NEWS RELEASE - FOR IMMEDIATE RELEASE

For information, contact Julie Westerlund, Minnehaha Creek Watershed District
at 952-471-0590 x209 or jwesterlund@minnehahacreek.org

MCWD Releases 2007 Water Quality Report Cards; Resumes Water Quality Monitoring

DEEPHAVEN, MN—May 1, 2008— It’s spring. The ice is out on Lake Minnetonka, the dam at Gray’s Bay is open, and Minnehaha Creek Watershed District’s (MCWD) lake monitoring program resumes in full swing.  The program measures water quality in district lakes, and summarizes the data with a grade for each the lake.

Even though rainfall was below normal last year from April to July, the water quality grades held steady with minor variations in water quality from 2006 to 2007. Normally, hot, dry weather leads to an increase in algae growth. “Typically, we would expect water quality – as measured by our lake grades - to go down in a drought-type situation, but with the unprecedented rainfall during the months of  August and September, it’s difficult to sort out the influence of year to year precipitation variation on the overall water quality grade,” said Dr. Udai Singh, MCWD’s water quality specialist.

During the 2008 season, MCWD’s water quality staff will continue collecting water quality data for 34 lakes including 26 sites on lake Minnetonka and 40 sites on 12 streams in the watershed, plus automated water depth measurements at 10 stream monitoring sites. 

In addition, they will complete a bathymetric survey (a detailed scan of water depth) of Lake Minnetonka for the creation of a detailed map of the underwater contours of the lake. The most recent publicly available map was created in 1957. 

To calculate lake grades, MCWD’s water quality monitoring staff measure water clarity, nutrient levels, and algae growth throughout the open water season.  Those results are averaged into a numerical score which is translated into a lake grade between A and F.

Lakes are graded on a curve; the C grade means that a lake is typical for lakes in the seven-county metropolitan area.  C lakes may not be ideal for swimming, boating, and fishing due to summer algae growth. Lake Nokomis, Lake of the Isles, and Powderhorn Lake in the Minneapolis chain of lakes and Dutch Lake, Long Lake, Schutz Lake and Lake Virginia in Upper Watershed lakes fall into this category.

A-quality lakes are generally healthy. Characterized by beautiful, clear water, these lakes are well-suited for recreational activities of all kinds throughout the summer. Lakes with a B grade are also good for swimming and recreation, but late summer algae blooms may cut the season short. Christmas Lake received an A grade and Lake Calhoun got an A- for 2007.  Thirteen bays in Lake Minnetonka and 4 other Lakes were classified as B-grade lakes (including B+ and B-) which include Cedar Lake in Minneapolis and Lake Minnewashta and Pierson Lake in Upper Watershed.

When a lake gets a D grade, it has severe algae problems, and F-rated lakes have very limited recreational value. Diamond Lake, Snyder Lake, Mud Lake and Forest Lake earned an F grade for 2007.

To view this past decade’s lake grades, visit www.minnehahacreek.org/wq_report_cards.php.

Since its formation in 1967, the MCWD, has been a regional leader in cutting edge research and technical expertise in the areas of water quality monitoring and management. The district protects, improves and manages water resources, runoff and related natural resources for 129 lakes, 8 major creeks and thousands of wetlands located within the 181 square mile watershed of Minnehaha Creek and Lake Minnetonka, in partnership with 29 communities, other agencies and concerned citizens.

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