Agency Lake South
Klamath County, OregonView mapDirections
Oregon DEQ publishes the water-quality measurements for Agency Lake South. Here is what has been measured.
- Hypereutrophic
- Impaired · Algal growth
- Public access
Agency Lake South in Klamath County, Oregon has water-quality measurements published by Oregon DEQ, shown here as reported. Phosphorus: 110 µg/L. Chlorophyll-a (algae): 61.6 µg/L.
Agency Lake South is a highly nutrient-loaded hypereutrophic lake in Klamath County, Oregon. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 6 public boat landings. Compared to the 16 other monitored lakes in Klamath County, Agency Lake South ranks #12 for water quality.
Source: EPA Water Quality Portal sampling records, Oregon DEQ, last sampled 2023-09-25. Methodology: how these readings are compared.
Agency Lake South has 6 public boat landings, so a lakefront rental is not the only way to get a boat on the water. For a place on the water, look through cabin and lake-house rentals near Agency Lake South on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Agency Lake South is good for
From access and monitoring records, not editorial picks.
- Boat launch6 documented ramps
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Agency Lake South is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.
Whether Agency Lake South is safe to swim in today is a call for the Oregon Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Agency Lake South
These are the measurements Oregon DEQ publishes for Agency Lake South, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 110 µg/L. Chlorophyll-a 61.6 µg/L. TSI 71.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 110µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 61.6µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 71 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Agency Lake South
Answers come straight from the public measurements and survey records on this page.
Recreation & Access
- Henzel ParkPublic
- Malone SpringsPublic
- Chiloquin AccessPublic
- Petric ParkPublic
- Waterwheel CampgroundSemi-private
- Agency Lake ResortSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Agency Lake South
Compare lakeside cabins, hotels, and vacation rentals near Agency Lake South in Klamath 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Agency Lake South are listed below.
Top-rated places to stay near Agency Lake South
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip? Cabins and lodging at Agency Lake South → · more Oregon lake trips
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Fishing Agency Lake South
Water Quality Trend: Worsening
Based on 4 years of monitoring (2020–2023).
Phosphorus
Worsening+34 µg/L/yr4 years
Chlorophyll-a
Stable-0.79 µg/L/yr4 years
EPA Impairment Status
Agency Lake South is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Drinking water, Aquatic life, Fish consumption, Recreation, Other.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit OR_LK_1801020303_05_100374 · Official waterbody report
Nearby Lakes in Klamath County
Frequently asked questions about Agency Lake South
Where is Agency Lake South?
- Agency Lake South is a lake in Klamath County, Oregon. Its water-quality measurements are published by Oregon DEQ and shown on this page as reported.
What is the water quality of Agency Lake South?
- Agency Lake South in Klamath County, Oregon has water-quality measurements published by Oregon DEQ, shown here as reported. Phosphorus: 110 µg/L. Chlorophyll-a (algae): 61.6 µg/L.
Is Agency Lake South safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Agency Lake South is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.
Are there boat ramps on Agency Lake South?
- Agency Lake South has 6 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Henzel Park, Malone Springs, Chiloquin Access, Petric Park, among others. Public access is listed as yes.
Can I fish at Agency Lake South?
- Agency Lake South has 6 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Oregon's fish and wildlife agency, so check its current regulations before you go.
Explore Agency Lake South across LakeQuality
Planning a trip around Crater Lake?
Agency Lake South is about 30 miles from Crater Lake National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Crater Lake →More lakes in Oregon
Other Lakes in Oregon
Hypereutrophic Lakes in Oregon
Where this data comes from
83 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- USGS Oregon Water Science Center
USGS-OR83 samples · 2020–2023
Analytical methods
- Nutrients, wu, WCA,persulfate,CF
- Chlorophyll a, phytoplankton
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory