Lake Laretta
Nelson County, North DakotaView mapDirections
Nutrients and algae run above the regional average.
- Eutrophic
- #1 of 4 in the county
- 45 ft max depth
- Limited data
Lake Laretta in Nelson County, North Dakota has a water quality grade of D (Nutrient-rich). Water clarity: 3.3 ft visibility. Phosphorus: 253.5 µg/L. Chlorophyll-a (algae): 21.7 µg/L.
- Clarity
- 3.3 ft
- Typical in September
- 63°F
- Max depth
- ~45 ft est.
- Type
- Eutrophic
- Phosphorus
- 253.5 µg/L
- Chlorophyll-a
- 21.7 µg/L
- Trend
- ↑ Improving
Stays via Stay22
Stays near Lake Laretta
Compare lakeside cabins, hotels, and vacation rentals near Lake Laretta in Nelson County, North Dakota — 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 Lake Laretta are listed below.
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Watch Lake Laretta’s letter
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Lake Laretta is a productive, nutrient-rich eutrophic lake in Nelson County, North Dakota with an estimated average depth of about 45 feet. Water quality is graded D based on 2 sampling years through 2023. Overall water quality is improving over recent sampling years. Compared to the 3 other monitored lakes in Nelson County, Lake Laretta ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, NDDEQ, last sampled 2023-10-16. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyLimited data
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.
The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
Very murky, less than 3.3 ft of visibility. Phosphorus 253.5 µg/L. Chlorophyll-a 21.7 µg/L. TSI 68. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.3 ft | Not graded |
| Phosphorus | 253.5 µg/L | Poor |
| Chlorophyll-a (Algae) | 21.7 µg/L | Poor |
| Trophic State Index (TSI) | 68 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Temperature
Lake Laretta typically sits around 63°F at the surface in September. Summer average is about 67°F. Usually warmest in Jul (about 73°F) and coldest in Feb (about 35°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 478 field readings (2010–2023) via the EPA Water Quality Portal. See the full Lake Laretta water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~45 ft est. |
| Average Depth | ~5 ft est. |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. North Dakota has not published bathymetry for Lake Laretta.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Lake Laretta
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +9.821 m/yr | 3 |
| Phosphorus | ↑ Improving | -12.61 µg/L/yr | 3 |
| Chlorophyll-a | ↑ Improving | -4.63 µg/L/yr | 4 |
County Ranking
Ranked #1 of 4 lakes in Nelson County
Nearby Lakes in Nelson County
Frequently asked questions about Lake Laretta
Where is Lake Laretta?
- Lake Laretta is a lake in Nelson County, North Dakota. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake Laretta?
- Lake Laretta in Nelson County, North Dakota has a water quality grade of D (Nutrient-rich). Water clarity: 3.3 ft visibility. Phosphorus: 253.5 µg/L. Chlorophyll-a (algae): 21.7 µg/L.
Is Lake Laretta safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Lake Laretta?
- Lake Laretta typically sits around 63°F at the surface in September, from 478 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
How deep is Lake Laretta?
- No published bathymetric survey covers Lake Laretta, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 45 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Lake Laretta across LakeQuality
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Where this data comes from
36 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- USGS North Dakota Water Science Center
USGS-ND36 samples · 2020–2023
Analytical methods
- P, wu, WCA, persulfate CF color
- Plant pigments, sonication & 445
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Depth, fish, and access data from North Dakota Game & Fish