Lake George Watershed Stream Assessment Project

Lake George Watershed Stream Assessment Project 

The Stream Assessment Project was started in 2006 and has managed to collect chemical, physical, and biological data in nearly 50 sites throughout the Lake George watershed. Roughly half of the water in Lake George comes from streams. The ecological health of streams has a great impact on the health of Lake George.

The Stream Assessment Project is currently accepting applications for a Stream Asssessment Field Assistant. Click here for a job description and application procedures.

The 2008 Stream Assessment Report is now available. Also see the 2007 Stream Assessment Report. These reports provide the results from each field season.

This map shows the locations of stream studied in 2007.

Chemical parameters included dissolved oxygen, pH, and specific conductance. Dissolved oxygen is the amount of oxygen dissolved in water and pH measures water acidity or alkalinity. Both dissolved oxygen and pH are important to the health of aquatic organisms. In Lake George streams, both rameters met state standards and at the moment are of little concern.

Specific conductance was also measured at sample sites, which measures the waters ability to pass electrical current. It indicates the presence of instream pollution including chlorides, sodium, calcium, phosphates, nitrates and others. Typically streams in the United States range from 50 to 1500 µS/cm, where higher levels are associated with more polluted streams. In Lake George streams, specific conductance varied between streams and higher specific conductance levels were found in streams located in more developed watersheds. These included East Brook, English Brook, Finkle Brook, Spring Hill tributary, and West Brook, which suggests these streams, are more polluted than the others.

Additionally, specific conductance was significantly higher at downstream locations in East Brook, English Brook, Northwest Bay Brook, and West Brook. The increase in specific conductance at the downstream site in Northwest Bay Brook was minimal, which is likely because it resides in a relatively undisturbed watershed. Whereas, the increase in specific conductance was much greater in East Brook, English Brook, and West Brook, which are in more developed watersheds. These data indicate streams in more developed watersheds are more polluted in downstream sites.

Specific conductance remained relatively stable in streams throughout the field season except in Finkle Brook and Spring Hill tributary (Figures 2 and 3). In these streams, it appeared to fluctuate considerably, which suggest the existence of pollutant sources within the stream's watershed.

Numerous parameters were used to visually assess the physical condition of the streams (Table).
Table: The physical parameters used to assess the physical conditions of streams.

Lake George streams varied in physical health; generally, streams surrounded by greater amounts of development were more physically impacted than those found in undeveloped areas.

Biological Data: Biological analysis was conducted through analysis of macroinvertebrate communities. They are used by a variety of state and federal agencies to determine water quality. Macroinvertebrates are large enough to see with the naked eye (macro-) and lack vertebrae (-invertebrate). Certain organisms are intolerant to pollution and found in clean water including stonefly nymphs, mayfly nymphs, and caddisfly larvae (Pictures). Other organisms are tolerant to pollutants and can inhabit dirty water (Pictures). By analyzing the type and number of organisms in a stream we can determine water quality. Unlike chemical or physical data, which often represent a single ‘snapshot' in a specific time and place, biological data is more representative of instream conditions because aquatic organisms are constantly exposed to their environment.

Biological samples were collected in 18 sample sites streams, of which 5 were determined to be non-impacted, 8 were determined to be slightly-impacted, and 1 was moderately impacted (Table). Biological data indicated the level of impaction varied between streams; generally, streams in more developed areas were more impacted than those in less developed areas.

In previous biological assessments, Dodd Hill tributary and Indian Brook were identified as non-impacted (Bode et al. 2004). Our data indicates that both streams have become slightly impacted. Therefore, a watershed assessment will be conducted to located and mitigate potential sources of impaction.

The portion of West Brook downstream of Route 9 was moderately impacted and had the lowest overall biological score. The water quality was decreased significantly from the upstream sample site, which suggest that the Route 9 corridor is a substantial source of pollution.

Collectively, from biological samples we are able to conclude that:
(1) certain tributaries in the Lake George basin have become impacted.
(2) Dodd Hill tributary and Indian Brook have recently become more impacted, and
(3) the Route 9 corridor is a substantial contributor to instream pollution.

This year we will continue to collect data on previous sample sites in the Lake George watershed. As the Program grows we hope to increase the number of sampling sites in the basin. We look forward to this years field season and look forward to the results of ongoing data collection.

For additional details on data collection by the Stream Assessment Program please contact Dawn Keppler at keeper2@nycap.rr.com or (518) 668-5913.

Additional links:

• Stroud Water Research Center
• NYS DEC Stream Biomonitoring Unit

Visit our other Lake Science pages:

• Lake Chemistry Monitoring
• Milfoil Monitoring Program
• Coliform Monitoring
• Stormwater Monitoring
• Atmospheric Deposition Monitoring