Each blue datapoint represents a Maine lake that is currently being NRTLD-monitored. Click on a datapoint to select a lake, or use the list at right.

NRTLD lake name  Town  Midas#
Auburn Lake   Auburn   3748
Clary Lake   Jefferson   5382
Cold Stream Pond   Enfield   2146
Craig Pond   Orland   4332
Damariscotta Lake   Jefferson   5400
Estes Lake   Sanford   0007
Great Moose Pond   Hartland   2590
Highland Lake   Falmouth   3734
Holbrook Pond   Holden   4274
Long Lake   St. Agatha   1682
Long Pond   Belgrade   5272
Loon Lake   Rangeley   2384
Mousam Lake   Acton   3838
Rangeley Lake   Rangeley   3300
Sebago Lake   Standish   5786
Sheepscot Pond   Palermo   4896
Thompson Lake   Oxford   3444
Upper Wilson Pond   Greenville   0410
Washington Pond   Washington   4894
Watchic Lake   Standish   5040
West Grand Lake   T5R1; GLS   1150
  21 lakes

 • Data plot of all NRTLD lakes,
        season by season

 • View the log of all recent data

 • Participating volunteers     [Join]

The goal of this Near Real-Time Lake Data pilot project is to provide volunteers and the public with a statewide perspective on current conditions for several lakes that are geographically distributed throughout Maine.

Certified volunteer lake monitors collect Secchi data and the information is entered directly into this website. It is important to note that the data displayed here are provisional— the normal quality assurance review of the data has not yet taken place.

There are many indicators that are used to assess lake water quality. The most universal and intuitive of these is a simple measurement of water clarity, also known as lake transparency—the distance that one can see down into the water. Lake transparency is measured with a device known as a Secchi disk. The distance down into the water that one can see the disk is measured routinely through the spring and summer months to estimate the concentration of algae in the water.

Secchi transparency varies not only from one lake to another, but also through time within any particular lake. A decline over time in the depth of transparency readings may indicate negative changes in lake water quality.

For more information about monitoring lake water quality, contact the Maine Volunteer Lake Monitoring Program.

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