These are the draft reports for the East Otter Tail SWCD Lake Assessment Reports project.  I have compressed the graphics so that the file size is smaller for the web.  If maps are fuzzy, they won’t be that way in the final report.  Lakes are listed in alphabetical order.

Overall notes:

  • Many of these lakes have excellent water quality
  • Six, Sybil, Pickerel, East Loon and Jewett Lakes are considered Cisco refuge lakes by the DNR, but all their DO profiles showed an anoxic hypolimnion in the summer
  • Many lakes without inlets (low residence times) that haven’t had septic inspections for over 15 years should be prioritized by the county for septic system re-checks (Devils, Eagle, Elbow, First Silver, Little McDonald, Marion, Pickerel)
  • Lakes of most concern: Sybil and Jewett due to excellent water quality and declining trends; Paul Lake’s lakeshed looks very disturbed, but the surface runoff mapping could show that much of the area is non-contributing.

-they will get updated one final time with surface runoff maps being created by the East Otter Tail SWCD

Otter Tail County Summary (DRAFT)

Big McDonald Lake
Comments: Lake is in great shape.  Shoreline runoff is main impact because it has a small watershed, no major inlets, and the septic systems were re-checked in 2010.

Blanche Lake
Comments: Well protected by Glendalough State Park and Lake Blanche WMA.

Boedigheimer Lake
Comments: The transparency varies greatly year to year – looks like it could be due to wet years vs dry years and runoff in the watershed.  Werner Creek could be a problem, but needs more monitoring to determine the impact.

Clear Lake
Comments: I’m not able to reach the Secchi volunteer.  I would like to ask a local some questions about water levels (since there is no outlet) and farm practices around the lake.  The surface runoff mapping will be useful for this lake to see if the ag is impacting the lake.

Deer Lake
Comments:  Lake is in good shape; gets continually flushed out by the Otter Tail River.  VERY large watershed.  Some ag in the south part of the lakeshed, but it is probably not impacting the lake.

Devils Lake
Comments: Septic systems have not been checked since 1995.  Because this lake has no inlet/outlet to flush it out, septic systems have a larger potential impact and should be checked again by the county ASAP.

East Battle Lake
Comments: Check buffers along Vining Creek inlet.  Could be ag draining to it.

East Loon Lake
Comments: Lake in good shape; expansion of housing from Vergas area is largest potential threat.

Elbow Lake
Comments: in excellent shape, protection focus, very small watershed.

First Silver Lake
Comments: Improving transparency.  High water, but not too much property damage.

Franklin Lake
Comments: in good shape, protection focus.  Not much ag in lakeshed.

Hoffman Lake
Comments: Natural eutrophic lake. Ag in lakeshed – runoff mapping will help with seeing if there’s an impact.  Otherwise the lake is in good shape.

Jewett Lake
Comments: Declining trend for transparency and increasing chlorophyll a.  Also very high conductivity and chloride – indicates runoff problem.  Could be from erosion from high water.  Low residence time means runoff sits in lake.  Need to target with shoreline restoration and rain gardens.

Johnson Lake
Comments: High water?  Low development and high ag.  Conservation easements around the shoreline would help protect the lake.

Kerbs Lake
Comments: in excellent shape, protection focus. Very small watershed, septic systems checked by county in 2012.

Leek Trowbridge Lake
Comments: in excellent shape, protection focus.  Keep an eye on Camp Trowbridge sale and hopefully it doesn’t get subdivided for development.

Lake Lizzie
Comments: Lake in good shape.  Transparency could be increasing from zebra mussels.  South basin could be protected by WMA or AMA.

Lake Lida
Comments: There’s evidence that Zebra mussels are improving the clarity.  South Lida chla is near the impaired waters standard.

Long Lake (by Elizabeth)
Comments: in good shape, protection focus.  Septic systems were last inspected in 1988, so it would be good to inspect again.

Marion Lake
Comments:  Lake looks good.  Septic systems haven’t been checked since 1993 and the lake has no inlets to flush it out so septic systems should be checked by the county again ASAP.

McDonald Lake
Comments: Lake in good shape, protection focus.

Otter Tail Lake
Comments: Lake in great shape.  Encourage stormwater management around shoreline and City of Ottertail – maybe SWCD could help with grants and site visits.

Paul Lake
Comments: Excellent water quality, but very high % of row crops to the south in the lakeshed.  Need to determine by overland flow runoff mapping if this area is contributing to the lake or not.  Could be that sandy soils cause everything to pass right through.

Pickerel Lake
Comments: interesting pattern of high phosphorus, algae blooms and low transparency in May.  Look for some source of spring nutrient loading.  Septic systems haven’t been inspected since 1989 and since there is no inlet to flush out the lake, the septic systems should be checked again by the county ASAP.  This is listed by the DNR as a Cisco refuge lake, but the hypolimnion looks anoxic mid-summer.

Prairie Lake
Comments: Looks good.  The low residence time helps flush out nutrients from runoff and the large watershed.

Rose Lake
Comments: Good water quality – protection focus.  DNR designated it a Cisco refuge lake, and the hypolimnion is oxygenated.

Round Lake (by Deer Lake)
Comments: Natural eutrophic lake.  No outlets – high water has been a problem.  Septic systems were just checked in 2006.  Otherwise, no immediate problems.

Lake Six
Comments: Excellent water quality and improving trend.  East shoreline owned by Five Lakes Resort could go into conservation easement for permanent protection.

South Turtle Lake
Comments: Looks good.  Septic systems should be checked.  High water since no outlet.

Star Lake
Comments: Good water quality, protection focus.  Lots of undeveloped lakeshore that would be great for pushing AMAs and Conservation Easements.

Stuart Lake
Comments: Good water quality.  Southern-most bay where inlet comes in would be an excellent location for an AMA.

Sybil Lake
Comments: possible declining trends in transparency and chl-a.  Chl-a has increasing trend, but is still under 10 ug/L.  Is this too low to matter?  Lots of ag (row crops) in lakeshed. Could be that sandy soils cause everything to pass right through.  Flow mapping will be helpful in determining the contributing and noncontributing flow areas.

Tamarac Lake
Comments: Interesting dynamics.  The transparency used to vary a lot, but has remained steady and increasing since 2004.  An aerator was also installed in 2004 to alleviate winterkill.  Could there be a correlation between the aerator and the improved clarity? Other reasons could be pasture land on the north that is now just subdivided back lots.  Something to watch for: CRP land to the north just came back out of CRP into potato fields.

Ten Mile Lake
Comments: Looks good.  Crops on the western shore look pretty close to the lake without much buffer.

West McDonald Lake
Comments: in excellent shape.  Protection focus.

West Olaf Lake
Comments: High water has been taken care of by adding an outlet.  Hopefully lower water will restore the emergent aquatic plants.  A lot of the lakeshore is well forested except for an area on the north and south ends of the lake (Figure 17).  Check these areas for buffers and runoff potential.

West Silent Lake
Comments: in excellent shape.  Protection focus.