Citation:

Yuan, Y. AND K. Mendelman. Understanding the Impact of Agricultural Conservation Practices on Hydrology and Water Quality in the Pacific Northwest. US EPA Region 10 Workshop: Exploring Regenerative Agriculture - Hydrology, Implementation and Funding, Spokane, WA, May 20 - 24, 2024.

Impact/Purpose:

Intensive agriculture (e.g., widespread conversion of perennial vegetation to row crops) not only increases nutrient and sediment discharge to nearby streams but also increases peak discharge Climate change is causing increases in the frequency and magnitude of high intensity storm events in many areas. According to NOAA’s 2021 U.S. Climate Extremes Index, the lower 48 states are experiencing increases in single-day extreme rainfall events. Such increases have already been observed in many regions including the Pacific Northwest (PNW) and are projected to continue to increase in the coming decades. Therefore, it is essential to find ways to increase soil infiltration, reduce peak discharge and runoff volume. For decades, agricultural conservation practices/best management practices (ACPs/ag BMPs) have been widely implemented for water quality protection but evaluating their potential co-benefits for peak flow/flood reduction has rarely been performed. Yet, we know that if we can reduce runoff, we reduce nutrient and sediment inputs to streams. Therefore, finding ways increasing infiltration and reducing nutrient losses from agricultural fields is paramount important for EPA program offices and regional partners to make informed decisions to better control nutrient losses from agricultural fields and mitigation downstream flood potentials.

Description:

Agricultural best management practices/conservation practices (ag BMPs/ACPs) have been widely implemented for nonpoint source pollution control. However, through a Region 10 R2P2 project, we have identified two critical knowledge gaps that limit broader adoption of ACPs in the Pacific Northwest (PNW). The first gap is current implementation: information is lacking on where, when, and how broadly those practices have been implemented and how effective they are at not only improving water quality, but also reducing peak flow and flow volumes. The second gap is regarding future implementation: what practices and how we best implement them in the PNW to achieve maximum benefits, not only for water quality improvement, but also for peak flow/flood mitigation. Thus, we proposed a Regional and Office of Research and Development Applied Research effort (ROAR) to address these two issues. The Hangman Creek watershed, which flows from headwaters in the foothills of the Rocky Mountains of Western Idaho to where the tributary empties into the Spokane River of Eastern Washington, was selected as the study area. This presentation briefly introduces the ROAR, the Hangman Creek watershed, past and existing ongoing efforts, as well as our plans for the project. It is our hope that a better scientific understanding of the effectiveness (co-benefits) of ACPs can be gained so that we can connect ACPs with other federal funding opportunities, such as the US Federal Emergency Management Agency (FEMA)’s flood mitigation funding, which provide funding to state and local governments, as well as tribes and territories, to engage in flood risk management efforts. In addition, recent influx of Bipartisan Infrastructure Law funding and Inflation Reduction Act funding now also allow farmers to access. Helping farmers to apply a wider range of funding opportunities would result in a broader adoption of ACPs to achieve water quality as well as flood reduction goals ultimately.

Record Details: