Elmwood Lake
Sullivan County, Missouri224 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #1 of 1 in the county
- 35 ft max depth
- Public access
- Limited data
Elmwood Lake in Sullivan County, Missouri has a water quality grade of F (Algae-prone). Water clarity: 2.7 ft visibility. Phosphorus: 70.8 µg/L. Chlorophyll-a (algae): 35.2 µg/L. Surface area: 224 acres.
- Clarity
- 2.7 ft
- Typical in August
- 81°F
- Max depth
- ~35 ft est.
- Area
- 224 acres
- Type
- Hypereutrophic
- Trend
- → Stable
- Public access
- Yes
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Stays near Elmwood Lake
Compare lakeside cabins, hotels, and vacation rentals near Elmwood Lake in Sullivan 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 Elmwood Lake are listed below.
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Elmwood Lake is a 224-acre highly nutrient-loaded hypereutrophic lake in Sullivan County, Missouri with an estimated average depth of about 35 feet. Water quality is graded F based on 2 sampling years through 2024. Phosphorus level 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 2024-07-30. Grade methodology: LakeQuality methodology.
What Elmwood Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming Safety
Grade onlyLimited data
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. Elmwood Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 2.7 ft of visibility. Phosphorus 70.8 µg/L. Chlorophyll-a 35.2 µg/L. TSI 65. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.7 ft | Not graded |
| Phosphorus | 70.8 µg/L | Poor |
| Chlorophyll-a (Algae) | 35.2 µg/L | Poor |
| Trophic State Index (TSI) | 65 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Elmwood Lake typically sits around 81°F at the surface in August. Summer average is about 81°F. Usually warmest in Jul (about 83°F) and coldest in May (about 69°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 25 field readings (2010–2024) via the EPA Water Quality Portal. See the full Elmwood Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~35 ft est. |
| Average Depth | ~14 ft est. |
| Surface Area | 224 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 Elmwood 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
- Elmwood Lake (Milan)Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Elmwood Lake
Water Quality Trend: → Stable
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↓ Declining | +55.3 µg/L/yr | 2 |
| Chlorophyll-a | ↑ Improving | -7.5 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Elmwood Lake is a man-made reservoir impounded by the Elmwood City Lake Dam (completed 1972), built primarily for water supply on the ELMWOOD BRANCH; earth-type dam, 47 ft tall and 850 ft long.
- Surface area
- 224 ac
- Normal storage
- 2,445 ac-ft
- Max storage
- 7,000 ac-ft
- Drainage area
- 6.41 sq mi
- Hazard class
- High
- Owner
- CITY OF MILAN
All listed purposes: Water Supply;Recreation.
Source: USACE National Inventory of Dams, NID ID MO10240 · Operator website · Matched by proximity (0.15 km)
EPA Impairment Status
Elmwood Lake 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_7146.00 · Official waterbody report · Matched by proximity (1.18 km)
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Elmwood Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Smithfield Fresh MeatsMilan · 0.4 mi away · NPDES MO0115487MajorRecent 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 Sullivan County
Nearby Lakes With Higher Grades
Elmwood Lake holds Grade F. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Sullivan County
Frequently asked questions about Elmwood Lake
Where is Elmwood Lake?
- Elmwood Lake is a lake in Sullivan County, Missouri. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Elmwood Lake?
- Elmwood Lake in Sullivan County, Missouri has a water quality grade of F (Algae-prone). Water clarity: 2.7 ft visibility. Phosphorus: 70.8 µg/L. Chlorophyll-a (algae): 35.2 µg/L. Surface area: 224 acres.
Is Elmwood Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Elmwood Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.
What is the water temperature of Elmwood Lake?
- Elmwood Lake typically sits around 81°F at the surface in August, from 25 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Elmwood Lake?
- No published bathymetric survey covers Elmwood Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 35 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 224 acres.
Are there boat ramps on Elmwood Lake?
- Elmwood Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Elmwood Lake (Milan). Public access is listed as yes.
Explore Elmwood Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
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
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Where this data comes from
9 measurements from 2 monitoring stations, 2023–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC6 samples · 2024 - Missouri Dept. of Natural Resources
MDNR3 samples · 2023
Analytical methods
- Depth, Secchi disk in meters
- Nitrogen and Phosphorus, Total, Whole-water, Alkaline Persulfate Digest
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
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
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