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Points to consider if planning a drainage project

By Janet Kubat Willette

Date Modified: 03/28/2013 8:58 PM

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NORTH MANKATO, Minn. — The annual Extension Drainage Design Workshop will be held in North Mankato from March 26-27 (this is a rescheduled date due to weather).

The workshop is a collaborative effort between University of Minnesota Extension and South Dakota State Extension Service. The two-day workshop starts at 8:30 a.m. and ends at 5 p.m. on day two.

The workshop will focus on the planning and design of agricultural tile drainage systems to meet both profitability and environmental objectives. The course content is taught in a hands-on manner with lots of discussion time.

The workshop is intended for those interested in a more complete understanding of the planning and design principles and practices for drainage and water table management systems, including: farmers, landowners, consultants, drainage contractors, government agency staff and water resource managers. Planning topics include legal aspects, basics of drainable soils, agronomic perspectives, considerations of doing your own tiling, land evaluation tools and conservation drainage concepts and techniques.

The design topics begin with basic design considerations and progress through individual small team projects, with several hands-on problem-solving examples covering basic design and layout principles, water flow calculations, tile spacing, sizing, and tile grades. Design principles for lift stations and conservation drainage practices are also considered.

For more information call Brad Carlson at 507-389-6745, or Gary Sands, Extension engineer, at 612-625-4756.

OWATONNA, Minn. — Is there a drainage project in your future?

University of Minnesota Extension educator Brad Carlson offered "10 Points to Consider When Planning an Agricultural Drainage System," during a presentation March 14 at the North American Farm and Power Show in Owatonna.

The first step is to file a Form 1026 with the Farm Service Agency.

Compliance with federal Swampbuster rules is the responsibility of the operator, so be sure to have a certified determination of wetlands from the Natural Resources Conservation Service before tiling begins, Carlson said.

Be aware that compliance with Swampbuster doesn't mean compliance with the state Wetlands Conservation Act or U.S. Army Corps of Engineers rules, he said. There are differences between the state and federal rules. Stop by the county Soil and Water Conservation District to be sure you're not in violation of state rules or Army Corps of Engineers rules.

Point No. 2 is to see if the property is part of a public drainage system.

"If you intend to connect to a public ditch or tile system, you should pay a quick visit to your county ditch inspector to ensure that you are permitted to do so," Carlson wrote in his handout.

The single biggest reported problem with tile systems is that they don't work, he said. Before tiling, make sure the outlet has the capacity to handle the amount of water that may discharge from your field at peak flow.

It's also a good idea to talk to neighbors who may be impacted by your tile project.

"Be sure that you are not flooding your neighbors by sending your water on them, or overloading tile mains," Carlson wrote.

If you don't have access to an outlet or it will be costly to install a new outlet, perhaps it's time to consider a conservation program or selling the property. The state wetland bank allows for the transfer of wetland credits, Carlson said. A link to the wetland bank can be found at

"In some cases, wetland mitigation credits can be sold for more than the property is worth," he said. Don't consume resources on marginal land, instead use those resources for other investments.

Carlson advises farmers to use science and experience for design. There is a science behind designing drainage systems, he said, and there is training available if you choose to do your own tiling.

"There is a difference between what works and what works best," Carlson wrote. "Think about whether you are choosing the correct tile layout, size, depth, spacing and grade."

When installing tile, make sure it has capacity for future drainage. Make consideration for retrofit for conservation drainage, woodchip bioreactors, saturated buffer drains, alternative surface intakes or other technologies.

It's worth thinking about these options before committing to a design, he said. It's not necessarily more expensive to design a system in a way to accommodate these emerging drainage technologies.