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LakeQuality

Shepard Mountain Lake Intake

Iron County, Missouri21 acresView mapDirections

D
Nutrient-rich

Nutrients and algae run above the regional average.

Water temp
~80°F
Typical for Aug · EPA WQP
Clarity
2.8 ft
Secchi · sampled 2020
Level
No reading
No gauge
Trend
No reading
Not enough history
  • Eutrophic
  • Impaired · Algal growth
  • #2 of 2 in the county
  • Limited data

Shepard Mountain Lake Intake in Iron County, Missouri has a water quality grade of D (Nutrient-rich). Water clarity: 2.8 ft visibility. Phosphorus: 37 µg/L. Chlorophyll-a (algae): 18.3 µg/L. Surface area: 21 acres.

Clarity
2.8 ft
Typical in August
80°F
Area
21 acres
Type
Eutrophic
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Stays near Shepard Mountain Lake Intake

Compare lakeside cabins, hotels, and vacation rentals near Shepard Mountain Lake Intake in Iron 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Shepard Mountain Lake Intake are listed below.

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Shepard Mountain Lake Intake is a 21-acre productive, nutrient-rich eutrophic lake in Iron County, Missouri. Water quality is graded D based on 2 sampling years through 2020. Compared to the 1 other monitored lakes in Iron County, Shepard Mountain Lake Intake ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2020-09-01. Grade methodology: LakeQuality methodology.

Swimming Safety

Grade only

Limited data

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 D is nutrients and algae, not a swimming clearance. Shepard Mountain Lake Intake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.

Compare the safest swimming lakes near St. Louis

Get alerts for Shepard Mountain Lake Intake

Water Quality Grade: D (Nutrient-rich)

Very murky, less than 2.8 ft of visibility. Phosphorus 37 µg/L. Chlorophyll-a 18.3 µg/L. TSI 59. The letter is not a swimming clearance.

MetricValueGrade
Water Clarity (Secchi Depth)2.8 ftNot graded
Phosphorus37 µg/LPoor
Chlorophyll-a (Algae)18.3 µg/LPoor
Trophic State Index (TSI)59Eutrophic

High nutrients, frequent algae, reduced clarity

Water Temperature

Shepard Mountain Lake Intake typically sits around 80°F at the surface in August. Summer average is about 80°F. Usually warmest in Jul (about 84°F) and coldest in May (about 74°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
74°
Jun
76°
Jul
84°
Aug
80°
Sep
Oct
Nov
Dec

Typical surface water temperature by month, from 33 field readings (20122020) via the EPA Water Quality Portal. See the full Shepard Mountain Lake Intake water temperature breakdown →

Lake Details

CharacteristicValue
Surface Area21 acres

No bathymetric survey has been published for Shepard Mountain Lake Intake, so its depth is not documented here.

Fishing Shepard Mountain Lake Intake

Reservoir Info (USACE NID)

Shepard Mountain Lake Intake is a man-made reservoir impounded by the Shepard Mountain Dam (completed 1955), built primarily for recreation on the TR-STOUTS CREEK; gravity-type dam, 33 ft tall.

Surface area
21 ac
Normal storage
168 ac-ft
Max storage
371 ac-ft
Drainage area
4,525 sq mi
Hazard class
High
Owner
CITY OF IRONTON

All listed purposes: Recreation;Water Supply.

Source: USACE National Inventory of Dams, NID ID MO30324 · Operator website · Matched by proximity (0.04 km)

EPA Impairment Status

Shepard Mountain Lake Intake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).

Causes of impairment

Algal growth

Source: EPA ATTAINS assessment unit MO_7333.00 · Official waterbody report · Matched by proximity (0.33 km)

Regulated Pollution Sources Nearby

5 EPA-permitted facilities operate within about 5 miles of Shepard Mountain Lake Intake under Clean Water Act (NPDES) discharge permits. 5 facilities have a reported Clean Water Act violation in the past three years.

  • Arcadia West Wwtf
    Arcadia · 1.6 mi away · NPDES MO0050687
    Recent violation
  • Arcadia East Wwtf
    Arcadia · 1.9 mi away · NPDES MO0080667
    Recent violation
  • Mawc, Ironton Wwtf
    Ironton · 2.3 mi away · NPDES MO0026514
    Recent violation
  • The Baptist Home Wwtf
    Ironton · 3 mi away · NPDES MO0051217
    Recent violation
  • Stricklin Wwtf
    Ironton · 4.2 mi away · NPDES MO0122319
    Recent 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 #2 of 2 lakes in Iron County

Nearby Lakes With Higher Grades

Shepard Mountain Lake Intake holds Grade D. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

Nearby Lakes in Iron County

Frequently asked questions about Shepard Mountain Lake Intake

Where is Shepard Mountain Lake Intake?

Shepard Mountain Lake Intake is a lake in Iron County, Missouri. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Shepard Mountain Lake Intake?

Shepard Mountain Lake Intake in Iron County, Missouri has a water quality grade of D (Nutrient-rich). Water clarity: 2.8 ft visibility. Phosphorus: 37 µg/L. Chlorophyll-a (algae): 18.3 µg/L. Surface area: 21 acres.

Is Shepard Mountain Lake Intake safe to swim in?

The D is nutrients and algae, not a swimming clearance. Shepard Mountain Lake Intake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth. Check local advisories before you swim.

What is the water temperature of Shepard Mountain Lake Intake?

Shepard Mountain Lake Intake typically sits around 80°F at the surface in August, from 33 EPA Water Quality Portal field readings (2012–2020). That is a typical value for the month, not a live reading.

Where this data comes from

20 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Univ. of Missouri, ColumbiaUMC20 samples · 2020

Analytical methods

  • Depth, Secchi disk in meters
  • 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
  • 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)