Lake Orient
Adair County, Iowa23 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #5 of 5 in the county
Lake Orient in Adair County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 1.3 ft visibility. Phosphorus: 674 µg/L. Chlorophyll-a (algae): 92.2 µg/L. Surface area: 23.4 acres.
- Clarity
- 1.3 ft
- Typical in September
- 70°F
- Area
- 23 acres
- Type
- Hypereutrophic
- Trend
- ↓ Declining
Stays via Stay22
Stays near Lake Orient
Compare lakeside cabins, hotels, and vacation rentals near Lake Orient in Adair County, Iowa — 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 Lake Orient are listed below.
Top-rated places to stay near Lake Orient
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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Watch Lake Orient’s letter
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Free interactive depth-contour map of Lake Orient, reaching a maximum surveyed depth of 10 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Lake Orient is a 23-acre highly nutrient-loaded hypereutrophic lake in Adair County, Iowa. Water quality is graded F based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years. Compared to the 4 other monitored lakes in Adair County, Lake Orient ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-29. Grade methodology: LakeQuality methodology.
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 F is nutrients and algae, not a swimming clearance. Lake Orient is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, pH / acidity, turbidity. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 1.3 ft of visibility. Phosphorus 674 µg/L. Chlorophyll-a 92.2 µg/L. TSI 82. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.3 ft | Not graded |
| Phosphorus | 674 µg/L | Poor |
| Chlorophyll-a (Algae) | 92.2 µg/L | Poor |
| Trophic State Index (TSI) | 82 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Lake Orient typically sits around 70°F at the surface in September. Summer average is about 78°F. Usually warmest in Jul (about 80°F) and coldest in Sep (about 70°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 29 field readings (2010–2023) via the EPA Water Quality Portal. See the full Lake Orient water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 23 acres |
No bathymetric survey has been published for Lake Orient, so its depth is not documented here.
Fishing Lake Orient
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.02 m/yr | 5 |
| Phosphorus | ↑ Improving | -23.11 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +19.48 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Lake Orient is a man-made reservoir impounded by the Orient Lake Dam (completed 1969), built primarily for water supply on the TR-EAST NODAWAY RIVER; earth-type dam, 23 ft tall and 867 ft long.
- Surface area
- 23.4 ac
- Normal storage
- 135 ac-ft
- Max storage
- 398 ac-ft
- Drainage area
- 0.94 sq mi
- Hazard class
- Significant
- Owner
- City of Orient
All listed purposes: Water Supply;Recreation.
Source: USACE National Inventory of Dams, NID ID IA00033 · Operator website
EPA Impairment Status
Lake Orient is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 05-NOD-1396 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Lake Orient under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Orient Stp (Sirwa)Orient · 1.5 mi away · NPDES IA0074535Recent 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 #5 of 5 lakes in Adair County
Nearby Lakes With Higher Grades
Lake Orient holds Grade F. 2 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 Adair County
Frequently asked questions about Lake Orient
Where is Lake Orient?
- Lake Orient is a lake in Adair County, Iowa. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake Orient?
- Lake Orient in Adair County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 1.3 ft visibility. Phosphorus: 674 µg/L. Chlorophyll-a (algae): 92.2 µg/L. Surface area: 23.4 acres.
Is Lake Orient safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Lake Orient is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, pH / acidity, turbidity. Check local advisories before you swim.
What is the water temperature of Lake Orient?
- Lake Orient typically sits around 70°F at the surface in September, from 29 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
Explore Lake Orient across LakeQuality
More Iowa Lake Rankings
Other Grade F Lakes in Iowa
Hypereutrophic Lakes in Iowa
Where this data comes from
54 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Iowa DNR Surface Water Monitoring Data
21IOWA_WQX54 samples · 2020–2024
Analytical methods
- Unknown
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- In-Vitro Determination of Chlorophyll
- ISU modification of APHA 2130-B
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)