Harrison County Lake Intake
Harrison County, Missouri292 acresView mapDirections
Nutrients and algae run above the regional average.
- Eutrophic
- Impaired · Algal growth
- #1 of 1 in the county
Harrison County Lake Intake in Harrison County, Missouri has a water quality grade of D (Nutrient-rich). Water clarity: 1.7 ft visibility. Phosphorus: 66.7 µg/L. Chlorophyll-a (algae): 27.6 µg/L. Surface area: 292 acres.
- Clarity
- 1.7 ft
- Typical in September
- 77°F
- Area
- 292 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
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Stays near Harrison County Lake Intake
Compare lakeside cabins, hotels, and vacation rentals near Harrison County Lake Intake in Harrison 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 Harrison County Lake Intake are listed below.
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Harrison County Lake Intake is a 292-acre productive, nutrient-rich eutrophic lake in Harrison County, Missouri. Water quality is graded D based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2024-07-30. Grade methodology: LakeQuality methodology.
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 D is nutrients and algae, not a swimming clearance. Harrison County Lake Intake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury. Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
Very murky, less than 1.7 ft of visibility. Phosphorus 66.7 µg/L. Chlorophyll-a 27.6 µg/L. TSI 66. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.7 ft | Not graded |
| Phosphorus | 66.7 µg/L | Poor |
| Chlorophyll-a (Algae) | 27.6 µg/L | Poor |
| Trophic State Index (TSI) | 66 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Temperature
Harrison County Lake Intake typically sits around 77°F at the surface in September. Summer average is about 80°F. Usually warmest in Jul (about 82°F) and coldest in May (about 70°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 60 field readings (2010–2024) via the EPA Water Quality Portal. See the full Harrison County Lake Intake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 292 acres |
No bathymetric survey has been published for Harrison County Lake Intake, so its depth is not documented here.
Fishing Harrison County Lake Intake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | 0 m/yr | 4 |
| Phosphorus | ↓ Declining | +7.77 µg/L/yr | 5 |
| Chlorophyll-a | → Stable | +0.35 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Harrison County Lake Intake is a man-made reservoir impounded by the West Fork of Big Creek C-1 Dam (completed 1992), built primarily for flood risk reduction on the LITTLE CREEK; earth-type dam, 49 ft tall and 1,500 ft long.
- Surface area
- 292 ac
- Normal storage
- 2,842 ac-ft
- Max storage
- 9,994 ac-ft
- Drainage area
- 17.2 sq mi
- Hazard class
- High
Source: USACE National Inventory of Dams, NID ID MO12370 · Operator website · Matched by proximity (0.08 km)
EPA Impairment Status
Harrison County 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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MO_7386.00 · Official waterbody report · Matched by proximity (1.29 km)
County Ranking
Ranked #1 of 1 lakes in Harrison County
Nearby Lakes in Harrison County
Frequently asked questions about Harrison County Lake Intake
Where is Harrison County Lake Intake?
- Harrison County Lake Intake is a lake in Harrison County, Missouri. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Harrison County Lake Intake?
- Harrison County Lake Intake in Harrison County, Missouri has a water quality grade of D (Nutrient-rich). Water clarity: 1.7 ft visibility. Phosphorus: 66.7 µg/L. Chlorophyll-a (algae): 27.6 µg/L. Surface area: 292 acres.
Is Harrison County Lake Intake safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Harrison County Lake Intake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury. Check local advisories before you swim.
What is the water temperature of Harrison County Lake Intake?
- Harrison County Lake Intake typically sits around 77°F at the surface in September, from 60 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
Explore Harrison County Lake Intake across LakeQuality
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Species activity outlook by water temperature and season
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Where this data comes from
89 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC89 samples · 2020–2024
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