Sparta Northwest Lake
Randolph County, IllinoisView mapDirections
Illinois EPA publishes the water-quality measurements for Sparta Northwest Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- Public access
- Limited data
Sparta Northwest Lake in Randolph County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 2.6 ft visibility. Phosphorus: 44.5 µg/L. Chlorophyll-a (algae): 32.5 µg/L.
Sparta Northwest Lake is a highly nutrient-loaded hypereutrophic lake in Randolph County, Illinois. Limited fish-species data available. Public access is available. Compared to the 2 other monitored lakes in Randolph County, Sparta Northwest Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-10-06. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
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. Sparta Northwest Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Sparta Northwest Lake is safe to swim in today is a call for the Illinois Environmental Protection Agency and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Sparta Northwest Lake
These are the measurements Illinois EPA publishes for Sparta Northwest 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 2.6 ft of visibility. Phosphorus 44.5 µg/L. Chlorophyll-a 32.5 µg/L. TSI 62.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 44.5µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 32.5µg/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. | 62 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Sparta Northwest Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Sparta Northwest Lake typically sits around 63°F at the surface in October. Summer average is about 69°F. Usually warmest in Aug (about 72°F) and coldest in Apr (about 54°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (54°F) to its warmest (72°F).
Typical surface water temperature by month, from 562 field readings (2011–2022) via the EPA Water Quality Portal. See the full Sparta Northwest Lake water temperature breakdown →
Stays via Stay22
Stays near Sparta Northwest Lake
Compare lakeside cabins, hotels, and vacation rentals near Sparta Northwest Lake in Randolph County, Illinois — 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 Sparta Northwest Lake are listed below.
Top-rated places to stay near Sparta Northwest Lake
Prices for Oct 23–25, 4 adults. Change dates on the map below.
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Fishing Sparta Northwest Lake
EPA Impairment Status
Sparta Northwest Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Other.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_SOC · Official waterbody report
Regulated Pollution Sources Nearby
6 EPA-permitted facilities operate within about 5 miles of Sparta Northwest Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- Sparta Northwest Stp, City OfSparta · 0.6 mi away · NPDES IL0066133Recent violation
- Sparta Southeast Stp, City OfSparta · 2.5 mi away · NPDES IL0031160Recent violation
- Knight Hawk Coal LlcSparta · 4.2 mi away · NPDES IL0079260Recent violation
- Alpena Vision Resources LlcSparta · 2.7 mi away · NPDES IL0055824
- Alpena Vision Resources- LlcSparta · 2.7 mi away · NPDES ILD055824
- Gemini Court StpSparta · 4.5 mi away · NPDES IL0074543
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 Randolph County
Frequently asked questions about Sparta Northwest Lake
Where is Sparta Northwest Lake?
- Sparta Northwest Lake is a lake in Randolph County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Sparta Northwest Lake?
- Sparta Northwest Lake in Randolph County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Water clarity: 2.6 ft visibility. Phosphorus: 44.5 µg/L. Chlorophyll-a (algae): 32.5 µg/L.
Is Sparta Northwest Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Sparta Northwest Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Sparta Northwest Lake?
- Sparta Northwest Lake typically sits around 63°F at the surface in October, from 562 EPA Water Quality Portal field readings (2011–2022). That is a typical value for the month, not a live reading.
Can I fish at Sparta Northwest Lake?
- Public access to Sparta Northwest Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Illinois's fish and wildlife agency, so check its current regulations before you go.
Explore Sparta Northwest Lake across LakeQuality
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Where this data comes from
42 measurements from 3 monitoring stations, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- illinois epa
IL_EPA_WQX42 samples · 2022
Analytical methods
- MEASURED IN FIELD
- Phosphorus by Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (3)
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)