Ben Branch Lake by Dam
Osage County, Missouri44 acresView mapDirections
Nutrients and algae run above the regional average.
- Eutrophic
- Impaired · Mercury
- #1 of 1 in the county
- 43 ft max depth
- Public access
Ben Branch Lake by Dam in Osage County, Missouri has a water quality grade of D (Nutrient-rich). Water clarity: 3.9 ft visibility. Phosphorus: 30.4 µg/L. Chlorophyll-a (algae): 22.8 µg/L. Surface area: 44 acres.
- Clarity
- 3.9 ft
- Typical in September
- 79°F
- Max depth
- ~43 ft est.
- Area
- 44 acres
- Type
- Eutrophic
- Phosphorus
- 30.4 µg/L
- Chlorophyll-a
- 22.8 µg/L
- Trend
- ↓ Declining
- Public access
- Yes
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Stays near Ben Branch Lake by Dam
Compare lakeside cabins, hotels, and vacation rentals near Ben Branch Lake by Dam in Osage 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 Ben Branch Lake by Dam are listed below.
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Ben Branch Lake by Dam is a 44-acre productive, nutrient-rich eutrophic lake in Osage County, Missouri with an estimated average depth of about 43 feet. Water quality is graded D based on 2 sampling years through 2022. Overall water quality is declining 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 2022-07-29. Grade methodology: LakeQuality methodology.
What Ben Branch Lake by Dam 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. Ben Branch Lake by Dam is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 3.9 ft. Phosphorus 30.4 µg/L. Chlorophyll-a 22.8 µg/L. TSI 57. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.9 ft | Not graded |
| Phosphorus | 30.4 µg/L | Fair |
| Chlorophyll-a (Algae) | 22.8 µg/L | Poor |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Temperature
Ben Branch Lake by Dam typically sits around 79°F at the surface in September. Summer average is about 82°F. Usually warmest in Jul (about 84°F) and coldest in Apr (about 57°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 23 field readings (2012–2022) via the EPA Water Quality Portal. See the full Ben Branch Lake by Dam water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~43 ft est. |
| Average Depth | ~15 ft est. |
| Surface Area | 44 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 Ben Branch Lake by Dam.
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
- Ben Branch Lake Conservation AreaPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Ben Branch Lake by Dam
Water Quality Trend: ↓ Declining
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.27 m/yr | 3 |
| Phosphorus | ↓ Declining | +9.5 µg/L/yr | 3 |
| Chlorophyll-a | ↓ Declining | +1.55 µg/L/yr | 3 |
Reservoir Info (USACE NID)
Ben Branch Lake by Dam is a man-made reservoir impounded by the Ben Branch Dam (completed 1984), built primarily for recreation on the BEN BRANCH; earth-type dam, 51 ft tall and 850 ft long.
- Surface area
- 44 ac
- Normal storage
- 675 ac-ft
- Max storage
- 1,210 ac-ft
- Drainage area
- 0.98 sq mi
- Hazard class
- High
- Owner
- MO DEPT OF CONSERVATION
All listed purposes: Recreation;Fish and Wildlife Pond.
Source: USACE National Inventory of Dams, NID ID MO31844 · Operator website · Matched by proximity (0.09 km)
EPA Impairment Status
Ben Branch Lake by Dam is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MO_7186.00 · Official waterbody report · Matched by proximity (0.31 km)
County Ranking
Ranked #1 of 1 lakes in Osage County
Nearby Lakes With Higher Grades
Ben Branch Lake by Dam holds Grade D. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Osage County
Frequently asked questions about Ben Branch Lake by Dam
Where is Ben Branch Lake by Dam?
- Ben Branch Lake by Dam is a lake in Osage County, Missouri. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Ben Branch Lake by Dam?
- Ben Branch Lake by Dam in Osage County, Missouri has a water quality grade of D (Nutrient-rich). Water clarity: 3.9 ft visibility. Phosphorus: 30.4 µg/L. Chlorophyll-a (algae): 22.8 µg/L. Surface area: 44 acres.
Is Ben Branch Lake by Dam safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Ben Branch Lake by Dam is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
What is the water temperature of Ben Branch Lake by Dam?
- Ben Branch Lake by Dam typically sits around 79°F at the surface in September, from 23 EPA Water Quality Portal field readings (2012–2022). That is a typical value for the month, not a live reading.
How deep is Ben Branch Lake by Dam?
- No published bathymetric survey covers Ben Branch Lake by Dam, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 43 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 44 acres.
Are there boat ramps on Ben Branch Lake by Dam?
- Ben Branch Lake by Dam has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Ben Branch Lake Conservation Area. Public access is listed as yes.
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Where this data comes from
26 measurements from 2 monitoring stations, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC20 samples · 2020 - Missouri Dept. of Natural Resources
MDNR6 samples · 2021–2022
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory