Cullaby Lake
Clatsop County, OregonView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #1 of 1 in the county
- 46 ft max depth
- Public access
- Limited data
Cullaby Lake in Clatsop County, Oregon has a water quality grade of F (Algae-prone). Chlorophyll-a (algae): 36.8 µg/L.
- Max depth
- ~46 ft est.
- Type
- Hypereutrophic
- Chlorophyll-a
- 36.8 µg/L
- Trend
- → Stable
- Public access
- Yes
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Stays near Cullaby Lake
Compare lakeside cabins, hotels, and vacation rentals near Cullaby Lake in Clatsop 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 Cullaby Lake are listed below.
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Cullaby Lake is a highly nutrient-loaded hypereutrophic lake in Clatsop County, Oregon with an estimated average depth of about 46 feet. Water quality is graded F based on 1 sampling years through 2025. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, Oregon DEQ, last sampled 2025-10-15. Grade methodology: LakeQuality methodology.
What Cullaby Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
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. Cullaby Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, noxious aquatic plants. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
No clarity data. Chlorophyll-a 36.8 µg/L. TSI 66. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 36.8 µg/L | Poor |
| Trophic State Index (TSI) | 66 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~46 ft est. |
| Average Depth | ~20 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 Cullaby 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
- Cullaby Lake ParkPublic
- CarnahanPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Cullaby Lake
Water Quality Trend: → Stable
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Chlorophyll-a | → Stable | +0.1 µg/L/yr | 2 |
EPA Impairment Status
Cullaby 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 OR_LK_1708000602_05_100655 · Official waterbody report
County Ranking
Ranked #1 of 1 lakes in Clatsop County
Nearby Lakes in Clatsop County
Frequently asked questions about Cullaby Lake
Where is Cullaby Lake?
- Cullaby Lake is a lake in Clatsop County, Oregon. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Cullaby Lake?
- Cullaby Lake in Clatsop County, Oregon has a water quality grade of F (Algae-prone). Chlorophyll-a (algae): 36.8 µg/L.
Is Cullaby Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Cullaby Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, noxious aquatic plants. Check local advisories before you swim.
How deep is Cullaby Lake?
- No published bathymetric survey covers Cullaby Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 46 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 Cullaby Lake?
- Cullaby Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Cullaby Lake Park, Carnahan. Public access is listed as yes.
Explore Cullaby Lake across LakeQuality
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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