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LakeQuality
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Lake Julia

Oneida County, WisconsinOligotrophic

Lake Julia earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Oneida County. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. Lake Julia reaches 45 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 404 acres, Lake Julia fits the Wisconsin median for monitored lakes, with partial shoreline records. Lake Julia ranks 52 of 140 in Oneida County — solidly in the upper half of the local distribution.

Lake Julia has at least one documented invasive species (Banded Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Lake Julia, one of 7 fish species on record for the lake. A documented public access point at Lake Julia makes the lake usable for shore fishing, paddle craft, and trailered boats. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-10-14. Grade methodology: LakeGrade methodology.

Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Crystal clear, you can see 23 ft down. Phosphorus level: 11.2 µg/L. Trophic State Index: 35.

MetricValueGrade
Water Clarity (Secchi Depth)23 ftA
Phosphorus11.2 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)35Oligotrophic

Low nutrients, clear water, excellent for swimming

Lake Details

CharacteristicValue
Maximum Depth45 ft
Surface Area404 acres
Public AccessYes

Fish Species

Click a species to see all Wisconsin and Minnesota lakes where it is found.

→ Best fishing times for Lake Julia (14-day solunar calendar)

→ Is it safe to eat fish from Lake Julia? (mercury & PFAS guide)

Lake Julia fishing regulations (limits, seasons, special rules)

Invasive Species

Banded Mystery SnailChinese Mystery SnailPurple LoosestrifeRusty Crayfish

Water Quality Trend: Declining

Based on 2 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-1.5 m/yr2
See year-by-year chart →

Recreation & Access

1
Boat Landings
Yes
Public Access

Location

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County Ranking

Ranked #52 of 140 lakes in Oneida County

Nearby Lakes in Oneida County

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2025).

Fish Species (DNR-rated)

Musky(Common)Panfish(Present)Largemouth Bass(Present)Smallmouth Bass(Present)Northern Pike(Present)Trout(Present)Walleye(Present)

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

Most recent sample: 2025-10-14

Monitoring stations: 1