Guest column: Don’t rush redesign of farmland drainage

Guest column: Don’t rush redesign of farmland drainage

MICHAEL BURKART is a hydrologist in Ames. Contact: burkartj15@ hotmail.com. • WILLIAM STOWE is D.M. public works director. Contact: wgstowe@dmgov.org.

Last November, the Iowa Water Resources Coordinating Council (WRCC) submitted flood plain management policy recommendations to Gov. Chet Culver and state legislators. The recommendations are intended to help the state rebuild safer, stronger and smarter in the wake of the historic 2008 floods. 
 
In light of those recommendations, a proposal for funding from the Iowa Department of Agriculture and Land Stewardship (IDALS) is counterintuitive and scientifically questionable. IDALS proposes to further enhance artificial drainage of Iowa farmland. The plan appears to be moving rapidly from concept to expensive experiment, despite serious questions raised by scientists and knowledgeable water resource professionals. 
 

What has been called the "Iowa Plan" redesigns and enlarges existing drainage systems and directs water flow to constructed wetlands. These wetlands are hypothesized to reduce nutrient loads delivered to Iowa lakes and streams. Restoring Iowa’s wetlands sounds appealing because this could benefit the hydrology and water quality that has been disturbed by – ironically – artificial drainage. In fact, the arguments supporting accelerated drainage are the same that resulted in the elimination of Iowa’s wetland ecosystem in the first place: increased agricultural production. Producers and commodity consumers tout the benefits of expanded production efficiency, but what about those of us who want to use the streams and lakes destined to receive more water, nutrients and pollution from accelerated drainage? If increased production efficiency resulted in the cultivation of less land, then this is a noble objective. History shows, however, that this has not been the case in Iowa.

The downstream consequences of accelerated drainage need to be carefully examined beyond the proposed token wetland Band-Aid. 
 
There are several things we know for certain: "Improved" artificial drainage in Iowa has increased stream flow in quantity and duration over the last 100-plus years. Artificial drainage flushes nitrogen and phosphorus from soil into lakes and streams, impairing those waters for drinking, recreation and aquatic life. And wetlands have the potential to reduce stream flow and nutrient loads.

What we don’t know: How much will stream flow and nutrient levels increase if drainage is further enhanced? What will be the effect of constructed wetlands on downstream flows and nutrient loads? Are producers willing to designate enough acreage to a constructed wetland such that it can function effectively? Furthermore, there is the risk that these constructed wetlands, which will be receiving enormous nutrient loads, will have deleterious effects on downstream water quality.

Under Iowa law, producers can construct drainage systems for their land using their own funds. If the negative environmental effects of accelerated drainage are only balanced out by a wetland system, how will the taxpayers of Iowa and the country benefit by subsidizing this activity? Will the water leaving these drainage systems be required to meet some quality and quantity objectives? 
 
Discussion of further modifying Iowa’s hydrology at taxpayer expense is crucial. A specific, scientifically sound project plan should be developed and reviewed. Assemble some of the best Iowa scientists familiar with the issues. A transparent planning and funding process should lead to evaluating competitive ideas rather than the process of directing taxpayer funds to a limited number IDALS’ friends. Such a review is generally required for competitive research funding, and Iowa should expect no less before embarking on a potentially expensive adventure in further (mis)managing its water resources.

If we learned nothing more from the Floods of ’08, let’s remember that accelerated drainage creates significant risks for downstream property owners and communities. We hope IDALS will propose changes in land practices that result in less flow and less nutrient pollution to the waters of the state of Iowa, rather than more.