lake levels - minnesota department of natural resources€¦ · gage locations sandy fecht. water...

Water Year Data Summary, 2007-2008 Water Year Data Summary, 2007-2008

The Lake Hydrology Program exists to support the DNR Waters director and staff by collecting and providing data on lake levels and other lake characteristics that are needed to effectively carry out DNR Waters’ statutory responsibilities and management programs.

A key component of the Lake Hydrology Program is the development and maintenance of the Lake Level Minnesota Monitoring Program. The Lake Level monitoring program primarily uses both temporary (movable) and permanent lake gages as in-dicators for measuring and determining the water surface level of certain lakes. A network of about 1000 lake gages is currently managed (Figure 1). The program relies on over 800 citizen volunteers and local government partners who record lake levels on a regular basis and submit the data to DNR Waters. Approximately 25% of the monitoring sites are managed currently under oral cooperative agreements with governmental units.

Lake LevelsIntroduction

Water level data are used by DNR field staff as rationale for decision making in the public waters permit program and appropriations permit program. The records are used as supporting data for establishing ordinary high water levels and historic high water elevations, which are also the founda-tion for setbacks within the land use management programs. Lake level data support many DNR Waters hydrologic and hydraulic analyses. A consistent record of lake levels provides a long-term in-dication and understanding of the hydrology of the lake, watershed, and the relation between surface water and ground water. The information is crucial to surface water and ground water interaction studies for appropriations decisions. Long-term records show normal fluctuations, as well as the ex-treme highs and lows. Data are used to calibrate hydrologic models, especially applications for flood levels and lake outlets.

Data Uses

36 surface water

Figure 1

Lake Level Minnesota

Gage Locations

Sandy Fecht

Water Year Data Summary, 2007-2008 Water Year Data Summary, 2007-2008

surface water 37

The data are used by local zoning officials for platting, locating structure sites, and for establishing low floor elevations for new construction. Watershed managers and planners use historical lake level data while preparing local water management plans and modeling lake water quality characteristics. Fisheries staff use data as one variable in studying impacts on habitat. Other researchers use the data for climate change studies. Water level data are used for decisions by lakeshore owners on dock location/timing, vegetative shoreline protection, and understanding the natural fluctuations of a lake.

All lake level readings received are entered into Lakes-DB©, a database program for storing and retrieving a variety of information on Minnesota’s lake basins. Over the last few years, the millions of items of information have been migrated from a stand-alone database to an updated web applica-tion.

The DNR Lake Finder web site is the best means for the public to access available data on more than 4,500 Minnesota lakes relating to lake water levels, fisheries information, lake area and maximum depth, depth maps, water quality and clarity, air photos, and topographic maps. After searching by county, lake name, or identification number for a particular lake, a click on the word, “go,” below “lake water levels/ruler” displays the Lake Water Level Report page. This report contains informa-tion, including:

reported historical and current lake levels period of record and number of readings highest recorded lake level highest known lake level lowest recorded lake level recorded range ordinary high water level [also shown as the red line on the 10-year graph] datum of the majority of elevations benchmarks most recent 10-year graph [X-axis Year tick mark references mid-year]

Information Management

• •••••••••

http://www.dnr.state.mn.us/lakefind/

Water Year Data Summary, 2007-2008

Over 1,300 of the lakes have a historical record of more than 100 water level readings. In addition to the sum-mary information, a Lake Finder user can retrieve and view all the reported lake elevations for a specific lake via the download of lake level data as dBase or ASCII from the center of the Lake Water Level report page.

Clicking on ASCII is the most common method used to view the water surface elevations and the date of the readings. The chronological water surface elevation data can then be viewed, saved, or highlighted and cop-ied into a computer software spreadsheet for sorting and graphing. Check out how the levels of a chosen lake compare to other historic drought or wet years or other lakes.

38 surface water

The primary factor that affects water level changes is the quantity and distribution of precipitation. Other factors that contribute to water level changes are soil moisture conditions, runoff, evapotranspiration, outlet conditions, beaver dams, human-made dams, ground water movement, and watershed characteristics and size (Figure 8, page 48).

Lake Levels

“Pulled dock out August 28 - lake too low to get boat near.”

“Water is 3 feet away from the lake gage.”

“I haven’t seen the lake this low since 1976.”

“Super dry based on my 30 years of volunteer gage reading.”

“Funny how we got rain, but it didn’t seem to do as much as I thought it would have. No runoff from our watershed

went into the lake.”

“Think rain!!”

Jerry Angst

Drought

The water levels of all lakes fluctuate dependent on their unique water budget - some more than others. A water budget is the sum of “incoming” resources minus “outgoing” resources. It is an estimation of the water resources available to “spend” or “save” and must take into account all available ground and surface water. Water enters the lake as precipitation, surface-water inflow, and ground-water inflow. Water leaves the lake as evaporation, surface-water outflow, and ground-water outflow (see Hydrologic Cycle, page iv).

In a prolonged dry cycle, runoff and rain may be absorbed first by the soil and not contribute to lake levels. Knowing, understanding, and accepting the history of water level fluctuations can help lake users deal with expectations and problems associated with the changing levels.


surface water 39

In contrast to the drought and areas of normal precipitation, other areas’ significant rainfalls were reflected in lake level increases during the 2007-2008 Water Years (Figure 4, page 42). Rapid snow melt followed by above average precipitation for the first half of 2007 saturated the region in west central and northwestern Minnesota. A dozen lakes in Otter Tail County reported their highest water levels in Spring 2007. Only scat-tered lakes in the state reached their highest waters during that time, reflecting the effects of the drought. By the end of August 2007, many locations in the southern third of the state set all-time monthly rainfall records which helped restore low lake levels. One Twin Cities gage reader wrote, “Water, water everywhere! What happened to the drought?”

A strong weather system in early September 2007 dropped over six to nine inches of rain in the Arrowhead region, tripling historical averages for the month. Many of these same locations in the northeastern counties also had one of their wettest Octobers ever with similar precipitation totals. These cumulative rain events spiked lake levels to a number of highest reported levels in St. Louis County. A volunteer reported, “My dock is under water, and the lake is still rising.”

(photo at left: Poplar Lake, Rockwood Lodge & Canoe Outfitters)

One of the most interesting fluctuations over a year came from our volunteer readers on Poplar Lake in Cook County. In May 2007, they apologized [without need!]for missing taking a gage reading during the Ham Lake fire. Early May had brought weather conditions that were highly conducive to dry conditions and spreading wildfire potential. There was some June recharge of their lake, but the lake levels quickly dropped below the gage by the end of August. The lake then received the double impact from historic rainfalls in both September and October as seen in the hydrograph in Figure 4 (page 42).

The influence of the Fall 2007 rains carried over into high lake levels for many St. Louis County lakes in Spring and Summer 2008. Climatology Office maps showed this area with more than 175% of normal precipi-tation through mid-June 2008. Lakes were kept high as that trend continued with close to 100% precipitation by the end of the summer.

Lake Level Responses

Comments like these from our volunteer readers illustrate the widespread drought in 2007 for the second summer in a row (Figure 2, page 40).

Rainfall totals for the summer were far short of the historical average in some loca-tions in west central and central locales. In response to the lack of precipitation in 2007 and the effects of the drought of 2006, many lakes receded to low water levels. The list of counties with large areas reporting over 150 of their lowest lake levels by the end of Water Year 2007 grew longer and longer: Aitkin, Carlton, Carver, Cass, Hennepin, Kandiyohi, McLeod, Pine, St. Louis, Scott. Over 35 gaged lakes in Washington County reached their all-time lowest reported levels by the end of summer in 2007. Crow Wing and Itasca County lakes had the next high-est number of gaged lakes with lowest reported levels in 2007. A number of gages had to be reset one to three times over the summer in deeper locations in order to capture any water level readings.

Water Year 2008 saw a prolonged dry spell for the third summer in a row for southern Minnesota, the Missis-sippi Headwaters, and parts of the northeast (Figure 3, page 41). Lakes in concentrated areas in Cass, Hub-bard, Itasca, Washington, and Martin Counties reached their lowest historic lake level in the summer of 2008.

The 2008 drought areas were lessened by lowered temperatures in the summer, holding evaporation rates close to normal. Remarks by our volunteer readers were few compared to the previous two years of impacts on many gaged lakes. Less than 60 lakes reported their lowest lake level during the summer of 2008, a sharp contrast to the large numbers in 2006 and 2007.

Sandy Fecht


40 surface water

Long Lake (77-0027), Todd County

1197.00

1197.50

1198.00

1198.50

1199.00

1199.50

1200.00

1200.50

4/21/05 7/21/05 10/21/05 1/21/06 4/21/06 7/21/06 10/21/06 1/21/07 4/21/07 7/21/07

Elevation (ft. - NGVD1929)

51-Year Average

Lowest reported: 1197.27 on 9/18/07

Long Lake (47-0177), Meeker County Tamarack Lake (58-0024), Pine County

Long Lake (77-0027), Todd County Gilbert Lake (18-0320), Crow Wing County

Chub Lake (09-0008), Carlton County

Gilbert Lake (18-0320), Crow Wing County

1172.00

1172.50

1173.00

1173.50

1174.00

1174.50

1175.00

1175.50

10/1/04 1/1/05 4/1/05 7/1/05 10/1/05 1/1/06 4/1/06 7/1/06 10/1/06 1/1/07 4/1/07 7/1/07


18-Year Average


Chub Lake (09-0008), Carlton County

1115.00

1115.50

1116.00

1116.50

1117.00

1117.50

1118.00

1118.50

1119.00

1119.50

10/2/04 1/2/05 4/2/05 7/2/05 10/2/05 1/2/06 4/2/06 7/2/06 10/2/06 1/2/07 4/2/07 7/2/07

Elevation (ft. - Local Datum)

21-Year Average


Long Lake (47-0177), Meeker County

1163.00

1163.50

1164.00

1164.50

1165.00

1165.50

1166.00

1166.50

10/4/04 1/4/05 4/4/05 7/4/05 10/4/05 1/4/06 4/4/06 7/4/06 10/4/06 1/4/07 4/4/07 7/4/07


60-Year Average


Tamarack Lake (58-0024), Pine County

1035.00

1035.50

1036.00

1036.50

1037.00

1037.50

1038.00

5/9/05 8/9/05 11/9/05 2/9/06 5/9/06 8/9/06 11/9/06 2/9/07 5/9/07 8/9/07


7-Year Average


Low Lake Levelsduring2007

Tamarack

ChubGilbert

Long

Long

Figure 2


surface water 41

Johnson Lake (31-0586), Itasca County

1360.00

1360.50

1361.00

1361.50

1362.00

1362.50

1363.00

10/14/05 1/14/06 4/14/06 7/14/06 10/14/06 1/14/07 4/14/07 7/14/07 10/14/07 1/14/08 4/14/08 7/14/08



29-Year Average

Hay Lake (11-0199), Cass County

Johnson Lake (31-0586), Itasca County Sand Lake (31-0438), Itasca County

1358.00

1358.50

1359.00

1359.50

1360.00

1360.50

1361.00

1361.50

10/10/05 1/10/06 4/10/06 7/10/06 10/10/06 1/10/07 4/10/07 7/10/07 10/10/07 1/10/08 4/10/08 7/10/08



22-Year Average

Sand Lake (31-0438), Itasca County

Bass Lake (82-0123), Washington CountyMonson Lake (76-0033), Swift County

Hay Lake (11-0199), Cass County

1334.00

1334.50

1335.00

1335.50

1336.00

1336.50

10/5/05 1/5/06 4/5/06 7/5/06 10/5/06 1/5/07 4/5/07 7/5/07 10/5/07 1/5/08 4/5/08 7/5/08



41-year Average

Monson Lake (76-0033), Swift County

1234.00

1234.50

1235.00

1235.50

1236.00

1236.50

1237.00

1237.50

1238.00

4/14/06 7/14/06 10/14/06 1/14/07 4/14/07 7/14/07 10/14/07 1/14/08 4/14/08 7/14/08



25-Year Average

Low Lake Levelsduring2008BassMonson

Hay

Johnson

Sand

Figure 3

Bass Lake (82-0123), Washington County

948.00

949.00

950.00

951.00

952.00

953.00

954.00

955.00

10/5/05 1/5/06 4/5/06 7/5/06 10/5/06 1/5/07 4/5/07 7/5/07 10/5/07 1/5/08 4/5/08 7/5/08



33-Year Average


Leek (Trowbridge) Lake (56-0532), Otter Tail County Spring 2007

1358.50

1359.00

1359.50

1360.00

1360.50

1361.00

1361.50

10/10/06 1/10/07 4/10/07 7/10/07 10/10/07 1/10/08 4/10/08 7/10/08


Highest reported: 1360.87 on 6/7/07

10-Year Average

Leek (Trowbridge) Lake (56-0532), Otter Tail CountySpring 2007

42 surface water

Orchard Lake (19-0031), Dakota County Summer 2007

975.50

976.00

976.50

977.00

977.50

978.00

10/5/06 1/5/07 4/5/07 7/5/07 10/5/07 1/5/08 4/5/08 7/5/08



47-Year Average

Orchard Lake (19-0031), Dakota CountySummer 2007

Sturgeon Lake (69-0939), St. Louis CountySpring 2008

Poplar Lake (16-0239), Cook CountyFall 2007

1852.00

1852.50

1853.00

1853.50

1854.00

1854.50

1855.00

1855.50

10/1/06 1/1/07 4/1/07 7/1/07 10/1/07 1/1/08 4/1/08 7/1/08



40-Year Average

Sturgeon Lake (69-0939), St. Louis CountySpring 2008

1370.00

1370.50

1371.00

1371.50

1372.00

1372.50

1373.00

1373.50

10/2/06 1/2/07 4/2/07 7/2/07 10/2/07 1/2/08 4/2/08 7/2/08


71-Year Average


Schelins Lake (69-0624), St. Louis County Summer 2008

1334.50

1335.00

1335.50

1336.00

1336.50

1337.00

10/1/06 1/1/07 4/1/07 7/1/07 10/1/07 1/1/08 4/1/08 7/1/08



7-Year Average

Schelins Lake (69-0624), St. Louis CountySummer 2008

Lake Level Responses

Poplar Lake (16-0239), Cook CountyFall 2007

Schelins

Sturgeon

Leek

Orchard

Poplar

Figure 4


surface water 43

Information has been collected and reported over a period of more than ten years for many of the lakes that are currently monitored. A ten-year average may be used as a point of reference when comparing water year data to a shorter or longer time period, or a ten-year climate cycle. It may be useful in discerning trends for an individual basin.

Ten-Year Trends

Landlocked Basins

A landlocked lake has no regularly-functioning surface outlet channel, and usually a small watershed. These types of lakes typically experience large, long-term water level fluctuations. The importance of ground water contributions to a landlocked lake can make the lake a good indicator of local ground water levels and movement. Examples of landlocked basins are shown in Figure 7 (page 47). Some of these lakes also reflect responses to the dry conditions of 2007 and 2008.

Minnesota lakes typically fluctuate one to two vertical feet in a given year, but historical fluctuations have been recorded in excess of ten feet. Assessing the annual fluctuation can be done by looking at the changes from one Water Year to the next. Another primary evaluation tool is the “starting point,” i.e. the elevation of the lake in spring, and how that compares to the end of the open water season and how that year compares to the “starting point,” “end point,” and pattern of other years. The lake levels and their patterns can then be evaluated in the context of historic climate data.

The statewide average fluctuation for Water Year 2007 was 1.24 feet, but decreased to 1.14 feet for the statewide average during Water Year 2008. Average fluctuations for the past ten Water Years are shown in the table on the next page. Link here to tables which display fluctuations, spring and fall elevations, ranges, reported highest and lowest lake levels and their dates, and averages for selected lakes grouped by county.

Additional summary information, ten-year trend graphs, and a comprehensive list of all reported lake levels for an individual lake may be found on the DNR Lake Finder web site.

Annual Lake Level Fluctuation

Velma Wesloh

Sandy Fecht

A selection of lakes is shown in Figures 5 (page 45) and 6 (page 46). Lake Vermilion reflected the high precipitation for the Northeast in Fall 2007 and Spring 2008. Reported lake levels in May 2008 were some of the high-est reported for Vermilion in our 58 years of records. Comparable spring levels can only be found in 1970 and 2001.

For these selected lakes, one lake remained below average during Water Year 2007 and most of Water Year 2008. Three of the lakes remained below their average throughout both Water Years 2007 and 2008. In Fall 2008, White Bear Lake reported its lowest level for the last 17 years. For more information from a past study of lake-ground water interaction at White Bear Lake following a drought, see this link.

http://files.dnr.state.mn.us/waters/surfacewater_section/lake_level_fluctuations0708.xls

http://www.dnr.state.mn.us/lakefind/

http://files.dnr.state.mn.us/publications/waters/wbl_98.pdf


44 surface water

1999 1.242000 1.052001 1.972002 1.332003 1.422004 1.242005 1.07200620072008

AverageFluctuation

Statewide (ft.)

1.291.241.14

Water Year

Sandy Fecht


surface water 45

Pelican Lake (18-0308), Crow Wing County

1202.00

1203.00

1204.00

1205.00

1206.00

1207.00

1208.00

1209.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08



10-Year Average


Pelican Lake (18-0308), Crow Wing County

Union Lake (60-0217), Polk County

Otter Tail Lake (56-0242), Otter Tail County

Vermilion Lake (69-0378), St. Louis County

Lake Itasca (15-0016), Clearwater County

Otter Tail Lake (56-0242), Otter Tail Couny

1317.00

1318.00

1319.00

1320.00

1321.00

1322.00

1323.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08

Elevation (ft. - 1912 datum)


10-Year Average


Vermilion Lake (69-0378), St. Louis County

1355.50

1356.50

1357.50

1358.50

1359.50

1360.50

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08



10-Year Average

Lowest Reported: 1356.07 on 11/28/1976

Lake Itasca (15-0016), Clearwater County

1465.00

1465.50

1466.00

1466.50

1467.00

1467.50

1468.00

1468.50

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08



10-Year Average


Union Lake (60-0217), Polk County

1207.00

1208.00

1209.00

1210.00

1211.00

1212.00

1213.00

1214.00

1215.00

1216.00

1217.00

1218.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08



10-Year Average


Figure 5


46 surface water

Lake Minnetonka (27-0133), Hennepin County

921.00

922.00

923.00

924.00

925.00

926.00

927.00

928.00

929.00

930.00

931.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08




10-Year Average

Francis Lake (47-0002), Meeker/Wright Cos.

Green Lake (34-0079), Kandiyohi County

Lake Minnetonka (27-0133), Hennepin County White Bear Lake (82-0167), Washington CountyWhite Bear Lake (82-0167), Washington County

919.00

920.00

921.00

922.00

923.00

924.00

925.00

926.00

927.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08

Elevation (ft. - 1912 datum)



10-Year Average

Green Lake (34-0079), Kandiyohi County

1153.00

1154.00

1155.00

1156.00

1157.00

1158.00

1159.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08




10-Year Average

Francis Lake (47-0002), Meeker/Wright Cos.

1044.00

1045.00

1046.00

1047.00

1048.00

1049.00

1050.00

1051.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08



10-Year Average


Heron Lake (32-0057-01), Jackson CountyHeron Lake (32-0057-01), Jackson County

1396.00

1397.00

1398.00

1399.00

1400.00

1401.00

1402.00

1403.00

1404.00

1405.00

1406.00

1407.00

1408.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08




10-Year Average

Francis

Figure 6


surface water 47

Belle Taine Lake (29-0146), Hubbard County

1415.00

1417.00

1419.00

1421.00

1423.00

1425.00

1427.00

1429.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08




Belle Taine Lake (29-0146), Hubbard County

Red Rock Lake (21-0291), Douglas County

1299.00

1299.50

1300.00

1300.50

1301.00

1301.50

1302.00

1302.50

1303.00

1303.50

1304.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08




Red Rock Lake (21-0291), Douglas County

Stony Lake (11-0371), Cass County

1370.00

1371.00

1372.00

1373.00

1374.00

1375.00

1376.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08




Stony Lake (11-0371), Cass County

Charlotte Lake (86-0011), Wright County

Itasca Lake (02-0110), Anoka CountyItasca Lake (02-0110), Anoka County

862.00

863.00

864.00

865.00

866.00

867.00

868.00

869.00

870.00

871.00

872.00

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08


Lowest Reported: 863.24 on 10/12/2000

Highest Reported: 871.49 on 08/06/1986

Charlotte Lake (86-0011), Wright County

947.50

948.50

949.50

950.50

951.50

952.50

953.50

954.50

955.50

956.50

7/1/98 7/1/99 7/1/00 7/1/01 7/1/02 7/1/03 7/1/04 7/1/05 7/1/06 7/1/07 7/1/08




Figure 7


48 surface water

Eagles Nest # 1 Lake (69-0285-01), St. Louis County Beaver dams removed mid-July 2008

1490.50

1490.70

1490.90

1491.10

1491.30

1491.50

1491.70

1491.90

1492.10

1492.30

1492.50

5/15/07 7/15/07 9/15/07 11/15/07 1/15/08 3/15/08 5/15/08 7/15/08 9/15/08


Eagles Nest #1 Lake (69-0285-01), St. Louis CountyBeaver dams removed mid-July 2008

Ann Lake (33-0040), Kanabec County Bog removed June 2008

1041.50

1042.00

1042.50

1043.00

1043.50

1044.00

1044.50

4/15/07 6/15/07 8/15/07 10/15/07 12/15/07 2/15/08 4/15/08 6/15/08 8/15/08


6-17-08

6-19-08

Ann Lake (33-0040), Kanabec CountyBog removed June 2008

Otter Lake (43-0085), McLeod CountyDam opened September 4, 2007 at noonOtter Lake (43-0085), McLeod County

Dam opened September 2007

1037.50

1038.00

1038.50

1039.00

1039.50

6/1/07 6/15/07 6/29/07 7/13/07 7/27/07 8/10/07 8/24/07 9/7/07


9-3-07

9-5-07

Long Lake (77-0027), Todd County Outlet impacts 2008

1197.00

1197.50

1198.00

1198.50

1199.00

1199.50

1200.00

5/1/07 7/1/07 9/1/07 11/1/07 1/1/08 3/1/08 5/1/08 7/1/08 9/1/08


Long Lake (77-0027), Todd CountyHeavy Rains during Fall 2007 & Outlet Plugged

Other Impacts on Lake Levels

Ann

Long

Eagles Nest #1

Otter

Figure 8

Sandy Fecht

9-5-07

9-3-07

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