Grassy Narrows Lake

Normal

Water level is right where you'd expect for mid-September and rising.

Low (317.82m)Normal rangeHigh (321.45m)

Current Weather

2d ago

13°C

Wind E 13 km/h

Humidity 74%

Mainly sunny

Environment Canada — Kenora - Nestor Falls

vs. Last Year

No data available

7-Day Trend

↑Rising

Up 5.9 cm over the past week

+5.9 cm over 7 days

Seasonal Position

27th percentile

Based on 44 years of records

Seasonal Outlook

Typical next 7 days

This lake usually holds steady over the next week.

Typical next 14 days

Over two weeks, levels typically rises moderately.

Tracking

This year is moving faster than usual.

Based on 44 years of seasonal patterns. This is a historical seasonal pattern, not a forecast.

Fish Consumption Advisories (10 species)

The following consumption advisories are in effect for fish caught in Grassy Narrows Lake.

⚠Cisco (Lake Herring)

Contaminant	Size	General pop.	Sensitive pop.
Mercury	45-50 cm	8/month	Do not eat
Mercury	40-45 cm	8/month	4/month
Mercury	35-40 cm	12/month	4/month
Mercury	30-35 cm	16/month	8/month
Mercury	25-30 cm	16/month	8/month
Mercury	20-25 cm	16/month	8/month

Lake Whitefish

Contaminant	Size	General pop.	Sensitive pop.
Mercury	45-50 cm	16/month	8/month
Mercury	50-55 cm	16/month	8/month
Mercury	55-60 cm	16/month	4/month
Mercury	30-35 cm	16/month	8/month
Mercury	35-40 cm	16/month	8/month
Mercury	40-45 cm	16/month	8/month

⚠Mooneye

Contaminant	Size	General pop.	Sensitive pop.
Mercury	30-35 cm	4/month	Do not eat
Mercury	20-25 cm	8/month	Do not eat
Mercury	25-30 cm	4/month	Do not eat

⚠Muskellunge

Contaminant	Size	General pop.	Sensitive pop.
Mercury	>75 cm	Do not eat	Do not eat

⚠Northern Pike

Contaminant	Size	General pop.	Sensitive pop.
Mercury	55-60 cm	4/month	Do not eat
Mercury	30-35 cm	4/month	Do not eat
Mercury	35-40 cm	4/month	Do not eat
Mercury	40-45 cm	4/month	Do not eat
Mercury	45-50 cm	4/month	Do not eat
Mercury	50-55 cm	4/month	Do not eat
Mercury	60-65 cm	4/month	Do not eat
Mercury	65-70 cm	4/month	Do not eat
Mercury	70-75 cm	2/month	Do not eat
Mercury	>75 cm	2/month	Do not eat

⚠Sauger

Contaminant	Size	General pop.	Sensitive pop.
Mercury	20-25 cm	2/month	Do not eat
Mercury	40-45 cm	Do not eat	Do not eat
Mercury	35-40 cm	Do not eat	Do not eat
Mercury	30-35 cm	Do not eat	Do not eat
Mercury	25-30 cm	Do not eat	Do not eat

⚠Smallmouth Bass

Contaminant	Size	General pop.	Sensitive pop.
Mercury	30-35 cm	4/month	Do not eat
Mercury	35-40 cm	4/month	Do not eat
Mercury	40-45 cm	4/month	Do not eat

⚠Walleye

Contaminant	Size	General pop.	Sensitive pop.
Mercury	65-70 cm	2/month	Do not eat
Mercury	45-50 cm	4/month	Do not eat
Mercury	50-55 cm	4/month	Do not eat
Mercury	55-60 cm	2/month	Do not eat
Mercury	60-65 cm	2/month	Do not eat
Mercury	20-25 cm	4/month	Do not eat
Mercury	25-30 cm	4/month	Do not eat
Mercury	30-35 cm	4/month	Do not eat
Mercury	35-40 cm	4/month	Do not eat
Mercury	40-45 cm	4/month	Do not eat

⚠White Sucker

Contaminant	Size	General pop.	Sensitive pop.
Mercury	30-35 cm	12/month	4/month
Mercury	50-55 cm	2/month	Do not eat
Mercury	45-50 cm	4/month	Do not eat
Mercury	40-45 cm	4/month	Do not eat
Mercury	35-40 cm	8/month	4/month

Yellow Perch

Contaminant	Size	General pop.	Sensitive pop.
Mercury	15-20 cm	16/month	8/month
Mercury	20-25 cm	16/month	8/month

Source: Guide to Eating Ontario Fish (2025). Advisory data is updated annually.

Lake Profile

Est. average depth6.4 m

Estimated from HydroLAKES v1.0 (Messager et al., 2016). Modeled geo-statistical estimate, not a direct survey measurement.

Water Level — Last 30 Days

Technical details

Current level: 318.71 m
Reference value: 318.71 m (rolling_6h_mean)
Percentile for date: 27th percentile
Years of record: 44
Source station: GRASSY NARROWS LAKE AT GRASSY NARROWS (05QE015)
Est. average depth: 6.4 m
Relationship type: direct_lake
Mapping confidence: medium
Today's normal range: 318.67–319.57 m
Same-date historical range: 317.82–321.45 m
30-day change: +17.7 cm
Data confidence: medium
Observed at: Sep 20, 2026
Last snapshot: Sep 20, 2026

Data source: ECCC Water Office — Station 05QE015. Water level readings are provisional and subject to revision. This is not a navigation or flood-warning service.