Q&A With a CCA: Drainage water recycling

By Wm. Bruce Clevenger, Ohio State University Extension, Field Specialist, Farm Management and Certified Crop Adviser

What is drainage water recycling (DWR)?

Two organizations, Transforming Drainage.org and the Environmental Defense Fund, provide practical descriptions for DWR. Drainage water recycling is the practice of capturing excess water drained from fields, storing it in a pond, reservoir, or drainage ditch, and using it to irrigate crops during periods of water deficit. These systems are typically comprised of three main components: pre-existing subsurface drainage, used to drain water from agricultural lands during times of excess water; a water storage system, used to capture and hold the excess water; and an irrigation system, used to resupply the stored water to agricultural lands during a water shortage. Since each component varies based on specific site characteristics and needs, drainage water recycling can take many different shapes and sizes.

What is the water supply for DWR, and how does water move about the system?

Water is introduced to the drainage water recycling system through precipitation. Excess water from precipitation exits the field as surface runoff or tile drainage into a storage basin. The remaining water in the soil is either used by the crop and evapotranspiration or lost through deep percolation, depending on the presence of a restrictive layer. Excess water in the storage basin is discharged through overflow to the downstream watershed. Remaining water in the storage basin is recycled back to the crop as irrigation or is lost through evaporation or seepage. In some DWR designs, a nearby stream or river with adequate flow could serve as a surface water source to supplement the storage basin.

What irrigation options are practical for DWR?

There are four main categories of agricultural irrigation systems: surface irrigation, sprinkler irrigation, microirrigation, and subirrigation, each with unique advantages and applications. Surface irrigation uses gravity to deliver water across the soil surface via overland flow, which is uncommon in Ohio and considered not ideal for DWR. Sprinkler irrigation, also known as center pivot irrigation, uses pressurized pipes to distribute water to the soil. It is the predominant form of irrigation in the United States, ideal for large fields. Microirrigation systems deliver small, frequent water volumes through emitters or applicators along a delivery line. Subsurface drip irrigation is a form of microirrigation, commonly used to irrigate specialty crops and some row crops, particularly in smaller or oddly shaped fields. Subirrigation delivers water below the soil surface to raise and maintain the water table in or near the root zone for crops. Subirrigation often uses the existing subsurface drainage system by delivering water through the drainage pipes and control structures to maintain the water table depth. Subirrigation can be preferable since it does not require investment and maintenance of a separate irrigation system. However, it does require greater drainage intensity, more closely spaced laterals, a larger tile main, and control structures. It is also limited to relatively flat fields with suitable and uniform soils.

Does DWR pay?  What’s the return on investment and payback period?

Although interest in DWR is growing, key questions remain about its cost, financial risk, and return on investment (ROI). Each DWR site will have unique costs, returns, and financial investment sources (private and public). The Environmental Defense Fund published a report titled “Economic Analysis of Drainage Water Recycling” in October 2025. The report utilized publicly available information from several Iowa organizations, entities, and Iowa State University. The study draws data from one planned and three existing DWR projects in the Midwest, as well as a literature review. To illustrate economic implications, costs and benefits were estimated for an idealized model site representing a 1,500‑acre drainage area with 125 to 155 irrigated acres and an appropriately sized storage reservoir.

In this study, a DWR investment analysis was completed for four different model site scenarios. For each scenario, an investment analysis of the site was completed to determine the financial outcomes and profitability. Drainage system costs and benefits were not included, as they are expected to occur independently of DWR. Center pivot irrigation was used for all analyses because its costs are more consistent across sites, and it was the most cost-effective option among scenarios. The four landowner investment scenarios yielded 25-year ROI ranging from 5% to 96%, with payback periods of 13 to 24 years. As ROI increases, payback periods decrease.

Can DWR work in Ohio?

Drainage water recycling is not a new concept in Ohio. For example, an 11-year project conducted by the USDA-ARS Soil Drainage Unit and the Ohio State University Extension examined yield and water-quality results from drainage-water recycling in Defiance, Fulton, and Van Wert Counties. In this project, drainage water was directed to a wetland and stored in a reservoir. Then, the stored water was sub-irrigated back into a corn and soybean crop when needed. The project’s three-site average yield increases for corn and soybeans, respectively, were 30.8% and 26.0% during drier growing seasons, 13.3% and 6.9% during near-average to wetter growing seasons, and 18.1% and 13.0% overall.

The Regenerative Farm at The Ohio State University Lima campus is part of a large research project involving Ohio State University, the Ohio Department of Agriculture, Soil and Water Conservation Districts, and others investigating DWR. Since 2022, OSU Lima has hosted field days that highlight and demonstrate several conservation projects directly related to DWR.  The OSU Lima farm and a few others around Ohio will be excellent farms to visit and learn if DWR is a practice that can be replicated in other parts of Ohio.  Dr. Vinayak Shedekar, OSU’s Extension Specialist in CFAES-Food, Agricultural & Biological Engineering, is leading many of these projects, grants, and education events related to DWR here in Ohio.

For more information, contact https://go.osu.edu/agwater or email Vinayak Shedekar, shedekar.1@osu.edu, or Wm. Bruce Clevenger, clevenger.10@osu.edu