Granite Lake
Granite Lake in Wright County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 4.6 ft visibility. Phosphorus: 42.5 µg/L. Chlorophyll-a (algae): 16 µg/L. Maximum depth: 34 ft. Surface area: 361.67 acres.
- Clarity
- 4.6 ft
- Typical in August
- 69°F
- Max depth
- 34 ft
- Area
- 362 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 9
- Open water
- 238 days
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Granite Lake →
Next lake in Wright County
Granite Lake is a 362-acre productive, nutrient-rich eutrophic lake in Wright County, Minnesota with a maximum depth of 34 feet (18-foot average). Water quality is graded D based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 13 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 50 other monitored lakes in Wright County, Granite Lake ranks #26 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-17. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyAlgae risk
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 4.6 ft. Phosphorus level: 42.5 µg/L. Chlorophyll-a: 16 µg/L. Trophic State Index: 57.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.6 ft | Not graded |
| Phosphorus | 42.5 µg/L | Poor |
| Chlorophyll-a (Algae) | 16 µg/L | Poor |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Granite Lake
Compare lakeside cabins, hotels, and vacation rentals near Granite Lake in Wright County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Granite Lake are listed below.
Top-rated places to stay near Granite Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Granite Lake typically sits around 69°F at the surface in August. Summer average is about 68°F. Usually warmest in Jul (about 69°F) and coldest in May (about 58°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 205 field readings (2010–2024) via the EPA Water Quality Portal. See the full Granite Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 34 ft |
| Average Depth | 17.7 ft |
| Surface Area | 362 acres |
| Shoreline Length | 3.8 mi |
| Littoral Zone | 30% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Granite LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Granite Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2024-08-26 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 45.08 | 0.15 lb |
| Bluntnose Minnow | 35.74 | — |
| Black Bullhead | 26.46 | 0.94 lb |
| Largemouth Bass | 19.70 | 0.83 lb |
| Green Sunfish | 13.27 | 0.11 lb |
| GOS | 13.20 | 0.1 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Bluegill
Black Bullhead
Largemouth Bass
Green Sunfish
From the 2024-08-26 survey
Granite Lake is a 353-acre lake located south of the city of Annandale in Wright County. The lake has a maximum depth of 34 feet with one public access located on the southwest side of the lake. The watershed is relatively small and primarily composed of agriculture, open water, and forest lands. Water clarity was…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Granite Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — GraniteFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Granite (2019)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — GraniteFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — GranitePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.057 m/yr | 6 |
| Phosphorus | ↓ Declining | +2.04 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +1.02 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (36 observations).
Estimated open water season: 238 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-10 (2024) | 2018-05-02 (2018) |
| Ice-In | 2014-11-15 (2014) | 2001-12-20 (2001) |
Most recent ice-out: 2024-03-10
EPA Impairment Status
Granite Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN86-0217-00 · Official waterbody report
County Ranking
Ranked #26 of 51 lakes in Wright County
Nearby Lakes With Higher Grades
Granite Lake holds Grade D. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Wright County
Frequently asked questions about Granite Lake
What is the water quality grade for Granite Lake?
- Granite Lake in Wright County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 4.6 ft visibility. Phosphorus: 42.5 µg/L. Chlorophyll-a (algae): 16 µg/L. Maximum depth: 34 ft. Surface area: 361.67 acres.
Is Granite Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Granite Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 16 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Granite Lake?
- Granite Lake typically sits around 69°F at the surface in August, from 205 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Granite Lake?
- Granite Lake has a maximum depth of 34 feet and an average depth of 17.7 feet. The lake covers 361.67 acres.
What fish are in Granite Lake?
- Fish species found in Granite Lake include black bullhead, black crappie, bluegill, brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, yellow bullhead, yellow perch. Granite Lake is located in Wright County, Minnesota.
When does Granite Lake thaw?
- Granite Lake typically has ice-out around Apr 9. Ice typically forms around Dec 3. The open water season is approximately 238 days.
Are there boat ramps on Granite Lake?
- Granite Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Granite Lake. Public access is listed as yes.
Explore Granite Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Wright County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Crow River Watershed, ranked by water quality
High nutrients, frequent algae, reduced clarity
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Granite Lake
Other Grade D Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
165 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA165 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate