|
|
Data
Info
Secchi
Depth
Trophic State Index
Lake Grades
Chlorophyll
Nutrients
GIS
Aquatic
Plant Surveys
|
|
Does
your lake get a passing grade?
A grading system
for water quality has been developed using surface total phosphorus,
chlorophyll, and secchi depth data by Dick Osgood (and subsequently
modified by John Barten). The criteria are shown in the table below.
|
Grade
|
Percentile
|
|
|
|
 |
>90
|
<
23
|
<
10
|
>
3
|
 |
70
to 90
|
23
to 32
|
10
to 20
|
2.2
to 3
|
 |
30
to 70
|
32
to 68
|
20
to 48
|
1.2
to 2.2
|
 |
10
to 30
|
68
to 152
|
48
to 77
|
0.7
to 1.2
|
 |
<10
|
>152
|
>77
|
<
0.7
|
>
means greater than
< means less than
|
