COMPARISON OF RUNOFF IN THE WINOOSKI AND OTTER WATERSHEDS OF VERMONT

During summer and fall 2000 we compared surface runoff and precipitation relationships for the Winooski and Otter Creek watersheds in the Lake Champlain basin in western Vermont. Bedrock in both watersheds is predominantly carbonate. The Winooski watershed covers an area of 1228 square miles and includes the cities of Burlington, Barre, and Montpelier. There are 764 miles of river, and 760 miles of perennial rivers in the watershed. More than 75% of the watershed is forested the remaining area of the watershed is urban and agricultural. The Otter Creek watershed has an area of 1102 square miles, including the city of Rutland. There are 822 miles of river, and 758 miles of perennial rivers. Land usage is approximately 50% forested, and 50% urban and agricultural. Stream discharge and precipitation data were collected between May 15 and November 15. Fifteen minute real-time discharge data were collected from the USGS for the Winooski River and Mad River in the Winooski watershed and Otter Creek and the New Haven River in the Otter watershed. Precipitation data for the Winooski watershed were collected from the USGS for the Mad River in 15 minute increments. Precipitation data for the Otter watershed were collected in hourly increments from NOAA. The volume of runoff was estimated from hydrograph separations. Hydrographs were separated using the straight-line and variable-line methods. The runoff volume was plotted against total precipitation for each watershed. The relationship between precipitation and runoff in the watersheds showed differences depending upon separation technique and land usage in the watershed.