Sweetbriar Dam Lake
Morton County, North DakotaView mapDirections
ND DEQ publishes the water-quality measurements for Sweetbriar Dam Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- Public access
Sweetbriar Dam Lake in Morton County, North Dakota has water-quality measurements published by ND DEQ, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 353 µg/L. Chlorophyll-a (algae): 54 µg/L.
Sweetbriar Dam Lake is a highly nutrient-loaded hypereutrophic lake in Morton County, North Dakota. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 3 other monitored lakes in Morton County, Sweetbriar Dam Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, NDDEQ, last sampled 2024-08-06. Methodology: how these readings are compared.
Swimming conditions
Readings onlyAlgae risk
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Sweetbriar Dam Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Sweetbriar Dam Lake is safe to swim in today is a call for the North Dakota Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Sweetbriar Dam Lake
These are the measurements ND DEQ publishes for Sweetbriar Dam Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 3 ft of visibility. Phosphorus 353 µg/L. Chlorophyll-a 54 µg/L. TSI 73.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 353µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 54µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 73 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Sweetbriar Dam Lake
Answers come straight from the public measurements and survey records on this page.
Stays via Stay22
Stays near Sweetbriar Dam Lake
Compare lakeside cabins, hotels, and vacation rentals near Sweetbriar Dam Lake in Morton 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Sweetbriar Dam Lake are listed below.
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Fishing Sweetbriar Dam Lake
Water quality readings over time
3 seasons of samples on record (2022–2024). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving2 years
Phosphorus
Worsening+62.5 µg/L/yr3 years
Chlorophyll-a
Improving-29.3 µg/L/yr3 years
EPA Impairment Status
Sweetbriar Dam Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit ND-10130203-005-L_00 · Official waterbody report
Nearby Lakes in Morton County
Frequently asked questions about Sweetbriar Dam Lake
Where is Sweetbriar Dam Lake?
- Sweetbriar Dam Lake is a lake in Morton County, North Dakota. Its water-quality measurements are published by ND DEQ and shown on this page as reported.
What is the water quality of Sweetbriar Dam Lake?
- Sweetbriar Dam Lake in Morton County, North Dakota has water-quality measurements published by ND DEQ, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 353 µg/L. Chlorophyll-a (algae): 54 µg/L.
Is Sweetbriar Dam Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Sweetbriar Dam Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Can I fish at Sweetbriar Dam Lake?
- Public access to Sweetbriar Dam Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by North Dakota's fish and wildlife agency, so check its current regulations before you go.
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Where this data comes from
109 measurements from 2 monitoring stations, 2022–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North Dakota Department Of Environmental Quality
21NDHDWQ_WQX109 samples · 2022–2024
Analytical methods
- Phosphorus by Colorimetry
- 447.0 ~ EPA; Chlorophyll a and b in phytoplankton by HPLC/UV
- 4500 NO3 E ~ Nitrate in Water- Cadmium Reduction
- Turbidity by Nephelometry
Monitoring station identifiers (2)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database