Sponsor: Walton Family Foundation

Background: Targeting the “right practice” to the “right place” is critical for successful interception of pollutant flowpaths.

Goals: To identify appropriate conservation practices for small watersheds in the basin

IGS Strategies: IGS developed an agro-hydrologic classification to identify N and P loss pathways and prioritize conservation practices in small watersheds in the U.S. Midwest, as well as a GIS framework to classify 11,010 small watersheds in the Upper Mississippi and Ohio River basins based on soil permeability and slope characteristics.

More Information: Hydrologic differences in cropped systems indicate that a one-size-fits-all approach to conservation selection will not work. This classification scheme could be an appropriate first step to identify appropriate conservation practices for small watersheds in the basin.

Sponsor: USDA National Institute of Food and Agriculture

Background: Recent studies in the Walnut Creek Watershed found that spatial nitrate (NO3-N) and orthophosphorus (OP) concentrations in upland and floodplain groundwater differ depending on the landscape setting.

Goal: To characterize spatial patterns of groundwater OP concentrations and loading rates within the an Iowa watershed over a two-year period.

IGS Strategies: Strategically siting conservation practices in floodplain areas for disproportionately larger water-quality benefits.

More Information: Groundwater orthophosphorus concentrations were higher in floodplains than in uplands. OP loading rates beneath floodplains are approximately three times higher than in uplands. It takes eight years to flush out existing OP mass present in shallow groundwater.

Sponsor: Iowa Department of Natural Resources

Background: Accurate measurement of total phosphorus (TP) concentrations in rivers are necessary to quantify loads and evaluate the progress of nutrient reduction strategies.

Goal: To accurately measure TP concentrations in rivers in order to quantify loads and evaluate the progress of nutrient reduction strategies.

IGS Strategies: New research focused on the relation of water-quality surrogates, turbidity, orthophosphorus (OP), chlorophyll a, chloride, and discharge to TP concentrations at 43 different river monitoring sites. IGS found that turbidity and OP are the dominant surrogates needed to estimate TP concentrations in Iowa rivers.