Drainage Water Quality in Iowa

Matthew Helmers, Faculty, Ag & Biosystems Engineering


Subsurface drainage has allowed for excellent agricultural production within many areas of Iowa.  However, these systems allow for short-circuiting of some agricultural pollutants, specifically nitrate-nitrogen, to nearby surface water bodies.  This has contributed to local and regional water quality concerns including hypoxia in the Gulf of Mexico.  Future system design and management as well as in-field nitrogen management will need to incorporate not only economic but also the environmental aspects.


Provide information about the benefits and drawbacks of subsurface drainage systems and how drainage-system design and management can include economic and environmental aspects.  Provide information about the impacts of in-field management on nitrate-nitrogen losses through subsurface drainage.


      In cooperation with the University of Minnesota Extension coordinated the Iowa-Minnesota Drainage Research Forum held in November 2005 in Dows, Iowa.  There were 70 individuals who participated in the meeting.  Attendees included producers, drainage contractors, university personnel, and agency representatives from both Iowa and Minnesota.  A total of 42 evaluations were received from this program

      Presented on subsurface drainage at the Iowa Drainage District Annual meeting in December 2005 and the Iowa Land Improvement Contractors Annual meeting in January 2006. 

      Presented at the Crop Advantage Series meetings in Spirit Lake and Strom Lake and the North Central Iowa Crop and Land Stewardship Clinic in Iowa Falls on the impacts of manure on drainage water quality. 

      Presented on impacts of manure and drainage water quality at the Ag and Environment Conference and the Integrated Crop Management conference.

      Through working with the Ag. Engineering field specialists, five Drainage Design Workshops were delivered in March 2006 across the State of Iowa.   These workshops were held in Lewis, Dows, Storm Lake, Ainsworth, and Oelwein. A total of 213 participants attended these workshops with the majority of participants being contractors and land owners. During these workshops, ISU Extension staff provided training on how to plan and design drainage for a site, economics of tiling, long term benefits of tiling, and impact of controlled drainage on water quality. ISU Extension collaborated with Jim Hudson Sr., Attorney specializing in Drainage Law, to help participants better understand legal issues involved in tiling projects.


      An outcome of this programming is that we are providing research-based information on drainage water quality to stakeholders including state agency personnel in Iowa and the Midwest with a goal of improving the knowledge of drainage water quality issues and practices that can be used to minimize drainage water quality impacts.

      Of 42 evaluations received as part of the 2005 IA-MN Drainage Research Forum 40 indicated the forum was worth their time.

      Feedback from the IA-MN Drainage Research Forum indicated attendees valued the research based presentations, the cooperation of Iowa State University and the University of Minnesota on drainage issues, and the mix of basic and applied studies that were presented at the meeting. 

      A goal of the IA-MN Drainage Research Forum is to bring together individuals from both Iowa and Minnesota to discuss drainage issues and allow for up-to-date dissemination of research.  Attendees indicated they learned about practices such as nitrate-removal wetlands, drainage water management, and potential cropping practices that could be used for reducing nitrate export.  One response indicated an improved general knowledge of soil, crop, and drainage interaction which will help in assisting landowners.  One attendee congratulated Iowa and Minnesota for organizing this valuable meeting.

September 2006

150 Environmental Stewardship

Page last updated: September 29, 2006
Page maintained by Linda Schultz, lschultz@iastate.edu