Anticipated Impacts of Bioenergy Crop Production on Water Resources

Growing and processing feedstocks for bioenergy production in the North Central Region will have major economic and environmental impacts. These impacts will be most immediate from continued and increased corn-grain ethanol production. Bioethanol production has increased ten-fold in the last 20 years. In 2010, an estimated 13 billion gallons of ethanol was produced in the United States, with the North Central states leading production. Demand for ethanol may become greater, as the EPA recently certified the use of E15 gasoline for a portion of the U.S. light duty fleet, and may expand this to older model vehicles in the future. The production of corn, its processing into ethanol, and the potential for expansion into production and processing of cellulosic feedstocks, will have impacts on agricultural landscapes and water resources.

Protection of water quality and quantity are both concerns when feedstock production increases to meet bioenergy demands. Producing feedstocks with irrigation will increase pressure on water availability. Ethanol processing plants use considerable water, and while modern plants are increasing efficiencies significantly, there is still the potential for strains on local water supplies. Finally, the potential for expansion ontomarginal or sensitive areas; for example, former Conservation Reserve Program (CRP) land that is highly erodible, or marginally productive farmland that requires greater chemical inputs or wetland areas, will increase the risk of significant nonpoint source pollution. Managing the production of bioenergy feedstocks, while protecting water and soil resources, will be the key to a sustainable bioenergy system.

Challenges facing the bioenergy feedstock production industry include: 1) minimizing landscape-level impacts of returning CRP land to crop production; 2) optimizing production on existing land to avoid expanding crop production to sensitive land; 3) using water resources in a sustainable manner; 4) understanding and reacting appropriately to bioenergy policy changes; and 5) producing, processing, and transporting feedstock in an efficient manner, while keeping releases of greenhouse gas emissions at a minimum.

Many of these challenges have a direct link to the quality and quantity of our water resources. Water quality and quantity considerations in bioenergy crop production include the water use of the biofuel crops, the site characteristics, infiltration and runoff potential, the water availability at the planting site, any changes caused by switching from the current land use to a bioenergy crop and the processing of that crop. Water use for agricultural production and processing, as well as the impacts changing to a bioenergy crop will have on other parts of the ecosystem, must be considered. Methods to minimize negative water cycle impacts and promote agricultural sustainability should be part of bioenergy planning.