Crystal-Morgan Lake
Morgan County, MissouriView mapDirections
Clarity, phosphorus, and algae all sit in the cleanest band for this region.
↑ up from B at the last regrade
- Mesotrophic
- #1 of 3 in the county
Crystal-Morgan Lake in Morgan County, Missouri has a water quality grade of A (Excellent). Water clarity: 6.2 ft visibility. Phosphorus: 15.5 µg/L. Chlorophyll-a (algae): 3.1 µg/L.
- Clarity
- 6.2 ft
- Typical in September
- 75°F
- Type
- Mesotrophic
- Phosphorus
- 15.5 µg/L
- Chlorophyll-a
- 3.1 µg/L
- Trend
- ↑ Improving
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Watch Crystal-Morgan Lake’s letter
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Crystal-Morgan Lake is a mesotrophic lake in Morgan County, Missouri. Water quality is graded A based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. Compared to the 2 other monitored lakes in Morgan County, Crystal-Morgan Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2024-08-20. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyLow algae
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 A is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: A (Excellent)
Murky, only visible to about 6.2 ft. Phosphorus 15.5 µg/L. Chlorophyll-a 3.1 µg/L. TSI 45. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.2 ft | Not graded |
| Phosphorus | 15.5 µg/L | Good |
| Chlorophyll-a (Algae) | 3.1 µg/L | Good |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Water Temperature
Crystal-Morgan Lake typically sits around 75°F at the surface in September. Summer average is about 79°F. Usually warmest in Jul (about 81°F) and coldest in May (about 75°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 16 field readings (2022–2024) via the EPA Water Quality Portal. See the full Crystal-Morgan Lake water temperature breakdown →
Fishing Crystal-Morgan Lake
Water Quality Trend: ↑ Improving
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.2 m/yr | 3 |
| Phosphorus | ↑ Improving | -1.5 µg/L/yr | 3 |
| Chlorophyll-a | ↑ Improving | -0.5 µg/L/yr | 3 |
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Crystal-Morgan Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Stover Southwest WwtpStover · 4.2 mi away · NPDES MO0047058Recent violation
- Ozark Recycling Center LlcVersailles · 4 mi away · NPDES MONX00596
- Stover Northwest WwtfStover · 4.3 mi away · NPDES MO0047040
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 #1 of 3 lakes in Morgan County
Nearby Lakes in Morgan County
Frequently asked questions about Crystal-Morgan Lake
Where is Crystal-Morgan Lake?
- Crystal-Morgan Lake is a lake in Morgan County, Missouri. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Crystal-Morgan Lake?
- Crystal-Morgan Lake in Morgan County, Missouri has a water quality grade of A (Excellent). Water clarity: 6.2 ft visibility. Phosphorus: 15.5 µg/L. Chlorophyll-a (algae): 3.1 µg/L.
Is Crystal-Morgan Lake safe to swim in?
- The A is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Crystal-Morgan Lake?
- Crystal-Morgan Lake typically sits around 75°F at the surface in September, from 16 EPA Water Quality Portal field readings (2022–2024). That is a typical value for the month, not a live reading.
Explore Crystal-Morgan Lake across LakeQuality
Species activity outlook by water temperature and season
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Moderate nutrients, good water quality
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Where this data comes from
46 measurements from 1 monitoring station, 2022–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC46 samples · 2022–2024
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)