20172018201920202021
Fall anhydrous plus
Nitrification Inhibitor
Fall Anhydrous without
Nitrification Inhibitor
In-Season Only281,723137,166148,057529,107219,339
Spring Pre-Plant6,487,3297,652,7386,950,0246,443,4435,165,386
Spring Side-Dress Split, 40-601,307,0862,004,2632,300,0091,907,5361,691,866

Data - Nitrogen Application Timing

The data showing the timing of commercial nitrogen applications were obtained from the Iowa Nutrient Research and Education Council's Survey of Agricultural Retailers, which has been conducted annually since 2017. The statewide proportions of the data were calculated using a stratified, weighted approach, based on each field's size and the number of observations within each major land resource area in Iowa.

Bioreactors, Saturated Buffers, and Multi-Purpose Oxbows

Bioreactors and saturated buffers are edge-of-field practices that are made by routing agricultural drainage water through a woodchip trench or vegetated buffer to remove nitrate before the water enters an adjacent stream, ditch, or tile main. At 43% and 50% reduction, respectively, these practices are highly effective at reducing annual nitrate loads to streams. The suitability of bioreactors and saturated buffers for a farm field is highly dependent upon the presence of tile drainage, topography, and soil types.

From 2011 to 2021, at least 107 bioreactors and 87 saturated buffers were installed throughout Iowa; using a conservative assumption that these practices each protect 50 acres of drained cropland, at least 9,700 acres are protected, as of the end of 2021.

Multi-purpose oxbows are similar edge-of-field practices that were added to the Iowa Nutrient Reduction Strategy in 2019. At 52% reduction, the practice is highly effective at reducing nitrate loads to streams. A naturally occurring oxbow is a floodplain wetland that forms when a stream or river cuts a straighter path through a loop of its meander or when a stream is channelized. Routing agricultural drainage water into a restored oxbow can reduce nitrate concentration in the tile flow before it moves to the adjacent stream. Multi-purpose oxbows will be reported as multi-purpose oxbow reporting becomes available.

Annual Acres Treated by New Bioreactors and Saturated Buffers in Iowa
Row Labels201020112012201320142015201620172018201920202021
Bioreactor - Acres Treated by New Practices Annually 150150502002502504008504001,1001,550
Saturated Buffer - Acres Treated by New Practices Annually50  50502504503003504003502,100
Cumulative Acres Treated By Bioreactors and Saturated Buffers in Iowa502003504507001,2001,9002,6003,8004,6006,0509,700

A summary of edge-of-field practice distribution in Iowa by HUC8 watershed is summarized in Appendix C.

Data Sources - Bioreactors, Saturated Buffers, and Multi-Purpose Oxbows

Acres protected by bioreactors and saturated buffers were summarized using state and federal conservation program data as well as practices known to be installed by IDALS staff, which provide detailed, spatial records of publicly funded practices. All state programs recorded by the Iowa Department of Agriculture and Land Stewardship were included in this analysis of cost-share practices, as well as practices under the federal Environmental Quality Incentive Program and Conservation Stewardship Program. Practices installed without financial assistance were primarily designed by Iowa State University. Due to variable data in early years of bioreactor and saturated buffer construction (e.g. 2011 to approximately 2015), an assumption of 50 acres protected by each practice was used. A Conservation Innovation Grant is currently evaluating information to better estimate acres protected.

Acres Protected by Water Quality Wetlands Installed Each Year in Iowa

Water quality wetlands that are designed for water quality improvement have an effectiveness of 52% nitrogen load reduction. In designing these types of wetlands, agricultural tile drainage is routed through the wetland for nitrate removal. Currently, water quality wetlands require higher financial investment and development time than many other best management practices but have a lifespan of multiple decades or more, and have a lower cost per protected pound of nitrogen making the practice very efficient. Most of Iowa’s wetlands have been constructed under the Conservation Reserve Enhancement Program (CREP), but novel wetland siting standards have been implemented over the past decade to expand wetlands from the traditional CREP break-point wetland design. Novel wetland positions on the landscape include lateral and in-stream designs, both intentionally designed to treat agricultural drainage water similar to the classic breakpoint design used for CREP-designed wetlands. Programs and individuals other than the Iowa Department of Agriculture and Land Stewardship and Farm Service Agency have installed wetlands in Iowa that are similarly sited and constructed to water quality wetland design standards, but data currently are not available to assess the full extent of this non-CREP implementation.

Currently, Iowa has 119 water quality wetlands, which have all been constructed since the 1980-96 baseline period of the Iowa Nutrient Reduction Strategy. These wetlands have a cumulative drainage area of 139,000 acres. Iowa experienced its highest rate of installations in 2021, with 24 new wetlands capturing nearly 26,500 acres. Program implementation continues, with wetland design types developed in recent years expanding the position on the landscape where nutrient removal wetlands can be sited. Water quality wetlands constructed since 2011 (i.e. since the 2006-10 benchmark period of the Iowa Nutrient Reduction Strategy) protect more than 88,000 acres of agricultural land.

Annual Acres Treated by New Nitrate Removal Wetlands Installed in Iowa
New Acres Treated Annually2,4882,18963410,94114,8005,96213,4148,0746,96513,5196,3344,940010,4484,5961,9456834,82926,481
Cumulative Acres Treated2,4884,6775,31116,25231,05237,01450,42858,50265,46778,98685,32090,26090,260100,708105,304107,249107,932112,761139,242

A summary of water quality wetland distribution in Iowa by HUC8 watershed is summarized in Appendix C.

Data Sources - Water Quality Wetlands in Iowa

Acres protected by water quality wetlands were estimated using data from the Iowa Department of Agriculture and Land Stewardship. A majority of these wetlands were installed under the Conservation Reserve Enhancement Program, but some were funded through other programs and partnerships.

Cumulative Acres Protected by Structural Erosion Control Practices Installed in Iowa Since 2011

The Iowa Nutrient Reduction Strategy Nonpoint Source Science Assessment identified a set of structural practices that capture sediment or reduce erosion within or at the edge of an agricultural field that reduce soil-bound phosphorus loss. These practices include terraces, water and sediment control basins (WASCOBs), farm ponds, and grade stabilization structures; their effectiveness at reducing phosphorus loads range from 77% to 85%.

Currently, it is assumed a significant portion of erosion control practices are constructed through the financial assistance of state and federal government cost-share programs and this report presents data from those sources. An estimated 290,000 acres are protected by terraces, WASCOBs, ponds, and grade stabilization that have been installed under government cost-share programs since 2011. Owing to the topography and soils of the southern and northeastern regions of Iowa, erosion control practices are concentrated primarily in those geographic areas.

The Iowa BMP Mapping Project is an ongoing effort that will estimate the extent of all erosion control installations—not just those funded by state or federal cost-share programs. The project’s data collection is complete for three time periods: the 1980s, 2007-10, and 2016-17. Efforts to utilize this invaluable data source include both the acres protected by practices, within each watershed and statewide, as well as the nutrient reduction benefits of practices. These active areas of research will be summarized as data becomes available.

Annual Acres Treated by New Structural Erosion Control Practices Installed in Iowa Since 2011
Terraces and Water & Sediment Control Basins - Acres Treated by New Practices Annually30,2778,78921,91727,94726,00824,13218,55817,01721,31223,15012,040
Grade Stabilization and Ponds - Acres Treated by New Practices Annually9,0434,6715,0496,4703,9936,8784,2622,3153,7926,2785,711
Cumulative Acres Treated by Terraces, Water & Sediment Control Basins, Grade Stabilization, and Ponds39,32052,78079,746114,163144,163175,174197,994216,189242,430271,858289,609

A summary of structural erosion practice distribution in Iowa by HUC8 watershed is summarized in Appendix C.

Data Sources - Structural Erosion Control Practices in Iowa

Structural erosion control practices were summarized using state and federal conservation program data, which provide detailed, spatial records of publicly funded cover crop acres. This report accounts for practices installed between 2011 and 2021. All state programs recorded by the Iowa Department of Agriculture and Land Stewardship were included in this analysis of cost-share practices, as well as practices under the federal Environmental Quality Incentive Program and Conservation Stewardship Program. Structural erosion control practices reported include terraces, water and sediment control basins, grade stabilization structures, ponds, and water and sediment control basins (NRCS practice codes 600, 350, 410, 378, and 638). The database for state programs provides an estimate of the acres protected by each erosion control practice. For terraces, water and sediment control basins, and grade stabilization structures, and within each HUC8 watershed, the state database’s mean acres protected per foot installed was applied to the federal cost-share practices to obtain an estimate of total acres protected. For ponds, there were no federal practices to extrapolate, so only state data were used.

Structural best management practice adoption prior to the INRS annual report tracking, which began in 2011, was summarized by the Iowa BMP Mapping Project. Practices visible in aerial imagery and high-resolution topography data (statewide LiDAR data) were reviewed and practices mapped. This integrates practices constructed over several decades to track best management practice adoption. Practices depicted by the Iowa BMP Mapping Project include both practices implemented with and without cost-share assistance; note that INRS reporting efforts only include practices that receive state or federal cost-share as self-funded practices are not reported annually the evaluation of all practice benefits will be explored in the future.

Tracking Point Source Nutrient Reduction Effort - Wastewater Treatment and Industrial Facilities

Understanding Point Source Efforts Associated with the Iowa Nutrient Reduction Strategy

The Iowa Nutrient Reduction Strategy identifies 161 industrial (54 permits) and municipal wastewater treatment point source facilities (107 permits) that are required to evaluate the amounts of nutrients in their discharges in order to meet the goals of the strategy. Upon receiving a National Pollutant Discharge Elimination System (NPDES) permit under the Strategy, each facility works to develop a feasibility study, which outlines the resources required to achieve nutrient reduction goals. The permits also incorporate requirements for measuring nutrient concentrations in influent and effluent to determine current nutrient removals and provide an empirical basis for feasibility studies.

As of January 1, 2022, municipal and industrial permits that have been amended with construction schedules to meet INRS goals are summarized in the table below.

Facilities with an Amended Permit as of January 1, 2022, with the Nutrient Loads Designed to Achieve INRS Point Source Goals.
Activity for PermitsMunicipal FacilitiesIndustrial Facilities
Count of Facilities4714
Earliest Completion DateAugust 1, 2018January 1, 2018
Latest Completion DateOctober 1, 2027December 1, 2025
Average Length of Construction Schedule4.3 Years3.4 Years

Point source facilities listed in the strategy are required to monitor raw waste and final effluent for total nitrogen (TN) and total phosphorus (TP). However, some industries (e.g., power plants) that do not have a treatment plant are required to monitor only the final effluent as water is only to cool equipment. This extensive monitoring effort has generated one of the country’s most complete sets of point source nutrient data, and the extent of this data collection will continue to increase as the remaining permits are issued. This data has enabled the facilities and the Iowa Department of Natural Resources to determine current TN and TP loads associated with these point sources, even before additional nutrient reduction technologies are installed.

A facility uses the data collected during the two-year period after permit issuance to evaluate the feasibility and reasonableness of reducing the amounts of nutrients discharged into surface water. The Iowa Nutrient Reduction Strategy establishes a target of reducing TN and TP from point sources by 66% and 75%, respectively. A facility’s feasibility study must include an evaluation of operational changes that could be implemented to reduce the amounts of TN and TP discharged. If the implementation of operational changes alone cannot achieve the targets, the facility must evaluate new or additional treatment technologies that could achieve reductions in the nutrient amounts discharged. At the end of 2021, 154 feasibility studies had been submitted.

Annual Progress of Issuing Point Source Facility Permits
YearPermits Issued with Feasibility Studies SubmittedPermits Issued, Awaiting Feasibility StudiesPermits Remaining to be Issued

For INRS priority watersheds, three major POTWs are in the process of revising their NPDES permits. Note that changes in the number of facilities by year reflect changes in facility flow resulting in the change of the POTW classification, demonstrating that a source is not a nutrient source (e.g., industrial cooling purposes), or the combination of facilities (e.g., industrial waste treated by a municipal plant).

As these feasibility studies are reviewed and approved by the Iowa Department of Natural Resources, the schedules these contain for installing nutrient reduction technologies or optimizing existing treatment are added to the facilities’ NPDES permits by amendment. Once the construction or optimization outlined by the schedules is complete and treatment processes are optimized, facilities will submit twelve months of effluent TN and TP sampling results. Effluent limits based on those sampling results will then be added to facilities’ permits and become enforceable.

Point source facility permits with Nitrogen and/or Phosphorus limits as of the end of 2021 are summarized in the table below.

Point Source Facility Permits with Nitrogen and/or Phosphorus Limits as of the End of 2021
YearINRS Permits with Nitrogen and Phosphorus LimitsINRS Permits with Nitrogen Limits OnlyINRS Permits with Phosphorus Limits OnlyTotal permits with nutrient monitoring

Of the permitted point source facilities, the number achieving INRS N and P load reduction goals since 2013 are summarized in the table below.

The number of facilities each year with raw (influent) or final (effluent) wastewater monitoring for Total Nitrogen (TN) or Total Phosphorus (TP).
YearNitrogen - Facilities Meeting Percent Reduction TargetsPhosphorus - Facilities Meeting Percent Reduction Targets

Reported N and P loads since the INRS was adopted in 2013 for major public and industrial facilities are summarized in the table below. The points source N and P load goals are 7,556 and 1,303 tons, respectively.

Annual Total Nitrogen and Phosphorus Loads from Major Publicly Owned Treatment Works, Minor Domestic, and Industrial Facilities with Biological Treatment of Process Wastewater.
YearNitrogen Load (tons)Phosphorus Load (tons)



An Overview of the Water Measurement Indicator

Monitored water quality reflects the dynamic interaction of current and historical land management practices, structural conservation practice adoption, and point source loading with the weather. The INRS Logic Model and reporting on efforts via the dashboards enable the documenting of key metrics that inform feedback to identify and focus inputs, activities, and outputs to advance the goals of the INRS. Reporting water quality changes includes modeled changes in nonpoint source nutrient export (point source tracking reported in the Land dashboard) based on agricultural management and BMPs adopted or installed and monitored nutrient loads from rivers.

This dashboard summarizes each tracked component of the Water indicator:

  • Modeled impacts of BMP adoption and construction, agronomic practices, and land use for which INRS progress is evaluated; and
  • Statewide, annual N and P export from Iowa based on measured loads from rivers.

The scales, spatially and temporally, at which water quality benefits might be anticipated to be detectable from monitoring data are reviewed in the next tab. This topic was explored for nitrogen loads for Iowa in a 2020 report titled How Long Will it Take to Measure an Improvement in Iowa's Water Quality? prepared for the Iowa DNR.

Changes from 1980-1996, the "baseline," to the initial INRS assessment from 2006-2010, the "benchmark," are summarized in the table below for nonpoint (NPS) and point (PS) loads. A summary of the nonpoint and point source changes between the two periods can be found here. Practice effects on nutrient loads are compared to the baseline period.

Summary of INRS Baseline (1980-1996) and Benchmark (2006-2010) Nitrogen and Phosphorus Loads by Source.
NutrientSourceBaseline Load (tons)Benchmark Load (tons)Change from Baseline to BenchmarkMajor Cause of Change
NitrogenNPS278,852*293,3955.2% IncreaseLand use change
PS13,17014,0546.7% IncreaseFlow increase
Total292,022307,4495.3% Increase 
PhosphorusNPS21,43616,80021.6% DecreaseReduced tillage and soil test P
PS2,3862,6239.9% IncreaseFlow increase
Total23,82219,42318.5% Decrease 

*The methods used to derive the total nitrogen estimate of 292,022 tons indirectly reflected the point source contributions.

Measuring N and P Load at Scale and Time

The scale at which changes in N and P loads can be measured is a continued area of focus for the INRS. With a goal of 45% N and P load reduction, the spatial and temporal scales within a watershed at which management and conservation practices – representing the land use, wastewater management improvements, and agronomic and conservation practice adoption – are reflected in nutrient loads. Ongoing research continues to examine the watershed and temporal scale at which load reductions can be quantified. Assessing the nutrient load over time is challenging due to “legacy nutrients” that vary in movement through soil and shallow groundwater before reaching streams and rivers. Measuring nutrient load changes at the landscape scale is equally challenging as flow, the amount of runoff that leaves fields, is the strongest predictor of nutrient loss and varies annually. Currently understood scales for which changes in water quality are likely detectable are summarized in the table below.

Overview of the Time Scale at which Changes in Nutrient Loads may be Reasonably Detected by Watershed Size.
Landscape ScaleProgress Measurable (years)Description of Scale
Edge of a Farm Field0-10Loss can occur through tile flow, soil loss, and runoff
Farm Fields in a Sub-Catchment0-10Crop rotations, buffer use, and erosion control vary by watershed
Small Watershed (HUC12)10+HUC12s average 22,500 acres, or about 16 per county
Large Watershed (HUC8)10-20HUC8s average 961 acres, or cover the area of about 2.5 counties
State of Iowa within the Mississippi River Basin20+Iowa covers 4.5% of the Mississippi River Basin by area

Water Quality Monitoring Infrastructure in Iowa

Statewide Monitoring
Tracking water quality for the NRS for statewide reporting in 2021 was conducted by the United States Geological Survey (USGS), the Iowa Department of Natural Resources (DNR), the Iowa Institute of Hydraulic Research (IIHR), and the Iowa Geological Survey (IGS). The USGS monitors a large number of sites for flow, providing a long-term historical record, that allows for nutrient loads to be estimated since 2000 at least based on monitoring efforts by state agencies. The Ambient Water Quality Monitoring Network was comprised of 62 monitoring sites to measure N and P in 2021. Of these 62 sites, statewide loads were estimated from monitoring sites near the boundaries of Iowa at 18 and 16 sites for N and P, respectively. Nutrient loads reported are the total for each river at the monitoring site, including loads that originated from outside of Iowa.  These sites utilize DNR monthly sampling data, and USGS sensor data or IIHR-operated probes that offer “real-time” data as available, for each monitoring site to estimate load based on USGS flow data for each site.

More information about USGS, DNR, or IIHR-administered monitoring sites can be found

Note that real-time data from sensors is made publicly available upon collection but records may not be certified until several months after data collection by the agency operating the gage or sensor.

Local Monitoring

Local monitoring efforts have been implemented by INRS-reporting partners to monitor baseline conditions or to measure the effect of implementing a BMP(s). These efforts include DNR programs other than the Ambient Stream Network that smaller rivers, streams, and lakes as well as research programs conducted by Regents Institutions, Iowa Soybean Association, and the Agriculture’s Clean Water Alliance. Efforts include the general monitoring of surface waters, small watersheds to monitor the impact of a BMP at the field or small catchment scale, or tile monitoring. Monitoring efforts submitted by reporting partners are summarized at the HUC-12 watershed scale in Appendix D.

Surface Water Monitoring Sites in Iowa

Statewide N and P loads are measured at monitoring sites on major rivers (18 N sites and 16 P sites) near the boundary of Iowa before flowing into the Mississippi or Missouri Rivers. The siting of these monitoring sites is able to cover the majority of the surface area of the Iowa. In addition, areas of river basins originating in Minnesota are included in the Iowa statewide load as loads are reported at the basin outlet. The rivers and contributing area, the upstream area draining to the monitoring point, are summarized by watershed size at the HUC-12 watershed scale in Appendix D. Note that only monitoring sites reported by INRS reporting partners are summarized.

Iowa Precipitation Summary

The INRS reports on nutrient loading and water yields at the state scale. However, the amount of water each region receives drives the amount of flow, varying regionally and temporally each year. In 2021, the average precipitation for Iowa was 31.06 inches, 4.45 inches greater than the long-term average. But, the 2021 average was within the average precipitation range for the INRS (29-36.5 inches). The water yield during the INRS baseline was approximately one-third of precipitation, comparable to 2021.

More information about Iowa's climate - monthly or annual climate summaries, maps, current conditions, and drought reports - can be found on the Iowa Climate Bureau's webpage at the Iowa Agriculture and Land Stewardship.

The Water Yield for Iowa

The net amount of water generated on the basis of stream flow versus precipitation regressions for watersheds across Iowa. Flow is summarized below and used to assess nutrient load relative to flow in subsequent sections.

Water Yield for Iowa - The Net Amount of Water Generated on the Basis of Stream Flow versus Precipitation Regressions for Watersheds Across Iowa
Flow (in/yr)4.2110.174.755.038.776.225.614.3518.3812.7120.811.093.5110.2510.8712.9515.7610.4517.8418.73105.45
Five-Year Average Flow (in/yr)    6.596.996.077.9910.6611.4514.3715.4713.311.6711.39.7310.6712.0613.5715.1514.5612.5

Measured Changes in N Export Based on River Monitoring

The nitrogen load from Iowa for 2021 was the second lowest observed during the period for which statewide data is available (2000). Similarly, the flow-weighted nitrate load (FWNL) was also low and recorded as the lowest since 2000. The FWNL characterizes changes in nitrate losses normalized to flow. Periods of low statewide flow correspond with low statewide N load as nitrogen is not lost through runoff from fields. Precipitation is the strongest predictor of N loads, precipitation in the current year and previous year, and can compound N losses following periods of prolonged low flow. Cyclical responses in statewide N load are anticipated and will reflect agronomic practices and BMPs adopted regarding N management.

Nitrogen Load From River Monitoring Sites using the Linear Interpolation Method to Fill in Concentrations Between Sampling Events and the N Load Normalized to the Amount of Flow During Each Year.

Annual Nitrate-N Load101,297300,428115,070144,048264,356186,995174,989450,132434,611281,028455,312297,24566,188342,921267,052417,793531,776318,111426,416396,289241,25481,619
5-year Moving Average Nitrate-N Load    185,040202,180177,092244,105302,217305,551359,215383,666306,877288,539285,744278,240325,146375,531392,230418,077382,769292,738
Annual Nitrate-N Flow-Weighted Load24,02329,53924,20628,63130,11330,03431,24831,35823,64222,10121,88926,78218,85233,44924,56532,23933,74130,41623,89521,15224,10214,959
5-year Moving Average Nitrate-N Flow-Weighted Load    27,30228,50528,84630,27729,27927,67726,04825,15422,65324,61525,10727,17728,56930,88228,97128,28926,66122,905

Annual data is driven primarily by flow within each monitoring year. Applying a five-year moving average assists in characterizing statewide loads and variability anticipated with changes in inter-annual precipitation. These trends are cyclical and are observed in the nearly twenty years of available data.

Water Quality - Nitrogen Monitoring

Quantifying nutrient loading from Iowa is reported as the monitored load in rivers (modeled for each river based on collected monitoring data) and modeled impact of land use practices on nutrient load. Information on how nonpoint and point source loads were determined for the INRS baseline can be found in the reports titled:

These resources established the baseline from which the nutrient load reduction goals for nonpoint and point sources are established. Both N and P nutrient loads during the baseline and benchmark periods (INRS-Science Assessment period of 2006-2010) are summarized in the reports above.

State agencies, universities, and the United States Geological Survey have expanded river monitoring over the past decades to improve understanding of flow and monitor nutrients. Monitoring infrastructure was not available to measure N loads during the INRS baseline period of 1980-1996 so nonpoint and point source loads were interpolated from wastewater and population data, land use, agronomic management, practice adoption, and precipitation during the time period. The infrastructure that has been available since at least 2000 now provides a means to quantify statewide nutrient loads - nutrient loads as concentration, the amount of a nutrient lost per unit time as a load, or normalize nutrient loss to the amount of flow within the river.

In 2017, the INRS science team evaluated and recommended the Linear Interpolation method be used to model N load for river monitoring data (see Schilling et al. 2017 and the NRS 2017 Supplemental report titled “Assessment of the Estimated Non-Point Source Nitrogen and Phosphorus Loading from Agricultural Sources from Iowa During the 1980-96 Hypoxia Task Force Baseline Period"). This method fills in data gaps between sampling events for each monitoring site by drawing a straight line and is not only simple, but provides a robust measure of N load. Frequent sampling provides the highest quality data with a longer time between sampling periods increasing the potential uncertainty in the modeled load.

Precipitation is the primary driver of stream flow in Iowa’s rivers with flow from rivers monitored by the USGS (see more about gaging locations in the previous panel). The amount of flow at each monitoring site is normalized each year. Flow is measured as the average depth of water that runs off the watershed and is calculated by deducting from precipitation that falls in the watershed from soil saturation and temperature. Statewide flow is then based on the weighted average flow of each watershed as a proportion of the area of the watershed.

Measured Changes in P Export Based on River Monitoring

Phosphorus loads are strongly correlated with the amount of flow, with large flood events regularly accounting for more than half of an annual load. With lower flow in 2020 and 2021, the P load and flow-weighted P load (FWPL) have been lower than the period for which P load data is available. Similar to N, the annual P load is “noisy” and a 5-year moving average is used to assess patterns over time. Since 2010, the 5-year moving average P load has been greater than the INRS load goal for P, driven by years of average or above-average flow.

The FWPL is largely below the INRS baseline for the available historical record annually, and the 5-year moving average FWPL is continuously below the baseline period. This demonstrates the impact of high flow years compared to the 5-year moving average. However, no trend in the 5-year moving average FWPL is observed.

Phosphorus Load From River Monitoring Sites using the LOADEST-K Model Using Flow, Season, Measured P, and Turbidity Data from Monitoring Stations to Calibrate the Model and the P Load Normalized to the Amount of Flow During Each Year (Loads may be updated in the future as improved calibration models are improved for rivers).

Annual Phosphorus Load6,78626,4998,3198,10218,1039,8746,91829,14238,64721,66938,83517,1446,06820,75428,19224,55424,36116,57232,05247,55113,6438,173
5-year Moving Average Phosphorus Load    13,56214,17910,26314,42820,53721,25027,04229,08724,47220,89422,19919,34220,78622,88725,14629,01826,83623,598
Annual Phosphorus Flow-Weighted Load1,6122,6061,7511,6112,0641,5881,2352,0312,1031,7051,8671,5461,7292,0252,5941,8961,5461,5861,7972,5391,3641,500
5-year Moving Average Phosphorus Flow-Weighted Load    1,9291,9241,6501,7061,8041,7321,7881,8501,7901,7741,9521,9581,9581,9291,8841,8731,7661,757

Between the baseline period and the historical record for which statewide P loads have become available, there were significant changes in farm operations. Farm tillage practices rapidly transitioned in the 1980s to meet soil conservation compliance established in the 1986 Farm Bill, the development of farm implement tools to manage higher residue systems, P application management in conjunction with soil testing, and crop protection practices. These phases of soil erosion conservation and P application management had significant impacts on statewide P losses during the INRS baseline period and before the release of the INRS in 2013.

Water Quality - P Monitoring

The river monitoring network for P is comparable to N  and infrastructure is described in that section as well as the Water Monitoring Infrastructure tab (bottom-left panel ). The mode by which the P load is calculated differs. In contrast with N, linear interpolation methods are not appropriate for estimating phosphorus (P). Phosphorus concentrations are dynamic and positively skewed, with some measurements far greater than the median concentration observed in a river under baseflow conditions. This means that phosphorus loads in rivers are strongly influenced by storms and high flow events, although infrequent, can strongly impact the P load. Linear interpolation as is used for N results in significant errors when modeling P, so more sophisticated modeling techniques are needed to quantify it.

Iowa’s annual P loads are modeled as two distinct chemical forms, orthophosphate (OP) and particulate phosphorus (Part P). Part P is the P bound to particulate matter, such as sediment, while OP represents the dissolved form of P. Summing these two P sources, OP and Part P, produce Iowa’s overall P load. Using data from monitoring stations P loads are estimated for each of 16 rivers near the border of Iowa using a combination of two modeling techniques: 1) the Weighted Regression on Time, Discharge and Season-Kalman Filter (WRTDS-K; Hirsch et al., 2010; Zhang & Hirsch, 2019) framework developed by the United States Geological Survey and 2) turbidity-based surrogacy models. A unique relationship between streamflow, measured P, and turbidity is used for each monitoring station to estimate P loads for that river. Data are made available for the state of Iowa but additional research is ongoing to improve estimates of P loads during high-flow events in several watersheds in the western half of the state.

The WRTDS-K models used for measuring P use streamflow, time of year, water quality trends, and observed P data to fill gaps between measured P concentrations. The surrogacy models use power regression to establish a relationship between turbidity, a measure of the water’s cloudiness, and Part P. These surrogacy models are more accurate than their WRTDS-K counterparts in estimating Part P and are used whenever on-site turbidity data are available.

More information about the WRTDS-K methodology may be found in the following references:

  • Hirsch, R. M., Moyer, D. L., & Archfield, S. A. (2010). Weighted regressions on time, discharge, and season (WRTDS), with an application to Chesapeake Bay river inputs. Journal of the American Water Resources Association, 46(5), 857-880. doi:10.1111/j.1752-1688.2010.00482.x
  • Zhang, Q., & Hirsch, R. M. (2019). River Water-Quality Concentration and Flux Estimation Can be Improved by Accounting for Serial Correlation Through an Autoregressive Model. Water Resources Research, 55(11), 9705-9723. doi:10.1029/2019WR025338

Changes in N from Nonpoint Sources

Consistent with modeling approaches as in the original INRS Science Assessment, load reduction estimates were calculated for a selection of INRS practices for which practice adoption data is available. The acreages and extent of these practices were determined using various data sources, including public conservation program databases, the Cropland Data Layer, INREC Survey, and the USDA Census of Agriculture. For more information on the approximation of BMP use in Iowa see the Land indicator dashboards or the Data tab below.

Modeled N load impacts of INRS practices for which reported practice adoption data is currently available compared to the baseline period. Negative values indicate a modeled N load reduction – practices are advancing statewide INRS N goals - and positive values indicate a modeled increase in N load for management or practice compared with the 1980-1996 INRS baseline period (292,022 tons N). The percent change for each practice is calculated independently of other practices and represents the benefits of the stand-alone practice without interaction with any other practice or management effect (values aren’t additive). The potential interaction of practices remains an active area to be assessed and will be integrated into reporting as methods become available.

Changes in Modeled N Load for Practices Since the Baseline Period
INRS PracticeImpact on N Load 2021 (tons)Per. N Load Impact in 2021 (%)
Cover Crop-12,015.7-4.1
N Timing: Nitrification Inhibitor-7,872.0-2.7
N Timing: Changes to Spring Pre-Plant, Sidedress, or In-Season-2,274.0-0.8
Water Quality Wetlands-947.3-0.3
Bioreactor or Saturated Buffer-56.00
N Rate Continuous Corn174.90.1
Extended to Continuous Corn1,432.30.5
Pasture, Grass, Hay or CRP to Continuous Corn1,782.80.6
Extended to Corn-Soybean2,239.20.8
Pasture, Grass, Hay or CRP to Corn/Soybean7,711.42.6
N Rate Corn-Soybean32,229.411

Adoption of BMPs that can be broadly adopted across Iowa increased in number, and the acreage benefitted from these practices since the 2019 INRS report. Cover crop adoption increased to an estimated 2.77 million acres in 2021 (INREC Ag Retailer Survey) – up from the 0.97 million acres reported in the last INRS report – and are estimated to reduce N losses from the baseline period by 4.1%, or more than 12,000 tons. A rye cover crop reduces N load by an estimated 31% per the INRS, accounting for more than 85% of cover crops planted in each of the past five years per the INREC Survey.

Similarly, practices that can be implemented at the edge-of-field, such as bioreactors, saturated buffers, and water quality wetlands, have seen an increase in practice adoption in recent years. These practices benefitted at least 9,700 acres and 139,000 for bioreactors/saturated buffers and wetlands, respectively. These practices reduced N loads by 56 and 947 tons for bioreactors/saturated buffers and wetlands in 2021. The adoption of these practices has increased primarily due to more recent development of these practices and increasing prioritization in the state to scale up installations.

The effect of in-field management and land use on modeled N load indicated an increase in statewide N load with changes in agronomic practices and land use. Agronomic management and land uses are cyclical and reflect market conditions and field access. The N application rate to corn in a corn-soybean rotation had the greatest estimated increase in statewide N load, with an increase of approximately 11% (32,200 tons) when compared to the estimated rate during the baseline period. These rates are stand-alone and compare rates from 2021 to the 1980-1996 baseline period. The adoption of other agronomic practices or BMPs (application timing, method, inhibitor use, etc.) that have been adopted at the same time N rates have increased are also depicted in the estimated N load.

For some nutrient reduction practices, insufficient data are available to complete a statewide assessment. The evaluation of other data sources for tracking these practices over time is ongoing.

Data Analysis - N Modelling of Nonpoint Sources

Consistent with modeling approaches as in the original INRS Science Assessment, load reduction estimates were calculated for a selection of INRS practices for which practice adoption data is available. The acreages and extent of these practices were determined using various data sources, including public conservation program databases, the Cropland Data Layer, the USDA Census of Agriculture, and the Iowa Nutrient Research Education Council Agricultural Retailer Survey. For more information on the approximation of conservation practice use in Iowa see the Land indicator dashboards. These assessments are on a per-practice basis and don’t factor in the additive or in-series effects of multiple or layered practices. Modeled load changes for the INRS are based on changes by Major Land Resource Area aggregated to the state level for individual practices.

Changes in P from Nonpoint Sources

Consistent with modeling approaches as in the original INRS Science Assessment, load reduction estimates were calculated for a selection of INRS practices for which practice adoption data is available. The acreages and extent of these practices were determined using various data sources, including public conservation program databases, the Cropland Data Layer, INREC Survey, and the USDA Census of Agriculture. For more information on the approximation of BMP use in Iowa, see the Land indicator sections.

Modeled P load impacts of INRS practices for which reported practice adoption data is currently available compared to the baseline period, except for terraces and basins that are compared to changes since 2010 (contingent on records availability). Negative values indicate a modeled P load reduction – practices are advancing statewide INRS P goals - and positive values indicate a modeled increase in P load for management or practice compared with the 1980-1996 INRS baseline period (23,822 tons P). The percent change for each practice is calculated independently of other practices and represents the benefits of the stand-alone practice without interaction with any other practice or management effect (values aren’t additive). The potential interaction of practices remains an active area to be assessed and will be integrated into reporting as methods become available.

Changes in Modeled P Load for Practices Since the Baseline Period
INRS PracticeImpact on P Load 2021 (tons)Per. P Load Impact in 2021 (%)
Cover Crop-2072.8-8.7
WASCOB, Grade Stabilization Structure, Pond-77.5-0.3
Conservation Tillage-19.3-0.1
Pasture, Grass, and Hay826.23.5

In contrast to N, nonpoint P losses in Iowa from fields are dominated by erosion of sediment and phosphorus bound to it. Adopting tillage practices that decrease soil disturbance or leave residue to protect soil is critical to reducing P loads. Tillage practices such as no-till and conservation tillage (leaving at least 30% residue) are estimated to reduce P loads by 90% and 33%, respectively, per the INRS. The adoption of these practices has grown to an estimated 9,461,121 and 5,253,814 acres, reflecting a reduction of 16.4% (3,920 tons) and 0.2% (19.3 tons) in statewide P load as of 2021, respectively.

Structural BMPs such as terraces and basins that can reduce or trap sediment offer similar benefits by preventing soil and thereby the attached phosphorus from leaving a field. Since 2010, practices that protect approximately 250,000 acres have been built using public financial assistance programs and are estimated to reduce P loads by 156 tons, or 0.7% of the baseline P load. The modeled benefits of practices are independent of other practices and the interaction of adopted BMPs, agronomic practices, and land use continue to be explored.

For some nutrient reduction practices, insufficient data are available to complete a statewide assessment. The evaluation of other data sources for tracking these practices over time is ongoing.

Data Analysis - P Modelling of Nonpoint Sources

The same sources for P modeling were used as N (see Data Analysis - N Modelling of Nonpoint Sources above).


Recommended citation: Iowa Department of Agriculture and Land Stewardship, Iowa Department of Natural Resources, and Iowa State University. (2023, August 6). Tracking the Iowa Nutrient Reduction Strategy. Version 2.0.…

Appendix A

Summary of INRS-Related Investment for State and Federal Conservation Programs from 2012-2021.
Program2012201320142015201620172018201920202021Program Total
Ag Drainage Well Closure (ADW) - IDALS $3,170,000  $1,920,000$1,920,000$1,875,000$1,875,000$1,875,000$1,875,000$14,510,000
Agricultural Conservation Easement Program (ACEP) - NRCS$21,100,000$13,900,000$11,000,000$10,714,000$12,500,000$14,500,000$10,500,000$9,400,000$12,300,000$29,400,000$145,314,000
Conservation Reserve Enhancement Program (CREP) - IDALS$1,000,000$1,000,000$1,000,000$1,000,000$1,000,000$1,000,000$1,000,000$1,000,000$1,000,000$1,000,000$10,000,000
Conservation Reserve Program (CRP) - FSA$212,942,766$216,365,107$214,402,613$221,360,787$243,650,296$318,308,819$360,771,362$387,472,169$387,472,174$382,490,928$2,945,237,021
Conservation Reserve Program (District Buffer Initiative) - IDALS$1,000,000$1,000,000$1,000,000$1,000,000$1,000,000$1,000,000$900,000$900,000$900,000$900,000$9,600,000
Conservation Stewardship Program (CSP) - NRCS$6,800,000$3,800,000$4,500,000$11,600,000$6,300,000$5,500,000$28,600,000$16,300,000$17,400,000$19,700,000$120,500,000
CWSRF - General Nonpoint Source Program (GNS) - DNR$1,448,374$19,097,952$5,855,169$33,087,739$9,031,750$7,317,468$6,066,869$15,818,908$5,658,638$2,910,041$106,292,908
CWSRF - Livestock Water Quality Facilities Program (LWQ) - DNR$7,920,004$5,354,917$5,426,596$3,047,121$3,340,508$1,805,882$2,517,174$5,331,462$990,299$600,155$36,334,118
CWSRF - Local Water Protection Program (LWPP) - DNR$5,841,175$3,462,811$2,903,378$2,419,318$1,824,691$1,739,977$2,023,572$1,708,438$1,583,310$1,216,129$24,722,799
CWSRF - Onsite Wastewater Assistance Program (OSWAP) - DNR$1,697,550$839,618$1,034,395$898,030$935,237$868,812$1,212,829$915,480$1,089,180$923,127$10,414,258
CWSRF - Sponsored Projects - DNR   $3,736,000$5,748,000$5,424,823$2,618,283$1,627,000$8,109,000$7,438,958$34,702,064
DNR - Water Quality Monitoring - DNR$2,955,000$2,955,000$2,955,000$2,955,000$2,955,000$2,955,000$2,955,000$2,955,000$2,955,000$2,955,000$29,550,000
Environmental Quality Incentives Program (EQIP) - NRCS$25,900,000$27,300,000$23,800,000$16,400,000$17,700,000$26,800,000$34,600,000$36,600,000$30,100,000$33,900,000$273,100,000
Farm Management Demonstration Program - IDALS$625,000$625,000$625,000$625,000$625,000$625,000$375,000$287,500$100,000 $4,512,500
GWP - IDALS Ag Drainage Well & Sinkhole - IDALS$611,656$684,090$666,739$698,244$713,765$756,085$732,645$729,870$741,396$794,343$7,128,832
In-Field Agricultural Practices Pilot Project - ISU    $1,230,000     $1,230,000
Iowa Financial Incentives Program - Publicly Owned Lakes (IFIP-POL) - IDALS$315,000$332,500$332,500$337,500$337,500$337,500$391,750$391,750$391,750$391,750$3,559,500
Iowa Financial Incentives Program (IFIP) - IDALS$5,985,000$6,317,500$6,317,500$6,412,500$6,412,500$6,412,500$7,443,250$7,443,250$7,443,250$7,443,250$67,630,500
Iowa Geological Survey - Water Resource Management - IGS       $495,000$495,000$495,000$1,485,000
Iowa Nutrient Research Center - ISU  $1,500,000$1,325,000$1,625,000$1,400,000$2,269,811$1,976,653$2,015,121$2,135,195$14,246,780
Lake Restoration - DNR$5,109,000$6,000,000$8,600,000$9,600,000$9,600,000$9,600,000$9,600,000$9,600,000$9,600,000$8,600,000$85,909,000
Leopold Center - ISU$1,643,615$1,838,630$1,791,916$1,876,738$1,918,525$2,032,465    $11,101,889
Loess Hills Development and Conservation Fund - Alliance Account - IDALS$118,750$131,250$150,000$159,375$150,000$150,000$40,000$40,000$40,000$40,000$1,019,375
Loess Hills Development and Conservation Fund - Hungry Canyons Account - IDALS$356,250$393,750$450,000$478,125$450,000$450,000$450,000$450,000$500,000$500,000$4,478,125
NPDES - 106 Grant - Wastewater Program Management - DNR$3,090,700$2,930,000$2,993,000$2,973,375$2,966,000$2,941,000$2,925,000$2,896,000$2,887,000$2,980,000$29,582,075
Regional Conservation Partnership Program (RCPP) - NRCS $406,785  $1,597,000$4,340,000$5,021,100$4,552,300$2,829,981 $18,747,166
Regional Conservation Partnership Program (RCPP-EQIP) - NRCS   $261,000     $2,212,878$2,473,878
Resource Enhancement and Protection Program (REAP) - Soil and Water Enhancement Account - IDALS$2,400,000$2,400,000$3,200,000$3,200,000$3,200,000$3,200,000$2,400,000$2,000,000$2,400,000$2,400,000$26,800,000
Section 319 - Nonpoint Source Activities - DNR$3,585,000$3,398,000$3,476,000$3,440,300$3,556,000$3,679,000$3,634,000$3,598,000$3,750,000$3,852,000$35,968,300
Soil and Water Conservation Administration - IDALS$2,000,000$2,550,000$2,550,000$2,550,000$2,700,000$2,800,000$3,800,000$3,800,000$3,800,000$3,800,000$30,350,000
Wastewater and Drinking Water Treatment Financial Assistance Program - IFA       $782,000$1,600,000$4,928,000$7,310,000
Water Quality Agriculture Infrastructure Program - IDALS       $1,955,000$4,000,000$15,000,000$20,955,000
Water Quality Financing Program - IFA       $879,750$1,800,000$6,750,000$9,429,750
Water Quality Initiative Fund - IDALS  $12,400,000$4,400,000$9,150,000$9,375,000$10,575,000$10,575,000$12,175,000$12,175,000$80,825,000
Water Quality Planning - 604b - DNR$193,000$183,000$192,000$191,000$183,000$181,000$219,000$217,000$217,000$217,000$1,993,000
Water Quality Urban Infrastructure Program - IDALS       $293,250$600,000$1,848,000$2,741,250
Watershed Improvement Fund - IDALS$2,000,000$4,000,000        $6,000,000
Watershed Protection - IDALS$900,000$900,000$900,000$900,000$900,000$900,000$900,000$900,000$900,000$900,000$9,000,000
Total by Year$317,537,840$331,335,910$320,021,805$347,646,152$355,219,772$438,320,331$506,416,645$535,765,780$529,718,098$562,771,754$4,244,754,088


Appendix B

Reported Events by County by Program Type from 2016 to 2021.
Community OutreachConferenceField DayWorkshopYouth and School VisitsTotalCommunity OutreachConferenceField DayWorkshopYouth and School VisitsTotalCommunity OutreachConferenceField DayWorkshopYouth and School VisitsTotalCommunity OutreachConferenceField DayWorkshopYouth and School VisitsTotalCommunity OutreachConferenceField DayWorkshopYouth and School VisitsTotalCommunity OutreachConferenceField DayWorkshopYouth and School VisitsTotal
AttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. EventsAttendanceNo. Events
Black Hawk5440025751172208163612274320013626140654251,518214024001708126741451,112247510006346136277651,62123200200321004037635107050041400461757216
Buena Vista74200110218055814221013920019847020040780000452151006032010010623031731329701001963001841380540100000010811482
Cerro Gordo000092200581150300009910010112002143100023013452518600001672001,28851,4557168100901000025820000000064166416
Des Moines00007512019921944150100862002592495500000300469246956610012160038122580000000000000000010011321133
Palo Alto000000000000000000341465249930000751151981188300000000000051000000643264833201000000003201
Van Buren00001292020012941742001031000027739120000111931285498100000012022183861000000178126420000000036243624

Appendix C

Summary of BMP Adoption by HUC-8 Watershed.
HUC-8 NameHUC-8 IDNo-TillConservation TillageCover CropsBioreactors and Saturated BuffersWater Quality WetlandsStructural Erosion Control Practices
Blue Earth070200096,719102,7082,715   
Coon-Yellow0706000147,07555,95110,8701 4,090
Upper Iowa0706000270,778161,99918,552  2,280
Grant-Little Maquoketa0706000344,17342,9448,870  990
Turkey07060004192,011329,96542,2643 3,420
Apple-Plum0706000561,72049,3987,778  830
Maquoketa07060006246,312353,47635,484  3,300
Copperas-Duck0708010182,06280,0309,0722 380
Upper Wapsipinicon07080102170,808384,71430,9481 820
Lower Wapsipinicon07080103181,792191,35416,4151 110
Flint-Henderson0708010453,99292,5787,8231 2,850
South Skunk07080105226,689364,02936,29914103,050
North Skunk07080106182,323129,00723,346 13,920
Upper Cedar0708020191,279244,56521,6011212650
Shell Rock0708020284,267203,82114,01715140
Winnebago0708020328,497164,5392,782 6 
West Fork Cedar0708020483,196238,88912,398 2100
Middle Cedar07080205360,231614,59670,75316121,660
Lower Cedar07080206189,038197,03829,4056 1,500
Upper Iowa07080207109,450384,93117,48428220
Middle Iowa07080208333,300315,47043,9085 1,640
Lower Iowa07080209325,454242,06963,892  12,400
Upper Des Moines0710000225,656277,1379,7282980
East Fork Des Moines0710000323,679319,79010,785 540
Middle Des Moines0710000481,852414,65120,2071110650
North Raccoon07100006174,148657,21338,32239181,520
South Raccoon07100007207,047194,40418,537 62,550
Lake Red Rock07100008347,683183,63627,47755212,000
Lower Des Moines07100009182,326204,65826,5741 15,100
Bear-Wyaconda0711000117,11625,7704,669  6,990
North Fabius071100025,4587,7921,862  1,050
Lower Big Sioux1017020385,460155,68312,429  4,930
Rock1017020479,416201,71817,285  3,100
Blackbird-Soldier10230001182,919104,3638,477  1,860
Floyd10230002112,483195,63014,3216 6,910
Little Sioux10230003240,052482,12522,382153,150
Monona-Harrison Ditch10230004203,594146,99610,201  2,180
Maple10230005130,569157,8637,633  2,070
Big Papillion-Mosquito10230006199,04757,8097,385  3,940
Boyer10230007308,661198,08318,103 16,610
Keg-Weeping Water10240001131,12237,1316,117  2,610
West Nishnabotna10240002581,332155,48825,6752 13,000
East Nishnabotna10240003392,85485,63521,158  11,400
Nishnabotna1024000424,47310,0321,544  420
Tarkio-Wolf10240005111,08931,7366,331  6,690
West Nodaway10240009237,05254,55211,800  8,190
Nodaway10240010116,97430,4967,154  5,920
Platte1024001282,76721,4693,546  3,440
One Hundred and Two1024001394,35421,3974,485  3,130
Upper Grand1028010177,56317,9092,640  4,920
Thompson10280102151,86054,02010,764  12,900
Lower Grand1028010317,02810,212722  870
Upper Chariton1028020182,06447,0925,364  18,700


Appendix D

Surface Water Monitoring by HUC-12 Watershed and Scale of Monitored Watershed.
HUC-12 NameHUC-12 IDLarge WatershedMedium WatershedSmall Catchment or Field-ScaleVery Small WatershedSmall WatershedTile
Drainage Ditch No 21070200090401     1
Iowa Lake070200090601    1 
Village Creek070600010602    1 
Clear Creek-Mississippi River070600010702    1 
Wexford Creek070600010706    1 
Lower Yellow River070600010906 3    
Bloody Run070600011002   13 
City of Prairie du Chien-Mississippi River0706000110031     
Town of Granger-Upper Iowa River070600020107 1    
Daisy Valley-Upper Iowa River070600020203 1    
Martha Creek-Upper Iowa River070600020206 1    
Canoe Creek070600020302    1 
City of Decorah-Upper Iowa River070600020404 1    
Waterloo Creek070600020502    2 
Paint Creek-Upper Iowa River070600020602 3    
French Creek070600020604    3 
Clear Creek-Upper Iowa River070600020605    1 
Middle Fork Little Maquoketa River070600030601    1 
Lower Little Maquoketa River070600030604    1 
Sny Magill Creek070600030701    1 
Lock and Dam No 10-Mississippi River0706000307041     
Spring Creek-Crane Creek070600040102    1 
Bohemian Creek070600040304    1 
Burr Oak Creek-Turkey River070600040308 1    
Brockamp Creek-Turkey River070600040309    1 
Coulee Creek-Volga River070600040504    1 
Mink Creek070600040602    1 
Nagle Creek-Volga River070600040604    1 
Honey Creek-Volga River070600040606 1    
Doe Creek-Volga River070600040608 1    
Village of Eldorado-Turkey River070600040703 1    
Bell Creek-Turkey River070600040707    1 
French Hollow-Turkey River070600040709 1    
Carlan Creek-Turkey River0706000409024     
Catfish Creek070600050102   11 
Allison Creek-Maquoketa River070600060210 1  1 
Rat Run-Bear Creek070600060303    1 
Mineral Creek070600060409    2 
Johns Creek070600060502   1  
Buck Creek-North Fork Maquoketa River070600060803 2    
Cedar Creek-North Fork Maquoketa River070600060804 1    
Pumpkin Creek-Maquoketa River070600061001 1    
Hainer Creek-Maquoketa River0706000610052     
Maquoketa River0706000610071     
Cattail Slough-Mississippi River0708010102045     
Upper Duck Creek070801010301     1
Lower Duck Creek070801010302    1 
Crow Creek070801010405    1 
Kickapoo Slu-Mississippi River070801010601  1  1
Watsons Creek-Wapsipinicon River070801020202    1 
Middle Crane Creek070801020402     4
Village of Oran-Little Wapsipinicon River070801020503    1 
Etter Creek-Wapsipinicon River070801020601 1    
Otterville Bridge State Access-Wapsipinicon River070801020801 1    
Malone Creek-Wapsipinicon River0708010208031     
Silver Creek-Buffalo Creek070801020904    1 
Helmer Creek-Buffalo Creek070801020906    1 
Heatons Creek-Wapsipinicon River0708010210021     
Dutch Creek-Wapsipinicon River0708010302011     
Hickory Creek070801030301     5
Walnut Creek070801030408     1
Brophy Creek070801030502    1 
Negro Creek-Silver Creek070801030601   1  
Silver Creek070801030602    1 
Barber Creek-Wapsipinicon River070801030603    11
McDonald Creek-Wapsipinicon River07080103060521    
Lost Creek070801030606    21
Big Hollow-Flint Creek070801041203    1 
West Branch Sugar Creek070801041601   11 
Picayune Creek-Sugar Creek070801041602   12 
Pitman Creek-Sugar Creek070801041604 1  2 
Drainage Ditch 71070801050102    1 
Lundys Creek-Squaw Creek070801050306  1   
Worrell Creek-Squaw Creek070801050307 2    
Miller Creek-South Skunk River070801050402    1 
Bear Creek070801050403  1 1 
Keigley Branch070801050405    1 
City of Ames-South Skunk River070801050406 1  1 
Mud Creek-Clear Creek070801050702    1 
Peoria Cemetery-Indian Creek070801050803    1 
Byers Branch-Indian Creek070801050804 1    
Turkey Creek-Indian Creek070801050805 1    
Walnut Creek070801050901   1 1
Drainage Ditch 13-South Skunk River070801050903 2    
Sugar Creek-South Skunk River070801050908 1    
Elk Creek070801051002     15
Carson Creek-South Skunk River070801051104     1
Van Zante Creek-South Skunk River070801051106 1 4  
Buckley Creek070801051201   11 
Ballinger Creek-South Skunk River070801051202   2  
Spring Creek-South Skunk River0708010512032 131 
Snyder Creek-South Skunk River0708010512041  221
Matrix Branch-South Skunk River070801051206   2  
South Skunk River070801051208  2  2
Snipe Creek070801060101  2   
Alloway Creek-North Skunk River070801060103    1 
Rock Creek-North Skunk River070801060104    1 
Burr Oak Creek-North Skunk River070801060105   2  
Sugar Creek070801060203    1 
Headwaters Middle Creek070801060301    1 
Moon Creek070801060402    1 
Pleasant Creek-North Skunk River070801060404    2 
Village of Delta-North Skunk River070801060601 1    
German Creek070801060603    1 
North Skunk River070801060604 1    
Upper West Fork Crooked Creek070801070101  1 11
Middle West Fork Crooked Creek070801070102  4 28
Lower West Fork Crooked Creek070801070103 1    
Honey Creek070801070304    1 
Coon Creek070801070501     1
Competine Creek070801070502   3  
Headwaters Cedar Creek070801070601   11 
Spring Creek-Cedar Creek070801070602  1  2
Buckeye Creek070801070603   114
Wolf Creek-Cedar Creek070801070604   31 
Church Creek-Cedar Creek070801070702 2    
Little Cedar Creek070801070707   11 
Summer Creek-Cedar Creek070801070708 2    
Wolf Creek070801070709   11 
Cedar Creek070801070710 4    
Shawnee Creek-Skunk Rvier0708010708021     
Headwaters Big Creek070801070901   1  
Brandywine Creek070801070902   3  
North Branch Big Creek-Big Creek070801070903   22 
Brush Creek-Big Creek070801070904   12 
Lynn Creek-Big Creek070801070905 1 12 
Fish Creek070801071001    1 
Prairie Creek-Skunk River0708010710022     
Cedar Creek070801071004    1 
Skunk River0708010710063   1 
Deer Creek070802010403    2 
Spring Creek070802010602   2  
Rock Creek070802010604  1 11
Beaver Creek070802010901  211 
Colwell County Park-Little Cedar River070802010902  1 1 
Little Cedar River070802010903 1    
Skunk Creek-Cedar River070802011001     3
Drainage Ditch 3070802011002    1 
Stewart Creek-Cedar River070802011003   2 3
Bloody Run-Cedar River0708020110052    4
Cedar Bend County Park-Cedar River0708020112041     
Village of Janesville-Cedar River0708020112053     
County Ditch No 55070802020106    1 
Headwaters Flood Creek070802020501    1 
Peters Creek-Flood Creek070802020503     1
Heery Woods State Park-Shell Rock River070802020704    1 
Shell Rock River0708020207053   1 
Headwaters Beaver Creek070802030107    1 
Clear Creek070802030201    2 
Cheslea Creek-Willow Creek070802030203    3 
Willow Creek070802030302    1 
Spring Creek070802030304    1 
City of Mason City-Winnebago River070802030306 1    
Mason Creek-Winnebago River070802030401    1 
Bailey Creek070802040102    1 
Buffalo Creek070802040301     1
Spring Creek070802040303    1 
Big Marsh State Wildlife Area-West Fork Cedar River070802040605    1 
West Fork Cedar River070802040607 2    
Middle Fork South Beaver Creek070802050101    1 
Headwaters South Beaver Creek070802050102    1 
South Beaver Creek070802050103 1    
Headwaters Beaver Creek070802050201    1 
North Beaver Creek070802050202    1 
Drainage Ditch 148-Beaver Creek070802050203    1 
Gran Creek-Beaver Creek070802050204 1    
Johnson Creek070802050301    1 
Phelps Creek-Beaver Creek070802050302    1 
Max Creek-Beaver Creek070802050303    1 
Hammers Creek-Beaver Creek070802050304 3    
South Fork Black Hawk Creek070802050401    1 
Headwaters North Fork Black Hawk Creek070802050402    1 
North Fork Black Hawk Creek070802050403 1    
Holland Creek070802050501    11
Headwaters Black Hawk Creek070802050502    1 
Mosquito Creek070802050503 1    
Minnehaha Creek-Black Hawk Creek070802050504    1 
Village of Reinbeck-Black Hawk Creek070802050505  2 13
Wilson Creek-Black Hawk Creek070802050601 1  12
Prescotts Creek-Black Hawk Creek070802050602 2  1 
Dry Run070802050701    4 
Waterloo Municipal Airport

Waterloo Muncipal Airport

070802050702    2 
Black Hawk Park-Cedar River0708020507031  1  
Little Wolf Creek070802050802    1 
Village of Conrad-Wolf Creek070802050803    2 
Fourmile Creek070802050804    1 
Coon Creek070802050805    1 
Rock Creek070802050806   12 
Twelvemile Creek070802050807    1 
Devils Run-Wolf Creek070802050808 1    
Wolf Creek070802050809 81 21
Elk Run070802050901    1 
Poyner Creek070802050902    1 
Indian Creek070802050903    1 
Headwaters Miller Creek070802050904  4313
Miller Creek070802050905  1337
Sink Creek-Cedar River0708020509061   2 
Rock Creek-Cedar River070802051001    32
Spring Creek070802051002    1 
Lime Creek070802051003    3 
Bear Creek-Cedar River070802051004    2 
McFarlane State Park-Cedar River070802051005     5
Pratt Creek070802051101  1 3 
Hinkle Creek070802051102    3 
Prairie Creek-Cedar River070802051103    1 
Mud Creek070802051104   23 
Dudgeon Lake State Wildlife Management Area-Cedar River0708020511051   11
Opossum Creek070802051201    2 
Wildcat Creek070802051202   12 
Little Bear Creek070802051203    1 
Bear Creek070802051204    2 
West Otter Creek070802051301    2 
East Otter Creek-Otter Creek070802051302    1 
Village of Van Horne-Prairie Creek070802051402    1 
Mud Creek-Prairie Creek070802051403    1 
Weasel Creek-Prairie Creek070802051404 2    
Prairie Creek070802051405 1    
East Branch Blue Creek070802051501    1 
Blue Creek070802051502    1 
Nelson Creek-Cedar River070802051504    1 
Dry Creek070802051505    1 
Morgan Creek0708020515062   3 
Silver Creek-Cedar River0708020515078   1 
Indian Creek070802060103    1 
Pleasant Run-Cedar River07080206040111    
Mill Creek-Cedar River0708020604051     
Community of Buchanan-Cedar River070802060407    1 
West Branch Wapsinonoc Creek070802060702   6  
Crane Creek-Cedar River0708020608064     
Headwaters West Branch Iowa River070802070101    1 
Drainage Ditch No 1070802070102    1 
Eagle Lake State Game Management Area-West Branch Iowa River070802070103    1 
West Branch Iowa River070802070104  1 11
Drainage Ditch No 9-East Branch Iowa River070802070204  1  4
East Branch Iowa River070802070205    2 
Elm Lake State Game Management Area-Iowa River070802070302 1   1
Headwaters Tipton Creek070802070401     2
Tipton Creek070802070402    1 
Beaver Creek070802070502   1  
Headwaters South Fork Iowa River070802070601   1  
Middle South Fork Iowa River070802070603    3 
Lower South Fork Iowa River07080207060413  1 
Pine Creek-Iowa River070802070902 2  2 
Brush Creek070802080202    1 
Timber Creek070802080206 1    
Headwaters Deer Creek070802080301    1 
Dry Branch-Iowa River0708020804031     
Davisons Creek-Iowa River070802080405 1    
Bennett Creek-Iowa River0708020804071     
Stein Creek070802080504    12
East Branch Salt Creek070802080505     1
Salt Creek070802080507 1    
Walnut Creek070802080603    1 
Richland Creek070802080701    1 
Otter Creek070802080702    1 
Big Bear Creek070802080806 1    
Village of Belle Plaine-Iowa River0708020809031     
Coon Creek-Iowa River070802080904    1 
Price Creek070802081002    1 
Mill Race-Iowa River0708020810031     
Lake MacBride-Mill Creek070802081008    1 
Upper Clear Creek070802090101   1  
Middle Clear Creek070802090102    3 
Lower Clear Creek070802090103   12 
Old Womans Creek-Old Mans Creek070802090207 3  1 
Deep River070802090403    1 
Devils Run070802090405    1 
Outlet North English River070802090408 1    
Ramsey Creek-English River070802090605 2    
English River070802090606 1    
Rapid Creek070802090701   21 
Ralston Creek-Iowa River0708020907033 12  
Davis Creek070802090801     3
Short Creek070802090805     3
Prairie Creek-Iowa River0708020908062     
North Fork Long Creek070802090901  1  1
South Fork Long Creek070802090902     3
Johnny Creek-Long Creek070802090905    1 
Long Creek070802090906 1  1 
Ditch No 25-Iowa River0708020911021     
Otter Creek-Iowa River0708020911048   1 
School Creek-Des Moines River0710000201061     
Headwaters Jack Creek071000020202    3 
Jack Creek071000020205  1   
Drainage Ditch 62-Silver Creek071000020301  1 1 
City of Emmetsburg-Des Moines River0710000204041     
Drainage Ditch 80071000020501    1 
Cylinder Creek071000020503  1   
Pilot Creek071000020703  1 15
Beaver Creek071000020803  1  2
Indian Creek071000020902  1  3
Drainage Ditch 35-Des Moines River0710000209032 1  1
Ditch No 40071000030106    1 
Okamanpeedan Lake-East Fork Des Moines River071000030108    1 
Black Cat Creek071000030504    1 
Drainage Ditch 51-East Fork Des Moines River071000030802 1    
Drainage Ditch 182071000030805  1  1
Drainage Ditch 94-East Fork Des Moines River071000030806 1    
East Fork Des Moines River0710000309031     
Headwaters North Branch Lizard Creek071000040101    1 
Upper North Branch Lizard Creek071000040102  1  1
Lower North Branch Lizard Creek071000040104  1 1 
Spring Creek071000040203     3
Lower South Branch Lizard Creek071000040204     1
Middle Lizard Creek071000040302  1   
Lower Lizard Creek071000040303 1  1 
Badger Creek071000040403    1 
Brushy Creek071000040504    1 
Prairie Creek071000040603  32 3
Gypsum Creek-Des Moines River0710000406041     
Crooked Creek071000040605     1
Skillet Creek071000040701     1
Allen Creek-Des Moines River0710000407021     
Bluff Creek071000040703    2 
Bear Creek071000040705     1
Big Creek071000040803    1 
West Beaver Creek071000040902     2
Beaver Branch-Beaver Creek071000040906    1 
Slough Creek071000040907  1 13
Little Beaver Creek-Beaver Creek071000040908     2
City of Bouton-Beaver Creek071000040909     7
Royer Creek-Beaver Creek071000040910 1    
Beaver Creek071000040911 4    
Murphy Branch-Des Moines River071000041001     4
Rock Creek-Des Moines River0710000410022     
Saylor Creek-Des Moines River0710000410032     
Drainage Ditch 117071000050101    1 
Headwaters Prairie Creek071000050102    1 
Drainage Ditch 116-Prairie Creek071000050103 12 11
Drainage Ditch 18-Prairie Creek071000050104  1 12
Headwaters Boone River071000050201     1
Middle Branch Boone River071000050202    1 
East Branch Boone River071000050203    12
Drainage Ditch 44-Boone River071000050204 1  1 
Drainage Ditch 1-Boone River071000050205 1  1 
West Otter Creek071000050301    1 
Headwaters Otter Creek071000050302    12
Otter Creek071000050303 1    
Little Eagle Creek071000050401    1 
Headwaters Eagle Creek071000050402    1 
Eagle Creek071000050403 11215
Headwaters White Fox Creek071000050501   12 
Buck Creek071000050502    2 
White Fox Creek071000050503 13 15
Joint Drainage Ditch 3-Boone River071000050601 1    
Drainage Ditch 9071000050602    1 
Drainage Ditch 3071000050603    1 
Drainage Ditch 4-Boone River071000050604 3   2
Drainage Ditch 46-Boone River071000050605 1    
Drainage Ditch 68-Boone River071000050606 1    
Lyons Creek071000050701    2 
Brewers Creek071000050702    1 
Drainage Ditch 206071000050703    21
Drainage Ditch 32-Boone River071000050704 2    
Prairie Creek-Boone River07100005070511 11 
Little Cedar Creek071000060103  1 21
Headwaters Cedar Creek071000060202  4 16
Drainage Ditch 74-Cedar Creek071000060204 1    
Prairie Creek071000060205    1 
Drainage Ditch 20-Cedar Creek071000060208 1    
Headwaters North Raccoon River071000060301  1  3
Lateral 6-North Raccoon River071000060303  1  1
Lateral 2071000060304  2 110
Poor Farm Creek071000060305    12
Lateral 3-North Raccoon River071000060306    1 
Outlet Creek071000060307   12 
Drainage Ditch 101-North Raccoon River071000060308 1  14
Buck Run071000060309  1  2
Sac City-North Raccoon River071000060310 1  1 
Wall Lake Inlet071000060401   13 
Indian Creek-North Raccoon River071000060403    1 
Camp Creek071000060505    1 
Drainage Ditch 13-Lake Creek071000060603    2 
Lake Creek071000060605    1 
Purgatory Creek071000060702    1 
Drainage Ditch 73-North Raccoon River071000060801 3    
Drainage Ditch 25-North Raccoon River071000060802  1  1
Prairie Creek071000060803    11
Elk Run-North Raccoon River071000060804  3329
Rainbow Bend County Park-North Raccoon River071000060805 13  3
Marrowbone Creek-North Raccoon River0710000608061111 1
East Cedar Creek071000060903     11
Cedar Creek071000060904 1    
Headwaters Hardin Creek071000061001    1 
Hardin Creek071000061005 11  3
East Buttrick Creek071000061102    11
Headwaters West Buttrick Creek071000061202     2
West Buttrick Creek071000061203    1 
Buttrick Creek071000061204 1  1 
Greenbrier Creek071000061302  1 11
Doe Brook-North Raccoon River071000061402    1 
Drainage Ditch 171-North Raccoon River0710000614053     
Fannys Branch-North Raccoon River071000061501     2
Swan Lake Branch071000061502   2  
Frog Creek-North Raccoon River071000061503 1   1
Hickory Creek-North Raccoon River0710000615051     
Walnut Creek071000061602    1 
Johnson Creek-Raccoon River0710000617022     
Jordan Creek-Raccoon River0710000617034   3 
Lower Willow Creek071000070104 1    
City of Carroll-Middle Raccoon River071000070203 1 1  
Spring Branch-Middle Raccoon River071000070204    1 
Willey Branch-Middle Raccoon River071000070205 1    
Upper Middle Raccoon River071000070206 1 2  
Upper Brushy Creek071000070301    1 
Middle Brushy Creek071000070302    33
Lower Brushy Creek071000070303 11  2
Mason Creek071000070403     2
City of Guthrie Center-South Raccon River071000070404 1    
Lower Mosquito Creek071000070502    1 
Lake Panorama-Middle Raccoon River071000070601 2  11
Bays Branch071000070602     1
City of Panora-Middle Raccoon River071000070603 4    
Town of Monteith-South Raccoon River071000070702    1 
Deer Creek-South Raccoon River071000070703    1 
Long Branch-South Raccoon River071000070704 1    
East Branch Panther Creek071000070802     1
Panther Creek071000070803 1    
Bear Creek071000070901    1 
Coal Creek-South Raccoon River071000070902 3    
Outlet South Raccoon River0710000709041     
Upper Fourmile Creek071000080101  291 15
Middle Fourmile Creek071000080102    2 
Lower Fourmile Creek071000080103    2 
Howerdon Creek071000080303    1 
Cedar Creek071000080401    1 
Badger Creek071000080402    1 
North River071000080405 2  1 
South Turkey Creek071000080603    1 
Jefferson Cemetary-Middle River071000080605  1   
Felters Branch-Middle River071000080701 2    
South Squaw Creek071000080801    1 
Lower Squaw Creek071000080804    2 
Short Creek-South River071000081201 2    
Headwaters White Breast Creek071000081302    1 
Little White Breast Creek071000081305    3 
Kirk Branch-White Breast Creek071000081403 2    
Yeader Creek-Des Moines River0710000815031   1 
Walnut Creek071000081505   11 
Wildcat Creek-Des Moines River0710000815071     
Wallingslock Creek-Des Moines River071000081509    1 
Headwaters English Creek071000090101    1 
English Creek071000090102    1 
Headwaters North Cedar Creek071000090201   1  
Hickory Creek071000090202    1 
Carruthers Creek071000090203    1 
North Cedar Creek071000090204    1 
Bleubaugh Branch071000090302   3  
Inghram Branch071000090303    1 
Coal Creek-Cedar Creek071000090304   1  
Whippoorwill Creek071000090305   1  
Whites Creek071000090306   1  
Whippoorwill Branch-Cedar Creek071000090308    1 
Walnut Creek071000090309    1 
Cedar Creek071000090310 2  1 
Price Creek-Des Moines River0710000905012     
Bluff Creek071000090503    1 
Middle Soap Creek071000090605    1 
Lower Soap Creek071000090607    1 
Brown Creek-Des Moines River0710000907041     
Bear Creek School-Bear Creek071000090706    1 
Kettle Creek-Des Moines River0710000907092   1 
Chippewa Creek-Des Moines River071000090710    1 
Tug Fork-Big Indian Creek071000091001    1 
Birch Creek-Sugar Creek071000091102  1  1
Coppers Creek-Des Moines River0710000912065   1 
Rollins Creek-Des Moines River071000091209    1 
Bitter Creek-Little Sioux River1020000000002039169715
Dickerson Branch-Thompson River103000000000 9  15