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Reducing Sediment and Nutrient Runoff: Problems

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In 2019, Lake Erie had the 5th largest Harmful Algae Bloom (HAB) due to record water runoff and 2-3 feet higher water levels than normal. Lake Erie also had the highest total sediment, total nitrogen, and total phosphorus loads ever recorded, but the extra water diluted the sediment and nutrient concentrations, possibly reducing the impact. Examining the facts and problems may offer some possible solutions. About 60% of phosphorus (P) nutrient loads come from the Maumee River watershed (Johnson, 2018). Roughly 30% of P comes from surface runoff and 70% from subsurface (tile) runoff through preferential flow (soil cracks, crevices) with about 90% of the losses occurring during the most intense rainfall events (Watters & Hoorman, 2018, Fussell et al. 2017). Depending on the soil and landscape, 60 -90% of P come from 10-40% of land, generally on soils located close to or with access for transportation to ditches and streams. Average Ohio P loss is 1-1.2# P/acre with a goal of losing l...