Tenmile Lake
Coos County, OregonView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #1 of 1 in the county
- 321 ft max depth
- Public access
- Limited data
Tenmile Lake in Coos County, Oregon has a water quality grade of F (Algae-prone). Chlorophyll-a (algae): 30.6 µg/L.
- Max depth
- ~321 ft est.
- Type
- Hypereutrophic
- Chlorophyll-a
- 30.6 µg/L
- Trend
- ↑ Improving
- Public access
- Yes
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Stays near Tenmile Lake
Compare lakeside cabins, hotels, and vacation rentals near Tenmile Lake in Coos County, Oregon — 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 Tenmile Lake are listed below.
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Tenmile Lake is a highly nutrient-loaded hypereutrophic lake in Coos County, Oregon with an estimated average depth of about 321 feet. Water quality is graded F based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 7 public boat landings.
Source: EPA Water Quality Portal sampling records, Oregon DEQ, last sampled 2025-10-16. Grade methodology: LakeQuality methodology.
What Tenmile Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch7 documented ramps
- Camping2 public campgrounds nearby
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. Tenmile Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury, oxygen depletion (low DO). Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
No clarity data. Chlorophyll-a 30.6 µg/L. TSI 64. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 30.6 µg/L | Poor |
| Trophic State Index (TSI) | 64 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~321 ft est. |
| Average Depth | ~65 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Oregon has not published bathymetry for Tenmile 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
- Spinreel CampgroundPublic
- Tenmile Lake ParkPublic
- 8th StreetPublic
- South 8th StreetPublic
- Osprey Point ResortSemi-private
- La PlayaSemi-private
Showing 6 of 7 documented landings from the USGS National Boat Ramps inventory.
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Public campgrounds near Tenmile Lake
- Eel Creek Campground2.3 km
- Spinreel Campground2.7 km
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Fishing Tenmile Lake
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Chlorophyll-a | ↑ Improving | -4.6 µg/L/yr | 2 |
EPA Impairment Status
Tenmile Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit OR_LK_1710030404_02_100224 · Official waterbody report
County Ranking
Ranked #1 of 1 lakes in Coos County
Nearby Lakes in Coos County
Frequently asked questions about Tenmile Lake
Where is Tenmile Lake?
- Tenmile Lake is a lake in Coos County, Oregon. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Tenmile Lake?
- Tenmile Lake in Coos County, Oregon has a water quality grade of F (Algae-prone). Chlorophyll-a (algae): 30.6 µg/L.
Is Tenmile Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Tenmile Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury, oxygen depletion (low DO). Check local advisories before you swim.
How deep is Tenmile Lake?
- No published bathymetric survey covers Tenmile Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 321 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Tenmile Lake?
- Tenmile Lake has 7 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Spinreel Campground, Tenmile Lake Park, 8th Street, South 8th Street, among others. Public access is listed as yes.
Are there campgrounds on Tenmile Lake?
- Tenmile Lake has 2 public campgrounds from USGS The National Map within 5 km, including Eel Creek Campground, Spinreel Campground. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Tenmile Lake across LakeQuality
13.5 mi away · 254 ft
Species activity outlook by water temperature and season
Where to stay at Oregon's top lakes, each with its grade
Very high nutrients, dense algae, poor clarity
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Where this data comes from
8 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Department of Environmental Quality - State of Oregon
OREGONDEQ8 samples · 2024–2025
Analytical methods
- 10200 H ~ Chlorophyll a-b-c Determination
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
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
Public campgrounds from USGS The National Map Structures, within about 3 miles