Henry Sever Lake
Knox County, Missouri160 acresView mapDirections
Nutrients and algae run above the regional average.
- Eutrophic
- #1 of 1 in the county
- 31 ft max depth
- Public access
Henry Sever Lake in Knox County, Missouri has a water quality grade of D (Nutrient-rich). Water clarity: 2.1 ft visibility. Phosphorus: 58 µg/L. Chlorophyll-a (algae): 25.4 µg/L. Surface area: 160 acres.
- Clarity
- 2.1 ft
- Typical in August
- 83°F
- Max depth
- ~31 ft est.
- Area
- 160 acres
- Type
- Eutrophic
- Phosphorus
- 58 µg/L
- Chlorophyll-a
- 25.4 µg/L
- Trend
- ↑ Improving
- Public access
- Yes
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Stays near Henry Sever Lake
Compare lakeside cabins, hotels, and vacation rentals near Henry Sever Lake in Knox 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 Henry Sever Lake are listed below.
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Henry Sever Lake is a 160-acre productive, nutrient-rich eutrophic lake in Knox County, Missouri with an estimated average depth of about 31 feet. Water quality is graded D based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2024-07-31. Grade methodology: LakeQuality methodology.
What Henry Sever Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
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 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 2.1 ft of visibility. Phosphorus 58 µg/L. Chlorophyll-a 25.4 µg/L. TSI 64. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.1 ft | Not graded |
| Phosphorus | 58 µg/L | Poor |
| Chlorophyll-a (Algae) | 25.4 µg/L | Poor |
| Trophic State Index (TSI) | 64 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Temperature
Henry Sever Lake typically sits around 83°F at the surface in August. Summer average is about 82°F. Usually warmest in Jul (about 83°F) and coldest in May (about 74°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 60 field readings (2010–2024) via the EPA Water Quality Portal. See the full Henry Sever Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~31 ft est. |
| Average Depth | ~10 ft est. |
| Surface Area | 160 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Missouri has not published bathymetry for Henry Sever Lake.
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.
Recreation & Access
- Henry Sever Lake Conservation AreaPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Henry Sever Lake
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.008 m/yr | 4 |
| Phosphorus | → Stable | +0.57 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -2.31 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Henry Sever Lake is a man-made reservoir impounded by the Henry Sever Dam (completed 1961), built primarily for recreation on the MEYERS BRANCH; earth-type dam, 41 ft tall and 1,160 ft long.
- Surface area
- 160 ac
- Normal storage
- 2,101 ac-ft
- Max storage
- 2,265 ac-ft
- Drainage area
- 3.1 sq mi
- Hazard class
- High
- Owner
- MO DEPT OF CONSERVATION
Source: USACE National Inventory of Dams, NID ID MO10110 · Operator website
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Henry Sever Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- Newark WwtfNewark · 0.9 mi away · NPDES MO0129976Recent violation
- Heartland Community WwtfNewark · 3.6 mi away · NPDES MO0119130Recent violation
- Labelle Dairy, LlcLa Belle · 4.1 mi away · NPDES MO0119962Recent violation
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 1 lakes in Knox County
Nearby Lakes With Higher Grades
Henry Sever 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 Knox County
Frequently asked questions about Henry Sever Lake
Where is Henry Sever Lake?
- Henry Sever Lake is a lake in Knox County, Missouri. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Henry Sever Lake?
- Henry Sever Lake in Knox County, Missouri has a water quality grade of D (Nutrient-rich). Water clarity: 2.1 ft visibility. Phosphorus: 58 µg/L. Chlorophyll-a (algae): 25.4 µg/L. Surface area: 160 acres.
Is Henry Sever Lake 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 Henry Sever Lake?
- Henry Sever Lake typically sits around 83°F at the surface in August, from 60 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Henry Sever Lake?
- No published bathymetric survey covers Henry Sever Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 31 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 160 acres.
Are there boat ramps on Henry Sever Lake?
- Henry Sever Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Henry Sever Lake Conservation Area. Public access is listed as yes.
Explore Henry Sever Lake across LakeQuality
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Where this data comes from
89 measurements from 2 monitoring stations, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC88 samples · 2020–2024 - Missouri Dept. of Natural Resources
MDNR1 sample · 2020
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
- Nitrogen and Phosphorus, Total, Whole-water, Alkaline Persulfate Digest
Monitoring station identifiers (2)
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)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory