The Nooksack River watershed and Bellingham Bay in Whatcom County, WA, face several issues linked to high nutrients in surface and groundwater. Riparian buffers can help with nutrient management and have significant co-benefits for other ecosystem services as well. Understanding the drivers of nutrient uptake by buffers will help prioritize locations for riparian restoration. However, understanding the policy landscape is also essential for determining the extent to which best available science gets applied in the watershed. Our proposed work has two integrated, multidisciplinary goals: 1) model the potential for riparian restoration to decrease nutrient inputs to the Salish Sea via the Nooksack River; and 2) map and evaluate the diversity of existing policies that apply to riparian buffers to better understand the constraints and opportunities for restoration they afford. This project will train three early career researchers. Two MS students in the Hooper Lab will take complementary approaches to modeling nutrient benefits of riparian buffers. Patrick Demaree will work to calibrate and validate the mechanistic Agricultural Policy/Environmental eXtender (APEX) model in small subwatersheds in the Nooksack basin. Astoria Tershy will work at larger scales, synthesizing existing data for current riparian restoration across the Nooksack watershed, and use simpler models of riparian buffer effectiveness to estimate current and potential benefits to nutrient load reductions. Co-PI Amanda Stahl, post-doc at Washington State University, will map the current riparian policy landscape with the goals of characterizing restoration capacity and identifying locations with environmental co-benefits to nutrient management.