Using digital tools from the USGS and the FHWA to address water-quality issues, December 3, 2025 скачать в хорошем качестве

Using digital tools from the USGS and the FHWA to address water-quality issues, December 3, 2025

Using digital tools from the U.S. Geological Survey and the Federal Highway Administration to address water-quality issues Prepared for the American Association of Highway and Transportation Officials (AASHTO) Stormwater Summit & Workshop, September 11, 2025 in Tempe, AZ and delivered to the AASHTO Stormwater Working Group on December 3. 2025. Speaker: Alana Spaetzel, Supervisory Hydrologist, U.S. Geological Survey Abstract: Stormwater practitioners in transportation agencies need scientifically defensible tools and techniques to address the potential for adverse effects of roadway runoff on receiving waters. This presentation provides information about robust methods to develop planning-level estimates to determine locations with the greatest risk for adverse effects of roadway runoff on receiving waters and estimates to determine what proportion of stormwater constituent load is coming from roads in a watershed that could be used in a Total Maximum Daily Loads (TMDL) analysis. The tools demonstrated in this presentation include the highway runoff database (HRDB v. 1.2), the Stochastic Empirical Loading and Dilution Model (SELDM v. 1.1.1), and the USGS StreamStats application. Because there is great uncertainty in the water quality of runoff and the upstream receiving water at any given point of interest, DOTs can use information about the highway, upstream basin characteristics from StreamStats, and a dilution-factor analysis from SELDM to quickly determine the portion of downstream flow comprised of roadway runoff. These tools provide for rapid and defensible assessments at many sites so DOT decisionmakers can target mitigation measures at sites where such measures would have the greatest benefits. In Southern New England (CT, MA, and RI), where the USGS has added roadway information to StreamStats it is easy to develop stormwater loading estimates for different road classes and the entire impervious area in a watershed. This presentation demonstrates this type of loading analysis for the Pawtuxet River watershed indicating that arterial roadways contribute only about 4% of the stormwater loads of total nitrogen this is similar to the analysis for the entire Narragansett Bay done by Granato and others (2023). As a side note, other DOTs without roadway information can use impervious areas and drainage areas from Streamstats with DOT roadway information to estimate roadway stormwater loads, but such estimates may not be as precise as the ones described in this video. For example, see the analysis done for CalTrans (Granato and Friesz, 2021). References: Granato, G.E., and Friesz, P.J., 2021, Approaches for assessing long-term annual yields of highway and urban runoff in selected areas of California with the Stochastic Empirical Loading and Dilution Model (SELDM): U.S. Geological Survey Scientific Investigations Report 2021–5043, 37 p., https://doi.org/10.3133/sir20215043 Granato, G.E., Spaetzel, A.B., and Jeznach, L.C., 2023, Approaches for assessing flows, concentrations, and loads of highway and urban runoff and receiving-stream stormwater in southern New England with the Stochastic Empirical Loading and Dilution Model (SELDM): U.S. Geological Survey Scientific Investigations Report 2023–5087, 152 p., https://doi.org/10.3133/sir20235087. Spaetzel, A.B., Granato, G.E., and Wares, K. M., 2024, Highway-Runoff Database (HRDB) Version 1.2.0: U.S. Geological Survey data release, https://doi.org/10.5066/P1KXPEBW.