DNR Travel Time Toolbox v2.0

The Travel Time Tool was created by the MN DNR to use GIS analysis for calculation of hydraulic travel time from gridded surfaces and develop a downstream travel time raster for each cell in a watershed. This hydraulic travel time process, known as Time of Concentration, is a concept from the science of hydrology that measures watershed response to a precipitation event. The analysis uses watershed characteristics such as land-use, geology, channel shape, surface roughness, and topography to measure time of travel for water. Described as Travel Time, it calculates the elapsed time for a simulated drop of water to migrate from its source along a hydraulic path across different surfaces of the replicated watershed landscape, ultimately reaching the watershed outlet. The Travel Time Tool creates a raster whereas each cell is a measure of the length of time (in seconds) that it takes water to flow across it, and then accumulates the time (in hours) from the cell to the outlet of the watershed. <br/><br/>The Travel Time Tool creates an impedance raster from Manning's Equation that determines the velocity of water flowing across the cell as a measure of time (in feet per second). The Flow Length Tool uses the travel time Grid for the impedance factor and determines the downstream flow time from each cell to the outlet of the watershed. <br/><br/>The toolbox works with ArcMap 10.6.1 and newer and ArcGIS Pro. <br/><br/>For step-by-step instructions on how to use the tool, please view <a href='https://resources.gisdata.mn.gov/pub/gdrs/apps/pub/us_mn_state_dnr/dnr_travel_time_tool/MN DNR TRAVEL TIME Detailed Instructions.pdf' target=_blank>MN DNR Travel Time Guidance.pdf</a>