Spring - Gull Chain of Lakes Association

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3 F I N A L R E P O R T O F W A T E R Q U A L I T Y S T U D I E S Robert Eliason When Lake Margaret was listed as impaired because of an excessive phosphorous concentration, your Association inquired whether there was water quality data for the other lakes in the chain. It was discovered that there was virtually no data for the other lakes in the chain except for Gull Lake and that there was no data for the streams flowing into the lakes. During the fall of 2006, your Association decided to embark on initiatives that would correct this. In the spring of 2007, a five-year study was begun to determine the phosphorous levels in the streams flowing into the chain. At that time, it also committed itself to a three-year study to obtain water quality data for Nisswa, Upper Gull, and Booming Out Bay of Gull Lake. More recently, a study of Roy Lake was added. All these studies have now concluded, and the results for Table 1. Lake data. Average Total Phosphorous in ppb with ± indicating standard deviation. Nisswa Roy 20 ±5 18 ±4 Upper Gull Booming Out Bay of Gull 22 ±5 23 ±4 total phosphorous concentrations are summarized below. The lake data are summarized in Table 1. When Lake Margaret was listed as impaired, its total phosphorous concentration was about 65 ppb. The natural total phosphorous concentration in the lakes within our Northern Lakes and Forest (NLF) ecological region has a range of 14-27 ppb. As can be seen, our results are within the expected phosphorous concentrations and well below that found in Lake Margaret. An implication is that these lakes are in a healthy state. Our Gull Chain of Lakes is a reservoir whose water level is controlled by the Army Corps of Engineers. The reservoir has five main inlets - none of which flows into Gull Lake itself. The water of two of the inlets, Home and Stony Brooks, flows basically off the land and directly into the lakes. The water from other three inlets originates from lakes. Home Brook, whose watershed is from west to northwest, flows into the southern end of Lake Margaret. Upper Gull has two inlets – Stony Brook, whose watershed is to the northwest, enters the west side and an unnamed stream from Mayo Lake, whose watershed is from northwest to north, enters the north end. Nisswa Lake has the remaining inlets. The main inlet is an unnamed stream from Lower Cullen Lake, whose watershed is from north to northeast, and the minor inlet is Lazy Brook from Clark Lake, whose watershed is from northeast to east. The land use for the watersheds of Home Brook, Stony Table 2. Stream data. Average Total Phosphorous in ppb with ± indicating standard deviation. Brook, and Mayo Lake is approximately 20% grassland/pasture, which is high for the NFL ecological region, 55% forest, and 25% open water/wetlands. The stream data is summarized in Table 2. There are two sets of results in Table 2. The first set of averages, listed directly under the streams, is from data collected when the ground was not frozen. The second set of averages, listed under ‘ground frozen’, is from data obtained during early spring thaw when the ground was still frozen. As can be seen in the first set, the concentration of total phosphorous in all the inlet streams, except the unnamed one from Lower Cullen Lake, is about 1.5 times higher than the maximum value expected (27 ppb) for our NLF ecological region. It is interesting that the total phosphorous concentration of water coming from Lower Cullen Lake is not only at the minimum value expected (14 ppb) for our NLF ecological region but also less than 1/2 to 1/3 of that of the other streams emanating from lakes. It appears that Lower Cullen Lake is quite healthy in terms of phosphorous whereas Mayo Lake and Clark Lake are quite unhealthy. The Cullen chain and Clark Lake lie in the same area, and yet water from Clark is much higher in phosphorous than that from Cullen. Why? The answer is unknown and must wait for further study. The second set of data (listed under ground frozen), which was obtained during the spring runoff, is very interesting. The concentration of total Continued on page 4 Stream flowing into Streams flowing into Streams flowing into Lake Margaret Upper Gull Lake Nisswa Lake Home Brook Stony Brook Unnamed Unnamed Lazy Brook from Mayo Lake from Cullen Lake from Clark Lake 54 ±12 53 ±23 41 ±24 14 ±7 36 ±24 ground frozen ground frozen ground frozen ground frozen ground frozen 144 ±37 147 ±47 38 ±26 9 ±2 24 ±2
F I N A L R E P O R T O F W A T E R Q U A L I T Y S T U D I E S Robert Eliason Continued from page 3 phosphorous of Home and Stony Brooks is simply enormous. The phosphorous levels in the other three streams are normal for those streams. A possible explanation for this spring runoff effect is as follows. Before the ground has thawed, melting snow water encounters thawed cattle feces, which were deposited on the grass and pasture land, and dissolves the phosphorous contained in them. Since this high phosphorous containing water cannot enter the ground, all of it flows into Home and Stony Brooks, which carry it into our lakes. Even though the Mayo Lake watershed has the same land use pattern as Home and Stony Brooks, the stream from Mayo Lake doesn’t exhibit this same spring runoff effect. This is because the water, from the grass/pasture land must flow through several lakes before reaching Mayo Lake. These lakes are Loon and Sibley, and they, along with Mayo itself, absorb much of the phosphorous. Thus, the water flowing out of Mayo Lake contains a level of phosphorous that is observed throughout the year. This spring runoff effect is shown in Figure 1. In March when the ground is still frozen, the phosphorous concentration is extremely high in both Home and Stony Brooks. After the ground has thawed by April, the phosphorous concentration is at a level to be found during the remainder of the year. Also as can be seen in Figure 1., the phosphorous level in the stream from Mayo Lake does not show a March spring runoff spike. The effect has been mitigated. This suggests that this spring runoff effect of Home and Stony Brooks might be mitigated by having the water run into a pond before it runs into our lakes. A pond created by beavers might work well. The 2011 Land and Water Tour (see Fall 2011 Newsletter) took participants to a ranch in each of the Home Brook and Stony Brook watersheds with the purpose of showing the methods being implemented to reduce nutrients and sediment in those streams. The stream data suggest that these practices may be having a positive effect in reducing what could be called a “rainstorm effect.” A rainstorm effect is an event caused by heavy rains of an inch or more, which results in a significant rise in the stream levels. The large volume of water runs over the ground mixing with manure and dissolving phosphorous. If all of this phosphorous laden water raced directly into the streams, a rise in phosphorous concentration would be expected. If, however, this water encounters a buffer zone, the flow rate slows allowing some of the phosphorous to be absorbed by the plants and soil. Measurements of the stream height of Stony Brook after heavy rains showed that it took about three days for the height to reach a maximum. So, three days after a heavy rain, samples for all streams were collected. In Figure 2, Home Brook shows no increase in phosphorous concentration as the stream level rises; there is no storm effect on the phosphorous concentration. For Stony Brook, it appears that there may be a slight storm effect, but the situation is more complicated. During periods of drought and very low stream levels up to about 2.5 inches, it was observed that Stony Brook under CSAH 29 was completely dry. However, Stony Brook still had a significant flow at our sample collection site (the bridge) in Fritz Loven Park. This flow was most likely due to springs along the two-mile route from CSAH 29 to the park. The phosphorous concentration in the springs would be expected to be low. This is borne out by examining the data in Figure 2 with stream levels up to about 2.5 inches. The phosphorous concentration in this water was a third of that normally observed. So, this data should not be included in the analysis, as it does not represent water from the watershed. If we do this, it still appears as if Stony Brook exhibits a slight storm effect, however. Since neither stream shows large spikes of the type observed for the spring runoff, a fair conclusion would be that stream buffers are helping. In conclusion, the high phosphorous levels in Home Brook suggest that that stream will continue to be an obstacle to removing Lake Margaret from impaired status. The high phosphorous levels in the streams flowing into Upper Gull could cause the phosphorous level in the lake to rise in the future. An interesting question is, since Upper Gull’s watershed is the same as Lake Margaret’s watershed, why has this lake remained healthy when Margaret has become unhealthy? The people deserving special thanks for their dedication of time and energy to collect all the samples required for these studies are Bob Borman, Rosemary Goff, Bob Grussendorf, Bill Radovich, and Bob Toborg. I would like to extend a personal thanks to Jack Warden who, these past four years, was a tremendous help collecting stream samples and was a great companion during the drive around the sampling route. 4
Page 4 and 5: 1 GULL CHAIN of LAKES ASSOCIATION T
Page 8 and 9: 5 SHERWOOD FOREST RESTAURANT S T O
Page 10 and 11: 7 L A K E M A R G A R E T A W A R D
Page 12 and 13: 9 P R O F E S S O R P R O P O S E S
Page 14 and 15: 11 DNR LAUNCHES NEW PREVENTION EFFO
Page 16 and 17: 13 GULL CHAIN OF LAKES FINANCIAL R
Page 18 and 19: 15 Eagles ($5,000+) Anonymous (1) C
Page 20 and 21: 17 MINNESOTA WATERS 2.0 AQUATIC INV
Page 22 and 23: 19 Having moved to the Lakes Area n
Page 24 and 25: 21 Thomas & Sally Amlie Mark & Lisa
Page 26: Claudia Allene - Associate Broker C

Spring - Gull Chain of Lakes Association

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