Stream conditions in SE Minnesota have been generally good for fishing since the traditional trout season opened in mid-April. Water levels have been somewhat higher than last year in larger streams, but stream sediment loads from thunderstorm events have only been a hindrance to fishing for a day or so in small streams and 3-4 days for the larger streams.
Hydrographic conditions are monitored in Minnesota through the DNR/MPCA Cooperative Stream Gaging program. Automated stream gauging stations throughout the state are available to the public at the DNR website: http://www.dnr.state.mn.us/waters/csg/index.html.
The current stream flow conditions presented here are based on the telemetry gauge at Lanesboro, MN, on the South Branch of the Root River. At this location, the gauge provides flow (discharge) data that result from recent precipitation, groundwater emergence, and surface runoff from the South Branch Root River watershed upstream of Lanesboro. Often, changes in Root River flows are indicative of the flows in SE Minnesota streams and NE Iowa streams, and may also represent flows typical of the southern half of the midwest Driftless Area.
The graph below shows the March to mid-July flows this year (2016) in the South Branch Root River, and rainfall at the Lanesboro, MN, stream gauge. One unusual feature of this graph is the enormous spike in precipitation at Lanesboro, with no subsequent spike in river flow. The Lanesboro gauge measures the result of all upstream inputs, thus, this graph indicates that the thunderstorm that Lanesboro experienced missed the upper reaches of the watershed, influencing flows downstream of Lanesboro. If you plan to travel to fish in SE MN streams, it is prudent to call ahead to get reports specific to the streams you want to fish.
Contrast this with the graph below showing flow and precipitation over the past year. Typical summer flows over the past year ranged from 200-400 cubic feet per second. Peak spring flows this year have been only half of those experienced last year, resulting in much clearer flows during 2016 in both large and small streams in the region.
These discharge charts are particularly relevant to those who may be considering a trip to the Driftless Area for trout fishing. Rising water levels with storm events often result in decreases in water transparency due to surface erosion or re-suspension of sediments already in the streams and rivers.
See also the MN DNR stream conditions report for this week at http://www.dnr.state.mn.us/areas/fisheries/lanesboro/stream_conditions.html.