Upper Pine Lake
Hardin County, Iowa110 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #1 of 2 in the county
- 31 ft max depth
- Public access
Upper Pine Lake in Hardin County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 1.3 ft visibility. Phosphorus: 112 µg/L. Chlorophyll-a (algae): 66.7 µg/L. Surface area: 110 acres.
- Clarity
- 1.3 ft
- Typical in September
- 72°F
- Max depth
- ~31 ft est.
- Area
- 110 acres
- Type
- Hypereutrophic
- Phosphorus
- 112 µg/L
- Chlorophyll-a
- 66.7 µg/L
- Trend
- ↑ Improving
- Public access
- Yes
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Stays near Upper Pine Lake
Compare lakeside cabins, hotels, and vacation rentals near Upper Pine Lake in Hardin 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 Upper Pine Lake are listed below.
Top-rated places to stay near Upper Pine Lake
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Free interactive depth-contour map of Upper Pine Lake, reaching a maximum surveyed depth of 16 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Upper Pine Lake is a 110-acre highly nutrient-loaded hypereutrophic lake in Hardin County, Iowa with an estimated average depth of about 31 feet. Water quality is graded F based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 1 other monitored lakes in Hardin County, Upper Pine Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-10-28. Grade methodology: LakeQuality methodology.
What Upper Pine Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
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. Upper Pine Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 1.3 ft of visibility. Phosphorus 112 µg/L. Chlorophyll-a 66.7 µg/L. TSI 72. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.3 ft | Not graded |
| Phosphorus | 112 µg/L | Poor |
| Chlorophyll-a (Algae) | 66.7 µg/L | Poor |
| Trophic State Index (TSI) | 72 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Upper Pine Lake typically sits around 72°F at the surface in September. Summer average is about 76°F. Usually warmest in Jul (about 80°F) and coldest in May (about 62°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 34 field readings (2010–2023) via the EPA Water Quality Portal. See the full Upper Pine Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~31 ft est. |
| Average Depth | ~15 ft est. |
| Surface Area | 110 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Iowa has not published bathymetry for Upper Pine 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
- Pine Lake State ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Upper Pine Lake
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.034 m/yr | 5 |
| Phosphorus | ↑ Improving | -13.8 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +11.78 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Upper Pine Lake is a man-made reservoir impounded by the Upper Pine Lake Dam (completed 1934), built primarily for recreation on the PINE CREEK; earth-type dam, 42 ft tall and 490 ft long.
- Surface area
- 110 ac
- Normal storage
- 890 ac-ft
- Max storage
- 2,710 ac-ft
- Drainage area
- 14 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA00441 · Operator website
EPA Impairment Status
Upper Pine Lake 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 02-IOW-760 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Upper Pine Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Steamboat Rock City Of StpSteamboat Rock · 2.2 mi away · NPDES IA0033324Recent 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 2 lakes in Hardin County
Nearby Lakes With Higher Grades
Upper Pine Lake holds Grade F. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Hardin County
Frequently asked questions about Upper Pine Lake
Where is Upper Pine Lake?
- Upper Pine Lake is a lake in Hardin County, Iowa. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Upper Pine Lake?
- Upper Pine Lake in Hardin County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 1.3 ft visibility. Phosphorus: 112 µg/L. Chlorophyll-a (algae): 66.7 µg/L. Surface area: 110 acres.
Is Upper Pine Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Upper Pine Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth. Check local advisories before you swim.
What is the water temperature of Upper Pine Lake?
- Upper Pine Lake typically sits around 72°F at the surface in September, from 34 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
How deep is Upper Pine Lake?
- No published bathymetric survey covers Upper Pine Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 31 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 110 acres.
Are there boat ramps on Upper Pine Lake?
- Upper Pine Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Pine Lake State Park. Public access is listed as yes.
Explore Upper Pine Lake across LakeQuality
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Where this data comes from
79 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_WQX79 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)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory