Controlled drainage, also known as drainage water management, is the practice of using a water control structure to raise the depth of the drainage outlet, holding water in the field during periods when drainage is not needed. Unlike conventional drainage systems that remove excess water to the design drain depth whenever it occurs, managed drainage conserves water by increasing the retention time of water in the soil profile. Thus, removal of excess soil water can be delayed and/or reduced, creating opportunities to provide drainage volumes.
Controlled drainage has been shown to be effective in reducing the outflow of water and nitrate-nitrogen (nitrate-N) from drainage systems. While field experiments with controlled drainage have often concentrated on water quality benefits, this project will focus on the potential of in-field water.
Understanding the Practice and its Benefits
- Questions and Answers about Drainage Water Management for the Midwest. 8 page overview by J. Frankenberger, E. Kladivko, G. Sands, D. Jaynes, N. Fausey, M. Helmers, R. Cooke, J. Strock, K. Nelson, and L. Brown. Purdue University Cooperative Extension Service
- NRCS introductory/promotional video. Drainage water management benefits landowners (2 minutes, December 2013)
- North Central Region Water Network webinar series. Managing Agricultural Drainage by Jane Frankenberger, Chris Hay, Richard Cooke (1 hour, May 2015).
- Midwest Ag Drainage Water Management webinar series, organized by Iowa State
University. Controlled Drainage, by Gary Sands and Tony Thompson (1 hour, August
- NRCS Drainage Water Management: Level 2 Series (Includes 8 Modules covering concepts, planning, layout, and management; 20 to 60 minutes each)
NRCS Practice and Suitable Cropland Information
- NRCS Geospatial Analysis - Suitable Cropland for Implementing Controlled Tile Drainage
- NRCS Conservation Practice Standard; Drainage Water Management (National) (pdf)
- NRCS Conservation Practice Effects Network Diagram; Drainage Water Management (pdf)
- Klemme, J. 2015. Taking tile to the next level. Prairiefarmland.com.
- Controlling Farm Runoff Could Have Multiple Benefits – MPR News