Next Generation Lake Assessment
The Next Generation Lake Assessment (NGLA) is a comprehensive, quantitative survey of a lake's condition which typically takes place over a one-to-two-day period during the summer months. These assessments, which began in 2010, collect data on a suite of physical, chemical and biological parameters from three areas within a lake or pond: the deep open water ‘index site’, ten randomly distributed shoreland and littoral habitat sites, and the inlets and outlet (see figures 1 and 2 as well as the complete list of parameters below). This survey is intended to provide a snapshot of the lake’s water quality, aquatic habitat potential, and physical conditions which, when assessed along with longer-term trend data, provide an excellent understanding of a lake’s ability to support recreational and habitat uses and what the principal stressors to a lake’s water quality are.
The NGLA reports (see table below) are intended to be interactive reports that, by clicking on different features on screen, can provide the user with a comprehensive description of what’s going on in their lake.
| Parameter | Location(s) Measured |
|---|---|
| Total Hardness (mg/L), Regular Alkalinity (mg/L), Total Calcium (mg/L), Total Magnesium (mg/L), Total Potassium (mg/L) Total Sodium (mg/L), Turbidity (NTU), Chlorophyll a (ug/L), Secchi (M), Dissolved Organic Carbon and Sediment Diatom Taxonomy | Index site |
| Conductivity (uS/cm), Dissolved Oxygen (mg/L & % saturation), pH, Temperature (C), Total Nitrogen (mg/L), Total Phosphorus (ug/L)P, Total Chloride (mg/L) | Index site, Tributaries and Outlet |
| Physical habitat complexity, shallow water habitat, lakeshore habitat, lakeshore disturbance, embeddedness, shading | 10 random sites around the lake |
| Crayfish | 3 sites with good crayfish habitat |
| Area and depth of deltas, Aquatic plant and algae % cover, note three dominant macrophyte species | Tributaries |
In addition to the sampling protocols enumerated in the table above, the Lake Assessment Program, in conjunction with the AIS program, is developing macrophyte biocriteria, which if successful, will be incorporated into routine Lake Assessment sampling protocol.
For more information about the NGLA process, check out these video tutorials in two lengths: