Otisco Lake
Onondaga County, WisconsinLimited DataEutrophic
Otisco Lake is a 2,291-acre productive, nutrient-rich eutrophic lake in Onondaga County, NY. Water quality is graded D based on 1 sampling years through 2020. Compared to the 3 other monitored lakes in Onondaga County, Otisco Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2020-09-23. Grade methodology: LakeGrade methodology.
Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Murky, only visible to about 5.2 ft. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.2 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 2.3K acres |
Location
County Ranking
Ranked #3 of 4 lakes in Onondaga County
Cleaner Lakes Within 30 Miles
Otisco Lake holds Grade D. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in Onondaga County
More Wisconsin Lake Rankings
Other Grade D Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Otisco Lake is a man-made reservoir impounded by the Otisco Lake Dam (completed 1956), built primarily for recreation on the NINEMILE CREEK; concrete-type dam, 18 ft tall and 310 ft long.
- Surface area
- 2,291 ac
- Normal storage
- 26,067 ac-ft
- Max storage
- 47,890 ac-ft
- Drainage area
- 39.15 sq mi
- Hazard class
- High
- Owner
- ONONDAGA COUNTY WATER AUTHORITY (OCWA)
All listed purposes: Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID NY00753 · Operator website
EPA Impairment Status
Otisco Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit NY0702-0011 · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Most recent sample: 2020-09-23
Monitoring stations: 1