BIG SUGAR BUSH LAKE Reviewing Weather and Lake Impact Special Report Big Sugar Bush Lake Association Becker County, Minnesota by Jimmy Olsen Spring 2016 INTRODUCTION “The impact of climate Addressing water issues at Big Sugar Bush Lake is a core must be included in all responsibility of the Big Sugar Bush Lake Association. This evaluations of water article focuses on a review of historical weather patterns and availability in lake level elevations over the recent past and available period Minnesota. Human of records. activity aside, surface The Weather. The diverse nature of the air masses and groundwater impacting Minnesota's climate leads to a high degree of quantity is driven by variability across space (spatial variation) and time (temporal variation. the balance between atmospheric input Spatial variations affect the weather around Big Sugar Bush from precipitation, and due to its location in the continent. The impact from various continental air masses is quite varied. Winter weather is losses due to primarily driven by cold, dry continental polar air, but evapotranspiration. sometimes replaced by somewhat milder maritime polar air. Very few of the During the summer, hot and dry continental tropical air watersheds in masses from the desert southwest share predominance with Minnesota extend warm and moist maritime tropical air that originates over the beyond the borders of Gulf of Mexico. Spring and fall seasons are the result of transitions between these sources. the State. Therefore, knowledge of Temporal variations (changes over time) are addressed Minnesota's climate during the current period of record using data from the nearby Tamarac National Wildlife Refuge weather station. patterns provides The period of record utilized is 1977 through 2015. important insight into water availability Lake Levels. Water level elevation data was taken from Minnesota Department of Natural Resources (DNR) records. issues.” For Big Sugar Bush, the current published period of record is Retrieved from: May 12, 1993 through May 7, 2015. Historical changes in Minnesota DNR lake surface area are evaluated from aerial photographs. Impacts. The relationship between recorded variations in precipitation, temperature and lake levels is addressed in this report. Also analyzed are relationships between lake ice-out WHAT’S INSIDE dates and recorded variations in temperature. 3 7 18 EARLY YEARS CURRENT YEARS THE WEATHER OF 2015 1 This Page Intentionally Left Blank 2 THE EARLY YEARS Reviewing Weather and Lake Impact BIG SUGAR BUSH Becker County, MN THE EARLY YEARS “Drought What in the world was going on in those 1930’s anyway? The 1930s changed the The aerial photo below provided by Steve Odegaard shows Big Sugar Bush wasn’t always its current size. As face of many area lakes, a matter of fact, at one time, it was essentially two lakes: shrinking them into Big Sugar Bush (the bigger lake) and Lake McGee (the ponds almost little lake). unrecognizable by The following statement from the Minnesota DNR lakeshore owners who provides a premise to understanding what happened settled Big Sugar Bush during this time to so dramatically reduce the lake size: beginning mostly in the “surface and groundwater quantity is driven by the late 1960s. In Big Sugar balance between atmospheric input from precipitation, Bush, the channel of and losses due to evapotranspiration. Based on this, it water between the big should be helpful to analyze both precipitation and temperature data for relevant periods to look for patterns island and shoreline of and likely causes. the Second Subdivision, roughly the southeast Since weather data is not recorded for Tamarac NWR station prior to 1977, the weather data from the Detroit end of the lake, did not Lakes weather station was analyzed for these early years. exist. Loggers sometimes crossed this dry channel to harvest Figure 1. Big Sugar Bush Lake – likely sometime during the 1920’s or 1930’s. Photo provided by Steve Odegaard. wood on the area now Source: U.S. Army Corps of Engineers archives. known as the island. This separated Big Sugar Bush into two parts, the smaller, where the Public Access now lies, forming a separate lake. Local residents called this little lake McGee Lake, named after owner of a log cabin by the shore.” Retrieved from: Sugar bush area history, www.bigsugarbush.net 3 THE EARLY YEARS Reviewing Weather and Lake Impact BIG SUGAR BUSH Becker County, MN The 1930’s – Not entirely to blame. While it is stated that the 1930s changed the face of area lakes, a review of temperature and precipitation data for Detroit Lakes, shows the primary impact declined after 1936. 1929-1936: Hot and Dry. Beginning in 1929 and continuing through 1936 there were some exceptionally hot days. Also, during this same period the annual precipitation declined significantly overall. This two punch trend of hot and dry weather appears to have been the major factors in significantly reducing the size of Big Sugar Bush and surrounding lakes. Chart 1. 1925-1936 Annual Precipitation & Hottest Day of the Year - Detroit Lakes, MN The chart shows the general trend toward dryer years from 1925 to the 1936 low of 12.35 inches of annual precipitation. More dramatic still is the trend of exceptionally hot days over topping 100°F during this period. It is also clear from the chart that 1936 was an extreme weather year. 1936 - A Year of Nationwide Extremes. The climatological summer (June-August) of 1936 was the warmest nationwide on record (since 1895) with an average temperature of 74.6°. and July of 1936 was the single warmest month ever measured with an average of 77.4°. Ironically, February of 1936 was the coldest such on record with an average nationwide temperature of 26.0°. Detroit Lakes recorded its record high of 107° F on July 7, 1936. And, true to the extremes that year, it recorded a low temperature on February 16 and 17 of -46° F. 4 THE EARLY YEARS Reviewing Weather and Lake Impact BIG SUGAR BUSH Becker County, MN The Great Heat Wave June 1936. June of 1936 saw unusual heat build initially “By July [1936] the in two nodes, one centered over the Southeast and another dome of heat locked in over the Rocky Mountains and western Plains. place over the central July 1936. By July the dome of heat locked in place over and northern Great the central and northern Great Plains and remained there Plains and remained for the entire month. there for the entire Around July 8-10 the ridge briefly extended all the way to month.” the East Coast when virtually every absolute maximum temperature record was broken from Virginia to New “The Great Heat Wave of 1936; York. This held true for most sites in the Ohio Valley, Hottest Summer in U.S. on Record” By: Christopher C. Burt , July 21, Upper Midwest, and Great Plains as well. 2011, Weather Underground. A Long Hot Week in July 1936. Here are the high temps for Detroit Lakes, MN from July 7th through July 14th: 107, 101, 101, 101, 107, 104, 105, 103 Figure 2. Heat Wave of July 1936 (From: “Extreme Weather: A Guide and Record Book”, by Christopher C. Burt) 5 THE EARLY YEARS Reviewing Weather and Lake Impact BIG SUGAR BUSH Becker County, MN “In 1941, George* remembered, it 1937–1949: The Recovery. started to rain, and rain, Rain. George Rousu was basically right – it did throughout the 40s, and McGee start to rain in the 1940’s; but actually it started lake joined Big Sugar Bush to to rain significantly again beginning in 1937 with reach the familiar shape we know a good rebound of 27.71 inches that year. The it today. Because the lake downpours continued year after year through the apparently has no inlet or outlet, 40’s with 1944 setting a record at for the period of 33.57 inches followed by 1946 with 32.81 it is thought to be spring fed, and inches. This did wonders for the lake recovery, finds its level primarily based on and Lake McGee and Big Sugar Bush joined to rainfall and evaporation. In produce the lake shoreline we know today. summer 1995 it stood at its Cooler. Just as significant, the temperature fever highest level in at least 20 years.” broke, with only one year registering a 100 *George Rousu, a lifelong area resident. degree day during the 1937 through 1949 period. Retrieved from: Sugar bush area history, Also, 1942 was the lowest, high temperature www.bigsugarbush.net recorded during this period at 91° F. Chart 2. 1937-1949 Annual Precipitation & Hottest Day of the Year - Detroit Lakes, MN 6 CURRENT YEARS Reviewing Weather and Lake Impact BIG SUGAR BUSH Becker County, MN Big Sugar Bush is a 472- THE CURRENT YEARS acre, scenic lake with many A number of lake association members have been on bays and peninsulas, Big Sugar Bush since the mid to late 1970’s. These residents have been eye witnesses to most of the located in north-central weather events and lake impacts since then. The Becker County within the published period of record for nearby Tamarac National White Earth Reservation. Wildlife Refuge weather station data begins in 1977 and is fairly consistent – while there are significant gaps in Water clarity remains high recorded data for Detroit Lakes. Therefore, because of with an average secchi disk this, and Tamarac’s closer proximity to the lake, its weather data is used for this report during the “current reading of 18.4 feet and years” time frame from 1977 to present (2015). many lakeshore property Changes during this time on the land surrounding the owners have retained lake have been significant with a number of cabins and cottages constructed, additional docks, road work, etc.