The NPS monitors the water flow at Coldwater Spring. This provides a baseline of the water flow rate and allows for observations of changes in it. The spring and reservoir are contributing elements to the Fort Snelling National Historic Landmark, and any changes to the flow of the spring represent potential impacts to this landmark.
The water is collected using the "Bucket Fill" method which uses a bucket and stopwatch. The bucket is placed into the water flow and the time it takes to completely fill the bucket is recorded. This process is repeated 3 times and the results are then averaged.
The NPS explored different water collection techniques, and this method provided the best results. See the analysis here.
The water flow is collected at two locations. The first is from a pipe that exits the southwest corner of the springhouse. The second is off a limestone rock in which the wetland south of the springhouse and reservoir drains.