Little Prairie Lake
Little Prairie Lake in Phelps County, Missouri is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.6 ft visibility. Phosphorus: 54 µg/L. Chlorophyll-a (algae): 8.9 µg/L. Surface area: 100 acres.
- Clarity
- 8.6 ft
- Typical in August
- 82°F
- Area
- 100 acres
- Trend
- → Stable
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Why Little Prairie Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Little Prairie Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by Missouri DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Little Prairie Lake is a 100-acre lake in Phelps County, Missouri. Water clarity is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2021-09-07. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Little Prairie Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Moderate clarity, visible to about 8.6 ft. Phosphorus level: 54 µg/L. Chlorophyll-a: 8.9 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.6 ft | Not graded |
| Phosphorus | 54 µg/L | Not graded |
| Chlorophyll-a (Algae) | 8.9 µg/L | Not graded |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Little Prairie Lake
Compare lakeside cabins, hotels, and vacation rentals near Little Prairie Lake in Phelps County, Missouri — 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.
Top-rated places to stay near Little Prairie Lake
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Water Temperature
Little Prairie Lake typically sits around 82°F at the surface in August. Summer average is about 83°F. Usually warmest in Jul (about 86°F) and coldest in Jun (about 82°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 10 field readings (2016–2021) via the EPA Water Quality Portal.
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 100 acres |
No bathymetric survey has been published for Little Prairie Lake, so its depth is not documented here.
Fishing Little Prairie Lake
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.303 m/yr | 4 |
| Phosphorus | → Stable | -0.19 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -2.03 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Little Prairie Lake is a man-made reservoir impounded by the William E. Towell Dam (completed 1965), built primarily for recreation on the TRIBUTARY OF BOUBEUSE RIVER; earth-type dam, 48 ft tall and 1,450 ft long.
- Surface area
- 100 ac
- Normal storage
- 1,300 ac-ft
- Max storage
- 2,490 ac-ft
- Drainage area
- 2.41 sq mi
- Hazard class
- High
- Owner
- MO DEPT OF CONSERVATION
Source: USACE National Inventory of Dams, NID ID MO30090 · Operator website · Matched by proximity (0.39 km)
EPA Impairment Status
Little Prairie Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MO_7287.00 · Official waterbody report · Matched by proximity (0.24 km)
Regulated Pollution Sources Nearby
10 EPA-permitted facilities operate within about 5 miles of Little Prairie Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- Glado Wastewater Treatment FacilityRolla · 1.5 mi away · NPDES MO0084191Recent violation
- Formerly Little Dixie Truck Port WwtfRolla · 1.7 mi away · NPDES MO0104493Recent violation
- Country Valley HomeSt. James · 2.7 mi away · NPDES MO0088064Recent violation
- Brewer Science, IncRolla · 1.6 mi away · NPDES MONX00017
- Brewer Science, Inc. - Building 3A/8Rolla · 1.7 mi away · NPDES MONX00995
- Mo-Sci CorporationRolla · 1.7 mi away · NPDES MONX00306
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.
Graded lakes near Little Prairie Lake
Little Prairie Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Phelps County
Frequently asked questions about Little Prairie Lake
Where is Little Prairie Lake?
- Little Prairie Lake is a lake in Phelps County, Missouri. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Little Prairie Lake?
- Little Prairie Lake in Phelps County, Missouri is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.6 ft visibility. Phosphorus: 54 µg/L. Chlorophyll-a (algae): 8.9 µg/L. Surface area: 100 acres.
Is Little Prairie Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Little Prairie Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Algae concentration (chlorophyll-a) is 8.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Little Prairie Lake?
- Little Prairie Lake typically sits around 82°F at the surface in August, from 10 EPA Water Quality Portal field readings (2016–2021). That is a typical value for the month, not a live reading.
Explore Little Prairie Lake across LakeGrade
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Where this data comes from
4 measurements from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Missouri Dept. of Natural Resources
MDNR4 samples · 2021
Analytical methods
- Depth, Secchi disk in meters
- Nitrogen and Phosphorus, Total, Whole-water, Alkaline Persulfate Digest
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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)