Aridity is increasing across the United States Great Plains region, shifting the dividing line between the humid East and arid West, and intensifying pressure on already stressed water resources. Within the Great Plains, the Eastern Kansas River Basin spans this dividing line and provides an opportunity to evaluate how climatic shifts will impact outcomes for agriculture and water resources. Using data from 2006-2024, we developed and integrated process-guided statistical models of irrigation water use, crop yields, agricultural net returns, and river nitrate export. We then evaluated tradeoffs between agricultural productivity and profitability, irrigation water use, and nitrate export under eight alternative management, land use scenarios, and two future climate scenarios using the multi-objective optimization NSGA-II algorithm. Within the optimization, land use (defined using crop type and irrigated/rainfed management) served as the decision variable for identifying outcomes that balance competing objectives, such as maximizing net returns and minimizing nitrate flux and irrigation water use. We found that under historic climate and land use conditions, years that minimized agro-economic and water resource tradeoffs were drier and characterized by higher-than-average soybean and wheat shares and lower corn and sorghum shares. Preliminary scenario results suggest that both diversified expansion and rainfed management maintain net returns while reducing impacts to water quantity and quality, highlighting promising pathways for climate-resilient agricultural planning in the Eastern Kansas River Basin and similar Great Plains landscapes.