Lower Pine Lake
Hardin County, Iowa85 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Lower Pine Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Algal growth
- Public access
Lower Pine Lake in Hardin County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.3 ft visibility. Phosphorus: 187 µg/L. Chlorophyll-a (algae): 73.5 µg/L. Surface area: 85 acres.
Free interactive depth-contour map of Lower Pine Lake, reaching a maximum surveyed depth of 16 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Lower Pine Lake is a 85-acre highly nutrient-loaded hypereutrophic lake in Hardin County, Iowa. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 2 public boat landings. Compared to the 1 other monitored lakes in Hardin County, Lower Pine Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-10-28. Methodology: how these readings are compared.
What Lower Pine Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
Swimming conditions
Readings onlyBacteria advisory
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.
Based on E. coli testing, Lower Pine Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 25 samples across 7 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Iowa’s current beach and health-department advisories before swimming.
Whether Lower Pine Lake is safe to swim in today is a call for the Iowa Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lower Pine Lake
These are the measurements Iowa DNR publishes for Lower Pine Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 1.3 ft of visibility. Phosphorus 187 µg/L. Chlorophyll-a 73.5 µg/L. TSI 75.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 187µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 73.5µg/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. | 75 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Lower Pine Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lower Pine Lake typically sits around 72°F at the surface in September. Summer average is about 77°F. Usually warmest in Jul (about 81°F) and coldest in May (about 63°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (63°F) to its warmest (81°F).
Typical surface water temperature by month, from 38 field readings (2010–2023) via the EPA Water Quality Portal.
Lake Details
Surface area
85 acres
Public access
Yes
Listed by Iowa DNR
No bathymetric survey has been published for Lower Pine Lake, so its depth is not documented here.
Recreation & Access
- Pine Lake State ParkPublic
- Pine Lake State ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Lower Pine Lake
Compare lakeside cabins, hotels, and vacation rentals near Lower 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Lower Pine Lake are listed below.
Top-rated places to stay near Lower Pine Lake
Prices for Oct 23–25, 4 adults. Change dates on the map below.
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Fishing Lower Pine Lake
Water Quality Trend: Improving
Based on 5 years of monitoring (2020–2024).
Water clarity
Improving5 years
Phosphorus
Improving-13.8 µg/L/yr4 years
Chlorophyll-a
Worsening+11.78 µg/L/yr5 years
Reservoir Info (USACE NID)
Lower Pine Lake is a man-made reservoir impounded by the Lower Pine Lake Dam (completed 1922), built primarily for recreation on the PINE CREEK; earth-type dam, 33 ft tall and 450 ft long.
- Surface area
- 85 ac
- Normal storage
- 360 ac-ft
- Max storage
- 924 ac-ft
- Drainage area
- 15.47 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
All listed purposes: Recreation;Other.
Source: USACE National Inventory of Dams, NID ID IA01346 · Operator website
EPA Impairment Status
Lower Pine Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 02-IOW-758 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Lower Pine Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger.
- Eldora City Of StpEldora · 0.8 mi away · NPDES IA0025933Major
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.
Nearby Lakes in Hardin County
Frequently asked questions about Lower Pine Lake
Where is Lower Pine Lake?
- Lower Pine Lake is a lake in Hardin County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Lower Pine Lake?
- Lower Pine Lake in Hardin County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.3 ft visibility. Phosphorus: 187 µg/L. Chlorophyll-a (algae): 73.5 µg/L. Surface area: 85 acres.
Is Lower Pine Lake safe to swim in?
- Based on E. coli testing, Lower Pine Lake never exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 0% of 25 samples across 7 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Lower Pine Lake is safe to swim in today is a call for Iowa's water agency and the county health department; check their current beach advisories before you swim.
What is the water temperature of Lower Pine Lake?
- Lower Pine Lake typically sits around 72°F at the surface in September, from 38 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
Are there boat ramps on Lower Pine Lake?
- Lower Pine Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Pine Lake State Park, Pine Lake State Park. Public access is listed as yes.
Can I fish at Lower Pine Lake?
- Lower Pine Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Iowa's fish and wildlife agency, so check its current regulations before you go.
Explore Lower Pine Lake across LakeQuality
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Where this data comes from
102 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_WQX102 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
- 2130 B ~ Nephelometric Method
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Named boat-access points from the USGS National Boat Ramps inventory