Creve Coeur Lake
St. Louis County, MissouriView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- #3 of 5 in the county
Creve Coeur Lake in St. Louis County, Missouri has a water quality grade of F (Algae-prone). Water clarity: 1.6 ft visibility. Phosphorus: 101 µg/L. Chlorophyll-a (algae): 35.4 µg/L.
- Clarity
- 1.6 ft
- Typical in September
- 79°F
- Type
- Hypereutrophic
- Phosphorus
- 101 µg/L
- Chlorophyll-a
- 35.4 µg/L
- Trend
- ↓ Declining
Stays via Stay22
Stays near Creve Coeur Lake
Compare lakeside cabins, hotels, and vacation rentals near Creve Coeur Lake in St. Louis County, Missouri — 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 Creve Coeur Lake are listed below.
Top-rated places to stay near Creve Coeur Lake
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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Watch Creve Coeur Lake’s letter
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Creve Coeur Lake is a highly nutrient-loaded hypereutrophic lake in St. Louis County, Missouri. Water quality is graded F based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years. Compared to the 4 other monitored lakes in St. Louis County, Creve Coeur Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2024-09-19. Grade methodology: LakeQuality methodology.
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.
The F is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 1.6 ft of visibility. Phosphorus 101 µg/L. Chlorophyll-a 35.4 µg/L. TSI 69. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | Not graded |
| Phosphorus | 101 µg/L | Poor |
| Chlorophyll-a (Algae) | 35.4 µg/L | Poor |
| Trophic State Index (TSI) | 69 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Creve Coeur Lake typically sits around 79°F at the surface in September. Summer average is about 84°F. Usually warmest in Jul (about 85°F) and coldest in Apr (about 64°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 46 field readings (2015–2024) via the EPA Water Quality Portal. See the full Creve Coeur Lake water temperature breakdown →
Fishing Creve Coeur Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.01 m/yr | 5 |
| Phosphorus | ↓ Declining | +7.75 µg/L/yr | 5 |
| Chlorophyll-a | ↓ Declining | +3.24 µg/L/yr | 5 |
Regulated Pollution Sources Nearby
16 EPA-permitted facilities operate within about 5 miles of Creve Coeur Lake under Clean Water Act (NPDES) discharge permits.
- World Wide Technology IncMaryland Heights · 2.2 mi away · NPDES MONX00569
- Medix Biochemica Usa IncMaryland Heights · 2.4 mi away · NPDES MONX00481
- Intoximeters IncMaryland Heights · 2.4 mi away · NPDES MONX00667
- Medix Biochemica Usa IncMaryland Heights · 2.4 mi away · NPDES MONX00888
- Kindeva Drug DeliveriesSt. Louis · 2.4 mi away · NPDES MONX00381
- Oerlikon Balzers Coating Usa IncSt Louis · 2.5 mi away · NPDES MONX00733
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #3 of 5 lakes in St. Louis County
Nearby Lakes With Higher Grades
Creve Coeur Lake holds Grade F. 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 St. Louis County
Frequently asked questions about Creve Coeur Lake
Where is Creve Coeur Lake?
- Creve Coeur Lake is a lake in St. Louis County, Missouri. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Creve Coeur Lake?
- Creve Coeur Lake in St. Louis County, Missouri has a water quality grade of F (Algae-prone). Water clarity: 1.6 ft visibility. Phosphorus: 101 µg/L. Chlorophyll-a (algae): 35.4 µg/L.
Is Creve Coeur Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Creve Coeur Lake?
- Creve Coeur Lake typically sits around 79°F at the surface in September, from 46 EPA Water Quality Portal field readings (2015–2024). That is a typical value for the month, not a live reading.
Explore Creve Coeur Lake across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Missouri's top lakes, each with its grade
Very high nutrients, dense algae, poor clarity
Missouri's cleanest and most-polluted lakes, ranked
Planning a trip around Gateway Arch?
Creve Coeur Lake is about 17 miles from Gateway Arch National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Gateway Arch →More Missouri Lake Rankings
Other Grade F Lakes in Missouri
Hypereutrophic Lakes in Missouri
Where this data comes from
119 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC119 samples · 2020–2024
Analytical methods
- Depth, Secchi disk in meters
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)