Agricultural chemicals such as phosphorus (P) and nitrogen (N) can be transported from surface soils by runoff and leaching to freshwater bodies. Therefore, agricultural watersheds, particularly in high rainfall areas may pose risk to the water quality in streams, rivers, and lakes. The NRCS technique utilizes existing climatic, hydrologic, and soil survey databases to estimate the loss of water and agricultural chemicals (P and N) by runoff and leaching from agricultural watersheds. It can be applied on a small watershed (20 to 40 ha) or a large area of agricultural land which may include thousands of hectares. The GIS software which utilizes available spatial soil and land cover layers as well as the predicted data for water and both P and N losses, can be applied to develop digital maps. These maps improve data presentation and communications with the clientele as well as identify P and N hot spots within a watershed. The technique was applied on Wagon Train (WT) watershed in southeast Nebraska, US. The objectives were to predict: 1) loss of water from the watershed by surface runoff and subsurface leaching, 2) loss of P and nitrate-N from soils by runoff, 3) loss of nitrate-N from soils by leaching, and 4) P and N loading for WT reservoir. The estimated annual loss of water by runoff was 4.32 million m3 and approximately one million m3 by leaching below the root zone. The predicted runoff water was in good agreement with the observed annual inflow for WT reservoir (4.25 million m3). The predicted annual P loss by runoff was 844 kg while the annual nitrate-N loss was 7.0 Mg. The predicted annual loss of nitrate-N by leaching was slightly higher (7.7 Mg) than that for runoff. Assuming that most of runoff water from the watershed flows into the reservoir, the amount of both P and N in runoff water could be considered as the annual loading for WT reservoir. No attempt was made to investigate the fate of water or nitrate lost by leaching below the root zone. The predicted P concentration in the runoff water at field sites was 196 µg/L. Phosphorous concentration observed in major streams at the beginning of rainy season (March) ranged from 99 to 240 µg/L with an average of 162 µg/L, and the average P concentration in water samples taken from different locations in the reservoir was 140 µg/L. Phosphorous uptake by algae, weeds, and aquatic plants, as well as high pH (8.45) in the reservoir and streams might explain the slight drop of P concentration in waters. Nitrate-N concentration in stream water samples collected at the beginning of the rainy season from 12 locations in the watershed ranged between 0.37 and 1.56 mg/L with an average of 0.90 mg/L. Further, the nitrate-N concentration in monthly samples collected for the entire rainy season (March through October) along the main stream before entering the reservoir ranged from 0.36 to 1.45 mg/L with an average of 0.81 mg/L. The observed concentration was generally lower than the predicted nitrate-N concentration of 1.63 mg/L for the entire watershed. Similar to P, this low nitrate-N concentration observed in streams could be attributed to the presence of heavy growth of algae, weeds, and aquatic plants as well as denitrification. We need to emphasize that the predicted P and nitrate-N values were calculated for runoff water generated at field sites and not in stream water. When we consider factors affecting P and N concentration in runoff after leaving field sites, the technique could provide a reasonable estimation of P and nitrate-N concentration in stream water. We concluded that the NRCS technique could be used as an exploratory technique to conduct quick evaluations and identify hot spots for large areas of agricultural land. Thus, lengthy and site-specific studies could be focused on certain areas of high risk.