Stream Flow Trends - 1999

During the latter half of the 1990s, the volume of water discharged in most of Minnesota's streams has been significantly greater than normal. Stream flow has a high correlation to precipitation. However, only 10 to 30 percent of water falling as precipitation ends up in Minnesota's streams on an annual basis. The remaining 70 to 90 percent recharges the groundwater or near surface aquifers, goes into storage such as lakes and wetlands, evaporates, or is used by plants and animals and transpired back into the air. Period of record hydrographs shown below are ten hydrographs showing the mean annual discharge in cubic feet per second for selected gaging sites. The mean annual discharge is the average of the daily discharges for a given year. Also included on the graphs, are the Q25 and Q75 exceedance levels and the 30 year moving average. Statistically, the mean annual discharge has exceeded the Q75 value 75% of the time and exceeded the Q25 value 25% of the time. The 30 year moving average shows the 30-year trend. Note that these graphs use annual statistics and show an annual summary. On a daily basis, flow may be significantly above or below these annual values.

Mississippi River at Anoka
Mississippi River at Grand Rapids
St. Croix River at St. Croix Falls
Minnesota River at Mankato
Pomme de Terre River at Appleton
Des Moines River at Jackson
Red River of the North at East Grand Forks
Red Lake River at Crookston
Rainy River at Manitou Rapids
St. Louis River at Scanlon

Map of 10 stream sites

View routinely updated information on statewide stream flow conditions.

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