Technical Abstract: The Tipton Creek watershed traverses Hamilton and Hardin counties in north central Iowa. Over the past 20 years, both counties have experienced substantial growth in livestock production, particularly confinement hog farms. However, overall nitrogen (N), phosphorus (P), and potassium (K) nutrient availability has not increased proportionately, attesting to the fact that producers are becoming more judicious in their use of crop nutrients. Available data shows that the efficiency of crop nutrient use has improved somewhat over the past 20 years. Notwithstanding the improvements in overall nutrient use, in-stream water quality data from the study area suggest that elevated nitrate-N levels in surface water resources are still a problem in Tipton Creek watershed. Results of the baseline analysis in this report provide a profile of current conditions, to which alternative scenarios or future changes can be compared. The calibrated computer simulation models used to estimate the baseline profile of the watershed can also be used to evaluate alternative practices that may improve receiving water quality without undue financial burden on farmers in the watershed.