The Maumee River network contributes a significant amount of total phosphorus (P), including both sediment-bound P (sed-P) and dissolved P, to the Western Lake Erie Basin. Most Maumee River headwater streams are agricultural, with conservation management focused on limiting sediment and nutrient transport from cropland to the stream network. However, several studies have shown streambank erosion to be another source of suspended sediment in these streams. This data release is comprised of four tables with data related to particle-size distribution and resultant estimate of sed-P mass based on streambed-sediment stored in the Black Creek, IN (U.S. Geological Survey number 04183038) and Little Flatrock Creek, OH (04191444) stream networks in July 2019. Data included provided for extrapolation from described reaches to the entire network upstream of the gage.